Nancy Atkinson, Author at Universe Today

November 20, 2008December 24, 2015 by Nancy Atkinson

MSL News: Landing Sites and Naming Contest

Landing sites for the Mars Science Laboratory have been narrowed down to four intriguing places on the Red Planet. The car-sized rover will have the capability to travel to more scientifically compelling sites, and with its radioisotope power source, it won’t need to rely on solar power, allowing for more flexibility in locations say project leaders at the Jet Propulsion Laboratory. After seeking input from international experts on Mars and engineers working on the landing systems, here are the four sites JPL announced (drumroll)…

Oh, before listing the sites, NASA is having a name the rover contest for MSL, so check that out, too!

Eberswalde: where an ancient river deposited a delta in a possible lake, south of Mars equator.

Gale: a crater with a mountain within that has stacked layers including clays and sulfates, near the equator. This was a favorite site for the Mars Exploration Rovers, but it was deemed to hazardous for them. Not so for MSL.

Holden: a crater containing alluvial fans, flood deposits, possible lake beds and clay-rich deposits, in the southern hemisphere.

Mawrth: , which shows exposed layers containing at least two types of clay, in the northern hemisphere, near the edge of a vast Martian highland.

“All four of these sites would be great places to use our roving laboratory to study the processes and history of early Martian environments and whether any of these environments were capable of supporting microbial life and its preservation as biosignatures,” said John Grotzinger of the California Institute of Technology, Pasadena. He is the project scientist for the Mars Science Laboratory.

Wheels were put on MSL in August 2008. Image Credit: NASA/JPL-Caltech

During the past two years, multiple observations of dozens of candidate sites by NASA’s Mars Reconnaissance Orbiter have augmented data from earlier orbiters for evaluating sites’ scientific attractions and engineering risks.

JPL is assembling and testing the Mars Science Laboratory spacecraft for launch in fall 2009.

“Landing on Mars always is a risky balance between science and engineering. The safest sites are flat, but the spectacular geology is generally where there are ups and downs, such as hills and canyons. That’s why we have engineered this spacecraft to make more sites qualify as safe,” said JPL’s Michael Watkins, mission manager for the Mars Science Laboratory. “This will be the first spacecraft that can adjust its course as it descends through the Martian atmosphere, responding to variability in the atmosphere. This ability to land in much smaller areas than previous missions, plus capabilities to land at higher elevations and drive farther, allows us consider more places the scientists want to explore.”

MSL is designed to hit a target area roughly 20 kilometers (12 miles) in diameter. Also, a new “skycrane” technology to lower the rover on a tether for the final touchdown can accommodate more slope than the airbag method used for Spirit and Opportunity.

Source: JPL

November 20, 2008December 24, 2015 by Nancy Atkinson

“Loner” Galaxy is Actually in the ‘Hood

NCG 1569. Image Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and A. Aloisi (STScI/ESA)

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Astronomers have long wondered why a small, nearby, isolated galaxy is pumping out new stars faster than any galaxy in our local neighborhood. Usually, galaxies need some sort of gravitational interaction with other galaxies to trigger star formation, and galaxy NGC 1569 appeared to be a loner, far away from other galaxies, but churning out new stars like crazy. Now, a new look at the galaxy with the Hubble Space Telescope shows the galaxy is farther away than originally thought, which places NCG 1569 in the middle of a group of about 10 galaxies. Gravitational interactions among the group’s galaxies may be compressing gas in NGC 1569 and igniting the star-birthing frenzy.

“Now the starburst activity seen in NGC 1569 makes sense, because the galaxy is probably interacting with other galaxies in the group,” said the study’s leader, Alessandra Aloisi of the Space Telescope Science Institute in Baltimore, Md., and the European Space Agency. “Those interactions are probably fueling the star birth.”

The farther distance not only means that the galaxy is intrinsically brighter, but also that it is producing stars two times faster than first thought. The galaxy is forming stars at a rate more than 100 times higher than the rate in the Milky Way. This high star-formation rate has been almost continuous for the past 100 million years.

Discovered by William Herschel in 1788, NGC 1569 is home to three of the most massive star clusters ever discovered in the local universe. Each cluster contains more than a million stars.

“This is a prime example of the type of massive starbursts that drive the evolution of galaxies in the distant and young universe,” said team member Roeland van der Marel of the Space Telescope Science Institute. “Starburst galaxies can only be studied in detail in the nearby universe, where they are much rarer. Hubble observations of our galactic neighborhood, including this study, are helping astronomers put together a complete picture of the galaxies in our local universe. Put the puzzle pieces in the right place, as for NGC 1569, and the picture makes much more sense.”

And besides all that, it’s just a pretty picture, too!

Source: HubbleSite

November 20, 2008December 24, 2015 by Nancy Atkinson

Astronomers Catch Binary Star Explosion Inside a Nebula

The nebula surrounding nova V458Vul before it erupted. Credit: UCL

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The explosion of a binary star inside a planetary nebula has been detected, an event not witnessed for more than 100 years – and of course the astronomical equipment to observe such an event is much improved since a century ago. At the ends of their lives, before an all-encompassing supernova explosion, some stars undergo nova explosions, caused by nuclear reactions on their surface. Astronomers who detected the event predict that the combined mass of the two stars in the system may be high enough for the stars to eventually spiral into each other, triggering a much bigger double supernova explosion.

“The star which erupted was a nova, an event caused when matter is transferred from one star in a close binary system onto its companion, eventually triggering a runaway thermonuclear explosion,” said Roger Wesson, lead astronomer behind the discovery at University College London in England.
“In August 2007, one such exploding star was discovered in a part of the sky that had serendipitously been observed by us only a few weeks previously,” he said.

Images taken prior to the explosion (above) showed that this particular star was surrounded by a planetary nebula.

The photos were taken as part of the Isaac Newton Telescope Photometric HAlpha Survey (IPHAS), which is the first digital survey of the Milky Way in visible light and is being undertaken by an international collaboration of universities.

Now, the light flash from the explosion is passing through and illuminating the surrounding nebula, the study says.

The nebula surrounding Nova V458 Vul, imaged before its central star erupted Three images showing the changes in the nebula as a result of the nova explosion, in August 2007, May 2008 and September 2008. Credit: UCL

Although several novae are discovered each year in our galaxy, only one previous nova has been seen to occur inside a planetary nebula – Nova Persei in 1901. The opportunity to watch in detail as the nova flash interacts with the nebula is a first in astronomy, said Wesson.

“The new nova, known as V458 Vulpeculae, provides an important test for models of how stars evolve,” he added. “The role of novae as potential future supernovae has thus far been difficult to analyse in detail, and so [this phenomenon] provides an opportunity to learn more about this aspect of stellar evolution.”

Source: University College of London

November 20, 2008December 24, 2015 by Nancy Atkinson

MRO Finds Huge Underground Glaciers on Mars

Possible underground glaciers on Mars. Credit: NASA

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There’s more than just a little ice under Mars’ surface. According to data from the Mars Reconnaissance Orbiter radar system, vast Martian glaciers of water ice lie buried under rocky debris. And this ice is not just at the Arctic region where the Phoenix lander scratched the surface in searching for ice. MRO found evidence for a huge amount of underground ice at much lower latitudes than any ice previously identified on the Red Planet. “Altogether, these glaciers almost certainly represent the largest reservoir of water ice on Mars that is not in the polar caps,” said John W. Holt of the University of Texas at Austin, who is lead author of the report. “Just one of the features we examined is three times larger than the city of Los Angeles and up to half a mile thick. And there are many more. In addition to their scientific value, they could be a source of water to support future exploration of Mars.”

Scientists say buried glaciers extend for dozens of miles from the edges of mountains or cliffs. A layer of rocky debris blanketing the ice may have preserved the underground glaciers as remnants from an ice sheet that covered middle latitudes during a past ice age. This discovery is similar to massive ice glaciers that have been detected under rocky coverings in Antarctica.

Scientists have been puzzled by what are known as aprons — gently sloping areas containing rocky deposits at the bases of taller geographical features — since NASA’s Viking orbiters first observed them on the Martian surface in the1970s. One theory has been that the aprons are flows of rocky debris lubricated by a small amount ice. Now, the shallow radar instrument on the Mars Reconnaissance Orbiter has provided scientists an answer to this Martian puzzle.

“These results are the smoking gun pointing to the presence of large amounts of water ice at these latitudes,” said Ali Safaeinili, a shallow radar instruments team member with NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The buried glaciers lie in the Hellas Basin region of Mars’ southern hemisphere. The radar also has detected similar-appearing aprons extending from cliffs in the northern hemisphere.

Artists concept of a glacier on Mars. Credit: NASA

Radar echoes received by the spacecraft indicated radio waves pass through the aprons and reflect off a deeper surface below without significant loss in strength. That is expected if the apron areas are composed of thick ice under a relatively thin covering. The radar does not detect reflections from the interior of these deposits as would occur if they contained significant rock debris. The apparent velocity of radio waves passing through the apron is consistent with a composition of water ice.

“There’s an even larger volume of water ice in the northern deposits,” said JPL geologist Jeffrey J. Plaut, who will be publishing results about these deposits in the American Geophysical Union’s Geophysical Research Letters. “The fact these features are in the same latitude bands, about 35 to 60 degrees in both hemispheres, points to a climate-driven mechanism for explaining how they got there.”

The rocky debris blanket topping the glaciers apparently has protected the ice from vaporizing, which would happen if it were exposed to the atmosphere at these latitudes.

“A key question is, how did the ice get there in the first place?” said James W. Head of Brown University in Providence, R.I. “The tilt of Mars’ spin axis sometimes gets much greater than it is now. Climate modeling tells us ice sheets could cover mid-latitude regions of Mars during those high-tilt periods. The buried glaciers make sense as preserved fragments from an ice age millions of years ago. On Earth, such buried glacial ice in Antarctica preserves the record of traces of ancient organisms and past climate history.”

Source: NASA

November 20, 2008December 24, 2015 by Nancy Atkinson

10 Years of the ISS in Pictures

The ISS 10 years ago, and today. Credit: NASA, collage, N. Atkinson

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Ten years ago today the Russian built Zarya control module was launched into space and the International Space Station was born. The orbiting outpost has gone from one small module to an expansive station with ten different modules made in several different countries, a huge backbone truss structure made of 12 large pieces, and three sets of the largest solar arrays ever sent into space. The current space shuttle mission is providing the furnishings to outfit the station into a five-bedroom, two bath, two kitchen space research outpost. 164 people have visited the station in these past ten years, as the 313 ton station has circled the Earth more than 57,300 times and traveled a distance of more than 1.3 billion miles (2 billion km). See a very nifty animation of how the station was built at USA Today, see a list of all the flights so far dedicated to ISS construction, and find all the stats you’ll ever want on the ISS here.

Frequent readers of Universe Today know I have a soft spot in my heart for the ISS, and today I’d like to share some of my favorite images from the past ten years of station construction. Above is a collage of the Zarya module a decade ago, (left) and the station’s current configuration.

Koichi Wakata zooms through Zvezda. Credit: NASA

Before the station could house its first occupants, it took several missions to outfit the ISS and bring up supplies. Here, astronaut Koichi Wakata from Japan floats through the Zvezda module in October of 2000, which the STS-92 crew stocked almost completely with supplies for the first crew. Permanent occupancy began just a few weeks later when the Expedition One crew of Bill Shepherd, Yuri Gidzenko, and Sergei Krikalev opened the ISS hatch on Nov. 2, 2000.

ISS with first set of solar arrays. Credit: NASA

Shortly after the Expedition One crew arrived, the STS-97 space shuttle crew visited and installed the P6 Truss, which contains the first set of the huge solar arrays. The P6 provided enough solar power so that that soon afterward, the first laboratory could be installed. The P6 was temporarily installed on top of the Z1 Truss in December 2000.

In February of 2001 space shuttle Atlantis brought up the Destiny Laboratory. Here, the lab is in the grasp of the shuttle’s remote manipulator system (RMS) robot arm, moving it from its stowage position in the shuttle’s cargo bay and attaching it to the ISS.

Astronauts work on the P-1 Truss. Credit: NASA

The truss sections make up the “backbone” of the station. Most of the trusses are huge in themselves, some weighing 27,000 pounds. But together, they expand the station’s length to the size of a football field. Here in November 2002, Astronauts John Herrington (left) and Michael Lopez-Alegria from the STS-113 shuttle crew, work on the newly installed Port One (P1) truss. This mission activated the “railcar” on the truss, allowing astronauts to move easily up and down the truss for construction and maintenance. The station’s robotic arm (SSRMS) can also be attached to the car.

Backdropped by the blackness of space and Earth’s horizon, this full view of the International Space Station was photographed by the departing Space Shuttle Discovery crew following undocking after a construction mission in August of 2005.

Astronaut Scott Parazynski prepares to repair torn solar arrays. Credit: NASA

In an emergency operation, astronaut Scott Parazynski anchored himself to a foot restraint on the end of the Orbiter Boom Sensor System to repair a torn solar array during the STS-120 in October of 2007. Parazynski cut a snagged wire and installed homemade stabilizers designed to strengthen the damaged solar array’s structure and stability after it was torn while re-deploying the array after it was moved to its permanent position.

A close-up view of the shiny new Columbus laboratory (top right), added during the STS-122 mission in February 2008, photographed by Space Shuttle Atlantis crew shortly after the undocking of the two spacecraft.

In March of 2008, astronauts installed a large robot named Dextre outside the station. The two-armed, $200-million robot will reduce the amount of time astronauts must spend outside the space station, and could eliminate the need for up to a dozen spacewalks a year. Here’s a comparison between Dex and Hal.

And finally, here’s a new image from the latest STS-126 mission. Astronauts Steve Bowen and Heidemarie Stefanyshyn-Piper (out of frame) worked to clean and lubricate part of the station’s starboard Solar Alpha Rotary Joints (SARJ) and to remove two of SARJ’s 12 trundle bearing assemblies. The spacewalkers also removed a depleted nitrogen tank from a stowage platform on the outside of the complex and moved it into Endeavour’s cargo bay. They also moved a flex hose rotary coupler from the shuttle to the station stowage platform, as well as removing some insulation blankets from the common berthing mechanism on the Kibo laboratory.

November 19, 2008December 24, 2015 by Nancy Atkinson

Cosmic Rays from Mysterious Source Bombarding Earth

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Scientists have discovered an unidentified source of high-energy cosmic rays bombarding Earth from space. They say it must be close to the solar system and it could be made of dark matter. “This is a big discovery,” says John Wefel of Louisiana State University and Principal Investigator for ATIC, Advanced Thin Ionization Calorimeter, a NASA funded balloon-borne instrument high over Antarctica. “It’s the first time we’ve seen a discrete source of accelerated cosmic rays standing out from the general galactic background.”

The new results show an unexpected surplus of cosmic ray electrons at very high energy — 300-800 billion electron volts — that must come from a previously unidentified source or from the annihilation of very exotic theoretical particles used to explain dark matter.

“This electron excess cannot be explained by the standard model of cosmic ray origin,” said Wefel. “There must be another source relatively near us that is producing these additional particles.”

According to the research, this source would need to be within about 3,000 light years of the sun. It could be an exotic object such as a pulsar, mini-quasar, supernova remnant or an intermediate mass black hole.

“Cosmic ray electrons lose energy during their journey through the galaxy,” said Jim Adams, ATIC research lead at NASA’s Marshall Space Flight Center in Huntsville, Ala. “These losses increase with the energy of the electrons. At the energies measured by our instrument, these energy losses suppress the flow of particles from distant sources, which helps nearby sources stand out.”

The scientists point out, however, that there are few such objects close to our solar system.

“These results may be the first indication of a very interesting object near our solar system waiting to be studied by other instruments,” Wefel said.

ATIC high-energy electron counts. Credit: J. Chang et al.

An alternative explanation is that the surplus of high energy electrons might result from the annihilation of very exotic particles put forward to explain dark matter. In recent decades, scientists have learned that the kind of material making up the universe around us only accounts for about five percent of its mass composition. Close to 70 percent of the universe is composed of dark energy (so called because its nature is unknown). The remaining 25 percent of the mass acts gravitationally just like regular matter, but does little else, so it is normally not visible.

The nature of dark matter is not understood, but several theories that describe how gravity works at very small, quantum distances predict exotic particles that could be good dark matter candidates.

“The annihilation of these exotic particles with each other would produce normal particles such as electrons, positrons, protons and antiprotons that can be observed by scientists,” said Eun-Suk Seo, ATIC lead at the University of Maryland, College Park.

The 4,300-pound ATIC experiment is carried to an altitude of about 124,000 feet above Antarctica using a helium-filled balloon about as large as the interior of the New Orleans Superdome. The goal of the project is to study cosmic rays that otherwise would be absorbed into the atmosphere.

Researchers from ATIC published the results in the Nov. 20 issue of the journal Nature.

Sources: NASA, Science@NASA

November 19, 2008December 24, 2015 by Nancy Atkinson

Where In The Universe #30

It’s time once again for the Where In The Universe Challenge. Hard to believe we’ve done thirty of these already, and our readers are getting really good at this. The goal of the WITU challenge is to test your skills and visual knowledge of our universe. Guess where this image is from, and give yourself extra points if you can guess which spacecraft is responsible for the image. Mull over the image, make your guess and post a comment if you’re brave enough. Check back tomorrow at this same post to find the answer and see how you did. Good luck!

UPDATE (11/20): The answer has now been posted below. If you haven’t made your guess yet, no peeking before you do!!

Again, nice job everyone! Yes, this is the surface of Venus, taken by the Venera 9 lander before it quickly succumbed to the heat and pressure of the planet. From June to October 1975, the Russian space probe Venera 9 became the first craft to orbit, land on, and photograph Venus. Venera 9 consisted of two main parts that separated in orbit, an orbiter and a lander. The 5,070-pound (2,300-kilogram) orbiter relayed communication and photographed the planet in ultraviolet light. The lander entered the Venusian atmosphere using a series of parachutes and employed a special panoramic photometer to produce 180-degree panoramic photos of the surface of the planet.

Great job! Come back again for next week’s WITU Challenge.

Source: National Geographic

November 19, 2008December 24, 2015 by Nancy Atkinson

Lost in Space: Tool Bag Overboard, Spider Missing

A tool bag floated away in space as spacewalking astronauts worked outside the International Space Station Tuesday. Heide Stefanyshyn-Piper had a grease gun explode inside her tool bag, getting the dark gray goop all over a camera, the inside of the bag, and her gloves. While she was trying to clean it up, the whole bag floated away. “Oh, great,” Piper said. It was one of the largest items ever to be lost by a spacewalker. Lost were two grease guns, needed to clean and lube the jammed Solar Alpha Rotary Joint for the space station’s solar arrays. Flight director Ginger Kerrick said the bag and also an errant screw that also floated past that spacewalkers posed no hazards to the ISS or shuttle. By late Tuesday, the bag was already well away from the complex, about 2.5 miles (4 km) in front of the shuttle-station complex. The rest of the spacewalk went well, as Piper and her partner Stephen Bowen shared tools and accomplished all the planned objectives. Mission planners are studying options for replacing, or doing without, two grease guns lost.

Also lost is one of two spiders on board a special experiment…

While one orb weaver spiders weaved away in an ususual unsymmetrical manner, one spider is MIA.
“We don’t believe that it’s escaped the overall payload enclosure,” said Kirk Shireman, NASA’s deputy station program manager. “I’m sure we’ll find him spinning a web sometime here in the next few days.”

“The web was more or less three-dimensional and it looked like it was all over the inside of the spider hab,” said NASA astronaut Sandra Magnus, the space station’s science officer. “We took some pictures of it.” And here’s an image:
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Painted lady butterfly larvae were also included as a separate part of the experiment.

Students will compare the space butterflies’ lifecycle and how the spiders weave webs and feed in weightlessness with similar spiders and butterflies on Earth.

Also inside the station, astronauts moved two 1,700-pound (770 kg) water recycling racks into the Destiny lab module, as well as combustion research gear, and a new toilet and crew sleep stations.

The water recycling gear, which will convert condensate and urine into pure water for drinking, food preparation, hygiene and oxygen generation, is crucial for NASA’s plans to boost the station’s crew size to six next year. The astronauts hoped to hook up the two water processing racks today (Wednesday) and to begin pumping stored urine into the system Thursday.

Water samples will be returned to Earth aboard Endeavour for detailed chemical analysis. A full three months of testing is planned in orbit, with additional ground tests after the next shuttle visit in February, before any astronauts are allowed to drink the recycled water.

Sources: MSNBC, UPI

November 19, 2008December 24, 2015 by Nancy Atkinson

NASA and Google Successfully Test Deep Space Internet

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Communication with spacecraft is vital for NASA, and since the World Wide Web has enabled easy, reliable and quick contact for people around the world, the space agency decided to model a new deep space communication system on the internet. A month-long test of this “Interplanetary Internet” was successfully conducted by transmitting dozens of images to and from the EPOXI spacecraft, now about 20 million miles from Earth. The system uses software called Disruption-Tolerant Networking, or DTN created by a partnership between NASA and Google vice president Vint Cerf. “This is the first step in creating a totally new space communications capability, an interplanetary Internet,” said Adrian Hooke, team lead and manager of space-networking architecture, technology and standards at NASA Headquarters in Washington.

NASA’s current communication system, the Deep Space Network, has been around since the early days of space travel, and NASA is looking to upgrade and enhance their ability to communicate with spacecraft. The Interplanetary Internet must be robust to withstand delays, disruptions and disconnections in space. Glitches can happen when a spacecraft moves behind a planet, or when solar storms and long communication delays occur. The delay in sending or receiving data from Mars takes between three-and-a-half to 20 minutes at the speed of light. Therefore, the DTN sends information using a method that differs from the normal Internet’s Transmission-Control Protocol/Internet Protocol, or TCP/IP, communication suite, which Cerf also co-designed.

Unlike TCP/IP on Earth, the DTN does not assume a continuous end-to-end connection. In its design, if a destination path cannot be found, the data packets are not discarded. Instead, each network node keeps the information as long as necessary until it can communicate safely with another node. This store-and-forward method, similar to basketball players safely passing the ball to the player nearest the basket means information does not get lost when no immediate path to the destination exists. Eventually, the information is delivered to the end user. This is all done automatically.

Engineers began a month-long series of DTN demonstrations in October. Data were transmitted using NASA’s Deep Space Network in demonstrations occurring twice a week. Engineers use NASA’s EPOXI spacecraft as a Mars data-relay orbiter. EPOXI spacecraft is the bus from the Deep Impact mission that send an impactor to Comet Temple 1 in July of 2005, and it is now on a mission to encounter Comet Hartley 2 in two years. There are 10 nodes on this early interplanetary network. One is the EPOXI spacecraft itself and the other nine, which are on the ground at JPL, simulate Mars landers, orbiters and ground mission-operations centers.

This month-long experiment is the first in a series of planned demonstrations to qualify the technology for use on a variety of upcoming space missions. As Ian reported last month, the next round of testing will be done on the International Space Station next summer.

In the next few years, the Interplanetary Internet could enable many new types of space missions. Complex missions involving multiple landed, mobile and orbiting spacecraft will be far easier to support through the use of the Interplanetary Internet. It also could ensure reliable communications for astronauts on the surface of the moon.

Source: NASA

November 18, 2008December 24, 2015 by Nancy Atkinson

New Telescope on the Lookout for Near Earth Asteroids, Comets

Pan-STARRS 1 prototype, part of the Panoramic Survey Telescope and Rapid Response System, Haleakala mountain, Maui. Photo / MIT Lincoln Laboratory

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A prototype telescope with an enhanced ability to find moving objects will soon be operational, and its mission will be to detect asteroids and comets that could someday pose a threat to Earth. The system is called Pan-STARRS (for Panoramic Survey Telescope and Rapid Response System) located on Haleakala mountain in Maui,Hawaii, and is the first of four telescopes that will be housed together in one dome. Pan-STARRS will feature the world’s largest and most advanced digital camera, providing more than a fivefold improvement in the ability to detect Near Earth Asteroids and comets. “This is a truly giant instrument,” said University of Hawaii astronomer John Tonry, who led the team developing the new 1.4-gigapixel camera. “We get an image that is 38,000 by 38,000 pixels in size, or about 200 times larger than you get in a high-end consumer digital camera.” The Pan-STARRS camera will cover an area of sky six times the width of the full moon and it can detect stars 10 million times fainter than those visible to the naked eye.

The Lincoln Laboratory at the Massachusetts Institute of Technology (MIT) developed charge-coupled device (CCD) technology is a key enabling technology for the telescope’s camera. In the mid-1990s, Lincoln Laboratory researchers developed the orthogonal-transfer charge-coupled device (OTCCD), a CCD that can shift its pixels to cancel the effects of random image motion. Many consumer digital cameras use a moving lens or chip mount to provide camera-motion compensation and thus reduce blur, but the OTCCD does this electronically at the pixel level and at much higher speeds.

The challenge presented by the Pan-STARRS camera is its exceptionally wide field of view. For wide fields of view, jitter in the stars begins to vary across the image, and an OTCCD with its single shift pattern for all the pixels begins to lose its effectiveness. The solution for Pan-STARRS, proposed by Tonry and developed in collaboration with Lincoln Laboratory, was to make an array of 60 small, separate OTCCDs on a single silicon chip. This architecture enabled independent shifts optimized for tracking the varied image motion across a wide scene.

“Not only was Lincoln the only place where the OTCCD had been demonstrated, but the added features that Pan-STARRS needed made the design much more complicated,” said Burke, who has been working on the Pan-STARRS project. “It is fair to say that Lincoln was, and is, uniquely equipped in chip design, wafer processing, packaging, and testing to deliver such technology.”

The primary mission of Pan-STARRS is to detect Earth-approaching asteroids and comets that could be dangerous to the planet. When the system becomes fully operational, the entire sky visible from Hawaii (about three-quarters of the total sky) will be photographed at least once a week, and all images will be entered into powerful computers at the Maui High Performance Computer Center. Scientists at the center will analyze the images for changes that could reveal a previously unknown asteroid. They will also combine data from several images to calculate the orbits of asteroids, looking for indications that an asteroid may be on a collision course with Earth.

Pan-STARRS will also be used to catalog 99 percent of stars in the northern hemisphere that have ever been observed by visible light, including stars from nearby galaxies. In addition, the Pan-STARRS survey of the whole sky will present astronomers with the opportunity to discover, and monitor, planets around other stars, as well as rare explosive objects in other galaxies.

Click here for more information about Pan-STARRS.

Source: MIT