This radar image of asteroid 2005 YU55 was obtained on Nov. 7, 2011. Credit: NASA/JPL/Caltech.
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Look up in a clear night sky. How many moons do you see? Chances are, you’re only going to count to one. Admittedly, if you count any higher and you’re not alone, you may get some funny looks cast in your direction. But even though you may not be able to actually see them, there may very well be more moons out there orbiting our planet.
For the time being, anyway.
Today, Earth has one major moon in orbit around it. (Technically the Earth-Moon system orbits around a common center of gravity, called the barycenter, but that’s splitting hairs for the purpose of this story.) At one time Earth may have had two large moons until the smaller eventually collided into the larger, creating the rugged lump we now call the farside highlands. But, that was 4 billion years ago and again not what’s being referred to here.
Right now, at his moment, Earth may very well have more than the one moon we see in the night sky. Surprise.
Of course, it would be a very small moon. Perhaps no more than a meter across. But a moon nonetheless. And there could even be others – many others – much smaller than that. Little bits of solar system leftovers, orbiting our planet even farther out than the Moon we all know and love, coming and going in short-lived flings with Earth without anyone even knowing.
This is what has been suggested by researcher Mikael Granvik of the University of Helsinki in Finland. He and his colleagues have created computer simulations of asteroids believed to be occupying the inner solar system, and what the chances are that any number of them could be captured into Earth orbit at any given time.
Orbit of 2006 RH120, a confirmed TCO identified in 2006.
The team’s results, posted Dec. 20 in the science journal Icarus, claim it’s very likely that small asteroids would be temporarily captured into orbit (becoming TCOs, or temporarily captured objects) on a regular basis, each spending about nine months in up to three revolutions around Earth before heading off again.
Some objects, though, might hang around even longer… in the team’s simulations one TCO remained in orbit for 900 years.
“There are lots of asteroids in the solar system, so chances for the Earth to capture one at any time is, in a sense, not surprising,” said co-author Jeremie Vauballion, an astronomer at the Paris Observatory.
In fact, the team suspects that there’s most likely a TCO out there right now, perhaps a meter or so wide, orbiting between 5 and 10 times the distance between Earth and the Moon. And there could be a thousand smaller ones as well, up to 10 centimeters wide.
So if these moons are indeed out there, why don’t we know about them?
Put simply, they are too small, too far, and too dark.
At that distance an object the size of a writing desk is virtually undetectable with the instruments we have now.. especially if we don’t even know exactly where to look. But in the future the Large Synoptic Survey Telescope (LSST) may, once completed, be able to spot these tiny satellites with its 3200-megapixel camera.
Once spotted, TCOs could become targets of exploration. After all, they are asteroids that have come to us, which would make investigation all the easier – not to mention cheaper – much more so than traveling to and back from the main asteroid belt.
“The price of the mission would actually be pretty small,” Granvik said. And that, of course, makes the chances of such a mission getting approved all the better.
Read more on David Shiga’s article on New Scientist here.
Dawn Orbiting Vesta. NASA's Dawn spacecraft achieved orbit at the giant asteroid Vesta in July 2011. The depiction of Vesta is based on images obtained by Dawn's framing cameras. Dawn is an international collaboration of the US, Germany and Italy. Credit: NASA/JPL-Caltech
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A year ago, 2011 was proclaimed as the “Year of the Solar System” by NASA’s Planetary Science division. And what a year of excitement it was indeed for the planetary science community, amateur astronomers and the general public alike !
NASA successfully delivered astounding results on all fronts – On the Story of How We Came to Be.
“2011 was definitely the best year ever for NASA Planetary Science!” said Jim Green in an exclusive interview with Universe Today. Green is the Director of Planetary Science for the Science Mission Directorate at NASA HQ. “The Search for Life is a significant priority for NASA.”
This past year was without doubt simply breathtaking in scope in terms of new missions, new discoveries and extraordinary technical achievements. The comprehensive list of celestial targets investigated in 2011 spanned virtually every type of object in our solar system – from the innermost planet to the outermost reaches nearly touching interplanetary space.
There was even a stunningly evocative picture showing “All of Humanity” – especially appropriate now in this Holiday season ! You and all of Humanity are here !
-- Earth & Moon Portrait by Juno from 6 Million miles away --
First Photo transmitted from Jupiter Bound Juno shows Earth (on the left) and the Moon (on the right). Taken on Aug. 26, 2011 when spacecraft was about 6 million miles (9.66 million kilometers) away from Earth. Credit: NASA/JPL-Caltech
Three brand new missions were launched and ongoing missions orbited a planet and an asteroid and flew past a comet.
“NASA has never had the pace of so many planetary launches in such a short time,” said Green.
And three missions here were awarded ‘Best of 2011’ for innovation !
Mars Science Laboratory (MSL), Dawn and MESSENGER named “Best of What’s New” in 2011 by Popular Science magazine. 3 NASA Planetary Science missions received the innovation award for 2011 from Popular Science magazine. Artist concept shows mosaic of MESSENGER, Mars Science Laboratory and Dawn missions. Credit: NASA/JPL-Caltech
Here’s the Top NASA Planetary Science Stories of 2011 – ‘The Year of the Solar System’ – in chronological order
1. Stardust-NExT Fly By of Comet Tempel 1
Starting from the first moments of 2011 at the dawn of Jan. 1, hopes were already running high for planetary scientists and engineers busily engaged in setting up a romantic celestial date in space between a volatile icy comet and an aging, thrusting probe on Valentine’s Day.
The comet chasing Stardust-Next spacecraft successfully zoomed past Comet Tempel 1 on Feb. 14 at 10.9 km/sec (24,000 MPH) after flying over 6 Billion kilometers (3.5 Billion mi).
6 Views of Comet Tempel 1 and Deep Impact crater during Stardust-NExT flyby on Feb. 14, 2011
Arrows show location of man-made crater created in 2005 by NASA’s prior Deep Impact comet mission and newly imaged as Stardust-NExT zoomed past comet in 2011. The images progress in time during closest approach to comet beginning at upper left and moving clockwise to lower left. Credit: NASA/JPL-Caltech/University of Maryland. Post process and annotations by Marco Di Lorenzo & Kenneth Kremer
The craft approached within 178 km (111mi) and snapped 72 astonishingly detailed high resolution science images over barely 8 minutes. It also fulfilled the teams highest hopes by photographing the human-made crater created on Tempel 1 in 2005 by a cosmic collision with a penetrator hurled by NASA’s Deep Impact spacecraft. The probe previously flew by Comet Wild 2 in 2004 and returned cometary coma particles to Earth in 2006
Tempel 1 is the first comet to be visited by two spaceships from Earth and provided the first-ever opportunity to compare observations on two successive passages around the Sun.
Don Brownlee, the original Principal Investigator, summarized the results for Universe Today; “A great bonus of the mission was the ability to flyby two comets and take images and measurements. The wonderfully successful flyby of Comet Tempel 1 was a great cap to the 12 year mission and provided a great deal of new information to study the diversity among comets.”
“The new images of Tempel showed features that form a link between seemingly disparate surface features of the 4 comets imaged by spacecraft. Combining data on the same comet from the Deep Impact and Stardust missions has provided important new insights in to how comet surfaces evolve over time and how they release gas and dust into space”.
2. MESSENGER at Mercury
On March 18, the Mercury Surface, Space Environment, Geochemistry, and Ranging, or MESSENGER, spacecraft became the first spacecraft inserted into orbit around Mercury, the innermost planet.
So far MESSENGER has completed 1 solar day – 176 Earth days- circling above Mercury. The probe has collected a treasure trove of new data from the seven instruments onboard yielding a scientific bonanza; these include global imagery of most of the surface, measurements of the planet’s surface chemical composition, topographic evidence for significant amounts of water ice, magnetic field and interactions with the solar wind.
“MESSENGER discovered that Mercury has an enormous core, larger than Earth’s. We are trying to understand why that is and why Mercury’s density is similar to Earth’s,” Jim Green explained to Universe Today.
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. Small gaps will be filled in during the next solar day. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
“The primary mission lasts 2 solar days, equivalent to 4 Mercury years.”
“NASA has granted a 1 year mission extension, for a total of 8 Mercury years. This will allow the team to understand the environment at Mercury during Solar Maximum for the first time. All prior spacecraft observations were closer to solar minimum,” said Green.
MESSENGER was launched in 2004 and the goal is to produce the first global scientific observations of Mercury and piece together the puzzle of how Mercury fits in with the origin and evolution of our solar system.
NASA’s Mariner 10 was the only previous robotic probe to explore Mercury, during three flyby’s back in the mid-1970’s early in the space age.
3. Dawn Asteroid Orbiter
The Dawn spacecraft achieved orbit around the giant asteroid Vesta in July 2011 after a four year interplanetary cruise and began transmitting the history making first ever close-up observations of the mysteriously diverse and alien world that is nothing short of a ‘Space Spectacular’.
“We do not have a good analog to Vesta anywhere else in the Solar System,” Chris Russell said to Universe Today. Russell, from UCLA, is the scientific Principal Investigator for Dawn.
Before Dawn, Vesta was just another fuzzy blob in the most powerful telescopes. Dawn has completely unveiled Vesta as a remarkably dichotomous, heavily battered and pockmarked world that’s littered with thousands of craters, mountains and landslides and ringed by mystifying grooves and troughs. It will unlock details about the elemental abundances, chemical composition and interior structure of this marvelously intriguing body.
Cataclysmic collisions eons ago excavated Vesta so it lacks a south pole. Dawn discovered that what unexpectedly remains is an enormous mountain some 16 miles (25 kilometers) high, twice the height of Mt. Everest.
Dawn is now about midway through its 1 year mission at Vesta which ends in July 2012 with a departure for Ceres, the largest asteroid. So far the framing cameras have snapped more than 10,000 never-before-seen images.
“What can be more exciting than to explore an alien world that until recently was virtually unknown!. ” Dr. Marc Rayman said to Universe Today. Rayman is Dawn’s Chief Engineer from NASA’s Jet Propulsion Lab (JPL) in Pasadena, Calif.
“Dawn is NASA at its best: ambitious, exciting, innovative, and productive.”
4. Juno Jupiter Orbiter
The solar powered Juno spacecraft was launched on Aug. 5 at Cape Canaveral Air Force Station in Florida, to embark on a five year, 2.8 billion kilometer (1.7 Billion mi) trek to Jupiter, our solar system’s largest planet. It was the first of three NASA planetary science liftoffs scheduled in 2011.
Juno Jupiter Orbiter soars skyward to Jupiter on Aug. 5, 2011 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer
Juno’s goal is to map to the depths of the planets interior and elucidate the ingredients of Jupiter’s genesis hidden deep inside. These measurements will help answer how Jupiter’s birth and evolution applies to the formation of the other eight planets.
The 4 ton spacecraft will arrive at the gas giant in July 2016 and fire its braking rockets to go into a polar orbit and circle the planet 33 times over about one year.
The suite of nine instruments will scan the gas giant to find out more about the planets origins, interior structure and atmosphere, measure the amount of water and ammonia, observe the aurora, map the intense magnetic field and search for the existence of a solid planetary core.
“Jupiter is the Rosetta Stone of our solar system,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary — to interpret what Jupiter has to say.”
5. Opportunity reaches Endeavour Crater on Mars
The long lived Opportunity rover finally arrived at the rim of the vast 14 mile (22 kilometer) wide Endeavour Crater in mid-August 2011 following an epic three year trek across treacherous dune fields – a feat once thought unimaginable. All told, Opportunity has driven more than 34 km ( 21 mi) since landing on the Red Planet way back in 2004 for a mere 90 sol mission.
Endeavour Crater Panorama from Opportunity Mars Rover in August 2011
Opportunity arrived at the rim of Endeavour on Sol 2681, August 9, 2011 after a three year trek. The robot photographed segments of the huge craters eroded rim in this panoramic vista. Endeavour Crater is 14 miles (22 kilometers) in diameter. Mosaic Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Kenneth Kremer
In November, the rover discovered the most scientifically compelling evidence yet for the flow of liquid water on ancient Mars in the form of a water related mineral vein at a spot dubbed “Homestake” along an eroded ridge of Endeavour’s rim.
Read my story about the Homestake discovery here, along with our panoramic mosaic showing the location – created by Ken Kremer and Marco Di Lorenzo and published by Astronomy Picture of the Day (APOD) on 12 Dec. 2011.
Watch for my upcoming story detailing Opportunity’s accomplishments in 2011.
6. GRAIL Moon Mappers
The Gravity Recovery and Interior Laboratory, or GRAIL mission is comprised of twin spacecraft tasked to map the moon’s gravity and study the structure of the lunar interior from crust to core.
Twin GRAIL Probes GO for Lunar Orbit Insertion on New Year’s Eve and New Year’s Day
GRAIL spacecraft will map the moon's gravity field and interior composition. Credit: NASA/JPL-Caltech
The dynamic duo lifted off from Cape Canaveral on September 10, 2011 atop the last Delta II rocket that will likely soar to space from Florida. After a three month voyage of more than 2.5 million miles (4 million kilometers) since blastoff, the two mirror image GRAIL spacecraft dubbed Grail-A and GRAIL-B are sailing on a trajectory placing them on a course over the Moon’s south pole on New Year’s weekend.
Each spacecraft will fire the braking rockets for about 40 minutes for insertion into Lunar Orbit about 25 hours apart on New Year’s Eve and New Year’s Day.
Engineers will then gradually lower the satellites to a near-polar near-circular orbital altitude of about 34 miles (55 kilometers).
The spacecraft will fly in tandem and the 82 day science phase will begin in March 2012.
“GRAIL is a Journey to the Center of the Moon”, says Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT). “GRAIL will rewrite the book on the formation of the moon and the beginning of us.”
“By globally mapping the moon’s gravity field to high precision scientists can deduce information about the interior structure, density and composition of the lunar interior. We’ll evaluate whether there even is a solid or liquid core or a mixture and advance the understanding of the thermal evolution of the moon and the solar system,” explained co-investigator Sami Asmar to Universe Today. Asmar is from NASA’s Jet Propulsion Laboratory (JPL)
7. Curiosity Mars Rover
The Curiosity Mars Science Lab (MSL) rover soared skywards on Nov. 26, the last of 2011’s three planetary science missions. Curiosity is the newest, largest and most technologically sophisticated robotic surveyor that NASA has ever assembled.
“MSL packs the most bang for the buck yet sent to Mars.” John Grotzinger, the Mars Science Laboratory Project Scientist of the California Institute of Technology, told Universe Today.
The three meter long robot is the first astrobiology mission since the Viking landers in the 1970’s and specifically tasked to hunt for the ‘Ingredients of Life’ on Mars – the most Earth-like planet in our Solar System.
Video caption: Action packed animation depicts sequences of Curiosity departing Earth, the nail biting terror of the never before used entry, descent and landing on the Martian surface and then looking for signs of life at Gale Crater during her minimum two year expedition across hitherto unseen and unexplored Martian landscapes, mountains and craters. Credit: NASA
Curiosity will gather and analyze samples of Martian dirt in pursuit of the tell-tale signatures of life in the form of organic molecules – the carbon based building blocks of life as we know it.
NASA is targeting Curiosity to a pinpoint touch down inside the 154 km (96 mile) 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 3 mile (5 km) high mountain.
“10 science instruments are all aimed at a mountain 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,” Grotzinger told me.
Titan Upfront
The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science InstituteCuriosity Mars Science Laboratory Rover and Ken Kremer - inside the Cleanroom at the Kennedy Space Center. Last View of Curiosity just prior to folding and encapsulation for launch. Credit: Ken Kremer
This past year Ken was incredibly fortunate to witness the ongoing efforts of many of these magnificent endeavors.
The Earth and Moon as seen from Mariner 10 en route to Venus. This could be a similar view of two moons as seen from Earth. Image credit: NASA/courtesy of nasaimages.org
But what if the Earth actually had a second permanent moon today? How different would life be? Astronomer and physicist Neil F. Comins delves into this thought experiment, and suggests some very interesting consequences.
This shot of Io orbiting Jupiter shows the scale between other moons and their planet. Image credit:NASA/courtesy of nasaimages.org
Our Earth-Moon system is unique in the solar system. The Moon is 1/81 the mass of Earth while most moons are only about 3/10,000 the mass of their planet. The size of the Moon is a major contributing factor to complex life on Earth. It is responsible for the high tides that stirred up the primordial soup of the early Earth, it’s the reason our day is 24 hours long, it gives light for the variety of life forms that live and hunt during the night, and it keeps our planet’s axis tilted at the same angle to give us a constant cycle of seasons.
A second moon would change that.
For his two-mooned Earth thought experiment, Comins proposes that our Earth-Moon system formed as it did — he needs the same early conditions that allowed life to form — before capturing a third body. This moon, which I will call Luna, sits halfway between the Earth and the Moon.
Luna’s arrival would wreak havoc on Earth. Its gravity would tug on the planet causing absolutely massive tsunamis, earthquakes, and increased volcanic activity. The ash and chemicals raining down would cause a mass extinction on Earth.
But after a few weeks, things would start to settle.
Luna would adjust to its new position between the Earth and the Moon. The pull from both bodies would cause land tides and volcanic activity on the new moon; it would develop activity akin to Jupiter’s volcanic moon Io. The constant volcanic activity would make Luna smooth and uniform, as well as a beautiful fixture in the night sky.
New Horizons captured this image of volcanic activity on Io. The same sight could be seen of Luna from Earth. Image credit: NASA/courtesy of nasaimages.org
The Earth would also adjust to its two moons, giving life a chance to arise. But life on a two-mooned Earth would be different.
The combined light from the Moon and Luna would make for much brighter nights, and their different orbital periods will mean the Earth would have fewer fully dark nights. This will lead to different kinds of nocturnal beings; nighttime hunters would have an easier time seeing their prey, but the prey would develop better camouflage mechanisms. The need to survive could lead to more cunning and intelligent breeds of nocturnal animals.
Humans would have to adapt to the challenges of this two-mooned Earth. The higher tides created by Luna would make shoreline living almost impossible — the difference between high and low tides would be measured in thousands of feet. Proximity to the water is a necessity for sewage draining and transport of goods, but with higher tides and stronger erosion, humans would have to develop different ways of using the oceans for transfer and travel. The habitable area of Earth, then, would be much smaller.
The measurement of time would also be different. Our months would be irrelevant. Instead, a system of full and partials months would be necessary to account for the movement of two moons.
A scale comparison of the Earth, the Moon, and Jupiter’s largest moons (the Jovian moons). Image credit:Image Credit: NASA/courtesy of nasaimages.org
Eventually, the Moon and Luna would collide; like the Moon is now, both moons would be receding from Earth. Their eventual collision would send debris raining through Earth’s atmosphere and lead to another mass extinction. The end result would be one moon orbiting the Earth, and life another era of life would be primed to start.
This image of the unusual asteroid Lutetia was taken by ESA’s Rosetta probe during its closest approach in July 2010. Lutetia, which is about 100 kilometres across, seems to be a leftover fragment of the same original material that formed the Earth, Venus and Mercury. It is now part of the main asteroid belt, between the orbits of Mars and Jupiter, but its composition suggests that it was originally much closer to the Sun. Credit: ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA
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According to data received from ESA’s Rosetta spacecraft, ESO’s New Technology Telescope, and NASA telescopes, strange asteroid Lutetia could be a real piece of the rock… the original material that formed the Earth, Venus and Mercury! By examining precious meteors which may have formed at the time of the inner Solar System, scientists have found matching properties which indicate a relationship. Independent Lutetia must have just moved its way out to join in the main asteroid belt…
A team of astronomers from French and North American universities have been hard at work studying asteroid Lutetia spectroscopically. Data sets from the OSIRIS camera on ESA’s Rosetta spacecraft, ESO’s New Technology Telescope (NTT) at the La Silla Observatory in Chile, and NASA’s Infrared Telescope Facility in Hawaii and Spitzer Space Telescope have been combined to give us a multi-wavelength look at this very different space rock. What they found was a very specific type of meteorite called an enstatite chondrite displayed similar content which matched Lutetia… and what is theorized as the material which dates back to the early Solar System. Chances are very good that enstatite chondrites are the same “stuff” which formed the rocky planets – Earth, Mars and Venus.
“But how did Lutetia escape from the inner Solar System and reach the main asteroid belt?” asks Pierre Vernazza (ESO), the lead author of the paper.
It’s a very good question considering that an estimated less than 2% of the material which formed in the same region of Earth migrated to the main asteroid belt. Within a few million years of formation, this type of “debris” had either been incorporated into the gelling planets or else larger pieces had escaped to a safer, more distant orbit from the Sun. At about 100 kilometers across, Lutetia may have been gravitationally influenced by a close pass to the rocky planets and then further affected by a young Jupiter.
“We think that such an ejection must have happened to Lutetia. It ended up as an interloper in the main asteroid belt and it has been preserved there for four billion years,” continues Pierre Vernazza.
Asteroid Lutetia is a “real looker” and has long been a source of speculation due to its unusual color and surface properties. Only 1% of the asteroids located in the main belt share its rare characteristics.
“Lutetia seems to be the largest, and one of the very few, remnants of such material in the main asteroid belt. For this reason, asteroids like Lutetia represent ideal targets for future sample return missions. We could then study in detail the origin of the rocky planets, including our Earth,” concludes Pierre Vernazza.
NASA put out this video last week and we missed covering it, but this is a very interesting little video that takes you on a narrated global tour of tens of millions of fires detected from space between July 2002 and July 2011. Yes, that’s right, tens of millions of fires on Earth, and these aren’t tiny little campfires — they are big enough to be seen from space. The video was created from new satellite data visualizations, and is combined with satellite views of vegetation and snow cover to show how fires relate to seasonal changes. The research helps scientists understand how fire affects our environment on local, regional and global scales. Continue reading “As the World Burns: Satellites Watch Fires Around the World”
Ice-coated mountaintops of Alexander Island, one of the largest islands off Antarctica. Credit: Michael Studinger/NASA.
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Views from the window of NASA’s DC-8 reveal sweeping expanses of ice and rock as part of the ongoing 2011 Operation IceBridge survey of Antarctica’s ice cover.
Now in its third season, Operation IceBridge is a six-year-long mission to study the dynamics of the Antarctic and Arctic ice sheets. It’s the largest ever aerial survey of the polar ice and will yield valuable data on the state of Earth’s vast reservoirs of frozen water, including the land and sea underneath and how they are being affected by today’s rapidly changing climate.
The ridges of the Shackleton Range cast shadows onto Antarctica's ice. Credit: Michael Studinger/NASA.
Researchers – like Michael Studinger, who took the incredible photos seen here – fly over Greenland during the months of March through May and over Antarctica in October and November. NASA’s instrument-laden DC-8 flies over these remote locations at a low altitude of about 1,500 feet, often with little or no advance weather data.
98 percent of Antarctica is covered with ice. Information obtained by Operation IceBridge will be combined with satellite data to create the most accurate models possible of Antarctic ice loss and how it will affect future sea level rise.
Mountains piled with snow and ice rise above the clouds on Alexander Island. Credit: Michael Studinger/NASA.
This season’s Antarctic IceBridge campaign features NASA’s DC-8, at 157 feet long the largest plane in the agency’s airborne research fleet, and will also feature the debut of the Gulfstream V (G-V) operated by the National Science Foundation and National Center for Atmospheric Research.
While the DC-8 flies at low altitudes, the G-V will fly above 30,000 feet to utilize its Land, Vegetation and Ice Sensor (LVIS), which makes detailed topographic studies of the surface.
“With IceBridge, our aim is to understand what the world’s major ice sheets could contribute to sea-level rise. To understand that you have to record how ice sheets and glaciers are changing over time.”
– Michael Studinger, IceBridge project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.
The wing of NASA's DC-8 cuts across the frozen expanse of the Brunt Ice Shelf, with its 100-foot-high cliff face. Credit: Michael Studinger/NASA.
This beautiful time-lapse video was created by photographer Joe Capra during his 17-day solo trek around Iceland in June 2011. A “photographer’s paradise”, summer in Iceland never gets fully dark as the Sun sets around midnight and rises three hours later. The stars don’t even reappear until August!
<>. Mission Poster for the Russian Phobos-Grunt soil sample return spacecraft set to launch to Mars and its moon Phobos in November 2011. Phobos-Grunt consistes Credit: Roskosmos - Russian Federal Space Agency
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Russia is marking the upcoming blastoff of their dauntingly complex Phobos-Grunt sample return mission to the Martian moon Phobos with the release of a quite cool looking mission poster – see above. Phobos-Grunt translates as Phobos-Soil and is due to liftoff on or about November 7, 2011 from the Baikonur Cosmodrome atop a Zenit rocket.
The holy grail of Mars exploration has long been a sample return mission. But with severe cutbacks to NASA’s budget that goal is realistically more than a decade away. That’s why Phobos- Grunt is so exciting from a scientific standpoint.
Phobos-Grunt Orbiter/Lander
Russia's Phobos-Grunt is designed to land on Mars' moon Phobos, collect soil samples and return them to Earth for study. The lander will also carry scientific instrumetns to study Phobos and its environment. It will travel to Mars together with Yinghuo-1, China's first mission to the Red Planet. Credit: NPO Lavochkin
Phobos-Grunt Robotic sampling arm. Credit: Roskosmos
If successful, this audacious probe will retrieve about 200 grams of soil from the diminutive moon Phobos and accomplish the round trip in three years time by August 2014. Scientists speculate that martian dust may coat portions of Phobos and could possibly be mixed in with any returned samples.
Included here are more photos and graphics of the Phobos-Grunt spacecraft which is equipped with two robotic arms and a sampling device to transfer regolith and rocks to the Earth return vehicle and an on board array of some 15 science instruments, including lasers, spectrometers, cameras and a microscope. Readers please feel free to help with Russian translations.
Phobos-Grunt Model
This is a full-scale mockup of Russia's Phobos-Grunt. The spacecraft will collect samples of soil on Mar's moon Phobos and to bring the samples back to Earth for detailed study. Credit: CNES
Phobos-Grunt is the first of Earth’s two missions launching to the Red Planet in 2011. NASA’s Curiosity Mars Science Laboratory is due to lift off on Nov. 25, 2011 from Cape Canaveral, Florida.
Compare the size of Eath to a prominence on the Sun on October 10, 2011. Credit: Ron Cottrell
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The Sun is big. And comparatively, Earth is a tiny Lilliputian. We’ve all seen images comparing the size of Earth to the Sun, but here are two images from October 10, 2011 that really bring home the size-scale of features on the Sun when compared to the size of Earth. Amateur astronomer Ron Cottrell from Oro Valley, Arizona took these images of two different features on the the Sun yesterday, overlaying the size of the Earth for reference. Both are viewed in Hydrogen- Alpha light, and the first is a fiery-looking huge prominence from the northwest limb of the Sun. Yikes!
Below, see a comparison of Earth to a current sunspot:
The Earth compared to Sunspot 1312 on 10-10-11. Credit: Ron Cottrell.
This is sunspot 1312 which has a classic sunspot shape with a core a that’s larger than the Earth.
Ron used a 40mm Coronado telescope and a webcam to capture the images. He explains the colors of the Sun in Hydrogen-Alpha, and in particular why the prominence appears fiery red:
“The red color of the prominence is very close to the color collected in the image. The yellow disk is enhanced. I actually capture the disk image in black and white and add the color. I can choose any color. The final image is a composite of two separate images. Prominences are, in general, much fainter than the bright disk. Therefore, the prominence image is captured at a slower shutter speed, e.g. 1/25 sec, compared to the disk image captured at 1/100 sec. The two images are combined in PhotoShop.”
And speaking of the Sun, activity on our closest star has been ramping up and last week a series of active regions were lined up one after the other across the upper half of the Sun. Interestingly, the Solar Dynamics Observatory was able to capture how these regions twisted and interacted with each other. The video shows activity from Sept. 28 – Oct. 2, 2011, as seen in extreme UV light. The magnetically intense active regions sported coils of arcing loops and numerous times these magnetic field lines above them can be seen connecting with the active region next door. Towards the end of the clip, a leading active region blasted out a coronal mass ejection, quickly succeeded by a blast from another active region. The disruption of the magnetic field from one likely triggered the second, a phenomenon that has been observed before by SDO.
Recent photo from the ISS showing the airglow layer
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In many of the photos that we have featured recently from astronauts aboard the International Space Station, a glowing greenish-yellow band can be seen just above Earth’s limb. I’ve been asked before what this is, so I thought I’d explain it here. This is a phenomenon known as “airglow”.
A photochemical reaction that occurs high in the atmosphere, airglow is the result of various atoms, molecules and ions that get excited (chemistry-excited, that is… not “whee!”-excited) by ultraviolet radiation from the Sun and then release that energy as visible – as well as infrared – light when they return to their “normal” state. It’s not entirely unlike glow-in-the-dark toys or paint!
This light is most visible to the crew of the ISS when it is orbiting over the night side of the planet, and thus is seen in images like the one above. It appears like a thin band because viewing the atmosphere at a shallow angle – rather than directly down through it – increases the airglow layer’s relative visibility.
Most of visible airglow comes from oxygen atoms and molecules, which glow green… as commonly seen in the aurora. Other contributing elements include sodium and nitrogen. While present in the atmosphere at all layers, the region that glows visibly is typically constrained to a narrow band 85 – 95km (53-60 miles) high. The band itself is usually about 6 – 10km (4-6 miles) wide. The reason for this is that below those heights the atoms and molecules are more concentrated and collide more readily, releasing their energy sooner, and above it the density of the atoms is too low to do much colliding at all (to put it very simply.)
There are a lot of other factors involved with airglow as well, such as temperature and altitude, as well as different kinds of airglow depending on when in the day they occur. Nightglow is not exactly the same as dayglow, and then there’s even twilightglow… one could say there’s a lot glowingon in the upper atmosphere!
