Nancy Atkinson, Author at Universe Today

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

November 18, 2008December 24, 2015 by Nancy Atkinson

Black Holes Supply Lifeblood for Galaxies

Chandra X-ray image of M84 (NASA/CXC/MPE/A.Finoguenov et al.); Radio (NSF/NRAO/VLA/ESO/R.A.Laing et al); Optical (SDSS)

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Obviously, today is the day for news on black holes. While one group of astronomers studied the violent flares of energy sent out by black holes in the near infrared and submillimeter wavelengths, another group used the Chandra X-Ray Observatory to see how black holes can pump energy in a gentler and rhythmic fashion, rather than violently. These scientists say the powerful black holes at the center of massive galaxies act as hearts to the systems, pumping energy out at regular intervals to regulate the growth of the black holes themselves, as well as star formation. “Just like our hearts periodically pump our circulatory systems to keep us alive, black holes give galaxies a vital warm component. They are a careful creation of nature, allowing a galaxy to maintain a fragile equilibrium,” said Alexis Finoguenov, of the Max-Planck Institute for Extraterrestrial Physics in Germany.

The scientists observed and simulated how the black hole at the center of elliptical galaxy M84 dependably sends bubbles of hot plasma into space, heating up interstellar space.

Here’s an animation of the regular pulses of bubbles.

This heat is believed to slow both the formation of new stars and the growth of the black hole itself, helping the galaxy remain stable. Interstellar gases only coalesce into new stars when the gas is cool enough. The heating is more efficient at the sites where it is most needed, the scientists say.

This finding helps to explain a decades-long paradox of the existence of large amounts of warm gas around certain galaxies, making them appear bright to the Chandra X-ray telescope.

“For decades astronomers were puzzled by the presence of the warm gas around these objects. The gas was expected to cool down and form a lot of stars” said Mateusz Ruszkowski, an assistant professor in the University of Michigan Department of Astronomy.

“Now, we see clear and direct evidence that the heating mechanism of black holes is persistent, producing enough heat to significantly suppress star formation. These plasma bubbles are caused by bursts of energy that happen one after another rather than occasionally, and the direct evidence for such periodic behavior is difficult to find.”

The bubbles form one inside another, for a sort of Russian doll effect that has not been seen before, Ruszkowski said. One of the bubbles of hot plasma appears to be bursting and its contents spilling out, further contributing to the heating of the interstellar gas.

“Disturbed gas in old galaxies is seen in many images that NASA’s Chandra observatory obtained, but seeing multiple events is a really impressive evidence for persistent black hole activity,” says Christine Jones, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

A paper on the research called “In-depth Chandra study of the AGN feedback in Virgo Elliptical Galaxy M84” has been published in Astrophysical Journal.

Source: University of Michigan

November 18, 2008December 24, 2015 by Nancy Atkinson

Milky Way’s Black Hole Sending Out Flares

Left: Submillimetre and infrared view of the Galactic Centre Right: Flares from the disk of material surrounding the black hole Sagittarius A*. Credit: ESO/APEX/2MASS/A. Eckart et al. , ESO/L. Calçada

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Two different telescopes simultaneously observed violent flares from the supermassive black hole in the center of the Milky Way. The outbursts from this region, known as Sagittarius A*, reveal material being stretched like bread dough out as it orbits in the intense gravity close to the central black hole. Using ESO’s Very Large Telescope (VLT) and the Atacama Pathfinder Experiment (APEX) telescope, both in Chile, to study light from Sagittarius A* at near-infrared wavelengths and the longer submillimeter wavelengths, astronomers have for the first time concurrently caught a flare with these telescopes. “Observations like this, over a range of wavelengths, are really the only way to understand what’s going on close to the black hole,” says Andreas Eckart of the University of Cologne, who led the team.

Sagittarius A* is located at the centre of our own Milky Way Galaxy at a distance from Earth of about 26,000 light-years. It is a supermassive black hole with a mass of about four million times that of the Sun. Most, if not all, galaxies are thought to have a supermassive black hole in their center.

“Sagittarius A* is unique, because it is the nearest of these monster black holes, lying within our own galaxy,” explains team member Frederick K. Baganoff of the Massachusetts Institute of Technology (MIT) in Cambridge, USA. “Only for this one object can our current telescopes detect these relatively faint flares from material orbiting just outside the event horizon.”

The emission from Sagittarius A* is thought to come from gas thrown off by stars, which then orbits and falls into the black hole.

The VLT pointed their telescope at Sagittarius A* and saw it was active, and getting brighter by the minute. They contacted their colleagues at the APEX telescope, who were able to also catch the flares. Both telescopes are in the southern hemisphere, which provides the best vantage point for studying the Galactic Center.

Over the next six hours, the team detected violently variable infrared emission, with four major flares from Sagittarius A*. The submillimeter-wavelength results also showed flares, but, crucially, this occurred about one and a half hours after the infrared flares.

The researchers explain that this time delay is probably caused by the rapid expansion, at speeds of about 5 million km/h, of the clouds of gas that are emitting the flares. This expansion causes changes in the character of the emission over time, and hence the time delay between the infrared and submillimetre flares.

Although speeds of 5 million km/h may seem fast, this is only 0.5% of the speed of light. To escape from the very strong gravity so close to the black hole, the gas would have to be travelling at half the speed of light – 100 times faster than detected – and so the researchers believe that the gas cannot be streaming out in a jet. Instead, they suspect that a blob of gas orbiting close to the black hole is being stretched out, like dough in a mixing bowl, and this is causing the expansion.

The team hopes that future observations will help them discover more about this mysterious region at the center of our Galaxy.

Read the team’s paper here.

Source: ESO

November 17, 2008December 24, 2015 by Nancy Atkinson

Evidence For Vast Oceans On Ancient Mars

This 3D map superimposes gamma-ray data from Mars Odyssey's Gamma-Ray Spectrometer onto topographic data from the laser altimeter onboard the Mars Global Surveyor.

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Data from the Mars Odyssey orbiter’s Gamma Ray Spectrometer provides new evidence for the controversial idea that oceans once covered about a third of ancient Mars. Spacecraft images going back to Mariner 9 in the early 1970s and the Viking orbiters and landers later in the 1970s up to the current orbiters and rovers have showed widespread evidence for a watery past for Mars. About 20 years ago, several studies sparked a scientific debate on the possible existence of ancient Martian oceans marked by visible shorelines. Images and topographic maps provide evidence for two different oceans in one area, perhaps occuring at different times in Mars history, a larger one at an earlier time, and a smaller once existing later. Odyssey’s GRS can detect subsurface elements, and new data confirms the right combination of elements for two ancient shorelines.

The spectrometer has the unique ability to detect elements buried as much as 1/3 meter, or 13 inches, below the surface by the gamma rays they emit. That capability led to GRS’ 2002 discovery of water-ice near the surface near Mars arctic region, leading to the decision for the Phoenix landing site.

“Our investigation posed the question, ‘Might we see a greater concentration of these elements within the ancient shorelines because water and rock containing the elements moved from the highlands to the lowlands, where they eventually ponded as large water bodies?'” said University of Arizona planetary geologist James M. Dohm, who led the international investigation. “We compared Gamma Ray Spectrometer data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars’ surface, and an inner shoreline believed to mark a younger, smaller ocean.”

Results suggest that past watery conditions likely leached, transported and concentrated such elements as potassium, thorium and iron, Dohm said. “The regions below and above the two shoreline boundaries are like cookie cutouts that can be compared to the regions above the boundaries, as well as the total region.”

The younger, inner shoreline is evidence that an ocean about 10 times the size of the Mediterranean Sea, or about the size of North America, existed on the northern plains of Mars a few billion years ago. The larger, more ancient shoreline that covered a third of Mars held an ocean about 20 times the size of the Mediterranean, the researchers estimate.

The potassium-thorium-iron enriched areas occur below the older and younger paleo-ocean boundaries with respect to the entire region, they said. The scientists used data from Mars Global Surveyor’s laser altimeter for topographic maps of the regions in their study.

Scientists studying spacecraft images have a hard time confirming “shoreline” landforms, the researchers said, because Mars shorelines would look different from Earth’s shorelines. Earth’s coastal shorelines are largely a direct result of powerful tides caused by gravitational interaction between Earth and the moon, but Mars lacks a sizable moon. Another difference is that lakes or seas on Mars could have formed largely from giant debris flows and liquefied sediments. Still another difference is that Mars oceans may have been ice-covered, which would prevent wave action.

“The GRS adds key information to the long-standing oceans-on-Mars controversy,” Dohm said. “But the debate is likely to continue well into the future, perhaps even when scientists can finally walk the Martian surface with instruments in hand, with a network of smarter spaceborne, airborne and ground-based robotic systems in their midst.”

Source: U of Arizona

November 14, 2008April 26, 2016 by Nancy Atkinson

Launch of Endeavour Lights Up the Night

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With a waning gibbous moon hanging over the launch pad, Space Shuttle Endeavour lit up the night sky with a spectacular and gorgeous liftoff, right on time at 7:55 EST. Endeavour is carrying a load of equipment for a “home improvement project” for the International Space Station. Included on board are a urine recycling system, a new toilet, a new galley and additional crew accommodations to enable an expanded ISS crew. Next year the station will be home to six astronauts instead of the current three, allowing scientific research to move to the forefront of ISS operations. Just before launch Commander Chris Ferguson radioed to Mission Control, “It’s our turn to take home improvement to a new level after 10 years of international space station construction,” Ferguson replied. “Endeavour’s ready to go.”

The launch was so spectacular that I’ll post more pictures of the launch as they become available. See below for a great ET separation image. And check out Spacewriter’s Ramblings for some screenshots she took of the events. And yes, we Twittered to each other!

Just a few minutes before scheduled launch, it looked like there might be a problem that could cause a launch scrub…

External tank is jettisoned. Credit: NASA

The White Room crew forgot to latch the inner door on the Orbiter Access arm, but the mission managers concluded that it should not cause any problems, and that the mission would be safe to fly. The loose door was visible on NASA TV views as the Orbiter Access Arm was retracted. It just looked a little odd, but caused no problems for Endeavour.

More images:

Here’s one from Bill Ingalls of Space.gs.

From NASA:

Endeavour's launch Nov. 14. Credit: NASA

November 14, 2008December 24, 2015 by Nancy Atkinson

Student Built Agricultural Camera Heading to the Space Station

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A new camera that will assist farmers, ranchers, foresters and educators is heading to the International Space Station. Students and faculty from the University of North Dakota built the Agricultural Camera, known as AgCam, which will be delivered by Space Shuttle Endeavour on the STS-126 mission to the ISS. The astronauts will install the system on the station but once its set up, students will control the camera remotely, sending commands from the Operations Center at UND.

AgCam will take images in visible and infrared light of growing crops, rangeland, grasslands, forests and wetlands in the northern Great Plains and Rocky Mountain regions. “The beauty of the AgCam is the combination of features it has to provide important data to a wide variety of people,” George Seielstad, the director of AgCam at told Universe Today. “Plus, students have the opportunity to do real engineering and provide valuable data to protect our environment.”

The information from AgCam will provide useful data about crops and other vegetation. “We’re getting two spectral bands, near infrared and red (in the visible),” said Seielstad, from Florida, where he and several of his team are to attend the launch at Kennedy Space Center, “but the difference between those two are the most critical for determining the health of the vegetation of any kind, be it crops, prairie, grassland, pasture, or a forest. So those two bands are critical.” The AgCam will also provide better resolution than Landsat, at 15-20 meter resolution.

AgCam web logo, showing the type of spectral images that will be available. Credit: UMAC

But the big advantage is the frequency of over passes. “The space station comes over sometimes more than once a day in a particular area,” said Seielstad. “But routinely, it comes over at least two or three times a week. Even if it’s cloudy one of those times you’re getting an image a week, and that hasn’t been available before.”

Seielstad said regular images will help people in the agricultural industries to monitor their crops and the environment. “The best thing is the change of getting an image regularly instead of only every once in awhile. It will be like getting a motion picture of your crop rather than the snapshot two or three times a season.”

The camera will only be operational during the growing season in the northern plains of the US, from about April to October. And even though there are times that the ISS goes over the region only at night, Seielstad said there are more times the camera will be gathering data than not during the growing season. “There will be some gaps in the data collection, but it’s a vast improvement from what is currently available,” he said.

Another advantage is the quick delivery of data. “The data comes back to us from the ISS, through the Marshall Space Flight Center to the UND operations center,” said Seielstad. “It can quickly be turned into usable data and sent out . You might be looking at data that’s only 24-48 hours old, which is very fast turnaround.”

All the data will be available to anyone on the AgCam website. “There are several Indian reservations in the area we serve and they manage their own resources, so it will be valuable for them as well,” said Seielstad. “Educators can also make use of it too as a tool to bring into the classroom.

“For every parameter, there are other satellites that can provide similar data, but it yet doesn’t exist in the full combination of what the AgCam will provide,” said Seielstad. AgCam imagery also may assist in disaster management, such as flood monitoring and wild fire mapping.

For more information on the AgCam, see the Upper Midwest Aerospace Consortium AgCam website, or NASA’s Ag Cam website.

November 14, 2008December 24, 2015 by Nancy Atkinson

Listen in on Communications for Today’s Space Shuttle Launch

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Just a reminder of this evening’s launch of Space Shuttle Endeavour. And this time, NASA is trying something new. During the countdown you can listen in to live audio of communications between launch controllers and the shuttle, something that is not normally done. NASA Television will provide a continuous “clean video feed” on its Media Channel of space shuttle Endeavour in the hours before its 7:55 p.m. EST liftoff today, Nov. 14. This means there won’t be the regular commentary, just the communications audio, beginning at 2:30 pm EST on the Media Channel. If you have satellite television, check your channel listings. To watch online, go here, and choose the Media Channel. And if you’d rather listen to the regular commentary, just go to the regular Public NASA TV channel. Or watch SpaceVidCast on UStream, if you prefer where you can text chat with other viewers…

The “clean feed” will include live audio of communications between launch controllers and the shuttle but not the commentary airing on NASA TV’s Public Channel. NASA TV commentary will air on both channels beginning approximately nine minutes before the scheduled launch time at the conclusion of what is known as the T minus 9 minute hold in the launch countdown.

During the shuttle’s 15-day STS-126 mission to the International Space Station, the crew will deliver supplies and equipment necessary to double the station crew size from three to six members and conduct four spacewalks.

November 14, 2008December 24, 2015 by Nancy Atkinson

Moon Impact Probe Hits Paydirt (or pay-regolith…)

close up pictures of the moon's surface taken by Moon Impact Probe (MIP) on November 14, 2008

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The lunar impactor from the Chandrayaan-1 mission today successfully made it to the surface of the moon, impacting inside the Shackleton crater on the moon’s south pole. Above is an image transmitted back by the 34 kg box-shaped MIP (Moon Impact Probe) before it slammed into the moon. Incoming!!! The MIP carried three instruments, and data was successfully transmitted from the 25-minute descent of the probe after it was ejected from the orbiting Chandrayaan-1. The impact, however caused a cessation of the instruments’ transmissions, but not before providing useful descent data. The ISRO has already released a couple of images.

The instruments included a video imaging system, a radar altimeter and a mass spectrometer. The video imaging system took pictures of the moon’s surface as MIP approached and the radar altimeter measured the rate of descent. These two instruments will help subsequent lunar missions for the ISRO, aiding in future soft landing missions to the moon. The mass spectrometer studied the extremely thin lunar atmosphere.

Here’s a recap of the probe’s mission today from the ISRO:

“MIP’s 25 minute journey to the lunar surface began with its separation from Chandrayaan-1 spacecraft at 20:06 hrs (8:06 pm) IST. This was followed by a series of automatic operations that began with the firing of its spin up rockets after achieving a safe distance of separation from Chandrayaan-1. Later, the probe slowed down with the firing of its retro rocket and started its rapid descent towards the moon’s surface. Information from the instruments was radioed to Chandrayaan-1 by MIP. The spacecraft recorded this in its onboard memory for later readout. Finally, the probe had a hard landing on the lunar surface that terminated its functioning.”

Chandrayaan-1 is now in its science orbit. During the spiraling flight to the moon, two payloads were turned on – the Terrain Mapping Camera (TMC) and Radiation Dose Monitor (RADOM). The eight other instruments on board will be activated in the coming days.

Source: ISRO

November 14, 2008April 26, 2016 by Nancy Atkinson

New NASA, New Administrator Under Obama?

NASA appears to be in the position of being a priority for our new president, somewhat of a rarity. So what can NASA expect under the Obama administration? NASA administrator Mike Griffin met with employees at the Kennedy Space Center on Thursday where workers asked if he would continue as administrator under the new president. “If the next president asks me to continue I would be happy to do it,” said Griffin, “But, I doubt that will happen.” However, if asked to stay, he would only if the Obama White House didn’t interfere with the direction NASA is going (presumably he meant the Constellation program and returning to the moon), and didn’t try to force any personnel on him. He also spoke out against extending the shuttle or using EELV rockets to transport humans to space instead of NASA’s current Ares I rocket design.“If somebody wanted me to stay on but said, ‘No, we need to go over here,’ well,” he said with a shrug, “do it with somebody else.” What else can NASA expect with the new presidential administration?

“While NASA usually does not factor as a near-term decision for incoming Administrations, this year the General Accounting Office highlighted Shuttle retirement as one of its top 13 urgent issues across the government,” NASA Deputy Administrator Shana Dale wrote in her blog after last week’s election. Dale said NASA has been developing a large set of reference material for the new presidential team to review.

Artists concept of the Ares Rocket. Credit: NASA

Officials close to Obama’s transition team have said the new president is likely to review Constellation, the replacement for the shuttle that suffers from technical and financial problems that could delay its first scheduled mission in 2015.

Some have speculated Constellation could be terminated and replaced by more space shuttle flights and a different rocket design.

U.S. Sen. Bill Nelson, one of Obama’s closest advisers on space, wants to keep Griffin as administrator, and lobbied the Obama team to keep Griffin, at least, for the time being.

Current NASA Administrator, Michael Griffin. Credit: NASA

Some congressional and industry sources have cited several potential replacements, from former astronaut Sally Ride to Lori Garver, a former top NASA administrator who heads Obama’s NASA transition team.

Dr. Scott Pace, Director of the Space Policy Institute told Universe Today that putting NASA through a big reorganization could be counterproductive. “Given that NASA has reached a point of stability internally and organizationally, I would hate to see a year or two wasted by yet another re-organizational exercise,” he said. “The new president should give NASA their priorities, tell them what budget they’re going to get and move on from there. NASA has a lot on its plate right now, simply with the transition from the shuttle to whatever comes next. They need to stay focused over the next couple of years on completing their flights safely. So they should focus on that and not reorganization.”

Sources: Orlando Sentinel, Huntsville Times, Shana Dale’s blog,

November 14, 2008December 24, 2015 by Nancy Atkinson

New Insights on Magnetars

Artists impression of a magnetar. Credits: © 2008 Sky & Telescope: Gregg Dinderman

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Neutron stars are leftovers of massive stars (10-50 times as massive as our Sun) that have collapsed under their own weight. Most are only about 20 km in diameter, but they are so compact that a teaspoon of neutron star stuff would weigh about one hundred million tons. Two other physical properties characterize a neutron star: their fast rotation and strong magnetic field. Magnetars form a class of neutron stars with ultra-strong magnetic fields, approximately a thousand times stronger than that of ordinary neutron stars, making them the strongest known magnets in the cosmos. But astronomers have been unsure exactly why magnetars shine in X-rays. Data from ESA’s XMM-Newton and Integral orbiting observatories are being used to test, for the first time, the X-ray properties of magnetars.

So far, about 15 magnetars have been found. Five of them are known as soft gamma repeaters, or SGRs, because they sporadically release large, short bursts (lasting about 0.1 s) of low energy (soft) gamma rays and hard X-rays. The rest, about 10, are associated with anomalous X-ray pulsars, or AXPs. Although SGRs and AXPs were first thought to be different objects, we now know that they share many properties and that their activity is sustained by their strong magnetic fields.

Magnetars are different from ‘ordinary’ neutron stars because their internal magnetic field is thought to be strong enough to twist the stellar crust. Like in a circuit fed by a gigantic battery, this twist produces currents in the form of electron clouds which flow around the star. These currents interact with the radiation coming from the stellar surface, producing the X-rays.

An artist's impression of XMM-Newton. Credits: ESA (Image by C. Carreau)

Until now, scientists could not test their predictions, because it is not possible to produce such ultra-strong magnetic fields in laboratories on Earth.

To understand this phenomenon, a team led by Dr Nanda Rea from the University of Amsterdam used XMM-Newton and Integral data to search for these dense electron clouds around all known magnetars, for the first time.

Rea’s team found evidence that large electron currents do actually exist, and were able to measure the electron density which is a thousand times stronger than in a ‘normal’ pulsar. They have also measured the typical velocity at which the electron currents flow. With it, scientists have now established a link between an observed phenomenon and an actual physical process, an important clue in the puzzle of understanding these celestial objects.

The team is now working hard to develop and test more detailed models on the same line, to fully understand the behavior of matter under the influence of such strong magnetic fields.

Source: ESA