Universe Today

November 8, 2008December 24, 2015 by Ian O'Neill

First Images of Asteroid 2008 TC3 Impact Aftermath

The long-lasting persistent train after the impact of 2008 TC3 over the Sudanese skies (NASA)

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A month after asteroid 2008 TC3 hit the Earth’s atmosphere, the first ground-based image of the event has surfaced on the Internet. Admittedly, it’s not the fireball everyone has been waiting to see, but it is visual evidence that something hit us above Sudan on October 7th. The image above was taken from a frame of video that was being recorded by Mr. Mohamed Elhassan Abdelatif Mahir in the dawn following the asteroid impact with the atmosphere. The smoky feature is the remnant of the fireball as the 3 meter-wide asteroid blasted through the upper atmosphere, eventually exploding. The long-lasting persistent train is seen hanging in the air, high altitude winds causing it to twist in the morning sunlight.

We may not have a dazzling fireball re-entry video of 2008 TC3, but this striking image provides the first ground-based evidence of the direct hit, and may help refine the search for any meteorites from the disintegrated asteroid…

Although details are sketchy, it would appear that a person on the ground observed the skies of Sudan shortly after 2008 TC3 exploded in the upper atmosphere. It is unclear whether the observer was part of a meteorite-hunting team, or a Sudanese resident videoing the scene, but it is very fortunate he captured this footage. Dr. Muawia H. Shaddad of the University of Karthoum communicated this single frame, and the picture is being showcased as the November 8th NASA Astronomy Picture of the Day.

It is currently the only ground-based evidence that something hit the Earth at the right time and right location as predicted by scientists using the Mount Lemmon telescope in Arizona as part of the NASA-funded Catalina Sky Survey for near-Earth objects. However, as Nancy reported on October 13th, indirect support for an atmospheric fireball came from a webcam on a beach in Egypt. Also, at 02:43 UTC on that Tuesday morning, an infrasound array in Kenya detected an explosion in the atmosphere (with an energy equivalent of 1.1–2.1 kT of TNT). These observations were backed up by the European weather satellite METEOSAT-8, capturing the fireball from orbit. The pilot of a KLM airliner also witnessed a bright flash, 750 miles from the impact location.

This was the first time that an asteroid has been discovered before it hit the Earth, thereby proving an early-warning system for future asteroid impacts is possible. Although there are 5-10 space rock collision events per year, this is the first time we knew something about it before it happened. This is an amazing achievement as 2008 TC3 was only 3 meters in diameter.

To aid the search for any 2008 TC3 debris, SpaceWeather.com is hoping this image of the aftermath of the October 7th impact will jog any potential witness memories of the African skies a month ago:

Readers, were you in Sudan on Oct. 7th? Send your fireball reports and photos to meteor expert Peter Jenniskens of the SETI Institute. Your data could improve the chances of recovering meteorites.

Sources: SpaceWeather.com, Astroengine.com, NASA APOD

November 8, 2008December 24, 2015 by Nancy Atkinson

Chandrayaan-1 Now Successfully in Lunar Orbit

Chandrayaan-1 in lunar orbit. Credit: ISRO

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Chandrayaan-1, India’s first unmanned spacecraft mission to moon, successfully entered lunar orbit on November 8. The spacecraft fired its engines to reduce velocity and enable the Moon’s gravity to capture it; engines were fired for 817 seconds when Chandrayaan-1 was about 500 km away from the moon. Next up for the spacecraft will be to reduce the height of its lunar orbit to about 100 km. Then, on Nov. 14th or 15th, the Moon Impact Probe (MIP) will be launched, and crash into the Moon’s surface (more about the MIP below). If you enjoy watching animations and want to see exactly how the spacecraft attained its lunar orbit, here’s a few animations for you:

A simple animation of how the spacecraft went from its spiraling elliptical orbit around Earth to its now spiraling elliptical orbit around the moon can be found on the India Space Agency’s site. (Sorry, the file was to big to insert here.)

Another quite large animation that was created by Doug Ellison (of UnmannedSpaceflight.com) shows how the X-ray Spectrometer aboard Chandrayaan-1 will work. This one takes a long time to download, but the wait is well worth it: the animation is spectacular.

Here’s a video that shows an animation of the entire mission; again, some great animation here. Enjoy.

The spacecraft is now orbiting the moon in an elliptical orbit that passes over the polar regions of the moon. The nearest point of this orbit (perigee) lies at a distance of about 504 km from the moon’s surface while the farthest point (apogee) lies at about 7502 km. Currently, Chandrayaan-1 takes about 11 hours to orbit the moon.

The MIP carries three instruments:

Radar Altimeter – measures the altitude of the probe during descent and for qualifying technologies for future landing missions.

Video Imaging System – acquires close range images of the surface of the Moon during descent. The video imaging system consists of analog CCD camera.

Mass Spectrometer measures the constituents of lunar atmosphere during descent.

Source: ISRO

November 8, 2008December 24, 2015 by Ian O'Neill

Declaration of Human Rights to be Sent to Space Station

[/caption]On December 10th 1948, the Universal Declaration of Human Rights (UDHR) was adopted by the United Nations General Assembly in a direct response to the atrocities committed during the Second World War. Since this landmark moment, the UDHR has been adopted and become the most translated document in history. The declaration consists of 30 articles (or 30 specific basic rights) and all have been worked into international law.

Now the one document that defines an individual’s rights on Earth will be launched into orbit and installed on the International Space Station (ISS), just in time for the 60th anniversary of the declaration’s signing…

All going well, November 14th will see the launch of STS-126, Space Shuttle Endeavour’s resupply mission to the ISS. The seven-member crew is set to deliver equipment to the ISS as well as repair the Solar Alpha Rotary Joints (SARJ). However, Endeavour will also have some extra special cargo on board.

To mark the 60th anniversary of the UDHR, a copy of the historic document will be hand-delivered and placed on board the European Space Agency’s Columbus module. The UDHR will remain on board the science laboratory permanently as a testament to the people on Earth and the astronauts in space who live by these rules.

On Friday, a copy of the declaration was handed to ESA’s Director General, Jean-Jacques Dordain, by Rama Yade (who is responsible of foreign affairs and human rights within the French government) at the Quai d’Orsay, the French Foreign Ministry. The UDHR has been sealed inside protective packaging to prevent damage from the ravages of space travel.

“The ESA Astronaut Corps welcomes this humanitarian initiative. In recognition of the fact that human beings are at times downtrodden, the Declaration can symbolically find its place ‘above’ all the peoples of the world,” said ESA astronaut Léopold Eyharts, who helped to install the Columbus module back in February.

Sources: ESA, Physorg.com

November 7, 2008December 24, 2015 by Nancy Atkinson

In Their Own Words: Apollo Astronauts say “We Went to the Moon”

Happy 40th Anniversary, Apollo 15! — Image from Apollo 15. Credit: NASA

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Someone approached me recently and wanted to ask about how the US faked going to the Moon back in the 1960’s and 70’s. I was so shocked, appalled and dumbfounded, I really didn’t know what to say. I just directed them to Phil Plait’s Moon Hoax Hoax info. Then I wondered, what do the Apollo astronauts say if someone asks them the same question? Now I know. I just finished watching “In the Shadow of the Moon,” a documentary of the Apollo era presented by Ron Howard, directed by David Sington (*correction). It’s a wonderful film with fantastic and rare footage along with interviews of several of the Apollo astronauts. I highly recommend it! And the end, as the credits are rolling, each of the astronauts responds to an unsaid question about the those who think this greatest adventure in human history was a hoax:

Mike Collins: “I don’t know how I would grab someone by the collar who didn’t believe and shake them and somehow change their mind.” And later Collins added, “I don’t know two Americans who could have a fantastic secret without one of them blurting it out to the press. Can you imagine thousands of people being able to keep this secret?”

Charlie Duke: “We’ve been to the moon nine times. If we faked it, why did we fake it nine times?”

Alan Bean: “Some of the tabloids are saying that we did this in a hanger in Arizona. Maybe that would have been a good idea!” (meaning, it would have been a lot safer)

Dave Scott: “Any significant event in history, somebody has had a conspiracy theory one way or the other about it.”

Gene Cernan: “Truth needs no defense. Nobody, nobody can ever take those footsteps that I made on the surface of the moon away from me.”

And Buzz Aldrin said this on a the UK TV show, “Where Are They Now:” “I’m an honest person. If I tell you I was on the moon and you choose not to believe it, forget it.”

The next time someone approaches me, I’ll be better prepared. And I can hardly wait for the Lunar Reconnaissance Orbiter’s launch early next year. LRO will carry a powerful camera into low orbit over the Moon’s surface. While its primary mission is not to photograph old Apollo landing sites, it will probably photograph them, many times, providing the first recognizable images of Apollo relics since 1972.

The spacecraft’s high-resolution camera, the LROC, or Lunar Reconnaissance Orbiter Camera, has a resolution of about half a meter. That means that a half-meter square on the Moon’s surface would fill a single pixel in its digital images.

Apollo moon rovers are about 2 meters wide and 3 meters long. So in the LROC images, those abandoned vehicles will fill about 4 by 6 pixels.

Check out “In the Shadow of the Moon” website.

November 7, 2008December 24, 2015 by Nancy Atkinson

Astronomers Discover Odd Kuiper Belt Pair

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Astronomers have discovered a pair of small Kuiper Belt Objects that are gravitationally bound to each other. This is somewhat unusual in itself. But even though these two objects are gravitationally connected, they have an enormous separation between them, about 125,000 kilometers (one third the distance from the Earth to the Moon). Astronomers say, as a comparison, this is equivalent to a pair of baseballs gravitationally “connected” and orbiting each other at a distance of 200 kilometers!

The extreme binary, 2001 QW322, orbits at 43 astronomical units or about 6.5 billion kilometers from the Sun. The pair was originally discovered in August 2001 with the Canada-France-Hawai‘i Telescope. Since then, (from 2002-2007), the pair has been monitored closely using 8-meter-class telescopes (Gemini North, Gemini South and the European Southern Observatory’s Very Large Telescope) to obtain high precision photometric observations of the faint double system.

In the above images, their separation was 1.8 arcseconds. Their radii are about 50 kilometers.
There are on the order of about a billion additional Kuiper Belt Objects in our solar system with Pluto and Charon being among the largest members of this important group of minor planets. These small icy bodies move in low eccentricity and low inclination orbits beyond Neptune, extending possibly as far as 1,000 times the distance from the Earth to the Sun.

Most Kuiper Belt Objects are single objects. The advent of adaptive optics and various survey techniques has created a surge in the discovery of binaries in the main asteroid and Kuiper belts. Astronomers say 2001 QW322 clearly stands out as the widest orbit, near-equal mass binary of the solar system.

Source: Gemini Observatory

November 7, 2008December 24, 2015 by Tammy Plotner

Grus

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The constellation of Grus was originally created by Petrus Plancius from the observations of Dutch sea navigators Pieter Dirkszoon Keyser and Frederick de Houtman when exploring the southern hemisphere. Grus’ stellar patterns became known when it appeared on a celestial globe in 1597 and was considered a constellation when it was added to Johann Bayer’s Uranometria catalog in 1603. It survived the years to become one of the 88 modern constellations recognized by the International Astronomical Union. Grus is located south of the ecliptic plane and covers approximately 366 square degrees of sky. It is bordered by the constellations of Piscis Austrinus, Microscopium, Indus, Tucana, Phoenix and Sculptor. The asterism consists of 7 main stars and there are 28 stars with Bayer/Flamsteed designations. Grus is visible to all observers at latitudes between +34° and ?34° and is best seen at culmination during the month of October.

Until the late 16th century, Grus was considered part of Piscis Austrinus – the “Southern Fish” – since most of its stars weren’t visible to northern latitudes. When exploration began below the equator many wondrous new creatures were discovered. One such bird was the fishing crane – Phoenicopterus – the flamingo. Perhaps this is how the constellation got is name, since Grus is also Dutch for “crane”!

First let’s take a binocular tour of Grus, starting with its brightest star, Alpha, the “a” symbol on our map. Alpha Gruis proper name is Alnair, the Arabic word for “bright one of the tail”. In this case, it was originally the tail of the fish. But besides being a bit “fishy”, Alnair is a hot, blue subgiant giant star about 101 light years away from Earth. Not only is it larger, hotter and brighter than our own Sol, but it a rather fast stellar rotation – making a complete rotation in under a day. Hop on to Beta Gruis, the “B” symbol on our map. Beta Gruis is a rare kind of star – a cooler class M giant star. It is very possible it is in an advanced state of evolution, losing mass and brightening with a dead carbon-oxygen core in preparation for sloughing its outer envelope – ready to become a Cepheid variable!

Now for visual and binocular double star, Delta 1 and Delta 2 Gruis – the “8” symbol in the center of the constellation. While this pair aren’t physically connect to one another, they do make a pleasing sight with their lovely yellow and red contrasting colors. For a true telescopic binary star, hop north to Upsilon. This disparate pair is separated by over a degree of arc and the difference between stellar magnitudes is a great experience.

For the telescope, tackle NGC 7213 (RA 22:09.3 Dec -47:10) about 16′ southeast of Alpha. This 10th magnitude Seyfert galaxy has definitely got some stories to tell. Not only is it a spiral galaxy, but one that has an incredible,giant H-alpha filament erupting from its nucleus. Another great challenge is NGC 7582, 7590 and 7599 (RA 023:19 Dec -42:3). Here is a small galaxy group consisting of three faint spirals in the same field, all tilted close to edge on. While at least an intermediate sized telescope is need to see them, a wide field eyepiece will place all three in the same field of view at around 100x magnification. Before we leave for the night, let’s try NGC 7410 (22:55.0 -39:40). This uniformly illuminated tilted spiral galaxy shows little sign of structure, despite its bright nature.

Sources: Wikipedia, SEDS
Chart courtesy of Your Sky.

November 7, 2008December 24, 2015 by Nancy Atkinson

Deepest Ultraviolet Image Shows a Sea of Distant Galaxies

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Dive right in to this image that contains a sea of distant galaxies! The Very Large Telescope has obtained the deepest ground-based image in the ultraviolet band, and here, you can see this patch of the sky is almost completely covered by galaxies, each one, like our own Milky Way galaxy, and home of hundreds of billions of stars. A few notable things about this image: galaxies were detected that are a billion times fainter than the unaided eye can see, and also in colors not directly observable by the human eye. In this image, a large number of new galaxies were discovered that are so far away that they are seen as they were when the Universe was only 2 billion years old! Also…

This image contains more than 27 million pixels and is the result of 55 hours of observation, made primarily with the Visible Multi Object Spectrograph (VIMOS) instrument. To get the full glory of this image, here’s where you can download the full resolution version. It’s worth the wait while it downloads. Or click here to be able to zoom around the image.

In this sea of galaxies – or island universes as they are sometimes called – only a very few stars belonging to the Milky Way are seen. One of them is so close that it moves very fast on the sky. This “high proper motion star” is visible to the left of the second brightest star in the image. It appears as a funny elongated rainbow because the star moved while the data were being taken in the different filters over several years.

The VLT folks describe this image as a “uniquely beautiful patchwork image, with its myriad of brightly coloured galaxies.” It shows the Chandra Deep Field South (CDF-S), one of the most observed and best studied regions in the entire sky. The CDF-S is one of the two regions selected as part of the Great Observatories Origins Deep Survey (GOODS), an effort of the worldwide astronomical community that unites the deepest observations from ground- and space-based facilities at all wavelengths from X-ray to radio. Its primary purpose is to provide astronomers with the most sensitive census of the distant Universe to assist in their study of the formation and evolution of galaxies.

The image encompasses 40 hours of observations with the VLT, just staring at the same region of the sky. The VIMOS R-band image was obtained co-adding a large number of archival images totaling 15 hours of exposure.

Source: ESO

November 7, 2008December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – November 7-9, 2008

Greetings, fellow StarGeezers! It’s Friiiii day… And another great weekend forecast. Does having all this Moon around get you down? It shouldn’t. Where else could you find another world that you could so intimately study detail with even the most modest of telescopes or binoculars? Instead of cursing Luna’s presence, get out your optics and enjoy! While we’re at it, we’ll take a look at some very interesting stars – both in the sky and from planet Earth. It’s time to head out into the dark… Cuz’ here’s what’s up!

Friday, November 7, 2008 – Today in 1996, the Mars Global Surveyor left on its journey. Just 30 years beforehand on this same day, Lunar Orbiter 2 was launched. Tonight let’s launch our way toward the Moon as we begin our observing evening with a look at a far northern crater – J. Herschel.

Residing on the mid-northern edge of Mare Frigoris, this huge, shallow old crater spans 156 kilometers and bear the scars of the years. Look for the deeper and younger crater Horrebow on the southwestern wall – for it has obliterated another, older wall crater.

Ready to aim for a bullseye? Then follow the “Archer” and head right for the bright, reddish star Aldebaran. Set your eyes, scopes or binoculars there and let’s look into the “eye” of the Bull.

Known to the Arabs as Al Dabaran, or “the Follower,” Alpha Tauri got its name because it appears to follow the Pleiades across the sky. In Latin it was called Stella Dominatrix, yet the Olde English knew it as Oculus Tauri, or very literally the “eye of Taurus.” No matter which source of ancient astronomical lore we explore, there are references to Aldebaran.

As the 13th brightest star in the sky, it almost appears from Earth to be a member of the V-shaped Hyades star cluster, but this association is merely coincidental, since it is about twice as close to us as the cluster is. In reality, Aldebaran is on the small end as far as K5 stars go, and like many other orange giants, it could possibly be a variable. Aldebaran is also known to have five close companions, but they are faint and very difficult to observe with backyard equipment. At a distance of approximately 68 light-years, Alpha is “only” about 40 times larger than our own Sun and approximately 125 times brighter. To try to grasp such a size, think of it as being about the same size as Earth’s orbit! Because of its position along the ecliptic, Aldebaran is one of the very few stars of first magnitude that can be occulted by the Moon.

Saturday, November 8, 2008 – Even if you only use binoculars tonight, you can’t miss the beautiful C-shape of Sinus Iridum as it comes into view on the lunar surface. As we have learned, the mountains ringing it are called the Juras, and the crater punctuating them is named Bianchini. Do you remember what the bright tips of the opening into the “Bay of Rainbows” are called? That’s right: Promontorium LaPlace to the northeast and Promontorium Heraclides to the southwest. Now take a good look at Heraclides… Just south of here is where Luna 17 landed, leaving the Lunokhod rover to explore!

Born on this day in 1656, the great Edmund Halley made his mark on history as he became best known for determining the orbital period of the comet which bears his name. English scientist Halley had multiple talents however, and in 1718 discovered that what were then referred to as “fixed stars,” actually displayed (proper) motion! If it were not for Halley, Sir Isaac Newton may never have published his now famous work on the laws of gravity and motion.

Now turn your eyes or binoculars just west of bright Aldebaran and have a look at the Hyades Star Cluster. As noted yesterday, Aldebaran appears to be part of this large, V-shaped group, but is not an actual member. The Hyades cluster is one of the nearest galactic clusters, and it is roughly 130 light-years away at its center. This moving group of stars is drifting slowly away toward Orion, and in another 50 million years will require a telescope to view!

Sunday, November 9, 2008 – Today is the birth date of Carl Sagan. Born in 1934, Sagan was an American planetologist, exobiologist, popularizer of science and astronomy, and novelist. During his lifetime, Sagan published more than 600 scientific papers and popular articles and was author, co-author, or editor of more than 20 books. His influential work and enthusiasm inspired us all. As Dr. Sagan once said, “Personally, I would be delighted if there were a life after death, especially if it permitted me to continue to learn about this world and others, if it gave me a chance to discover how history turns out.”

May his dreams live on..

If Carl were with us tonight, he would encourage amateurs at every level of astronomical ability! So let us honor his memory by beginning with an optical pairing of stars known as Zeta and Chi Ceti, a little more than a fistwidth northeast of bright Beta. Now have a look with binoculars or small scopes because you’ll find that each has its own optical companion!

Now drop south-southwest less than a fistwidth to have a look at something so unusual that you can’t help but be charmed – the UV Ceti System (RA 01 39 01 Dec -17 57 01).

What exactly is it? Also known as L 726-8, you are looking at two of the smallest and faintest stars known. This dwarf red binary system is the sixth nearest star to our solar system and resides right around nine light-years away. While you are going to need at least an intermediate-size scope to pick up these near 13th magnitude points of light, don’t stop observing right after you locate it. The fainter member of the two is what is known as a “Luyten’s Flare Star” (hence the “L” in its name). Although it doesn’t have a predictable timetable, this seemingly uninteresting star can jump two magnitudes in less than 60 seconds and drop back to “normal” within minutes – the cycle repeating possibly two or three times every 24 hours. A most incredible incident was recorded in 1952 when UV jumped from magnitude 12.3 to 6.8 in just 20 seconds!

No matter what you choose to look at tonight, as Dr. Sagan would say: “We are all star stuff.”

Have a great week and I’ll see you… Under the stars!

This week’s awesome photos are: Crater J. Herschel – Credit: Wes Higgins, Aldebaran – Credit: Palomar Observatory, courtesy of Caltech, Sinus Iridum – Credit: Wes Higgins, Edmund Halley (widely used public image), The Hyades Star Cluster – Credit: NASA, Carl Sagan (widely used public image), and Chi and the UV Ceti System – Credit: Palomar Observatory, courtesy of Caltech. Our many thanks to you!

November 6, 2008December 24, 2015 by Nancy Atkinson

Are We Close to Finding Dark Matter?

Dark Matter Halo. Credit: Virgo Consortium

Scientists say he search for the mysterious substance which makes up most of the Universe could soon be at an end. A massive computer simulation was used to show the evolution of a galaxy like the Milky Way, and analysts were able to “see” gamma-rays given off by dark matter. Dark matter is believed to account for 85 per cent of the Universe’s mass but has remained invisible to telescopes since scientists inferred its existence from its gravitational effects more than 75 years ago. If the computations are correct, the findings could help NASA’s Fermi Telescope to search for the dark matter and open a new chapter in our understanding of the Universe.

The consortium of scientists, called Virgo Consortium looked at dark matter halos – structures surrounding galaxies – which contain a trillion times the mass of the Sun. The simulations showed how the galaxy’s halo grew through a series of violent collisions and mergers between much smaller clumps of dark matter that emerged from the Big Bang.

The researchers found that gamma-rays produced when particles collided in areas of high dark matter density could be most easily detectable in regions of the Milky Way lying close to the Sun in the general direction of the galaxy’s centre.

They suggest the Fermi Telescope should search in this part of the galaxy where they predict that gamma-rays from dark matter should glow in “a smoothly varying and characteristic pattern”.

If Fermi does detect the predicted emission from the Milky Way’s smooth inner halo the Virgo team believes it might be able to see otherwise invisible clumps of dark matter lying very close to the Sun.

The Virgo research involved scientists from the Max Planck Institute for Astrophysics in Germany, The Institute for Computational Cosmology at Durham University, UK, the University of Victoria in Canada, the University of Massachusetts, USA, and the University of Groningen in the Netherlands.

Professor Carlos Frenk, Director of the Institute for Computational Cosmology, at Durham University, said: “Solving the dark matter riddle will be one of the greatest scientific achievements of our time.

“The search for dark matter has dominated cosmology for many decades. It may soon come to an end.”

Sources: EurekAlert, Virgo Consortium

November 6, 2008December 24, 2015 by Nancy Atkinson

Floating Battle Droids On Board ISS

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Three free-flying spheres are currently zooming around inside the International Space Station. Is the crew of Expedition 18 using them to hone their light-saber battle skills a la Luke Skywalker or sharpen their ability to detect UFOs? No, these bowling-ball sized spherical satellites are part of an experiment devised by students at the Massachusetts Institute of Technology (MIT) to test autonomous rendezvous and docking maneuvers for future formation flying spacecraft. Called SPHERES – which stands for Synchronized Position Hold, Engage, Reorient, Experimental Satellites — these color-coded robots are flying inside the ISS, testing different flight formations. But these have to be a lot of fun to play with during off hours on the space station: zero-g bowling or space volleyball, anyone?

Astronauts Greg Chamitoff, Mike Fincke and spaceflight participant Richard Garriott posed with SPHERES. Credit: NASA

Each satellite is self-contained with power, propulsion, computers and navigation equipment. The results are important for satellite servicing, vehicle assembly and formation flying spacecraft configurations. One future formation flying mission is the Terrestrial Planet Finder Interferometer, which will use multiple small vehicles flying in formation to create an orbiting infrared interferometer.

Terrestrial Planet Finder Interferometer array.

If successful, these mini-satellites, and their potentially larger versions, would be able to refuel/repair other satellites, establish positioning around space-based telescopes, and support space docking routines. So, battle droids would become maintenance droids.

And smaller, multiple satellite missions are economical and provide redundancy. Instead of launching one big, heavy satellite, launching lots of little is easier. They can orbit Earth in tandem, each doing their own small part of the overall mission. If a solar flare zaps one satellite—no problem. The rest can close ranks and carry on. Launch costs are reduced, too, because tiny satellites can hitch a ride inside larger payloads, getting to space almost free of charge.

The SPHERES can also test the ability to build spaceships in orbit. One way to build a larger ship to go to, for instance, Mars, is to assemble it piece by piece in Earth orbit. The SPHERES are helping engineers design software that could be used to maneuver the pieces of a spaceship together.

Sources: Science@NASA, NASA, MIT