Special Delivery, Low-Earth Orbit Style!

A Progress resupply vehicle seen on approach to the ISS on Jan. 27, 2012. (NASA)

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When you’re cruising along in low-Earth orbit, running out of supplies is not an option. Fortunately there are Progress vehicles: Russian spacecraft that carry much-needed supplies and equipment to the astronauts aboard the Space Station.

The photo above, taken by Expedition 30 crew members, shows the unmanned Progress 46 vehicle approaching the ISS on January 27, 2012.

Progress 46 carried 2,050 pounds of propellant, 110 pounds oxygen and air, 926 pounds of water and 2,778 pounds of parts and experiment hardware, for a total of 2.9 tons of food, fuel and equipment for the Expedition 30 crew.

The Progress is similar in appearance and design to Soyuz spacecraft, which serve as human transportation to and from the Space Station, but differs in that the second of the spacecraft’s three sections (as prior to launch) is a refueling module, and the third uppermost section is a cargo module.

In addition to bringing supplies to the ISS, Progress vehicles also serve as – for lack of a better term – “garbage trucks”, undocking from the Station loaded with trash and re-entering the atmosphere, during which time much of the refuse inside gets incinerated.

Progress 46 successfully docked to the Space Station at 7:09 p.m. (EST) on Jan. 27, 2012.

Image: NASA

How Plants May Have Helped Create Earth’s Unique Landscapes

Credit: Wikimedia Commons

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According to conventional thinking, plant life first took hold on Earth after oceans and rivers formed; the soil produced by liquid water breaking down bare rock provided an ideal medium for plants to grow in. It certainly sounds logical, but a new study is challenging that view – the theory is that vascular plants, those containing a transport system for water and nutrients, actually created a cycle of glaciation and melting, conditions which led to the formation of rivers and mud which allowed forests and farmland to later develop. In short, they helped actually create the landscapes we see today.

The evidence was just published in two articles in a special edition of Nature Geoscience.

In the first article, analysis of the data proposes that vascular plants began to absorb the carbon dioxide in the atmosphere about 450 million years ago. This led to a cooling of temperatures on a global scale, resulting in widespread glaciation. As the glaciers later started to melt, they ground up the Earth’s surface, forming the kind of soils we see today.

The second article goes further, stating that today’s rivers were also created by vascular plants – the vegetation broke the rocks down into mud and minerals and then also held the mud in place. This caused river banks to start forming, acting as channels for water, which up until then had tended to flow over the surface much more randomly. As the water was channeled into more specific routes, rivers formed. This led to periodic flooding; sediments were deposited over large areas which created rich soil. As trees were able to take root in this new soil, debris from the trees fell into the rivers, creating logjams. This had the effect of creating new rivers and causing more flooding. These larger fertile areas were then able to support the growth of larger lush forests and farmland.

According to Martin Gibling, a professor of Earth science at Dalhousie University, “Sedimentary rocks, before plants, contained almost no mud. But after plants developed, the mud content increased dramatically. Muddy landscapes expanded greatly. A new kind of eco-space was created that wasn’t there before.”

The new theory also leads to the possibility that any exoplanets that happen to have vegetation would look different from Earth; varying circumstances would create a surface unique to each world. Any truly Earth-like exoplanets might be very similar in general, but the way that their surfaces have been modified might be rather different.

It’s an interesting scenario, but it also raises other questions. What about the ancient river channels on Mars? Some appear to have been formed by brief catastrophic floods, but others seem more similar to long-lived rivers here on Earth, especially if there actually was a northern hemisphere ocean as well. How did they form? Does this mean that rivers could form in a variety of ways, with or without plant life being involved? Could Mars have once had something equivalent to vascular plant life as well? Or could the new theory just be wrong? Then there’s Titan, which has numerous rivers still flowing today. Albeit they are liquid methane/ethane instead of water, but what exactly led to their formation?

From the editorial in Nature Geoscience:

Without the workings of life, the Earth would not be the planet it is today. Even if there are a number of planets that could support tectonics, running water and the chemical cycles that are essential for life as we know it, it seems unlikely that any of them would look like Earth. Even if evolution follows a predictable path, filling all available niches in a reproducible and consistent way, the niches on any Earth analogue could be different if the composition of its surface and atmosphere are not identical to those of Earth. And if evolution is random, the differences would be expected to be even larger. Either way, a glimpse of the surface of an exoplanet — if we ever get one — may give us a whole new perspective on biogeochemical cycling and geomorphology.

Just as the many exoplanets now being found are of a previously unknown and amazingly wide variety, and all uniquely alien, even the ones that (may) support life are likely to be just as diverse from each other as they are from Earth itself. Earth’s “twin” may be out there, but in terms of outward appearance, it may be somewhat more of a fraternal twin than an exact replica.

Getting to the Core of Earth’s Falling Snow

Visualization of the GPM Core Observatory and Partner Satellites. Credit: NASA

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An international plan is unfolding that will launch satellites into orbit to study global snowfall precipitation with unprecedented detail. With the upcoming Global Precipitation Measurement (GPM) satellites, for the first time we will know when, where and how much snow falls on Earth, allowing greater understanding of energy cycles and how best to predict extreme weather.

Snow is more than just a pretty winter decoration… it’s also a very important contributor to fresh water supply in many regions around the world, especially those areas that rely on spring runoff from mountains.

The snowmelt from the Sierra Nevadas, for example, accounts for a third of the water supply for California.

But changing climate and recent drought conditions have affected how much snow the mountains receive in winter… and thus how much water is released in the spring. Unfortunately, as of now there’s no reliable way to comprehensively detect and measure falling snow from space… whether in the Sierras or the Andes or the Alps.

Engineers are building and testing the GPM Core Observatory at Goddard Space Flight Center. (NASA/GSFC)

The GPM Core satellite, slated to launch in 2014, will change that.

“The GPM Core, with its ability to detect falling snows, it’s one of the very first times that we’ve put sensors in space to specifically look at falling snow,” said GPM Deputy Project Scientist Gail Skofronick-Jackson in an online video. “We’re at that edge where rain was fifty years ago. We’re still figuring out how to measure snow.”

And why is snow such a difficult subject to study?

“Rain tends to be spherical like drops,” says Skofronick-Jackson. “But if you’ve ever been out in a snowfall and you’ve looked at your shirt, you see the snow comes in all different forms.”

Once GPM scientists calculate all the various types of snowflake shapes, the satellite will be able to detect them from orbit.

“The GPM Core, with its additional frequencies and information on the sensors, is going to be able to provide us for the first time a lot more information about falling snow than we’ve ever done before.”

Knowing where and how much snow and rain falls globally is vital to understanding how weather and climate impact both our environment and Earth’s energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters.

Snowfall is a missing part of the puzzle, and GPM will fill those pieces in.

Find out more about the GPM program at pmm.nasa.gov/GPM.

GPM Core is currently being assembled at NASA’s Goddard Space Flight Center and scheduled to launch in 2014 on a Japanese H-IIA rocket.  Initiated by NASA and the Japanese Aerospace Exploration Agency (JAXA), GPM consists of a consortium of international agencies, including the Centre National d’Études Spatiales (CNES), the Indian Space Research Organization (ISRO), the National Oceanic and Atmospheric Administration (NOAA), the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), and others. 

NASA’s Blue Marble…Side B.

Earth's eastern hemisphere made from Suomi NPP satellite images. (NASA/NOAA)

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In response to last week’s incredibly popular “Blue Marble” image, NASA and NOAA have released a companion version, this one showing part of our planet’s eastern hemisphere.

The image is a composite, made from six separate high-resolution scans taken on January 23 by NASA’s recently-renamed Suomi NPP satellite.

From the description on NASA Goddard Space Flight Center’s Flickr page:

Compiled by NASA Goddard scientist Norman Kuring, this image has the perspective of a viewer looking down from 7,918 miles (about 12,742 kilometers) above the Earth’s surface from a viewpoint of 10 degrees South by 45 degrees East. The four vertical lines of ‘haze’ visible in this image shows the reflection of sunlight off the ocean, or ‘glint,’ that VIIRS captured as it orbited the globe. Suomi NPP is the result of a partnership between NASA, NOAA and the Department of Defense.

Last week’s “Blue Marble” image is now one of the most-viewed images of all time on Flickr, receiving nearly 3.2 million views!

See the previously released image here.

NASA launched the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (or NPP) on October 28, 2011 from Vandenberg Air Force Base. On Jan. 24, NPP was renamed Suomi National Polar-orbiting Partnership, or Suomi NPP, in honor of the late Verner E. Suomi. It’s the first satellite designed to collect data to improve short-term weather forecasts and increase understanding of long-term climate change.

Image credit: NASA/NOAA

Added: check out a “zoomified” version of this image on John Williams’ StarryCritters site.

 

Amazing Panorama of Western Europe at Night from Space Station

Western Europe at Night With hardware from the Earth-orbiting International Space Station appearing in the near foreground, a night time European panorama reveals city lights from Belgium and the Netherlands at bottom center. the British Isles partially obscured by solar array panels at left, the North Sea at left center, and Scandinavia at right center beneath the end effector of the Space Station Remote Manipulator System or Canadarm2. This image was taken by the station crew on Jan. 22, 2012. Credit: NASA

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An amazing panorama revealing Western Europe’s ‘Cities at Night’ with hardware from the stations robotic ‘hand’ and solar arrays in the foreground was captured by the crew in a beautiful new image showing millions of Earth’s inhabitants from the Earth-orbiting International Space Station (ISS).

The sweeping panoramic vista shows several Western European countries starting with the British Isles partially obscured by twin solar arrays at left, the North Sea at left center, Belgium and the Netherlands (Holland) at bottom center, and the Scandinavian land mass at right center by the hand, or end effector, of the Canadian-built ISS robotic arm known as the Space Station Remote Manipulator System (SSRMS) or Canadarm2.

European Space Agency astronaut Andre Kuipers gazing at Earth from the Cupola dome of the ISS

Coincidentally European Space Agency astronaut Andre Kuipers from Holland (photo at left) is currently aboard the ISS, soaring some 400 kilometers (250 miles) overhead.

The panoramic image was taken by the ISS residents on January 22, 2012.

The Expedition 30 crew of six men currently serving aboard the ISS (photo below) hail from the US, Russia and Holland.

NASA astronaut Dan Burbank is the commander of Expedition 30 and recently snapped awesome photos of Comet Lovejoy.

“Cities at Night” – Here’s a portion of a relevant ISS Blog post from NASA astronaut Don Pettit on Jan. 27, 2012:

“Cities at night are different from their drab daytime counterparts. They present a most spectacular display that rivals a Broadway marquee. And cities around the world are different. Some show blue-green, while others show yellow-orange. Some have rectangular grids, while others look like a fractal-snapshot from Mandelbrot space.”

“Patterns in the countryside are different in Europe, North America, and South America. In space, you can see political boundaries that show up only at night. As if a beacon for humanity, Las Vegas is truly the brightest spot on Earth. Cities at night may very well be the most beautiful unintentional consequence of human activity,” writes NASA astronaut Don Pettit currently residing aboard the ISS.

Comet Lovejoy on 22 Dec. 2011 from the International Space Station. Comet Lovejoy is visible near Earth’s horizon in this nighttime image photographed by NASA astronaut Dan Burbank, Expedition 30 commander, onboard the International Space Station on Dec. 22, 2011. Credit: NASA/Dan Burbank
Expedition 30 Crew: Pictured on the front row are NASA astronaut Dan Burbank, commander; and Russian cosmonaut Oleg Kononenko, flight engineer. Pictured from the left (back row) are Russian cosmonauts Anton Shkaplerov and Anatoly Ivanishin; along with European Space Agency astronaut Andre Kuipers and NASA astronaut Don Pettit, all flight engineers. Photo credit: NASA and International Space Station partners

Toronto Teens Launch “Lego Man in Space”

Toronto Teens Launch Lego Main In Space to the Stratosphere - Jan 2012. Stunning space imagery was captured by Canadian teenagers Mathew Ho and Asad Muhammad when they lofted a tiny ‘Lego Man in Space’ astronaut to an altitude of 16 miles (25 kilometers) using on a helium filled weather balloon. Credit: Mathew Ho and Asad Muhammad. Watch the YouTube below

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Updated:Jan. 30

Two teens from Toronto,Canada have launched “Lego Man in Space” using a helium filled weather balloon and captured stunning video of the miniature toy figure back dropped by the beautiful curvature of Earth and the desolate blackness of space that’s become a worldwide YouTube sensation – over 2 million hits !

17 year olds Mathew Ho and Asad Muhammad lofted the tiny 2 inch tall Lego figure from a local Toronto soccer field up to a height of about 85,000 feet, or 16 miles (25 kilometers), where the 22 foot (7 m) diameter helium balloon burst in what is technically known as the stratosphere. The homemade styrofoam capsule – equipped with two video cameras and two digital cameras (Canon) – then parachuted back to Earth.

“We launched the project on January 7,” Mathew Ho told Universe Today.

“Altogether, we used 4 cameras, two cameras taking stills, and two taking video – Canon, Sony, GoPro – in the 1 cubic foot capsule,” Ho explained.

“After endless hours of hard work, we managed to capture stunning views of our atmosphere and put a ‘Lego’ man into near space!” said the ambitious teens who are 12th graders at the Agincourt Collegiate Institute.

The pair posted a YouTube video (below) documenting the entire voyage and some camera snapshots on their website on January 25.

Lego Man even snapped cool Moon shots – look closely at the video and photo below.

“Lego Man in Space” – The Video

The duo recounted the details of their sensational space tale of science on a shoestring for Canadian TV and newspapers.

“Upon launch we were very relieved. But we had a lot of anxiety on launch day because there were high winds when we were going up after all the hard work,” said Ho in a studio interview on Canadian TV (CTV).

“We were also scared because now we would have to retrieve it back after it came down,” Asad chimed in.

“We had no idea it would capture photos like that and would be so good,” said Ho. “We were blown away when we saw them back home.”

The toy Lego astronaut is seen standing atop a thin runway protruding precariously from one end of the small, box shaped capsule as though he was walking the plank and about to plunge into the ocean of space. All the while, cameras were aimed directly out towards him recording the entire rollicking journey from liftoff to the stratosphere to landing, with a constantly changing Earth in the background.

Altogether they netted two videos and 1500 photos.

Lego Man in Space shoots the Moon !
Credit: Mathew Ho and Asad Muhammad

Coincidentally, several Lego toys are constantly flying even higher above the Earth at this very moment aboard the International Space Station as part of an educational outreach effort by NASA and Lego. And 3 more Lego figurines are speeding to Jupiter aboard NASA’s Juno orbiter.

Legoman’s spectacular journey lasted some 97 minutes. He’s beaming proudly throughout the video while holding the Canadian National flag – the Red Maple Leaf. The rollercoaster-like scenery may well challenge the stomachs of those with fear of heights.

The tumbling Lego Man in Space capsule upon the violent descent captured the moment before the parachute was activated. Credit: Mathew Ho and Asad Muhammad

Mathew and Asad worked over about four months one day a week on Saturdays to assemble the rig in Mathew’s kitchen and successfully accomplished the feat on a shoestring budget of merely 400 dollars. They used GPS trackers to locate “Lego Man in Space” and recover the intact capsule holding the imagery.

After the balloon burst at 85,000 feet, the parachute assisted descent back to Earth took about 32 minutes. Winds aloft caused the capsule to drift some 76 miles (122 kilometers) away from the launch site before landing at Rice Lake in one piece.

Lego Man in Space capsule after landing 76 miles (122 kilometers) away from the Toronto soccor field launch site. Credit: Mathew Ho and Asad Muhammad

“We were jumping for joy when we saw the capsule and the parachute. We were ecstatic when we found it,” said Ho.

“We have a long history of passionate building and working together,” Ho told CTV.

The project began after they saw that MIT students had sent a camera to the edge of space with a balloon and captured stunning views.

“We were inspired by videos and pictures we had seen online two years ago and we began working on this in the Fall of 2011. In total the project cost about $400 Canadian,” Ho told me.

“We hope to publish more pictures and video to our Facebook page and website soon,” Ho added.

And now we know another truth about Lego’s – Not only can they withstand the destructive forces of kids, but outer space too !

Blue Marble 2012: Amazing High Definition Image of Earth

A 'Blue Marble' image of the Earth taken from the VIIRS instrument aboard NASA's most recently launched Earth-observing satellite - Suomi NPP. This composite image uses a number of swaths of the Earth's surface taken on January 4, 2012. Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring.

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A new high-definition version of the ‘Blue Marble’ has been taken from the newest Earth observation satellite. The just-renamed Suomi NPP satellite took numerous images on January 4, 2012 and this composite image was created from several “swaths” of Earth. It is a stunningly beautiful look at our home planet, with the largest versions of the image showing about 1.6 km (1 mile) per pixel. This Sun-synchronous Earth-orbiting satellite is 824 kilometers (512 miles) above Earth, and it gets a complete view of our planet every day. It is the first of a new generation of satellites that will observe many facets of how our Earth may be changing.

Originally launched as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP), it was just renamed ‘Suomi NPP’ on to honor a pioneer in the use of satellites, the late Verner E. Suomi.

See below for an image showing these “swaths” from global images taken on November 24, 2011.

The Suomi NPP satellite gets a complete view of our planet every day. This image uses 20 orbital ‘swaths’ from November 24, 2011, and is the first complete global image from the VIIRS instrument. Credit: NASA Earth Observatory.

These images were taken with the The Visible/Infrared Imager Radiometer Suite or VIIRS instrument aboard Suomi NPP.

VIIRS images the surface in long wedges measuring 3,000 kilometers (1,900 miles) across. The swaths from each successive orbit overlap one another, so that at the end of the day, the sensor has a complete view of the globe. The Arctic is missing because it is too dark to view in visible light during the winter.

The NPP satellite was placed in a Sun-synchronous orbit, so its path takes the satellite over the equator at the same local (ground) time in every orbit. This orbit allows the satellite to maintain the same angle between the Earth and the Sun so that all images have similar lighting. This consistent angle is important because it allows scientists to compare images from year to year without worrying about extreme changes in shadows and lighting.

Suomi NPP is carrying five instruments on board, and the biggest and most important instrument is VIIRS.

Unfortunately, an anomaly has been discovered in the instrument. During the checkout phase after it launched in October 2011, engineers detected a larger than expected decrease in sensor sensitivity in four of VIIRS’s near-infrared and visible channels.

An analysis revealed an anomalous material on the surface of the mirror, and further investigation on the ground discovered a non-standard process that occurred during the mirror coating as a potential source of tungsten oxide contamination on the VIIRS mirrors. Tungsten oxides could cause the surface of the mirror to darken.

This evidence suggests that the cause of the contamination is limited to the VIIRS instrument, and is not a concern for other NPP instruments. Officials from NPP said that while this problem is likely irreversible, the darkening of the VIIRS mirror caused by the contamination is expected to reach a plateau and remain at that level for the life of the mission. Although testing on this issue is continuing, NPP mission managers expect this plateau to still provide sufficient margins to allow VIIRS to meet its design requirements.

Still, the images have been spectacular so far from Suomi NPP and we look forward to more high definition views of our Blue Marble.

See the complete set of images from this spacecraft on their Flickr site.

More info on the Suomi NPP

A Space Moonrise (and the PromISSe of a New Future)

The Moon rises above (below?) Earth's limb in this view from the ISS. (ESA/NASA)

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“The moon looks the same from the ISS as it does on Earth. Only we see it rise and set again and again.”

ESA astronaut André Kuipers tweeted this message earlier today, accompanied by the wonderful photo above showing a distant Moon resting along Earth’s limb. The solar panels of the docked Soyuz TMA-03M spacecraft are seen in the foreground.

André arrived at the Space Station on December 23 along with Expedition 30 crewmates Oleg Kononeko and Don Pettit.

In addition to conducting over 45 experiments for ESA, NASA and JAXA during his five months in orbit, André’s PromISSe mission will help educate children about math, science, engineering, technology, and the benefits – and challenges – of working in space.

The program will also encourage the next generation of space explorers to stay fit with the second edition of the international fitness initiative Mission X: Train Like an Astronaut.

A medical doctor, André serves as flight engineer aboard the ISS and will be highly involved in docking procedures for the new Dragon (SpaceX) and Cygnus (Orbital Sciences) capsules as part of NASA’s next-generation commercial spaceflight program.

Read ESA’s PromISSe mission blog here, and follow André Kuipers on Twitter @astro_andre for more Expedition 30 mission updates.

Does Life on the Seafloor Predict Life on Other Worlds?

Hydrothermal vents deep in Earth's oceans. Could similar types of vents power the transport of silica and other materials out from Enceladus? Credit: NOAA
Hydrothermal vents deep in Earth's oceans. Could similar types of vents power the transport of silica and other materials out from Enceladus? Credit: NOAA

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Scientists have recently discovered communities of previously unknown species living on the seafloor near Antarctica clustered around hydrothermal vents. This discovery is certainly exciting for biologists, but it’s also important for astrobiologists. It begs the question — if life can thrive in the deep, dark oceans without sunlight, could similar life thrive elsewhere in our solar system or the universe?

For decades, scientists assumed the deep oceans were barren; sunlight can’t reach the ocean floor, making it an impossible environment for life as we know it to arise. But in 1977, oceanographers from the Scripps Institute discovered hydrothermal vents.

A schematic diagram of deep sea vent chemistry. Image credit: National Oceanic and Atmospheric Administration

These fissures, found along mid-ocean ridges on the seafloor of the Pacific, Atlantic, and Indian Oceans, create a natural, deep-sea plumbing system. Heat and minerals from the Earth’s interior vents out, providing a complex ecosystem that can reach up to 382 degrees Celsius (almost 720 degrees Fahrenheit). These ecosystems can support unique life forms that get their energy not from the Sun but from breaking down chemicals issued from the vents such as hydrogen sulphide.

The latest life forms, discovered in the Antarctic region by teams from the University of Oxford, University of Southampton and British Antarctic Survey, include a new species of yeti crab, starfish, barnacles, sea anemones, and potentially an octopus.

“These findings are yet more evidence of the precious diversity to be found throughout the world’s oceans,” said Professor Rogers of Oxford University’s Department of Zoology. “Everywhere we look, whether it is in the sunlit coral reefs of tropical waters or these Antarctic vents shrouded in eternal darkness, we find unique ecosystems that we need to understand and protect.”

Jupiter's moon Europa. The lines on the surface are breaks in the ice that lie on top of vast oceans. Image credit: NASA/courtesy of nasaimages.org

But it isn’t only biologists studying life on Earth that can benefit from this latest discovery. These peculiar environments on and beneath the seafloor could be a model for the origin of life on Earth and on other planets.

One particular target is Jupiter’s moon Europa. Recent research has confirmed that the moon has vast oceans buried beneath its frozen surface ice; it’s estimated to hold twice as much water as Earth. As such, it is a target for NASA in the search for life. It could be the case that some type of hydrothermal vent system exists on Europa, making its distance from the Sun irrelevant for life.

But just because sulfur or methane-based life on Earth can thrive around deep-ocean vents doesn’t mean the same is true on Europa. The presence of hydrothermal vents depends on geologic activity and a hot interior, neither of which has been confirmed. The possibility remains that light energy from the Sun could travel the distance to the moon and provide shallower portions of the subsurface oceans with life-giving light.

In any case, as scientists discover life in the more extreme environments on Earth, analogies are drawn with other worlds. If life is discovered in hostile parts of our planet, the same could theoretically arise in similar environments on other worlds.

Source: ‘Lost World’ discovered around Antarctic vents.

Does Earth Have Many Tiny Moons?

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.

The team’s published paper can be found here.