Contributing writer Tim Reyes is a former NASA software engineer and analyst who has supported development of orbital and lander missions to the planet Mars since 1992. He has an M.S. in Space Plasma Physics from University of Alabama, Huntsville.
A discovery photo of the ringed formation, 2km (1.24 miles) that AWI researchers are proposing is a meteorite impact site. (Credit:Tobias Binder, AWI)
Endless blinding white ice as far as the eye can see. This is the common scene from the window of planes delivering researchers to Antarctica. However, this is not always the case. While there are mountain ranges and valleys, for a recent research expedition, a large ringed structure came into view on the King Baudouin ice shelf as they were beginning aerial surveys.
Geophysicist Christian Mueller with the Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Germany, was looking out the window of an instrument laden plane when the previously unknown ringed formation, 2000 meters (1.24 miles) in diameter, came into view. Looking into research publications, he found evidence that this may be a meteorite impact event from 2004.
Research team members from Alfred Wegener Institute in Germany embark from a landing site at Princess Elisabeth, Antarctica. They discovered something totally unexpected – a large ringed formation on a nearby ice shelf. (Credit: AWI)
The discovery occurred on December 20th from the AWI Polar 6 aircraft as they were flying over the Princess Ragnhild Coast. The formation is located on the King Baudouin Ice Shelf not far from their landing site at Princess Elizabeth station.
Two studies were found in the literature by the researchers which pointed to a possible impact event over east Antarctica in 2004. Triangulation of infrasound monitoring data pointed to the area where the ringed formation is located. The infrasound monitoring sites are located worldwide and primarily used to detect nuclear testing events. On February 15, 2013, the same type of data was used to better understand the asteroid explosion over Chelyabinsk, Russia.
Location of the ring formation on the ice shelf off the Antarctic continent. The site is on the King Baudouin Ice Shelf. (Map Credits: Google Maps, NOAA)
The second study involved local observations. A separate set of researchers, located at Davis Station, an Australian base off the coast of east Antarctica, reported seeing a dust trail in the upper atmosphere during the same time.
Researcher Mueller stated in the AWI provided video, “I looked out of the window, and I saw an unusual structure on the surface of the ice. There was some broken ice looking like icebergs, which is very unusual on a normally flat ice shelf, surrounded by a large, wing-shaped, circular structure.” Altogether, the AWI researchers said that they make the claim “without any confidence.” They intend to request funding to make followup studies to determine its origin.
Cheryl Santa Maria, of the Digital Reporter, also reported that there are survey images showing this structure that date back 25 years. Furthermore, a story by LiveScience quoted Dr. Peter Brown of Centre of Planetary Science and Exploration at the University of Western Ontario as stating that the size of a meteorite is roughly 5 to 10% of the impact crater’s diameter. This would indicate an impactor about 100 meters in size and much larger than the estimated size of the event as estimated by infrasound data from 2004.
The infrasound data estimated that the asteroid was probably the size of a house, about 10 meters (33 feet) across. In contrast, the asteroid that exploded over Chelyabinsk, Russia, had an estimated size of 20 meters. Dr. Brown was quoted as expressing doubt that the formation is an impact site. The effects of a 100 meter object would have been much more distinctive and likely more readily detected by researchers located in eastern Antarctica. Thus, reporting of the ring formation by the AWI researchers is bringing to light additional information and comments from experts that raises doubts. Follow up studies will be necessary to determine the true origins of the ringed structured.
The presently known largest trans-Neptunian objects (TNO) - are likely to be surpassed by future discoveries. Which of these trans-Neptunian objects (TNO) would you call planets and which "dwarf planets"? (Illustration Credit: Larry McNish, Data: M.Brown)
The self-professed “Pluto Killer” is at it again. Dr. Michael Brown is now reminiscing about the good old days when one could scour through sky survey data and discover big bright objects in the Kuiper Belt. In his latest research paper, Brown and his team have concluded that those days are over.
Ten years ago, Brown discovered what is now known as the biggest Kuiper Belt object – Eris. Brown’s team found others that rivaled Pluto in size and altogether, these discoveries led to the demotion of Pluto to dwarf planet. Now, using yet another sky survey data set but with new computer software, Brown says that its time to move on.
Instigators of the big heist – Rabinowitz, Brown and Trujillo, left to right. The researchers co-discovered dozens of Kuiper Belt objects (KBO) including nine of the ten largest KBOs including the largest, Eris.
Like the famous Bugs Bunny cartoon, its no longer Rabbit Season or Duck Season and as Bugs exclaims to Elmer Fudd, there is no more bullets. Analyzing seven years worth of data, Brown and his team has concluded we are fresh out of Pluto or Charon-sized objects to be discovered in the Kuiper Belt. But for Dr. Brown, perhaps it now might be Oort Cloud season.
His latest paper, A Serendipitous All Sky Survey For Bright Objects In The Outer Solar System, in pre-print, describes the completion of analysis of two past sky surveys covering the northern and southern hemisphere down to 20 degrees in Galactic latitude. Using revised computer software, his team scoured through the data sets from the Catalina Sky Survey (CSS) and the Siding Spring Survey (SSS). The surveys are called “fast cadence surveys” and they primarily search for asteroids near Earth and out to the asteroid belt. Instead Brown’s team used the data to look at image frames spaced days and months apart.
Update: In a Twitter communique, Dr. Brown stated, “I would say we’re out of BRIGHT ones, not big ones. Could be big ones lurking far away!” His latest work involved a southern sky survey (SSS) to about magnitude 19 and the northern survey (CSS) to 21. Low albedo (dark) and more distant KBOs might be lurking beyond the detectability of these surveys that are in the range of Charon to Pluto in size.
Animation showing the movement of Eris on the images used to discover it. Eris is indicated by the arrow. The three frames were taken over a period of three hours. More images over several weeks were necessary to determine its orbit.(Credit: Brown, et al.)
Objects at Kuiper Belt distances move very slowly. For example, Pluto orbits the Sun at about 17,000 km/hr (11,000 mph), taking 250 years to complete one orbit. These are speeds that are insufficient to maintain ven a low-Earth orbit. Comparing two image frames spaced just hours apart will find nearby asteroids moving relative to the star fields but not Kuiper belt objects. So using image frames spaced days, weeks or even months apart, they searched again. Their conclusion is that all the big Kuiper belt objects have been found.
The only possibility of finding another large KBO lies in a search of the galactic plane which is difficult due to the density of Milky Way’s stars in the field of view. The vast number of small bodies in the Kuiper belt and Oort Cloud lends itself readily to statistical analysis. Brown states that there is a 32% chance of finding another Pluto-sized object hiding among the stars of the Milky Way.
Artists concept of the view from Eris with Dysnomia in the background, looking back towards the distant sun. Credit: Robert Hurt (IPAC)
Dr. Brown also released a blog story in celebration of the discovery of the largest of the Kuiper Belt objects, Eris, ten years ago last week. Ten years of Eris, reminisces about the great slew of small body discoveries by Dr. Brown, Dr. Chad Trujillo of Gemini Observatory and Dr. David Rabinowitz of Yale Observatory.
Brown encourages others to take up this final search right in the galactic plane but apparently his own intentions are to move on. What remains to be seen — that is, to be discovered — are hundreds of large “small” bodies residing in the much larger region of the Oort Cloud. These objects are distributed more uniformly throughout the whole spherical region that the Cloud defines around the Sun.
Furthermore, Dr. Brown maintains that there is a good likelihood that a Mars or Earth-sized object exists in the Oort Cloud.
Small bodies within our Solar System along with exo-planets are perhaps the hottest topics and focuses of study in Planetary Science at the moment. Many graduate students and seasoned researchers alike are gravitating to their study. There are certainly many smaller Kuiper belt objects remaining to be found but more importantly, a better understanding of their makeup and origin are yet to be revealed.
Artist’s concept of the Dawn spacecraft at the protoplanet Ceres Illustration of Dawn’s approach phase and RC3 orbit This artist’s concept of NASA’s Dawn spacecraft shows the craft orbiting high above Ceres, where the craft will arrive in early 2015 to begin science investigations. (Image credit: NASA/JPL-Caltech)
Presently, the Dawn spacecraft is making final approach to the dwarf planet Ceres in the Asteroid belt. The first close up images of Ceres are only a few days away as Dawn is now just a couple of 100 thousand miles away approaching at a modest speed. And much farther from our home planet, scientists led by Dr. Alan Stern of SWRI are on final approach to the dwarf planet Pluto with their space probe, New Horizons. The Pluto system is now touted as a binary dwarf planet. Pluto and its moon Charon orbit a common point (barycenter) in space that lies between Pluto and Charon.
So Dr. Brown and team exits stage left. No more dwarf planets – at least not soon and not in the Kuiper belt. Will that upstage what is being called the year of the Dwarf Planet?
But next up for close inspection for the first time are Ceres, Pluto and Charon. It should be a great year.
The relative sizes of the inner Solar System, Kuiper Belt and the Oort Cloud. (Credit: NASA, William Crochot)
An artist's concept of a trans-Neptunian object(TNOs). The distant sun is reduced to a bright star at a distance of over 3 billion miles. The Dark Energy Survey (DES) has now released discovery of more TNOs. (Illustration Credit: NASA)
Sometimes when you stare at something long enough, you begin to see things. This is not the case with optical sensors and telescopes. Sure, there is noise from electronics, but it’s random and traceable. Stargazing with a telescope and camera is ideal for staring at the same patches of real estate for very long and repeated periods. This is the method used by the Dark Energy Survey (DES), and with less than one percent of the target area surveyed, astronomers are already discovering previously unknown objects in the outer Solar System.
The Dark Energy Survey is a five year collaborative effort that is observing Supernovae to better understand the structures and expansion of the universe. But in the meantime, transient objects much nearer to home are passing through the fields of view. Trans-Neptunian Objects (TNOs), small icy worlds beyond the planet Neptune, are being discovered. A new scientific paper, released as part of this year’s American Astronomical Society gathering in Seattle, Washington, discusses these newly discovered TNOs. The lead authors are two undergraduate students from Carleton College of Northfield, Minnesota, participating in a University of Michigan program.
The Palomar Sky Survey (POSS-1, POSS-2), the Sloan Digital Sky Survey, and every other sky survey have mapped not just the static, nearly unchanging night sky, but also transient events such as passing asteroids, comets, or novae events. The Dark Energy Survey is looking at the night sky for structures and expansion of the Universe. As part of the five year survey, DES is observing ten select 3 square degree fields for Type 1a supernovae on a weekly basis. As the survey proceeds, they are getting more than anticipated. The survey is revealing more trans-Neptunian objects. Once again, deep sky surveys are revealing more about our local environment – objects in the farther reaches of our Solar System.
DES is an optical imaging survey in search of Supernovae that can be used as weather vanes to measure the expansion of the universe. This expansion is dependent on the interaction of matter and the more elusive exotic materials of our Universe – Dark Energy and Dark Matter. The five year survey is necessary to achieve a level of temporal detail and a sufficient number of supernovae events from which to draw conclusions.
In the mean time, the young researchers of Carleton College – Ross Jennings and Zhilu Zhang – are discovering the transients inside our Solar System. Led by Professor David Gerdes of the University of Michigan, the researchers started with a list of nearly 100,000 observations of individual transients. Differencing software and trajectory analysis helped identify those objects that were trans-Neptunian rather than asteroids of the inner Solar System.
While asteroids residing in the inner solar system will pass quickly through such small fields, trans-Neptunian objects (TNOs) orbit the Sun much more slowly. For example, Pluto, at an approximate distance of 40 A.U. from the Sun, along with the object Eris, presently the largest of the TNOs, has an apparent motion of about 27 arc seconds per day – although for a half year, the Earth’s orbital motion slows and retrogrades Pluto’s apparent motion. The 27 arc seconds is approximately 1/60th the width of a full Moon. So, from one night to the next, TNOs can travel as much as 100 pixels across the field of view of the DES survey detectors since each pixel has a width of 0.27 arc seconds.
Composite Dark Energy Camera image of one of the sky regions that the collaboration will use to study supernovae, exploding stars that will help uncover the nature of dark energy. The outlines of each of the 62 charge-coupled devices can be seen. This picture spans 2 degrees across on the sky and contains 520 megapixels. (Credit: Fermilab)
The scientific sensor array, DECam, is located at Cerro Tololo Inter-American Observatory (CTIO) in Chile utilizing the 4-meter (13 feet) diameter Victor M. Blanco Telescope. It is an array of 62 2048×4096 pixel back-illuminated CCDs totaling 520 megapixels, and altogether the camera weighs 20 tons.
A simple plot of the orbit of one of sixteen TNOs discovered by DES observations. (Credit: Dark Energy Detectives)
With a little over 2 years of observations, the young astronomers stated, “Our analysis revealed sixteen previously unknown outer solar system objects, including one Neptune Trojan, several objects in mean motion resonances with Neptune, and a distant scattered disk object whose 1200-year orbital period is among the 50 longest known.”
Object 2013 TV158 is one of the objects discovered by the Carleton College and University of Michigan team. Observed more than a dozen times over 10 months, the animated gif shows two image frames from August 2014 taken two hours apart. 2013 TV158 takes 1200 years to orbit the Sun and is likely a few hundred kilometers across – about the size of the Grand Canyon. (Credit: Dark Energy Detectives)
“So far we’ve examined less than one percent of the area that DES will eventually cover,” says Dr. Gerdes. “No other survey has searched for TNOs with this combination of area and depth. We could discover something really unusual.”
Illustration of color distribution of the trans-Neptunian objects. The horizontal axis represents the difference in intensity between visual (green & yellow) and blue of the object, while the vertical axis is the difference between visual and red. The distribution indicates how TNOs share a common origin and physical makeup, as well as common weathering in space. Yellow objects serve as reference: Neptune’s moon Triton, Saturn’s moon Phoebe, centaur Pholus, and the planet Mars. The object’s color represents the hue of the object. The size of the objects are relative – the larger objects are more accurate estimates, while smaller objects are simply based on absolute magnitude. (Credit: Wikimedia, Eurocommuter)
What does it all mean? It is further confirmation that the outer Solar System is chock-full of rocky-icy small bodies. There are other examples of recent discoveries, such as the search for a TNO for the New Horizons mission. As New Horizons has been approaching Pluto, the team turned to the Hubble space telescope to find a TNO to flyby after the dwarf planet. Hubble made short shrift of the work, finding three that the probe could reach. However, the demand for Hubble time does not allow long term searches for TNOs. A survey such as DES will serve to uncover many thousands of more objects in the outer Solar System. As Dr. Michael Brown of Caltech has stated, there is a fair likelihood that a Mars or Earth-sized object will be discovered beyond Neptune in the Oort Cloud.
Over forty years separate the step made by an Apollo astronaut and the cleated wheel of the Curiosity Rover on Mars. (Photo Credits: NASA)
With robotic spacecraft, we have explored, discovered and expanded our understanding of the Solar System and the Universe at large. Our five senses have long since reached their limits and cannot reveal the presence of new objects or properties without the assistance of extraordinary sensors and optics. Data is returned and is transformed into a format that humans can interpret.
Humans remain confined to low-Earth orbit and forty-three years have passed since humans last escaped the bonds of Earth’s gravity. NASA’s budget is divided between human endeavors and robotic and each year there is a struggle to find balance between development of software and hardware to launch humans or carry robotic surrogates. Year after year, humans continue to advance robotic capabilities and artificial intelligence (A.I.), and with each passing year, it becomes less clear how we will fit ourselves into the future exploration of the Solar System and beyond.
On July 21, 1969, Neil Armstrong photographed Buzz Aldrin on the Moon. The Apollo 13 astronauts hold the record as having been the most distant humans from Earth – 249,205 miles. Since December 1972, 42 years, the furthest humans have traveled from Earth is 347 miles (equivalent to SF to LA) – to service the Hubble space telescope. The Mars Science Laboratory, Curiosity Rover resides at least 34 million miles and as far as 249 million from Earth, while the Voyager 1 probe is 12,141,887,500 miles from Earth. Having traveled billions of miles and peered into billions of light years of space, NASA robotic vehicles have rewritten astronomical textbooks.(Photo Credits: NASA)
Is it a race in which we are unwittingly partaking that places us against our inventions? And like the aftermath of the Kasparov versus Deep Blue chess match, are we destined to accept a segregation as necessary? Allow robotics, with or without A.I., to do what they do best – explore space and other worlds?
In May 1997, Garry Kasparov accepted a rematch with Deep Blue and lost. In the 17 years since the defeat, super-computing power has increased by a factor of 50,000 (FLOPS). Furthermore, Chess software has steadily improved. Advances in space robotics have not relied on sheer computing performance but rather from steady advances in reliability, memory storage, nanotechnology, material science, software and more. (Photo Credit: Reuters)
Should we continue to find new ways and better ways to plug ourselves into our surrogates and appreciate with greater detail what they sense and touch? Consider how naturally our children engross themselves in games and virtual reality and how difficult it is to separate them from the technology. Or is this just a prelude and are we all antecedents of future Captain Kirks and Jean Luc Picards?
The NASA 2015 budget passed on December 13, 2014, as part of the Continuing Resolution & Omnibus Bill (HR 83). Each chart segment lists the allocated funds, the percent of the total budget, the percent change relative to NASA’s 2014 budget and percent change relative to the 2015 White House budget request. (Credit: T.Reyes)
Approximately 55% of the NASA budget is in the realm of human spaceflight (HSF). This includes specific funds for Orion and SLS and half measures of supporting segments of the NASA agency, such as Cross-Agency Support, Construction and Maintenance. In contrast, appropriations for robotic missions – project development, operations, R&D – represent 39% of the budget.
The appropriation of funds has always favored human spaceflight, primarily because HSF requires costlier, heavier and more complex systems to maintain humans in the hostile environment of space. And while NASA budgets are not nearly weighted 2-to-1 in favor of human spaceflight, few would contest that the return on investment (ROI) is over 2-to-1 in favor of robotic driven exploration of space. And many would scoff at this ratio and counter that 3-to-1 or 4-to-1 is closer to the advantage robots have over humans.
For NASA enthusiasts, NASA Administrator Charles Bolden and Texas representative Lamar Smith, chairman of the Committee on Science, Space and Technology in the 113th Congress, have raised CSPAN coverage to moments of high drama. The lines of questioning and decision making define the line in the sand between Capital Hill and the White House’s vision of NASA’s future. (Credit: CSPAN,Getty Images)
Politics play a significantly bigger role in the choice of appropriations to HSF compared to robotic missions. The latter is distributed among smaller budget projects and operations and HSF has always involved large expensive programs lasting decades. The big programs attract the interest of public officials wanting to bring capital and jobs to their districts or states.
NASA appropriations are complicated further by a rift between the White House and Capitol Hill along party lines. The Democrat-controlled White House has favored robotics and the use of private enterprise to advance NASA while Republicans on the Hill have supported the big human spaceflight projects; further complications are due to political divisions over the issue of Climate Change. How the two parties treat NASA is the opposite to, at least, how the public perceives the party platforms – smaller government or more social programs, less spending and supporting private enterprise. This tug of war is clearly seen in the NASA budget pie chart.
The House reduced the White House request for NASA Space Technology by 15% while increasing the funds for Orion and SLS by 16%. Space Technology represents funds that NASA would use to develop the Asteroid Redirect Mission (ARM), which the Obama administration favors as a foundation for the first use of SLS as part of a human mission to an asteroid. In contrast, the House appropriated $100 million to the Europa mission concept. Due to the delays of Orion and SLS development and anemic funding of ARM, the first use of SLS could be to send a probe to Europa.
While HSF appropriations for Space Ops & Exploration (effectively HSF) increased ~6% – $300 million, NASA Science gained ~2% – $100 million over the 2014 appropriations; ultimately set by Capitol Hill legislators. The Planetary Society, which is the Science Mission Directorate’s (SMD) staunchest supporter, has expressed satisfaction that the Planetary Science budget has nearly reached their recommended $1.5 billion. However, the increase is delivered with the requirement that $100 million shall be used for Europa concept development and is also in contrast to cutbacks in other segments of the SMD budget.
Note also that NASA Education and Public Outreach (EPO) received a significant boost from Republican controlled Capital Hill. In addition to the specific funding – a 2% increase over 2014 and 34% over the White House request, there is $42 million given specifically to the Science Mission Directorate (SMD) for EPO. The Obama Adminstration has attempted to reduce NASA EPO in favor of a consolidated government approach to improve effectiveness and reduce government.
The drive to explore beyond Earth’s orbit and set foot on new worlds is not just a question of finances. In retrospect, it was not finances at all and our remaining shackles to Earth was a choice of vision. Today, politicians and administrators cannot proclaim ‘Let’s do it again! Let’s make a better Shuttle or a better Space Station.’ There is no choice but to go beyond Earth orbit, but where?
From a Soyuz capsule, Space Shuttle Endeavour, during Expedition 27, is docked to the ISS, 220 miles above the Earth. Before even Apollo 11 landed on the Moon, plans were underway for the next generation spacecraft that would lower the cost of human spaceflight and make trips routine. Forty years have passed since the last Saturn rocket launch and four years since the last Shuttle. Legislators on Capital Hill appear ready to accept a replacement for the Shuttle that, while inherently safer, will cost $600 million per launch excluding the cost of the payload. The Space Launch System (SLS) is destined to serve both human spaceflight and robotic missions. (Photo Credit: NASA)
While the International Space Station program, led by NASA, now maintains a continued human presence in outer space, more people ask the question, ‘why aren’t we there yet?’ Why haven’t we stepped upon Mars or the Moon again, or anything other than Earth or floating in the void of low-Earth orbit. The answer now resides in museums and in the habitat orbiting the Earth every 90 minutes.
The retired Space Shuttle program and the International Space Station represent the funds expended on human spaceflight over the last 40 years, which is equivalent to the funds and the time necessary to send humans to Mars. Some would argue that the funds and time expended could have meant multiple human missions to Mars and maybe even a permanent presence. But the American human spaceflight program chose a less costly path, one more achievable – staying close to home.
Mars, the forbidden planet? No. The Amazing planet? Yes. Foreboding? Perhaps. Radiation exposure, electronic or mechanical mishaps and years of zero or low gravity are the perils that the first Mars explorers face. But humanity’s vision of landing on Mars remains just illustrations from the ’50s and ’60s. A select few – Mars Rover navigators – have experienced the surface of Mars in virtual reality. (Photo Credits: Franklin Dixon, June 12, 1964 (left), MGM (right))
Ultimately, the goal is Mars. Administrators at NASA and others have become comfortable with this proclamation. However, some would say that it is treated more as a resignation. Presidents have been defining the objectives of human spaceflight and then redefining them. The Moon, Lagrangian Points or asteroids as waypoints to eventually land humans on Mars. Partial plans and roadmaps have been constructed by NASA and now politicians have mandated a roadmap. And politicians forced continuation of development of a big rocket; one which needs a clear path to justify its cost to taxpayers. One does need a big rocket to get anywhere beyond low-Earth orbit. However, a cancellation of the Constellation program – to build the replacement for the Shuttle and a new human-rated spacecraft – has meant delays and even more cost overruns.
During the ten years that have transpired to replace the Space Shuttle, with at least five more years remaining, events beyond the control of NASA and the federal government have taken place. Private enterprise is developing several new approaches to lofting payloads to Earth orbit and beyond. More countries have taken on the challenge. Spearheading this activity, independent of NASA or Washington plans, has been Space Exploration Technologies Corporation (SpaceX).
The launch of a SpaceX Falcon 9 is scheduled for Tuesday, December 5, 2015 and will include the return to Earth of the 1st stage Falcon core. Previous attempts landed the core into the Atlantic while this latest attempt will use a barge to attempt a full recovery. The successful soft landing and reuse of Falcon cores will be a major milestone in the history of spaceflight. (Photo Credits: SpaceX)
SpaceX’s Falcon 9 and soon to be Falcon Heavy represent alternatives to what was originally envisioned in the Constellation program with Ares I and Ares V. Falcon Heavy will not have the capability of an Ares V but at roughly $100 million per flight versus $600 million per flight for what Ares V has become – the Space Launch System (SLS) – there are those that would argue that ‘time is up.’ NASA has taken too long and the cost of SLS is not justifiable now that private enterprise has developed something cheaper and done so faster. Is Falcon Nine and Heavy “better”, as in NASA administrator Dan Golden’s proclamation – ‘Faster, Better, Cheaper’? Is it better than SLS technology? Is it better simply because its cheaper for lifting each pound of payload? Is it better because it is arriving ready-to-use sooner than SLS?
Humans will always depend on robotic launch vehicles, capsules and habitats laden with technological wonders to make our spaceflight possible. However, once we step out beyond Earth orbit and onto other worlds, what shall we do? From Carl Sagan to Steve Squyres, NASA scientists have stated that a trained astronaut could do in just weeks what the Mars rovers have required years to accomplish. How long will this hold up and is it really true?
Man versus Machine? All missions whether robotic or human spaceflight benefit mankind but the question is raised: how will human boots fit into the exploration of the universe that robotics has made possible. (Photo Credits: NASA, Illustration – J.Schmidt)
Since Chess Champion Garry Kasparov was defeated by IBM’s Deep Blue, there have been 8 two-year periods representing the doubling of transistors in integrated circuits. This is a factor of 256. Arguably, computers have grown 100 times more powerful in the 17 years. However, robotics is not just electronics. It is the confluence of several technologies that have steadily developed over the 40 years that Shuttle technology stood still and at least 20 years that Space Station designs were locked into technological choices. Advances in material science, nano-technology, electro-optics, and software development are equally important.
While human decision making has been capable of spinning its wheels and then making poor choices and logistical errors, the development of robotics altogether is a juggernaut. While appropriations for human spaceflight have always surpassed robotics, advances in robotics have been driven by government investments across numerous agencies and by private enterprise. The noted futurist and inventor Ray Kurzweil who predicts the arrival of the Singularity by around 2045 (his arrival date is not exact) has emphasized that the surpassing of human intellect by machines is inevitable due to the “The Law of Accelerating Returns”. Technological development is a juggernaut.
In the same year that NASA was founded, 1958, the term Singularity was first used by mathematician John von Neumann to describe the arrival of artificial intelligence that surpasses humans.
Unknowingly, this is the foot race that NASA has been in since its creation. The mechanisms and electronics that facilitated landing men on the surface of the Moon never stopped advancing. And in that time span, human decisions and plans for NASA never stopped vacillating or stop locking existing technology into designs; suffering delays and cost overruns before launching humans to space.
David Hardy’s illustration of the Daedalus Project envisioned by the British Interplanetary Society – a spacecraft to travel to the nearest stars. Advances in artificial intelligence and robotics leads one to wonder who shall reside inside such vessels of the future – robotic surrogates or human beings or something in between. (Credit: D. Hardy)
So are we destined to arrive on Mars and roam its surface like retired geologists and biologists wandering in the desert with a poking stick or rock hammer? Have we wasted too much time and has the window passed in which human exploration can make discoveries that robotics cannot accomplish faster, better and cheaper? Will Mars just become an art colony where humans can experience new sunrises and setting moons? Or will we segregate ourselves from our robotic surrogates and appreciate our limited skills and go forth into the Universe? Or will we mind meld with robotics and master our own biology just moments after taking our first feeble steps beyond the Earth?
An excerpt of page 3 of NASA’s FY15 Agency Mission Planning Model (AMPM[alt]); a 20 year plan. This figure emphasizes the list of planned projects and missions for human spaceflight (HEOMD), orange, and the Science Mission Directorate (SMD), green, representing robotic development and missions. The lopsided list is indicative of the cost advantage of robotics over human spaceflight. The robotic missions will amount to hundreds of years of combined mission lifetime in comparison to the HEOMD missions that are still limited to months by individual astronauts in flight.(Credit: NASA)References:
Two spacecraft, Dawn and New Horizon will reach their final objectives in 2015 - Dwarf Planets - Ceres and Pluto. (Credit: NASA, Illustration - T.Reyes)
Together, the space probes Dawn and New Horizons have been in flight for a collective 17 years. One remained close to home and the other departed to parts of the Solar System of which little is known. They now share a common destination in the same year: dwarf planets.
At the time of these NASA probes’ departures, Ceres had just lost its designation as the largest asteroid in our Solar System. Pluto was the ninth planet. Both probes now stand to deliver measures of new data and insight that could spearhead yet another revision of the definition of planet.
A comparison of the trajectories of New Horizons (left) and the Dawn missions (right). (Credit: NASA/JPL, SWRI, Composite- T.Reyes)
Certainly, NASA’s Year of the Dwarf Planet is an unofficial designation and NASA representatives would be quick to emphasize another dozen or more missions that are of importance during the year 2015. However, these two missions could determine the fate of billions or more small bodies just within our galaxy, the Milky Way.
If Ceres and Pluto are studied up close – mission success is never a sure thing – then what is observed could lead to a new, more certain and accepted definition of planet, dwarf planet, and possibly other new definitions.
The New Horizons mission became the first mission of NASA’s New Frontiers program, beginning development in 2001. The probe was launched on January 19, 2006, atop an Atlas V 551 (5 solid rocket boosters plus a third stage). Utilizing more compact and lightweight electronics than its predecessors to the outer planets – Pioneer 10 & 11, and Voyager 1 & 2 – the combination of reduced weight, a powerful launch vehicle, plus a gravity assist from Jupiter has lead to a nine year journey. On December 6, 2014, New Horizons was taken out of hibernation for the last time and now remains powered on until the Pluto encounter.
This “movie” of Pluto and its largest moon, Charon, by NASA’s New Horizons spacecraft taken in July 2014 clearly shows that the barycenter – the center of mass of the two bodies – resides outside (between) both bodies. The 12 images that make up the movie were taken by the spacecraft’s best telescopic camera – the Long Range Reconnaissance Imager (LORRI) – at distances ranging from about 267 million to 262 million miles (429 million to 422 million kilometers). Charon is orbiting approximately 11,200 miles (about 18,000 kilometers) above Pluto’s surface. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)
The arrival date of New Horizon is July 14, 2015. A telescope called the Long Range Reconnaissance Imager (LORRI) has permitted the commencement of observations while still over 240 million kilometers (150 million miles) from Pluto. The first stellar-like images were taken while still in the Asteroid belt in 2006.
Pluto was once the ninth planet of the Solar System. From its discovery in 1930 by Clyde Tombaugh until 2006, it maintained this status. In that latter year, the International Astronomical Union undertook a debate and then a membership vote that redefined what a planet is. The change occurred 8 months after New Horizons’ launch. There were some upset mission scientists, foremost of which was the principal investigator, Dr. Alan Stern, from the Southwest Research Institute in San Antonio, Texas. In a sense, the rug had been pulled from under them.
A gentleman’s battle ensued between opposing protagonists Dr. Stern and Dr. Michael Brown from Caltech. In 2001, Dr. Brown’s research team began to discover Kuiper belt objects (Trans-Neptunian objects) that rivaled the size of Pluto. Pluto suddenly appeared to be one of many small bodies that could likely number in the trillions within just one galaxy – ours. According to Dr. Brown, there could be as many as 200 objects in our Solar System similar to Pluto that, under the old definition, could be defined as planets. Dr. Brown’s work was the straw that broke the camel’s back – that is, it led to the redefinition of planet, and the native of Huntsville, Alabama, went on to write a popular book, How I Killed Pluto and Why It Had It Coming.
Dr. Stern’s story involving Pluto and planetary research is a longer and more circuitous one. Stern was the Executive Director of the Southwest Research Institute’s Space Science and Engineering Division and then accepted the position of Associate Administrator of NASA’s Science Mission Directorate in 2007. Clearly, after a nine year journey, Stern is now fully committed to New Horizons’ close encounter. More descriptions of the two protagonists of the Pluto debate will be included in a follow on story.
Artist’s concept depicting the Dawn spacecraft thrusting with its ion propulsion system as it travels from Vesta (lower right) to Ceres (upper left). The galaxies in the background are part of the Virgo supercluster. Dawn, Vesta, and Ceres are currently in the constellation Virgo from the perspective of viewers on Earth. (Image credit: NASA/JPL)
The JPL and Orbital Science Corporation developed Dawn space probe began its journey to the main asteroid belt on September 27, 2007. It has used gravity assists and flew by the planet Mars. Dawn spent 14 months surveying Vesta, the 4th largest asteroid of the main belt (assuming Ceres is still considered the largest). While New Horizons has traveled over 30 Astronomical Units (A.U.) – 30 times the distance from the Earth to the Sun – Dawn has remained closer and required reaching a little over 2 A.U. to reach Vesta and now 3 A.U. to reach Ceres.
The Dawn mission had the clear objective of rendezvous and achieving orbit with two asteroids in the main belt between Mars and Jupiter. Dawn was also sent packing the next generation of Ion Propulsion. It has proven its effectiveness very well, having used ion propulsion for the first time to achieve an orbit. Pretty simple, right? Not so fast.
As Dawn was passing critical design reviews during development, the redefinition of planet lofted its second objective – the asteroid 1 Ceres – to a new status. While Pluto was demoted, Ceres was promoted from its scrappy status of biggest of the asteroids – the debris, the leftovers of our solar system’s development – to dwarf planet. Even 4 Vesta is now designated a proto-planet.
Artist rendition of Dawn spacecraft orbiting Vesta. (Credit: NASA/JPL-Caltech)
So now the stage is set. Dawn will arrive first at a dwarf planet – Ceres – in April. With a small, low gravity body and ion propulsion, the arrival is slow and cautious. If the two missions fair well and achieve their goals, 2015 is likely to become a pivotal year in the debate over the classification of non-stellar objects throughout the universe.
Just days ago, at the American Geophysical Union Conference in San Francisco, Dr. Stern and team described the status and more details of the goals of New Horizons. Since arriving, more moons of Pluto have been discovered. There is the potential that faint rings exist and Pluto may even harbor an interior ocean due to the tidal forces from its largest moon, Charon. And Dawn mission scientists have seen the prospects for Ceres’ change. Not just the status, the latest Hubble images of Ceres is showing bright spots which could be water ice deposits and could also harbor an internal ocean.
The Solar System is becoming a more crowded place. This picture shows the sizes of dwarf planets Pluto, Ceres, Eris, and Makemake as compared to Earth and Earth’s Moon, here called “Luna.” None of the distances between objects are to scale. (Credit: NASA)
So other NASA missions notwithstanding, this is the year of the dwarf planet. NASA will provide Humanity with its first close encounters with the most numerous of small round – by their self-gravity – bodies in the Universe. They are now called dwarf planets but ask Dr. Stern and company, the public, and many other planetary scientists and you will discover that the jury is still out.
From the ground, aurora have mystified humans since we began to question the world. The space age revealed more mystery - the Theta Auroral Oval (inset) and the challenge of understanding the phenomena. (Photo Credit: NASA/APOD)
The mystery of the northern lights – aurora – spans time beyond history and to cultures of both the southern and northern hemispheres. The mystery involves the lights, fantastic patterns and mystical changes. Ancient men and women stood huddled under them wondering what it meant. Was it messages from the gods, the spirits of loved ones, warnings or messages to comfort their souls?
Aurora reside literally at the edge of space. While we know the basics and even more, we are still learning. A new published work has just added to our understanding by explaining how one type of aurora – the Theta Aurora – is created from the interaction of the charged particles, electric and magnetic fields surrounding the Earth. Their conclusions required the coordination of simultaneous observations of two missions.
The Theta Auroral Oval as observed by the NASA IMAGE FUV camera on September 15, 2005 and anlayzed using Cluster data in the paper by Fear et al. (Credit: NASA/SWRI)
We were not aware of Thetas until the advent of the space age and our peering back at Earth. They cannot be recognized from the ground. The auroras that bystanders see from locales such as Norway or New Zealand are just arcs and subsets of the bigger picture which is the auroral ovals atop the polar regions of the Earth. Ground based all-sky cameras and polar orbiting probes had seen what were deemed “polar cap arcs.” However, it was a spacecraft Dynamics Explorer I (DE-1) that was the first to make global images of the auroral ovals and observed the first “transpolar arcs”, that is, the Theta aurora.
They are named Theta after the Greek letter that they resemble. Thetas are uncommon and do not persist long. Early on in the exploration of this phenomenon, researchers have been aware that they occur when the Sun’s magnetic field, called the Interplanetary Magnetic Field (IMF) turns northward. Most of the time the IMF in the vicinity of the Earth points south. It is a critical aspect of the Sun-Earth interaction. The southerly pointing field is able to dovetail readily with the normal direction of the Earth’s magnetic field. The northward IMF interacting with the Earth’s field is similar to two bar magnets turned head to head, repelling each other. When the IMF flips northward locally, a convolution takes place that will, at times, but not always, produce a Theta aurora.
A group of researchers led by Dr. Robert Fear from the Department of Physics & Astronomy, University of Leicester, through analysis of simultaneous spacecraft observations, has identified how the particles and fields interact to produce Theta aurora. Their study, “Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere” in the Journal Science (December 19, 2014, Vol 346) utilized a combination of data from ESA’s Cluster spacecraft mission and the IMAGE spacecraft of NASA. The specific event in the Earth’s magnetosphere on September 15, 2005 was observed simultaneously by the spacecraft of both missions.
Illustrations of the Cluster II spacecraft in orbit and formation around the Earth and the NASA IMAGE spacecraft vehicle design. The two mission’s observations were combined to correlate numerous auroral and magnetospheric events. Cluster II remains in operation as of December 2014 (14 yr lifespan). (Credit: ESA, NASA)
Due to the complexity of the Sun-Earth relationship involving neutral and charged particles and electric and magnetic fields, space scientists have long attempted to make simultaneous measurements with multiple spacecraft. ISEE-1, 2 and 3 were one early attempt. Another was the Dynamics Explorer 1 & 2 spacecraft. DE-2 was in a low orbit while DE-1 was in an elongated orbit taking it deeper into the magnetosphere. At times, the pair would align on the same magnetic field lines. The field lines are like rails that guide the charged particles from far out in the magneto-tail to all the way down to the upper atmosphere – the ionosphere. Placing two or more spacecraft on the same field lines presented the means of making coordinated observations of the same event. Dr. Fear and colleagues analyzed data when ESA’s Cluster resided in the southern lobe of the magnetotail and NASA’s IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) spacecraft resided above the south polar region of the Earth.
Cluster is a set of four spacecraft, still in operation after 14 years. Together with IMAGE, five craft were observing the event. Fear, et al utilized ESA spacecraft Cluster 1 (of four) and NASA’s IMAGE. On that fateful day, the IMF turned north. As described in Dr. Fear’s paper, on that day, the north and south lobes of the magnetosphere were closed. The magnetic field lines of the lobes were separated from the Solar wind and IMF due to what is called magnetic reconnection. The following diagram shows how complex Earth’s magnetosphere is; with regions such as the bow shock, magnetopause, cusps, magnetotail, particle belts and the lobes.
Illustration of the Earth’s magnetosphere showing it complexity. The Theta Aurora are now confidently linked to magnetic reconnection events in the lobes of the magnetotail. (Credit: NASA)
The science paper explains that what was previously observed by only lower altitude spacecraft was captured by Cluster within the magnetotail lobes. The southerly lobe’s plasma – ionized particles – was very energetic. The measurements revealed that the southern lobe of the magnetotail was acting as a bottle and the particles were bouncing between two magnetic mirrors, that is, the lobes were close due to reconnection. The particles were highly energetic.
The presence of what is called a double loss cone signature in the electron energy distribution was a clear indicator that the particles were trapped and oscillating between mirror points. The consequences for the Earth’s ionosphere was that highly energetic particles flooded down the field lines from the lobes and impacted the upper atmosphere transferring their energy and causing the magnificent light show that we know as the Northern Lights (or Southern) in the form of a Theta Auroral Oval. This strong evidence supports the theory that Theta aurora are produced by energized particles from within closed field lines and not by energetic particles directly from the Solar Wind that find a path into the magnetosphere and reach the upper atmosphere of the Earth.
A video of an observed major geomagnetic storm (July 15, 2000, southward IMF) taken by the Far Ultraviolet Imaging System (FUV) on the spacecraft IMAGE. IMAGE operated from 2000 until December 2005 when communications were inexplicably lost. (Credit: NASA/SWRI) [click to view the animated gif]Without the coordination of the observations and the collective analysis, the Theta aurora phenomenon would continue to be debated. The analysis by Dr. Fear, while not definitive, is strong proof that Theta aurora are generated from particles trapped within closed field lines.
The analysis of the Cluster mission data as well as that of many other missions takes years. Years after observations are made researchers can achieve new understanding through study of arduous details or sometimes by a ha-ha moment. Aurora represent the signature of the interaction of two magnetic fields and two populations of particles – the Sun’s field and energetic particles streaming at millions of miles per hour from its surface reaching the Earth’s magnetic field. The Earth’s field is transformed by the interaction and receives energetic particles that it bottles up and energizes further. Ultimately, the Earth’s magnetic field directs some of these particles to the topside of our atmosphere. For thousands and likely tens of thousands of years, humans have questioned what it all means. Now another piece of the puzzle has been laid down with a good degree of certainty; one that explains the Theta aurora.
After a 20 month trek across Mars and careful analysis of data, NASA scientists have announced two separate detection of organics - in the surface and the air of Mars. (Photo Credit: NASA/JPL, Illustration - T. Reyes)
On Tuesday, December 16, 2014, NASA scientists attending the American Geophysical Union Fall Meeting in San Francisco announced the detection of organic compounds on Mars. The announcement represents the discovery of the missing “ingredient” that is necessary for the existence – past or present – of life on Mars.
Indeed, the extraordinary claim required extraordinary evidence – the famous assertion of Dr. Carl Sagan. The scientists, members of the Mars Science Lab – Curiosity Rover – mission, worked over a period of 20 months to sample and analyze Martian atmospheric and surface samples to arrive at their conclusions. The announcement stems from two separate detections of organics: 1) ten-fold spikes in atmospheric Methane levels, and 2) drill samples from a rock called Cumberland which included complex organic compounds.
The Tunable Laser Spectrometer, one of the tools within the Sample Analysis at Mars (SAM) laboratory on NASA’s Curiosity Mars rover. By measuring absorption of light at specific wavelengths, it measures concentrations of methane, carbon dioxide and water vapor in Mars’ atmosphere. (Image Credit: NASA/JPL-Caltech)
Methane, of the simplest organic compounds, was detected using the Sample Analysis at Mars instrument (SAM). This is one of two compact laboratory instruments embedded inside the compact car-sized rover, Curiosity. Very soon after landing on Mars, the scientists began to use SAM to periodically measure the chemical content of the Martian atmosphere. Over many samples, the level of Methane was very low, ~0.9 parts per billion. However, that suddenly changed and, as scientists stated in the press conference, it was a “wow” moment that took them aback. Brief daily spikes in Methane levels averaging 7 parts per billion were detected.
The detection of methane at Mars has been claimed for decades, but more recently, in 2003 and 2004, independent research teams using sensitive spectrometers on Earth detected methane in the atmosphere of Mars. One group led by Vladimir Krasnopolsky of Catholic University, and another led by Dr. Michael Mumma from NASA Goddard Space Flight Center, detected broad regional and temporal levels of Methane as high as 30 parts per billion. Those announcements met with considerable skepticism from the scientific community. And the first atmospheric measurements by Curiosity were negative. However, neither group backed down from their claims.
Regions where methane appears notably localized in Northern Summer (A, B1, B2), and their relationship to mineralogical and geo-morphological domains. (A.) Observations of methane near the Syrtis Major volcanic district. (B.) Geologic map of Greeley and Guest (41) superimposed on the topographic shaded-relief from MOLA (42). The most ancient terrain (Npld, Nple) is Noachian in age (~3.6 – 4.5 billion years old, when Mars was wet), and is overlain by volcanic deposits from Syrtis Major of Hesperian (Hs) age (~3.1 – 3.6 billion yrs old). (Credit: Mumma, et al., 2009, Figure 3)
The sudden detection of ten-fold spikes in methane levels in Gale crater is not inconsistent with the earlier remote measurements from Earth. The high seasonal concentrations were in regions that do not include Gale Crater, and it remains possible that the Curiosity measurements are of a similar nature but due to some less active process than exists at the regions identified by Dr. Mumma’s team.
This graphic shows tenfold spiking in the abundance of methane in the Martian atmosphere surrounding NASA’s Curiosity Mars rover, as detected by a series of measurements made with the Tunable Laser Spectrometer instrument in the rover’s Sample Analysis at Mars laboratory suite. (Image Credit: NASA/JPL-Caltech)
The NASA scientists at AGU led by MSL project scientist Dr. John Grotzinger emphasized that they do not yet know how the methane is being generated. The process could be biological or not. There are abiotic chemical processes that could produce methane. However, the MSL SAM detections were daily spikes and represent an active real on-going process on the red planet. This alone is a very exciting aspect of the detection.
The team presented slides to describe how methane could be generated. With the known low background levels of methane at ~ 1 part per billion, an external cosmic source, for example micro-meteoroids entering the atmosphere and releasing organics which is then reduced by sunlight to methane, could be ruled out. The methane source must be of local origin.
This image illustrates possible ways methane might be added to Mars’ atmosphere (sources) and removed from the atmosphere (sinks). NASA’s Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur on modern Mars. A longer caption discusses which are sources and which are sinks. (Image Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan)
The scientists illustrated two means of production. In both instances, there is some daily – or at least periodic – activity that is releasing methane from the subsurface of Mars. The source could be biological which is accumulated in subsurface rocks then suddenly released. Or an abiotic chemistry, such as a reaction between the mineral olivine and water, could be the generator.
The subsurface storage mechanism of methane proposed and illustrated is called clathrate storage. Clathrate storage involves lattice compounds that can trap molecules such as methane which can subsequently be released by physical changes in the clathrate, such as solar heating or mechanical stresses. Through press Q&A, the NASA scientists stated that such clathrates could be preserved for millions and billions of years underground.
The second discovery of organics involved more complex compounds in surface materials. Also since arriving at Mars, Curiosity has utilized a drilling tool to probe the interiors of rocks. Grotzinger emphasized how material immediately at the surface of Mars has experienced the effects of radiation and the ubiquitous soil compound perchlorate reducing and destroying organics both now and over millions of years. The detection of no organics in loose and exposed surface material had not diminished NASA scientists’ hopes of detecting organics in the rocks of Mars.
Comparisons between the amount of an organic chemical named chlorobenzene detected in the “Cumberland” rock sample and amounts of it in samples from three other Martian surface targets analyzed by NASA’s Curiosity Mars rover. (Image Credit: NASA/JPL-Caltech)
Drilling was performed on several selected rocks and it was finally a mud rock called Cumberland that revealed the presence of organic compounds more complex than simple methane. The scientists did emphasize that what exactly these organic compounds are remains a mystery because of the confounding presence of the active chemical perchlorate which can quickly breakdown organics to simpler forms.
Examples from the Sample Analysis at Mars (SAM) laboratory’s detection of Martian organics in a sample of powder that the drill on NASA’s Curiosity Mars rover collected from a rock target called “Cumberland.” (Image Credit: NASA/JPL-Caltech)
The detection of organics in the mud rock Cumberland required the drilling tool and also the scoop on the multifaceted robotic arm to deliver the sample into the SAM laboratory for analysis. To detect methane, SAM has an intake valve to receive atmospheric samples.
Dr. Grotzinger described how Cumberland was chosen as a sample source. The rock is called a mud stone which has undergone a process called digenesis – the metamorphosis of sediment to rock. Grotzinger emphasized that fluids will move through such rock during digenesis and perchlorate can destroy organics in the process. Such might be the case for many metamorphic rocks on the Martian surface. The panel of scientists showed a comparison between rock samples measured by SAM. Two in particular – from the rock “John Klein” and the Cumberland rock — were compared. The former showed no organics as well as other rocks that were sampled; but Cumberland’s drill sample from its interior did reveal organics.
Illustration of some of the reasons why finding organic chemicals on Mars is challenging. Whatever organic chemicals may be produced on Mars or delivered to Mars face several possible modes of being transformed or destroyed. (Image Credit: NASA/JPL-Caltech)
The analysis of the work was painstaking – harking back to the Sagan statement. The importance of discovering organics on Mars could not be understated by the panel of scientists and Grotzinger called these two discoveries as the lasting legacy of the Mars Curiosity Rover. Furthermore, he stated that the discovery and analysis methods will go far to guide the choice of instruments and their use during the Mars 2020 rover mission.
The discovery of organics completes the necessary set of “ingredients” for past or present life on Mars: 1) an energy source, 2) water, and 3) organics. These are the basic requirements for the existence of life as we know it. The search for life on Mars is still just beginning and the new discoveries of organics is still not a clear sign that life existed or is present today. Nevertheless, Dr. Jim Green, introducing the panel of scientists, and Dr. Grotzinger both emphasized the magnitude of these discoveries and how they are tied into the objectives of the NASA Mars program — particularly now with the emphasis on sending humans to Mars. For the Mars Curiosity rover, the journey up the slopes of Mount Sharp continues and now with greater earnestness and a continued search for rocks similar to Cumberland.
Illustration of a rocky planet being bombarded by comets. (Image credit: NASA/JPL-Caltech)
Where did all of our water come from? What might seem like a simple question has challenged and intrigued planetary scientists for decades. So results just released by Rosetta mission scientists have been much anticipated and the observations of the Rosetta spacecraft instruments are telling us to look elsewhere. The water of comet 67P/Churyumov-Gerasimenko does not resemble Earth’s water.
Because the Earth was extremely hot early in its formation, scientists believe that Earth’s original water should have boiled away like that from a boiling kettle. Prevailing theories have considered two sources for a later delivery of water to the surface of the Earth once conditions had cooled. One is comets and the other is asteroids. Surely some water arrived from both sources, but the question has been which one is the predominant source.
There are two areas of our Solar System in which comets formed about 4.6 billion years ago. One is the Oort cloud far beyond Pluto. Everything points to Comet 67P’s origins being the other birthplace of comets – the Kuiper Belt in the region of Neptune and Pluto. The Rosetta results are ruling out Kuiper Belt comets as a source of Earth’s water. Previous observations of Oort cloud comets, such as Hyakutake and Hale-Bopp, have shown that they also do not have Earth-like water. So planetary scientists must reconsider their models with weight being given to the other possible source – asteroids.
The question of the source of Earth’s water has been tackled by Earth-based instruments and several probes which rendezvous with comets. In 1986, the first flyby of a comet – Comet 1P/Halley, an Oort cloud comet – revealed that its water was not like the water on Earth. How the water from these comets –Halley’s and now 67P – differs from Earth’s is in the ratio of the two types of hydrogen atoms that make up the water molecule.
Illustration of the Rosetta spacecraft showing the location of the ROSINA mass spectrometer instrument, DFMS. The difference between a Deuterium and Hydrogen atom is also illustrated. A water molecule with Deuterium is known as heavy water due to the additional mass of Dueterium vs. Hydrogen (i.e., an extra neutron). (Credit: ESA/Rosetta)
Measurements by spectrometers revealed how much Deuterium – a heavier form of the Hydrogen atom – existed in relation to the most common type of Hydrogen in these comets. This ratio, designated as D/H, is about 1 in 6000 in Earth’s ocean water. For the vast majority of comets, remote or in-situ measurements have found a ratio that is higher which does not support the assertion that comets delivered water to the early Earth surface, at least not much of it.
Most recently, Hershel space telescope observations of comet Hartley 2 (103P/Hartley) caused a stir in the debate of the source of Earth’s water. The spectral measurements of the comet’s light revealed a D/H ratio just like Earth’s water. But now the Hershel observation has become more of an exception because of Rosetta’s latest measurements.
A plot displaying the Deuterium/Hydrogen (D/H) ratio of Solar System objects. Asteroids have a D/H ratio that matches that of the Earth, while comets – except for two measured to date – have higher ratios. Objects are grouped by color: planets & moons (blue), chrondritic meteorites from the asteroid belt (grey), Oort cloud comets (purple), and Jupiter family comets (pink). Diamond markers = In Situ measurements; circles = remote astronomical measurements. (Credit: Altwegg, et al. 2014)
The new measurements of 67P were made by the ROSINA Double Focusing Mass Spectrometer (DFMS) on board Rosetta. Unlike remote observations using light which are less accurate, Rosetta was able to accurately measure the quantities of Deuterium and common Hydrogen surrounding the comet. Scientists could then simply determine a ratio. The results are reported in the paper “67P/Churyumov-Gerasimenko, a Jupiter Family Comet with a high D/H ratio” by K. Altwegg, et al., published in the 10 December 2014 issue of Science.
New Rosetta mission findings do not exclude comets as a source of water in and on the Earth’s crust but does indicate comets were a minor contribution. A four-image mosaic comprises images taken by Rosetta’s navigation camera on 7 December from a distance of 19.7 km from the centre of Comet 67P/Churyumov-Gerasimenko. (Credit: ESA/Rosetta/Navcam Imager)
The ROSINA instrument observations determined a ratio of 5.3 ± 0.7 × 10-4, which is approximately 3 times the ratio of D/H for Earth’s water. These results do not exclude comets as a source of terrestrial water but they do redirect scientists to consider asteroids as the predominant source. While asteroids have much lower water content compared with comets, asteroids, and their smaller versions, meteoroids, are more numerous than comets. Every meteor/falling star that we see burning up in our atmosphere delivers a myriad of compounds, including water, to Earth. Early on, the onslaught of meteoroids and asteroids impacting Earth was far greater. Consequently, the small quantities of water added delivered by each could add up to what now lies in the oceans, lakes, streams, and even our bodies.
A new research paper reveals more details of the effect gamma ray bursts (GRB) have had on the development of complex life throughout the cosmos. Illustration depicts a beam from a GRB as might have been directed toward early life on Earth during the Cambrian or Ordovician periods, ~500 million years ago. (Illustration Credit: T. Reyes)
If too close to an environment harboring complex life, a gamma ray burst could spell doom for that life. But could GRBs be the reason we haven’t yet found evidence of other civilizations in the cosmos? To help answer the big question of “where is everybody?” physicists from Spain and Israel have narrowed the time period and the regions of space in which complex life could persist with a low risk of extinction by a GRB.
GRBs are some of the most cataclysmic events in the Universe. Astrophysicists are astounded by their intensity, some of which can outshine the whole Universe for brief moments. So far, they have remained incredible far-off events. But in a new paper, physicists have weighed how GRBs could limit where and when life could persist and evolve, potentially into intelligent life.
In their paper, “On the role of GRBs on life extinctions in the Universe”, published in the journal Science, Dr. Piran from Hebrew University and Dr. Jimenez from University of Barcelona consider first what is known about gamma ray bursts. The metallicity of stars and galaxies as a whole are directly related to the frequency of GRBs. Metallicity is the abundance of elements beyond hydrogen and helium in the content of stars or whole galaxies. More metals reduce the frequency of GRBs. Galaxies that have a low metal content are prone to a higher frequency of GRBs. The researchers, referencing their previous work, state that observational data has shown that GRBs are not generally related to a galaxy’s star formation rate; forming stars, including massive ones is not the most significant factor for increased frequency of GRBs.
As fate would have it, we live in a high metal content galaxy – the Milky Way. Piran and Jimenez show that the frequency of GRBs in the Milky Way is lower based on the latest data available. That is the good news. More significant is the placement of a solar system within the Milky Way or any galaxy.
The brightest gamma-ray burst ever seen in X-rays temporarily blinded Swift’s X-ray Telescope on 21 June 2010. This image merges the X-rays (red to yellow) with the same view from Swift’s Ultraviolet/Optical Telescope, which showed nothing extraordinary. Credit: NASA/Swift/Stefan Immler
The paper states that there is a 50% chance of a lethal GRB’s having occurred near Earth within the last 500 million years. If a stellar system is within 13,000 light years (4 kilo-parsecs) of the galactic center, the odds rise to 95%. Effectively, this makes the densest regions of all galaxies too prone to GRBs to permit complex life to persist.
The Earth lies at 8.3 kilo-parsecs (27,000 light years) from the galactic center and the astrophysicists’ work also concludes that the chances of a lethal GRB in a 500 million year span does not drop below 50% until beyond 10 kilo-parsecs (32,000 light years). So Earth’s odds have not been most favorable, but obviously adequate. Star systems further out from the center are safer places for life to progress and evolve. Only the outlying low star density regions of large galaxies keep life out of harm’s way of gamma ray bursts.
The paper continues by describing their assessment of the effect of GRBs throughout the Universe. They state that only approximately 10% of galaxies have environments conducive to life when GRB events are a concern. Based on previous work and new data, galaxies (their stars) had to reach a metallicity content of 30% of the Sun’s, and the galaxies needed to be at least 4 kilo-parsecs (13,000 light years) in diameter to lower the risk of lethal GRBs. Simple life could survive repeated GRBs. Evolving to higher life forms would be repeatedly set back by mass extinctions.
Piran’s and Jimenez’s work also reveals a relation to a cosmological constant. Further back in time, metallicity within stars was lower. Only after generations of star formation – billions of years – have heavier elements built up within galaxies. They conclude that complex life such as on Earth – from jelly fish to humans – could not have developed in the early Universe before Z > 0.5, a cosmological red-shift equal to ~5 billion years ago or longer ago. Analysis also shows that there is a 95% chance that Earth experienced a lethal GRB within the last 5 billion years.
The question of what effect a nearby GRB could have on life has been raised for decades. In 1974, Dr. Malvin Ruderman of Columbia University considered the consequences of a nearby supernova on the ozone layer of the Earth and on terrestrial life. His and subsequent work has determined that cosmic rays would lead to the depletion of the ozone layer, a doubling of the solar ultraviolet radiation reaching the surface, cooling of the Earth’s climate, and an increase in NOx and rainout that effects biological systems. Not a pretty picture. The loss of the ozone layer would lead to a domino effect of atmospheric changes and radiation exposure leading to the collapse of ecosystems. A GRB is considered the most likely cause of the mass extinction at the end of the Ordovician period, 450 million years ago; there remains considerable debate on the causes of this and several other mass extinction events in Earth’s history.
The paper focuses on what are deemed long GRBs – lGRBs – lasting several seconds in contrast to short GRBs which last only a second or less. Long GRBs are believed to be due to the collapse of massive stars such as seen in supernovas, while sGRBs are from the collision of neutron stars or black holes. There remains uncertainty as to the causes, but the longer GRBs release far greater amounts of energy and are most dangerous to ecosystems harboring complex life.
The paper narrows the time and space available for complex life to develop within our Universe. Over the age of the Universe, approximately 14 billion years, only the last 5 billion years have been conducive to the creation of complex life. Furthermore, only 10% of the galaxies within the last 5 billion years provided such environments. And within only larger galaxies, only the outlying areas provided the safe distances needed to evade lethal exposure to a gamma ray burst.
This work reveals how well our Solar System fits within the ideal conditions for permitting complex life to develop. We stand at a fairly good distance from the Milky Way’s galactic center. The age of our Solar System, at approximately 4.6 billion years, lies within the 5 billion year safe zone in time. However, for many other stellar systems, despite how many are now considered to exist throughout the Universe – 100s of billions in the Milky Way, trillions throughout the Universe – simple is probably a way of life due to GRBs. This work indicates that complex life, including intelligent life, is likely less common when just taking the effect of gamma ray bursts into consideration.
This is the signature of one of 100s of trillions of particle collisions detected at the Large Hadron Collider. The combined analysis lead to the discovery of the Higgs Boson. This article describes one team in dissension with the results. (Photo Credit: CERN)
At the Large Hadron Collider (LHC) in Europe, faster is better. Faster means more powerful particle collisions and looking deeper into the makeup of matter. However, other researchers are proclaiming not so fast. LHC may not have discovered the Higgs Boson, the boson that imparts mass to everything, the god particle as some have called it. While the Higgs Boson discovery in 2012 culminated with the awarding in December 2013 of the Nobel Prize to Peter Higgs and François Englert, a team of researchers has raised these doubts about the Higgs Boson in their paper published in the journal Physical Review D.
The discourse is similar to what unfolded in the last year with the detection of light from the beginning of time that signified the Inflation epoch of the Universe. Researchers looking into the depths of the Universe and the inner depths of subatomic particles are searching for signals at the edge of detectability, just above the noise level and in proximity to the signals from other sources. For the BICEP2 telescope observations (previous U.T. articles), its pretty much back to the drawing board but the Higgs Boson (previous U.T. articles) doubts are definitely challenging but needing more solid evidence. In human affairs, if the Higgs Boson was not detected by the LHC, what does one do with an awarded Nobel Prize?
Cross-section of the Large Hadron Collider where its detectors are placed and collisions occur. LHC is as much as 175 meters (574 ft) below ground on the Franco-Swiss border near Geneva, Switzerland. The accelerator ring is 27 km (17 miles) in circumference. (Photo Credit: CERN)
The present challenge to the Higgs Boson is not new and is not just a problem of detectability and acuity of the sensors as is the case with BICEP2 data. The Planck space telescope revealed that light radiated from dust combined with the magnetic field in our Milky Way galaxy could explain the signal detected by BICEP2 that researchers proclaimed as the primordial signature of the Inflation period. The Higgs Boson particle is actually a prediction of the theory proposed by Peter Higgs and several others beginning in the early 1960s. It is a predicted particle from gauge theory developed by Higgs, Englert and others, at the heart of the Standard Model.
This recent paper is from a team of researchers from Denmark, Belgium and the United Kingdom led by Dr. Mads Toudal Frandsen. Their study entitled, “Technicolor Higgs boson in the light of LHC data” discusses how their supported theory predicts Technicolor quarks through a range of energies detectable at LHC and that one in particular is within the uncertainty level of the data point declared to be the Higgs Boson. There are variants of Technicolor Theory (TC) and the research paper compares in detail the field theory behind the Standard Model Higgs and the TC Higgs (their version of the Higgs boson). Their conclusion is that a TC Higgs is predicted by Technicolor Theory that is consistent with expected physical properties, is low mass and has an energy level – 125 GeV – indistinguishable from the resonance now considered to be the Standard Model Higgs. Theirs is a composite particle and it does not impart mass upon everything.
So you say – hold on! What is a Technicolor in jargon of particle physics? To answer this you would want to talk to a plumber from South Bronx, New York – Dr. Leonard Susskind. Though no longer a plumber, Susskind first proposed Technicolor to describe the breaking of symmetry in gauge theories that are part of the Standard Model. Susskind and other physicists from the 1970s considered it unsatisfactory that many arbitrary parameters were needed to complete the Gauge theory used in the Standard Model (involving the Higgs Scalar and Higgs Field). The parameters consequently defined the mass of elementary particles and other properties. These parameters were being assigned and not calculated and that was not acceptable to Susskind, ‘t Hooft, Veltmann and others. The solution involved the concept of Technicolor which provided a “natural” means of describing the breakdown of symmetry in the gauge theories that makeup the Standard Model.
Technicolor in particle physics shares one simple thing in common with Technicolor that dominated the early color film industry – the term composite in creating color or particles.
Dr. Leonard Susskind, a leading developer of the Theory of Technicolor (left) and Nobel Prize winner Dr. Peter Higgs who proposed the existence of a particle that imparts mass to all matter – the Higgs Boson (right). (Photo Credit: University of Stanford, CERN)
If the theory surrounding Technicolor is correct, then there should be many techni-quark and techni-Higgs particles to be found with the LHC or a more powerful next generation accelerator; a veritable zoo of particles besides just the Higgs Boson. The theory also means that these ‘elementary’ particles are composites of smaller particles and that another force of nature would be needed to bind them. And this new paper by Belyaev, Brown, Froadi and Frandsen claims that one specific techni-quark particle has a resonance (detection point) that is within the uncertainty of measurements for the Higgs Boson. In other words, the Higgs Boson might not be “the god particle” but rather a Technicolor Quark particle comprised of smaller more fundamental particles and another force binding them.
This paper by Belyaev, Brown, Froadi and Frandsen is a clear reminder that the Standard Model is unsettled and that even the discovery of the Higgs Boson is not 100% certain. In the last year, more sensitive sensors have been integrated into CERN’s LHC which will help refute this challenge to Higgs theory – Higgs Scalar and Field, the Higgs Boson or may reveal the signatures of Technicolor particles. Better detectors may resolve the difference between the energy level of the Technicolor quark and the Higgs Boson. LHC researchers were quick to state that their work moves on beyond discovery of the Higgs Boson. Also, their work could actually disprove that they found the Higgs Boson.
Contacting the co-investigator Dr. Alexander Belyaev, the question was raised – will the recent upgrades to CERN accelerator provide the precision needed to differentiate a technie-Quark from the Higg’s particle?
“There is no guarantee of course” Dr. Belyaev responded to Universe Today, “but upgrade of LHC will definitely provide much better potential to discover other particles associated with theory of Technicolor, such as heavy Techni-mesons or Techni-baryons.”
Resolving the doubts and choosing the right additions to the Standard Model does depend on better detectors, more observations and collisions at higher energies. Presently, the LHC is down to increase collision energies from 8 TeV to 13 TeV. Among the observations at the LHC, Super-symmetry has not fared well and the observations including the Higgs Boson discovery has supported the Standard Model. The weakness of the Standard Model of particle physics is that it does not explain the gravitational force of nature whereas Super-symmetry can. The theory of Technicolor maintains strong supporters as this latest paper shows and it leaves some doubt that the Higgs Boson was actually detected. Ultimately another more powerful next-generation particle accelerator may be needed.
In a previous Universe Today story, the question was raised – is the Standard Model a Rube Goldberg Device? Most theorists would say ‘no’ but it is unlikely to reach the status of the ‘theory of everything’ (Illustration Credit: R.Goldberg- the toothpaste dispenser, variant T.Reyes)
For Higgs and Englert, the reversal of the discovery is by no means the ruination of a life’s work or would be the dismissal of a Nobel Prize. The theoretical work of the physicists have long been recognized by previous awards. The Standard Model as, at least, a partial solution of the theory of everything is like a jig-saw puzzle. Piece by piece is how it is being developed but not without missteps. Furthermore, the pieces added to the Standard Model can be like a house of cards and require replacing a larger solution with a wholly other one. This could be the case of Higgs and Technicolor.
At times like children somewhat determined, physicists thrust a solution into the unfolding puzzle that seems to fit but ultimately has to be retracted. The present discourse does not yet warrant a retraction. Elegance and simplicity is the ultimate characteristics sought in theoretical solutions. Particle physicists also use the term Naturalnesswhen describing the concerns with gauge theory parameters. The solutions – the pieces – of the puzzle created by Peter Higgs and François Englert have spearheaded and encouraged further work which will achieve a sounder Standard Model but few if any claim that it will emerge as the theory of everything.
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