Supernova Candidate Stars May Signal “Impending Doom”

This Large Binocular Telescope image below of the Whirlpool Galaxy, otherwise known as M51, is part of a new galaxy survey by Ohio State University, where astronomers are searching for signs that stars are about to go supernova. The insets show one particular binary star system before (left) and after (right) one of its stars went supernova. Image by Dorota Szczygiel, courtesy of Ohio State University.

[/caption] This past year has given both backyard and professional astronomers a rare treat – a very visible supernova event. Hosted in the Whirlpool Galaxy (M51), these stellar death throes may have been clued to us by a rather ordinary binary star system. In a recent study done by researchers at Ohio State University, a galaxy survey may have captured evidence of a “stellar signal” just before it went supernova!

Employing the Large Binocular Telescope located in Arizona, the OSU team was undertaking a survey of 25 galaxies for stars that changed their magnitude in usual ways. Their goal was to find a star just before it ended its life – a three-year undertaking. As luck would have it, a binary star system located in M51 produced just the results they were looking for. One star dropped amplitude just a short period of time before the other exploded. While the probability factor of them getting the exact star might be slim, chances are still good they caught its brighter partner. Despite that, principal investigator Christopher Kochanek, professor of astronomy at Ohio State and the Ohio Eminent Scholar in Observational Cosmology, remains optimistic as their results prove a theory.

“Our underlying goal is to look for any kind of signature behavior that will enable us to identify stars before they explode,” he said. “It’s a speculative goal at this point, but at least now we know that it’s possible.”

“Maybe stars give off a clear signal of impending doom, maybe they don’t,” said study co-author Krzystof Stanek, professor of astronomy at Ohio State, “But we’ll learn something new about dying stars no matter the outcome.”

Postdoctoral researcher Dorota Szczygiel, the leader of the supernova study tells us why the galaxy survey remains paramount.

“The odds are extremely low that we would just happen to be observing a star for several years before it went supernova. We would have to be extremely lucky,” she said. “With this galaxy survey, we’re making our own luck. We’re studying all the variable stars in 25 galaxies, so that when one of them happens go supernova, we’ve already compiled data on it.”

On May 31, 2011, the whole astronomy world was abuzz when SN2011dh gave both amateurs and professionals a real thrill as an easily observable event. As luck would have it, it was a binary star system being studied by the OSU team, and consisted of both a blue and red star. At this point, the astronomers surmise the red star was the one that dimmed significantly over the three-year period while the blue one blew its top. When reviewing the LBT data, the Ohio team found that when compared with Hubble images, the red star dimmed at about 10% over the final three-year period at an estimated 3% per previous years. As a curiosity, the researchers surmise the red star may have actually survived the supernova event.

“After the light from the explosion fades away, we should be able to see the companion that did not explode,” Szczygiel said.

As the team continues to collect valuable information, they estimate they could also detect another candidate set of stars at a rate of about one per year. There is also a strong possibility these detections could act as a type of test bed to predict future supernova events… looking for signals of impending doom. However, according to the news release, the Sun won’t be one to bother with.

“There’ll be no supernova for the Sun – it’ll just fizzle out,” Kochanek said. “But that’s okay – you don’t want to live around an exciting star.”

Original Story Source: Ohio State Research News.

Ancient Zircons Help Reveal Early Earth Atmosphere

Image courtesy of NASA

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Roughly 2.4 billion years ago, Earth’s atmosphere underwent a huge change known as the “Great Oxidation Event”. This switch from an oxygen-poor to an oxygen-rich environment may be accountable for giving rise to life. However, scientists are extremely curious about what our atmosphere may have been like not long after our planet formed. Now researchers from the New York Center for Astrobiology at Rensselaer Polytechnic Institute are using some of the oldest minerals known to exist to help understand what may have occurred some five million years after Earth arose.

For the most part, scientists have theorized that early-Earth atmosphere was dominated by noxious methane, carbon monoxide, hydrogen sulfide, and ammonia. This highly reduced mixture results in a limited amount of oxygen and has led to a wide variety of theories about how life may have started in such a hostile environment. However, by taking a closer look at ancient minerals for oxidation levels, scientists at Rensselaer have proved the early-Earth atmosphere wasn’t like that at all… but held copious amounts of water, carbon dioxide, and sulfur dioxide.

“We can now say with some certainty that many scientists studying the origins of life on Earth simply picked the wrong atmosphere,” said Bruce Watson, Institute Professor of Science at Rensselaer.

How can they be so sure? Their findings depend on the theory that Earth’s atmosphere was formed volcanically. Each time magma flows to the surface, it releases gases. If it doesn’t come to the top, then it interacts with the surrounding rocks where it cools and becomes a rocky deposit in its own right. These deposits – and their elemental construction – allows science to paint an accurate portrait of the conditions at the time of their formation.

“Most scientists would argue that this outgassing from magma was the main input to the atmosphere,” Watson said. “To understand the nature of the atmosphere ‘in the beginning,’ we needed to determine what gas species were in the magmas supplying the atmosphere.”

One of the most important of all magma components is zircon – a mineral nearly as old as Earth itself. By determining the oxidation levels of the magmas that formed these ancient zircons, scientists are able to deduce how much oxygen was being released into the atmosphere.

“By determining the oxidation state of the magmas that created zircon, we could then determine the types of gases that would eventually make their way into the atmosphere,” said study lead author Dustin Trail, a postdoctoral researcher in the Center for Astrobiology.

To enable their work, the team set about cooking up magma in a laboratory setting – which led to the creation of an oxidation gauge to assist them in comparing their artificial specimens against natural zircons. Their study also included a watchful eye for a rare Earth metal called cerium that can exist in two oxidation states. By exposing cerium in zircon, the team can be confident the atmosphere was more oxidized after their creation. These new findings point to an atmospheric state more like our present day conditions… setting the stage for a new starting point on which to base life’s beginnings on Earth.

“Our planet is the stage on which all of life has played out,” Watson said. “We can’t even begin to talk about life on Earth until we know what that stage is. And oxygen conditions were vitally important because of how they affect the types of organic molecules that can be formed.”

While “life as we know it” is highly dependent on oxygen, our current atmosphere probably isn’t the ideal model for spawning primordial life. It’s more likely a methane-rich atmosphere might “have much more biologic potential to jump from inorganic compounds to life-supporting amino acids and DNA.” This leaves the door wide open to alternate theories, such as panspermia. But don’t sell the team’s results short. They still reveal the beginning nature of gases here on Earth, even if they don’t solve the riddle of the Great Oxidation Event.

Original Story Source: Rensselaer Polytechnic Institute News Release.

Astrophoto: The Moon by Brian Brushwood

The Moon, by Brian Brushwood
The Moon, by Brian Brushwood

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Here’s a beautiful photograph of the Moon captured by Brian Brushwood. If that name sounds a little familiar, Brian is the pointy-haired host of Scam School, NSFW, and many other podcasts and web shows. I was totally shocked and surprised to learn that Brian is actually an amateur astronomer, with a sweet 8″ dobsonian telescope. Amazingly, he captured this image by just holding up his iPhone camera to the telescope eyepiece and snapped the image.

You can see Brian’s original post over at Google+, with the complete collection of images he captured that night.

Nice work Brian! Welcome to the hobby of astrophotography – bid farewell to whatever free time you thought you had.

5,000,000 Pageviews in November!

Universe Today stats (always lower in the summer)

[/caption]I know I rarely share the business side of Universe Today, but here’s a very interesting metric: visitors to Universe Today viewed a total of 5 million pages in November, 2011. That’s up about 100% from this time last year.

So, if you think that interest in science and astronomy is declining, allow me to offer this retort. You’re totally wrong. Millions of people every month are subscribed to, or seeking out, the material we’re offering here on Universe Today. People are choosing to read a website that’s only about space and astronomy. You can see the demand for shows like Mythbusters, podcasts like the Skeptic’s Guide to the Universe, or blogs like Bad Astronomy.

I’ll put most of the kudos on Nancy Atkinson’s leadership and the amazing writing team we’ve got here: 15 contributors at last count, growing every month. But the real heroes (to steal a line from Stephen Colbert) are you, the science enthusiasts. It’s your interest in science news that keeps the whole engine going; it’s thrilling to be a part of it, and I guarantee you haven’t seen anything yet.

Thank you for reading, sharing and participating in Universe Today.

Fraser Cain
Publisher

P.S. And for those of you wondering if you can actually make a living as a “blogger”. The answer is yes, and it’s getting easier every day.

Why Silicon-based Aliens Would Rather Eat our Cities than Us: Thoughts on Non-carbon Astrobiology

A graphic associated with the original 'War of the Worlds' by H.G. Wells.

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Editor’s note: Bruce Dorminey, science journalist and author of “Distant Wanderers: The Search for Planets Beyond the Solar System,” interviews NASA astrochemist Max Bernstein for Universe Today about the possibility of Silicon-based life.

Conventional wisdom has long had it that carbon-based life, so common here on earth, must surely be abundant elsewhere; both in our galaxy and the universe as a whole.

This line of reasoning is founded on two major assumptions; the first being that complex carbon chain molecules, the building blocks of life as we know it, have been detected throughout the interstellar medium.  Carbon’s abundance appears to stretch across much of cosmic time, since its production is thought to have peaked some 7 billion years ago, when the universe was roughly half its current age.

The other major assumption is that life needs an elixir, a solvent on which it can advance its unique complex chemistry.  Water and carbon go hand in hand in making this happen.

While the world as we know it runs on carbon, science fiction’s long flirtation with silicon-based life — “It’s life, but not as we know it” — has become a familiar catchphrase.  But life of any sort should evolve, eat, excrete, reproduce, and respond to stimulus.

And although non-carbon based life is a very long shot, we thought we’d broach the issue  with one of the country’s top astrochemists — Max Bernstein, the Research Lead of the Science Mission Directorate at NASA headquarters in Washington,D.C.

Bruce DormineyIS IT WRONG TO ASSUME THAT LIFE COULD BE BASED ON SOMETHING OTHER THAN CARBON?

Max Bernstein. Credit: NASA

Max Bernstein — It’s important for us to keep an open mind about alien life, lest we come across it and miss it. On the other hand, carbon is much better than any other element in forming the main structures of living things.  Carbon can form many stable complex structures of great diversity. When carbon forms molecules containing cxygen and nitrogen, the carbon bonds to nitrogen and oxygen are stable.  But not so much so that they can’t be fairly easily undone, unlike silicon-oxygen bonds, for example.

DormineyDOES THE RECENT NASA-FUNDED RESEARCH AT MONO LAKE, CALIFORNIA WHICH TOUTED THE DISCOVERY OF BACTERIA WITH DNA THAT USES ARSENIC INSTEAD OF PHOSPHORUS RATTLE THE CURRENT PARADIGM?

Bernstein — That was a really cool result, but the basic structure was still carbon. The arsenic was said to have replaced phosphorus, not carbon.  The discovery of this putative arsenic organism may prove to be incorrect, but it’s a hypothesis with science behind it, and not just someone tossing out an idea and leaving it at the level of what if you replaced carbon with silicon?

The structure of silane, the silicon-based analogue of methane.

DormineySILICON SEEMS TO BE THE MOST POPULAR NON-CARBON BASED CANDIDATE, ARE THERE OTHERS THAT ALSO MIGHT BE FEASIBLE?

Bernstein — It’s hard to imagine anything that would be more likely that silicon because there is nothing closer to carbon than silicon in terms of its chemistry. It’s in the right place on the periodic table, just below carbon.  On the face of it, [silicon-based life] doesn’t seem too absurd since silicon, like carbon, forms four bonds. CH4 is methane and SiH4 is silane.  They are analogous molecules so the basic idea is that perhaps silicon could form an entire parallel chemistry, and even life.  But there are tons of problems with this idea.   We don’t see a complex stable chemistry [solely] of silicon and hydrogen, as we see with carbon and hydrogen.  We use hydrocarbon chains in our lipids (molecules that make up membranes), but the analogous silane chains would not be stable.  Whereas carbon-oxygen bonds can be made and unmade — this goes on in our bodies all the time — this is not true for silicon.  This would severely limit silicon’s life-like chemistry.  Maybe you could have something silicon-based that’s sort of alive, but only in the sense that it passes on information.

DormineyIF SILICON-BASED LIFE IS OUT THERE, HOW COULD WE EVER DETECT IT REMOTELY?

Bernstein — We are seriously arguing about how we would remotely detect life just like us, so I really couldn’t say.  Presumably technology-using organisms, whatever their biochemistry, will produce technology, so the Search for Extraterrestrial Intelligence (SETI) may be our best shot.

DormineyHOW WOULD YOU LOOK FOR SILICON-BASED LIFE HERE ON EARTH?

Bernstein — When seeking an alien organism its really tough because you just don’t know what molecules to look for.  One would have to be satisfied by something a bit more ambiguous, like sets of molecules that should not be there. For example, if you were an alien Silicon organism, you might not be looking for our biochemistry, but the fact that you kept seeing exactly the same chain lengths over and over again might tip you off to the fact that those darn carbon chains might actually be the basis of an organism’s membranes.

A Horta, a fictional silicon-based life-form in the Star Trek universe. Image from Star Trek: The Original Series © 1967 Paramount Pictures

DormineyWHERE ARE THE LARGEST CONCENTRATIONS OF SILICON HERE?
IN SAND?

Bernstein — In sand or rock. There are literally megatons of silicate minerals on Earth.

DormineyHAS ANYONE EVER CLAIMED DETECTION OF SELF-REPLICATING EXAMPLES OF SILICON HERE ON EARTH?

Bernstein — There have been ideas about minerals holding information just as DNA holds information.  DNA holds information in a chain that is read from one end to the other.  In contrast, a mineral could hold information in two dimensions [on its surface].  A crystal grows when new atoms arrive on the surface, building layer upon layer.  So, if a crystal sheet cleaved off and then started to grow that would be like the birth of a new organism and would carry information from generation to generation.  But is a replicating crystal alive?  To date, I don’t think that there is actually any evidence that minerals pass information like this.

DormineyIS THE CRUX OF THE PROBLEM THAT SILICON-BASED LIFE WOULD BE SO SLOWLY REPLICATING THAT IT COULD NEVER MAKE IT IN A DYNAMIC UNIVERSE?

Bernstein — I don’t think that any Silicon life form could be a biological threat to us.  If they were high tech, they might eat our buildings or shoot guns at us but I don’t see how they could infect us.  We run hot and move fast.  If we don’t, things will catch us and eat us.

If they are also tougher than we are and whatever feeds on them is also slow and Silicon based maybe being slow doesn’t matter.

DormineyWHAT WOULD BE THE SIGNATURES OF SILICON-BASED LIFE?

Bernstein — If they are not technological, they would be very tough to detect.  We could look for unstable, unexpected silicon molecules; some high energy molecule that should not be there, or molecular chains of all the same length.

DormineyDO YOU THINK THAT SILICON-BASED LIFE MIGHT EXIST SOMEWHERE OUT THERE?

Bernstein — Maybe deep below the surface of a planet in some very hot hydrogen-rich, Oxygen-poor environment, you would have this complex silane chemistry.  There, maybe silanes would form reversible silicon bonds with selenium or tellurium.

DormineyIF SUCH SILICON-BASED LIFE DID CROP UP, WHAT WOULD BE ITS EVOLUTIONARY ENDGAME?

Bernstein — If it could evolve past the protist [microorganism] stage, then I think it could evolve intelligence.  I have no idea how likely it is for intelligence to evolve, but I can believe in silicon crystals passing information from layer to layer or in silicon artificial intelligence, but I don’t expect to see silicon apes playing their equivalent of “Angry Birds” on their Silicon-Phones.

DormineyIF SILICON-LIFE DID EVOLVE, WOULD ITS LIFESPAN BE MUCH LONGER THAN ITS CARBON-BASED ANALOGUES?

Bernstein — The replicating mineral that I described earlier would be living very, very slowly on Earth’s surface.  But maybe somewhere very much hotter, its lifespan would be shorter.  That’s because presumably lifespan is connected to the pace of your chemistry, which depends on temperature.

DormineyFINALLY, WHAT WOULD ENDANGER NON-CARBON-BASED LIFE?

Bernstein — Physical harm for sure.  Presumably you could take a jackhammer to it?

But our biochemistry would not be pathogens to it; we could not “infect” them as was the case in “War of the Worlds.”

Did a Neutron Star Create the “Christmas Burst”?

A neutron star's outer atmosphere engulfs another star in this concept rendering. (NASA/GSFC)

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On December 25, 2010, at 1:38 p.m. EST, NASA’s Swift Burst Alert Telescope detected a particularly long-lived gamma-ray burst in the constellation Andromeda. Lasting nearly half an hour, the burst (known as GRB 101225A) originated from an unknown distance, leaving astronomers to puzzle over exactly what may have created such a dazzling holiday display.

Now there’s not just one but two theories as to what caused this burst, both reported in papers by a research team from the Institute of Astrophysics in Granada, Spain. The papers will appear in the Dec. 1 issue of Nature.

Gamma-ray bursts are the Universe’s most luminous explosions. Most occur when a massive star runs out of nuclear fuel. As the star’s core collapses, it creates a black hole or neutron star that sends intense jets of gas and radiation outwards. As the jets shoot into space they strike gas previously shed by the star and heat it, generating bright afterglows.

NASA's Swift observatory is a satellite in low-Earth orbit, scanning the sky for the presence of gamma-ray bursts and gravitational wave forces. (NASA)

If a GRB jet happens to be aimed towards Earth it can be detected by instruments like those aboard the Swift spacecraft.

Luckily GRBs usually come from vast distances, as they are extremely powerful and could potentially pose a danger to life on Earth should one strike directly from close enough range. Fortunately for us the odds of that happening are extremely slim… but not nonexistent. That is one reason why GRBs are of such interest to astronomers… gazing out into the Universe is, in one way, like looking down the barrels of an unknown number of distant guns.

The 2010 “Christmas burst”, as the event also called, is suspected to feature a neutron star as a key player. The incredibly dense cores that are left over after a massive star’s death, neutron stars rotate extremely rapidly and have intense magnetic fields.

One of the new theories envisions a neutron star as part of a binary system that also includes an expanding red giant. The neutron star may have potentially been engulfed by the outer atmosphere of its partner. The gravity of the neutron star would have caused it to acquire more mass and thus more momentum, making it spin faster while energizing its magnetic field. The stronger field would have then fired off some of the stellar material into space as polar jets… jets that then interacted with previously-expelled gases, creating the GRB detected by Swift.

This scenario puts the source of the Christmas burst at around 5.5 billion light-years away, which coincides with the observed location of a faint galaxy.

An alternate theory, also accepted by the research team, involves the collision of a comet-like object and a neutron star located within our own galaxy, about 10,000 light-years away. The comet-like body could have been something akin to a Kuiper Belt Object which, if in a distant orbit around a neutron star, may have survived the initial supernova blast only to end up on a spiraling path inwards.

The object, estimated to be about half the size of the asteroid Ceres, would have broken up due to tidal forces as it neared the neutron star. Debris that impacted the star would have created gamma-ray emission detectable by Swift, with later-arriving material extending the duration of the GRB into the X-ray spectrum… also coinciding with Swift’s measurements.

Both of these scenarios are in line with processes now accepted by researchers as plausible explanations for GRBs thanks to the wealth of data provided by the Swift telescope, launched in 2004.

“The beauty of the Christmas burst is that we must invoke two exotic scenarios to explain it, but such rare oddballs will help us advance the field,” said Chryssa Kouveliotou, a co-author of the study at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

More observations using other instruments, such as the Hubble Space Telescope, will be needed to discern which of the two theories is most likely the case… or perhaps rule out both, which would mean something else entirely is the source of the 2010 Christmas burst!

Read more on the NASA mission site here.

 

NASA Planetary Science Trio Honored as ‘Best of What’s New’ in 2011- Curiosity/Dawn/MESSENGER

Popular Science magazine names NASA’s Mars Science Laboratory, Dawn and MESSENGER missions as ‘Best of What’s New’ in innovation in 2011. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech

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A trio of NASA’s Planetary Science mission’s – Mars Science Laboratory (MSL), Dawn and MESSENGER – has been honored by Popular Science magazine and selected as ‘Best of What’s New’ in innovation in 2011 in the aviation and space category.

The Curiosity Mars Science Laboratory was just launched to the Red Planet on Saturday, Nov. 26 and will search for signs of life while traversing around layered terrain at Gale Crater. Dawn just arrived in orbit around Asteroid Vesta in July 2011. MESSENGER achieved orbit around Planet Mercury in March 2011.

Several of the top mission scientists and engineers provided exclusive comments about the Popular Science recognitions to Universe Today – below.

“Of course we are all very pleased by this selection,” Prof. Chris Russell, Dawn Principal Investigator, of UCLA, told Universe Today.


Dawn is the first mission ever to specifically investigate the main Asteroid Belt between Mars and Jupiter and will orbit both Vesta and Ceres – a feat enabled solely thanks to the revolutionary ion propulsion system.

“At the same time I must admit we are also not humble about it. Dawn is truly an amazing mission. A low cost mission, using NASA’s advanced technology to enormous scientific advantage. It is really, really a great mission,” Russell told me.

Vesta is the second most massive asteroid and Dawn’s discoveries of a surprisingly dichotomous and battered world has vastly exceeded the team’s expectations.

Asteroid Vesta from Dawn - Exquisite Clarity from a formerly Fuzzy Blob
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers). Before Dawn, Vesta was just a fuzzy blob in the most powerful telescopes. Dawn entered orbit around Vesta on July 15, and will spend a year orbiting the body before firing up the ion propulsion system to break orbit and speed to Ceres, the largest Asteroid. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“Dawn is NASA at its best: ambitious, exciting, innovative, and productive,” Dr. Marc Rayman, Dawn’s Chief Engineer from the Jet Propulsion Lab (JPL), Pasadena, Calif., told Universe Today.

“This interplanetary spaceship is exploring uncharted worlds. I’m delighted Popular Science recognizes what a marvelous undertaking this is.”

JPL manages both Dawn and Mars Science Laboratory for NASA’s Science Mission Directorate in Washington, D.C.

Dawn is an international science mission. The partners include the German Aerospace Center (DLR), the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute.

“Very cool!”, John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.

“MSL packs the most bang for the buck yet sent to Mars.”

Last View of Curiosity Mars Science Laboratory Rover - inside the Cleanroom at KSC.
Curiosity just before Encapsulation for 8 month long interplanetary Martian Journey and touchdown inside Gale Crater. Credit: Ken Kremer

Curiosity is using an unprecedented precision landing system to touch down inside the 154 km (96 miile) wide Gale Crater on Aug. 6, 2012. The crater exhibits exposures of phyllosilicates and other minerals that may have preserved evidence of ancient or extant Martian life and is dominated by a towering mountain.

“10 instruments all aimed at a mountain higher than any in the lower 48 states, whose stratigraphic layering records the major breakpoints in the history of Mars’ environments over likely hundreds of millions of years, including those that may have been habitable for life.”

“It’s like a trip down the Grand Canyon 150 years ago, with the same sense of adventure, but with a lot of high tech equipment,” Grotzinger told me.

MSL also has an international team of over 250 science investigators and instruments spread across the US, Europe and Russia.

Curiosity Mars Science Laboratory rover soars to Mars atop an Atlas V rocket on Nov. 26 at 10:02 a.m. EST from Cape Canaveral, Florida. Credit: Ken Kremer

MESSENGER is the first probe to orbit Mercury and the one year primary mission was recently extended by NASA.

Sean Solomon, of the Carnegie Institution of Washington, leads the MESSENGER mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft for NASA.

“Planetary has 3 missions there… Dawn, MESSENGER, and MSL,” Jim Green proudly said to Universe Today regarding the Popular Science magazine awards. Green is the director, Planetary Science Division, NASA Headquarters, Washington

“Three out of 10 [awards] is a tremendous recognition of the fact that each one of our planetary missions goes to a different environment and takes on new and unique measurements providing us new discoveries and constantly changes how we view nature, ourselves, and our place in the universe.”

The First Solar Day
After its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury’s surface features as well as the color and compositional variations across the planet. The orthographic views seen here, centered at 75° E longitude, are each mosaics of thousands of individual images. At right, images taken through the wide-angle camera filters at 1000, 750, and 430 nm wavelength are displayed in red, green, and blue, respectively.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Read more about the Popular Science citations and awards here
.
Read continuing features about Curiosity, Dawn and MESSENGER by Ken Kremer starting here:

Curiosity Mars Rover Launch Gallery – Photos and Videos
Curiosity Majestically Blasts off on ‘Mars Trek’ to ascertain ‘Are We Alone?
Dawn Discovers Surprise 2nd Giant South Pole Impact Basin at Strikingly Dichotomous Vesta
Amazing New View of the Mt. Everest of Vesta
MESSENGER Unveiling Mercurys Hidden Secrets

Microscopic Worms May Help to Colonize Mars

A Caenorhabditis elegans worm. Credit: Creative Commons

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Once the realm of science fiction, the prospect of colonizing other planets is getting closer to reality. The most logical first place, besides the Moon, has always been Mars. Venus is a bit closer, but the scorching conditions there are, well, much less than ideal. There is still technology that needs to be developed before we can send humans to Mars at all, never mind stay there permanently. But now there may be help from an unlikely and lowly companion. – worms.

Ok, not the kind of worms you find in your garden, but tiny microscopic worms called Caenorhabditis elegans (C. elegans). Similar biologically to humans in some ways, they are being studied by scientists at the University of Nottingham in the UK to help see how people are affected by long-duration space travel.

In December 2006, 4,000 of them were sent into orbit aboard the Space Shuttle Discovery. This was followed by another mission in 2009. The scientists found that in space, the worms develop and produce progeny just as they do on Earth. The research has been published in the November 30, 2011 issue of Interface, a journal of The Royal Society.

According to Dr. Nathaniel Szewczyk of the Division of Clinical Physiology in the School of Graduate Entry Medicine, “While it may seem surprising, many of the biological changes that happen during spaceflight affect astronauts and worms and in the same way. We have been able to show that worms can grow and reproduce in space for long enough to reach another planet and that we can remotely monitor their health. As a result C. elegans is a cost-effective option for discovering and studying the biological effects of deep space missions. Ultimately, we are now in a position to be able to remotely grow and study an animal on another planet.”

He added: “Worms allow us to detect changes in growth, development, reproduction and behaviour in response to environmental conditions such as toxins or in response to deep space missions. Given the high failure rate of Mars missions use of worms allows us to safely and relatively cheaply test spacecraft systems prior to manned missions.”

So while a manned space mission to Mars is still a ways off, some lucky worms may get there first, making the voyage of a lifetime, even if they don’t realize it!

Empowering Curiosity, Numerous Systems Required to Land Martian Rover

If all goes according to how it is planned, Curiosity will touch down safely on the surface of Mars in August of 2012. Photo Credit: Alan walters/awaltersphoto.com


Launch video provided courtesy of United Launch Alliance

CAPE CANAVERAL, Fla – It is a mission years in the making. However, it would not be possible without the hard work of an army’s worth of engineers – and the systems that they built. How many different systems and engines are required to get the Mars Science Laboratory (MSL) rover named Curiosity to the surface of the Red Planet? The answer might surprise you.

Including the two engines that are part of the Atlas V 541 launch vehicle, it will take 50 different engines and thrusters in total to work perfectly to successfully deliver Curiosity to the dusty plains of Mars.

Starting with the launch vehicle itself, there are six separate engines that power the six-wheeled rover, safely ensconced in its fairing, out of Earth’s gravity well. For the first leg of the journey four powerful Solid Rocket Boosters (SRBs) provided by Aerojet (each of these provides 400,000 lbs of thrust) will launch the rover out of Earth’s atmosphere.

The United Launch Alliance (ULA) Atlas launch vehicle has two rocket engines that provide the remaining amount of thrust required to get MSL to orbit and send the rover on its way to Mars. The first is the Russian-built RD-180 engine (whose thrust is split between two engine bells) the second is the Centaur second stage. There are four Aerojet solid rocket motors that help the booster and Centaur upper stage to separate.

The Centaur’s trajectory is controlled by both thrust vector control of the main engine as well as a Reaction Control System or RCS comprised of liquid hydrazine propulsion systems (there are twelve roll control thrusters on the Centaur upper stage).

MSL’s cruise stage separates entirely from the Centaur upper stage and is on the long road to the Red Planet. The cruise stage has eight one-pound-thrust hydrazine thrusters that are used for trajectory maneuvers for the nine-month journey to Mars. These are used for minor corrections to keep the spacecraft on the correct course.

Curiosity’s first physical encounter with the Martian environment is referred to as Entry, Descent and Landing (EDL) – more commonly known as “six minutes of terror” – the point when mission control, back on Earth, loses contact with the spacecraft as it enters the Martian atmosphere.


Video courtesy of Lockheed Martin

Even though Mars only has roughly one percent of Earth’s atmosphere, the friction of the atmosphere caused by a spacecraft impacting it at 13,200 miles per hour (about 5,900 meters per second) – is enough to melt Curiosity if it were exposed to these extremes. The heat shield, located at the base of the cruise stage, prevents this from happening.

The heat shield, provided by Lockheed-Martin, on MSL’s cruise stage is 14.8 feet (4.5 meters) in diameter. By comparison, the heat shields that were used on the Apollo manned missions to the Moon were 13 feet (4 meters) in diameter and the ones that allowed the Mars Exploration Rovers Spirit and Opportunity to safely reach the surface of Mars were 8.7 feet (2.65 meters) in diameter.

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At this point in the mission eight engines, each providing 68 pounds of thrust come into play. These engines provide all of the trajectory control during EDL – meaning they will fire almost continuously.

Shortly thereafter – BOOM – the parachute deploy. Then the heat shield is ejected. After the parachute slow the spacecraft down to a sufficient degree, both they and the back aeroshell depart leaving just the rover and its jet pack.

Curiosity will employ a very unique method to touch down on Mars. What is essentially a jet-pack, called the SkyCrane will be used to allow the rover to hover in mid-air as it is lowered via cables to the ground. Photo Credit: Alan Walters/awaltersphoto.com

During the landing phase the “SkyCrane” comes alive with eight powerful hydrazine engines, each of which give Curiosity 800 pounds of thrust. Aerojet’s Redmond Site Executive, Roger Myers, talked a bit about this segment of the landing, considered by many to be the most dramatic method of getting a vehicle to the surface of Mars.

“Because of the control requirements for the SkyCrane these engines had to be very throttleable,” Myers said. “Keeping the SkyCrane level is a must, you must have very fine control of those engines to ensure stability.”

Although the SkyCrane is often highlighted as an aspect that will add complexity to MSL's mission - there are numerous systems that can cause an early end to the mission. Image Credit: NASA/JPL

If all has gone well up to this point, the Curiosity rover will be lowered the remaining distance to the ground via cables. Once contact with the Martian surface is detected, the cables are cut, the SkyCrane’s engines throttle up and the jet pack flies off to conduct a controlled crash (approximately a mile or so away from where Curiosity is located).

Every powered landing on Mars conducted in the U.S. unmanned space program has utilized Aerojet’s thrusters. The reliability of these small engines was recently proven – in a mission that is now almost three-and-a-half decades old.

Tucked in between the aeroshell and the heat shield, Curiosity is prepared to take the long trip to the Red Planet. Photo Credit: NASA/JPL

Voyager recently conducted a course correction some 34 years after it was launched – highlighting the capability of these thrusters to perform well after launch.

“Our engines have allowed missions to fly to every planet in the solar system and we are currently on our way to Mercury and Pluto,” Myers said. “When NASA explores the solar system – Aerojet provides the propulsion components.”

Hundreds of different components, provided by numerous contractors and sub-contractors all must work perfectly to ensure that the Mars Science Laboratory makes it safely to Mars. Photo Credit: Alan Walters/awaltersphoto.com

New Planet Kepler-21b Confirmed From Both Space And Ground

The Kepler field as seen in the sky over Kitt Peak National Observatory. The approximate position of HD 179070 is indicated by the circle (sky imaged using a diffraction grating to show spectra of brighter stars, credit J. Glaspey; telescopes imaged separately and combined, credit P. Marenfeld)

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Are you ready to add another planet to the growing list of discoveries? Thanks to work done by Steve Howell of the NASA Ames Research Center and his research team, the Kepler Mission has scored another. Cataloged as 21-b, this “new” planet measures about one and half times the Earth’s radius and no more than 10 times the mass… but its “year” is only 2.8 days long!

With such a speedy orbit around its parent star, this little planet quickly drew attention to itself. Kepler 21-b’s sun is much like our own and one of the brightest in the Kepler field. Given its unique set of circumstances, it required a team of over 65 astronomers (that included David Silva, Ken Mighell and Mark Everett of NOAO) and cooperation with several ground-based telescopes including the 4 meter Mayall telescope and the WIYN telescope at Kitt Peak National Observatory to confirm its existence.

At this point, observations place this hot little planet at about 6 million kilometers away from the parent star, where it has estimated temperatures of about 1900 K, or 2960 F. While this isn’t even anywhere near a life-supporting type of planet, Kepler 21-b remains of interest because of its size. The parent star, HD 179070, is just slightly larger than the Sun and about half its age. Regardless, it can still be seen with optical aid and it is only about 352 light years away from Earth.

Kepler light curve of HD 179070 showing the eclipse of Kepler-21b. The data cover 15 months. The figure shows the binned, and phase folded-data based on 164 individual transits over-plotted by the model fit (red line).

Why are findings like these exciting? Probably because a large amount of stars show short period brightness oscillations – which means it’s difficult to detect a planetary passage from a normal light curve. In this case, it took 15 long months to build up enough information – including spectroscopic and imaging data from a number of ground based telescopes – to make a confident call on the planet’s presence.

It ain’t easy being a little planet… But they can be found!

Original Story Source: NOAO News Release.