Posted on by Nancy Atkinson

MESSENGER Provides New Insights on Mercury

mercury_plains..Credit: NASA/JHUAP/Arizona State University

Data from the MESSENGER spacecraft’s first flyby of Mercury in January of 2008 are now turning into science results. Several scientists discussed their findings at a press conference today highlighting the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission, the first spacecraft to visit Mercury since NASA’s Mariner 10 made three flyby passes in 1974 and 1975. Among the findings, scientists discovered volcanism has played a more extensive role in shaping the surface of Mercury than previously thought. MESSENGER data has also identified and mapped surface rock units that
correspond to lava flows, volcanos, and other geological features, showing an apparent planet-wide iron deficiency in Mercury’s surface rocks. Additionally, other instruments made the first observations about the surface and atmospheric composition of the closest world to the sun.

“We have now imaged half of the part of Mercury that was never seen by Mariner 10,” says Mark S. Robinson of Arizona State University, lead author of s study on composition variations in Mercury’s surface rocks using their multispectral colors. “The picture is still incomplete, but we’ll get the other half on October 6th.”

MESSENGER will make two more Mercury flybys (October 6, 2008 and September 29, 2009) before
going into orbit around the planet, March 18, 2011.

MESSENGER’s big-picture finding, says Robinson, is the widespread role played by volcanism. While impact craters are common, and at first glance Mercury still resembles the Moon, much of the planet has been resurfaced through volcanic activity.

“For example, according to our color data the Caloris impact basin is completely filled with smooth plains material that appears volcanic in origin,” Robinson explains. “In shape and form these deposits are very similar to the mare basalt flows on the Moon. But unlike the Moon, Mercury’s smooth plains are low in iron, and thus represent a relatively unusual rock type.”

Mercury’s surface also has a mysterious, widespread low-reflective material Robinson says, “It’s an important and widespread rock that occurs deep in the crust as well as at the surface, yet it has very little ferrous iron in its silicate minerals.”

Another experiment measured the charged particles in the planet Mercury’s magnetic field, which enabled the first observations about the surface and atmospheric composition of Mercury. “We now know more about what Mercury’s made of than ever before,” said Thomas Zurbuchen, a professor at the University of Michigan. “Holy cow, we found way more than we expected!”

Zurbuchen is project leader of the Fast Imaging Plasma Spectrometer (FIPS), a soda can-sized sensor on board the MESSENGER spacecraft.

FIPS detected silicon, sodium, sulfur and even water ions around Mercury. Ions are atoms or molecules that have lost electrons and therefore have an electric charge.

Because of the quantities of these molecules that scientists detected in Mercury’s space environment, they surmise that they were blasted from the surface or exosphere by the solar wind. The solar wind is a stream of charged particles emanating from the sun. It buffets Mercury, which is 2/3 closer to the sun than the Earth, and it causes particles from Mercury’s surface and atmosphere to sputter into space. FIPS measured these sputtered particles.

Mercury and MESSENGER form the subject of 11 papers in a special section devoted to the January flyby in the July 4, 2008, issue of the scientific journal Science.

News Sources: University of Arizona, MESSENGER site

Posted on by Nancy Atkinson

International Group Studies Mars Sample Return Mission

Until humans can actually set foot on the Red Planet, the next best thing would be a sample return mission, to bring Martian soil samples back to Earth. A sample return would exponentially increase our knowledge and understanding Mars and its environment. And in order to pull off a mission of this magnitude, international cooperation might be required, and in fact, may be preferred. The International Mars Exploration Working Group (IMEWG), organized an international committee to study an international architecture for a Mars Sample Return (MSR) mission concept. After several months of collective work by scientists and engineers from several countries worldwide, the “iMARS” group is ready to publish the outcome of its deliberations and the envisioned common architecture for a future international MSR mission, and they will discuss their findings at an international conference on July 9 and 10 in France.

The conference will be held at the Auditorium of the Bibliothèque Nationale de France in Paris, and will bring together members of the scientific and industrial communities as well as representatives of space agencies around the world to discuss the status and prospects for Mars exploration over the coming decades. Attendees will have the opportunity to hear the current international thinking on Mars Sample Return and to interact with key players in the global endeavor of exploring and understanding Mars.

A Mars Sample Return mission would use robotic systems and a Mars ascent rocket to collect and send samples of Martian rocks, soils, and atmosphere to Earth for detailed chemical and physical analysis. Researchers on Earth could measure chemical and physical characteristics much more precisely than they could by via remote control. On Earth, they would have the flexibility to make changes as needed for intricate sample preparation, instrumentation, and analysis if they encountered unexpected results. In addition, for decades to come, the collected Mars rocks could yield new discoveries as future generations of researchers apply new technologies in studying them.

Keynote speakers at the upcoming conferencewill are Steve Squyres of Cornell University, principal investigator under the MER mission, and Jean-Pierre Bibring of the Institut d’Astrophysique Spatiale, principal investigator for a key instrument on Mars Express.

Interested in attending? Check out their website

Original News Source: ESA

Posted on by Nancy Atkinson

Explosive Spacewalk?

Explosive bolts that help detach the Russian Soyuz capsule from the International Space Station may be the source of the problems the spacecraft has encountered during the last two landings. Investigative space journalist and Jim Oberg at MSNBC, who is one of the best experts on the inner workings of the Russian space program recently wrote a very interesting article detailing Russian engineers’ plans to fix the problem: have two Russian cosmonauts conduct a spacewalk on July 10 to remove one of the explosive bolts and bring it inside the space station. The bolts, Oberg says, packs twice the explosive force of an M-80 firecracker when ignited, and the cosmonauts will be handling the bolts directly during what will be a very delicate, if not dramatic, operation.

Oberg reports that Russian space engineers say the bolts at one particular location failed to work properly during each of the two previous Soyuz landings, in October 2007 and then in April 2008. As a result, in each case the landing capsule was twisted out of proper orientation and underwent excess heating on unshielded surfaces before tearing loose from the propulsion module and falling to Earth.

NASA has scheduled a press briefing on July 8 to discuss the spacewalk, but Oberg uncovered details about the spacewalk from status reports and discussions with NASA engineers. The engineers in Houston said that, to their knowledge, no such pyrotechnic device has ever been brought into the space station in its 10-year history.

There are five pairs of explosive bolts that break the connections between the spacecraft’s crew capsule and its propulsion module during descent. Russian experts told NASA at one particular location, position 5, apparently failed to fire during both previous Soyuz descents, preventing a clean separation.

The two cosmonauts, station commander Sergey Volkov and flight engineer Oleg Konenenko will remove the position 5 bolt and place it in a shielded safety canister that was brought to the ISS on the last shuttle mission in May for this spacewalk. So obviously, the plan for this spacewalk has been in the works for quite some time.

Russians engineers assured NASA that the remaining four latches will be adequate to hold the two modules together during any other maneuvers in space.

Check out Jim’s article for more details.

Posted on by Nancy Atkinson

Next TEGA “Bake” Could Be Last for Phoenix

The “vibrating” done to get the first Mars arctic soil sample into Phoenix’s TEGA (Thermal and Evolved Gas Analyzer) oven may have caused a short circuit that could happen again the next time the oven is used, perhaps with fatal results. A team of engineers and scientists assembled to assess TEGA after a short circuit was discovered in the instrument, and came to a fairly disheartening conclusion. “Since there is no way to assess the probability of another short circuit occurring, we are taking the most conservative approach and treating the next sample to TEGA as possibly our last,” said Peter Smith, Phoenix’s principal investigator. Therefore, the Phoenix team is doing everything they can to assure the next sample delivered to TEGA will be ice-rich.

The short circuit was believed to have been caused when TEGA’s oven number four was vibrated repeatedly over the course of several days to break up clumpy soil so that it could get inside the oven. Delivery to any TEGA oven involves a vibration action, and turning on the vibrator in any oven will cause oven number 4 to vibrate as well, which could cause a short.

A sample taken from the trench called “Snow White” that was in Phoenix’s robotic arm’s scoop earlier this week likely has dried out, so the soil particles are to be delivered to the lander’s optical microscope on Thursday. If material remains in the scoop, the rest will be deposited in the Wet Chemistry Laboratory, possibly early on Sunday.

The mission teams will mark the Independence Day holiday with a planned “stand down” from Thursday morning, July 3, to Saturday evening, July 5. A skeleton crew at the University of Arizona in Tucson, at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and Lockheed Martin Space Systems in Denver, Colo., will continue to monitor the spacecraft and its instruments over the holiday period.

“The stand down is a chance for our team to rest, but Phoenix won’t get a holiday,” Smith said. The spacecraft will be operating from pre-programmed science commands, taking atmospheric readings and panoramas and other images.

Once the sample is delivered to the chemistry experiment, Smith said the highest priority will be obtaining the ice-rich sample and delivering it to TEGA’s oven number zero.

The Phoenix team will conduct tests and trial runs so the instruments can deliver the icy sample quickly, in order to avoid sublimation of materials during the delivery process, so the solid ice doesn’t vaporize.

Original News Source: Phoenix News

Posted on by Nancy Atkinson

Where In The Universe Challenge #10

I’ve been enjoying a few lazy days of summer relaxing by a lake. The weather has been perfect, the lake is clear and warm, the food and drinks plentiful; a perfect vacation. But I finally realized (late in the day) today is Wednesday, and its time for another “Where In The Universe” challenge. So, here’s an image, and your mission is to guess where in the universe this picture was taken. You get extra points for guessing the spacecraft that is responsible for the image, too. So take your time, maybe put your feet up and grab a cold beverage on this warm day and ponder this image for awhile. No peeking below for the answer until you’ve made your guess.

When I first saw this image, I thought for sure it was a picture of some icy planetary surface or body of water. But actually, its not ice at all. This is Lake Erie, in the United States, and the image was taken on May 28th, 2006 at about noon local time, on a nice summer day. The sun is just at the right angle that causes a glint off the water, giving it an icy appearance. The image shows features on the surface of Lake Erie, about 50 kilometers (30 miles) west of Cleveland, Ohio.

The image shows V-shaped wakes of small water craft, as well as broad patterns of larger craft, probably large freighters carrying cargo, that displace and disturb more water during passage. These larger wakes are aligned with the direct course between Detroit and Cleveland (not shown in the image). Some of the broad, ill-defined swaths of light and dark (aligned from lower left to upper right) are streaks of wind-roughened water, which reflect the Sun differently.

This image was taken by an astronaut on board the International Space Station with a Kodak 760C digital camera using an 800 mm lens. They are provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center.

So, where ever you are, you can now enjoy gazing at a lake, just like I’ve been doing all week. My lake is a lot smaller than Lake Erie, though. But, enjoy!

Learn more about this image at NASA’s Earth Observatory site.

Posted on by Nancy Atkinson

GLAST Powers Up

The GLAST (Gamma-ray Large Area Space Telescope) spacecraft blasted off on June 11, 2008, and after acclimating to the cold reaches of space, the instruments on board are now powering up and have sent back signals to Earth indicating that all systems are operational. Meanwhile back on Earth, several bases of operations for the telescope are gearing up for processing data from the various instruments.

The Large Area Telescope (LAT), one of two instruments aboard GLAST has sent back data to Stanford Linear Accelerator Center’s Instrument Science Operations Center (ISOC) where it will be monitored, processed, and distributed to the rest of the science team worldwide. The observatory is commanded from the Mission Operations Center (MOC) at NASA Goddard Space Flight Center, and during the present initial on-orbit commissioning phase is staffed by a team from across the mission.

Manager Rob Cameron said, “Powering up the LAT has been even smoother than we had hoped. Everything has worked well-in fact, it’s going great. We’re already receiving high-quality data that we
can use to get the instrument ready for the best science return.”

Peter Michelson, of Stanford University, spokesperson and principal investigator for the LAT collaboration, said, “We’re off to a great start and we’re looking forward to a new view of our universe once science operations begin.”

GLAST will explore the most extreme, high energy environments in the universe, and seek answers to questions about dark matter, supermassive black hole systems, pulsars, and the origin of cosmic rays. It also will study the mystery of gamma-ray bursts.

VIDEO of GLAST and gamma rays from pulsars

After the 60-day checkout and initial calibration period, the project will begin science operations in earnest. The LAT will perform a full-sky survey for the first year of the mission and will rapidly respond to gamma-ray bursts detected by both GLAST instruments.

NASA’s GLAST mission has been developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

Original News Source: NASA’s GLAST Site

Posted on by Nancy Atkinson

STEREO Maps Far Reaches of Solar System

NASA’s twin STEREO spacecraft have been studying the sun since their launch in 2006. But the mission made a surprising and unexpected discovery by detecting particles from the edge of the solar system, and for the first time, scientists have now been able to map the region where the hot solar wind meets up with the cold interstellar medium. However, this wasn’t done with optical instruments imaging in visible light, but by mapping the region by means of neutral, or uncharged, atoms. This breakthrough is a “new kind of astronomy using neutral atoms,” said Robert Lin, from the University of California Berkeley, and lead for the suprathermal electron sensor aboard STEREO. “You can’t get a global picture of this region, one of the last unexplored regions of the heliosphere, any other way because it is too tenuous to be seen by normal optical telescopes.” The findings also help clear up a discrepancy in the amount of energy in the region found by the Voyager 2 spacecraft as it passed through the edge of the solar system last year.

The heliosphere stretches from the sun to more than twice the distance of Pluto. Beyond its edge, called the heliopause, lies the relative quiet of interstellar space, at about 100 astronomical units (AU) – 100 times the Earth-sun distance. The termination shock is the region of the heliosphere where the supersonic solar wind slows to subsonic speed as it merges with the interstellar medium. The heliosheath is the region of churning plasma between the shock front and the interstellar medium.

The twin STEREO spacecraft, in Earth’s orbit about the sun, take stereo pictures of the sun’s surface and measure magnetic fields and ion fluxes associated with solar explosions.

Between June and October 2007, however, the suprathermal electron sensor in the IMPACT (In-situ Measurements of Particles and CME Transients) suite of instruments on board each STEREO spacecraft detected neutral atoms originating from both the shock front and the heliosheath beyond.

“The suprathermal electron sensors were designed to detect charged electrons, which fluctuate in intensity depending on the magnetic field,” said lead author Linghua Wang, a graduate student in UC Berkeley’s Department of Physics. “We were surprised that these particle intensities didn’t depend on the magnetic field, which meant they must be neutral atoms.”

UC Berkeley physicists concluded that these energetic neutral atoms were originally ions heated up in the termination that lost their charge to cold atoms in the interstellar medium and, no longer hindered by magnetic fields, flowed back toward the sun and into the suprathermal electron sensors on STEREO.

“This is the first mapping of energetic neutral particles from beyond the heliosphere,” Lin said. “These neutral atoms tell us about the hot ions in the heliosheath. The ions heated in the termination shock exchange charge with the cold, neutral atoms in the interstellar medium to become neutral, and then flow back in.”

According to Lin, the neutral atoms are probably hydrogen, since most of the particles in the local interstellar medium are hydrogen.

The findings from STEREO, reported in the July 3 issue of the journal Nature, clear up a discrepancy in the amount of energy dumped into space by the decelerating solar wind that was discovered last year when Voyager 2 crossed the solar system’s termination shock and entered the surrounding heliosheath.

The newly discovered population of ions in the heliosheath contains about 70 percent of the energy dissipated in the termination shock, exactly the amount unaccounted for by Voyager 2’s instruments, the UC Berkeley physicists concluded. The Voyager 2 results are reported in the same issue of Nature.

A new NASA mission, the Interstellar Boundary Explorer (IBEX), is planned for launch later this year to map more thoroughly the lower-energy energetic ions in the heliosheath by means of energetic neutral atoms to discover the structure of the termination shock and how hydrogen ions are accelerated there.

Original News Source: EurekAlert

Posted on by Nancy Atkinson

Proposed Mission Could Study Space-Time Around Black Holes

What do black holes, magnetars and supernovae have in common? They all emit X-rays. But it’s difficult, if not impossible to study certain aspects of the X-ray emissions from these powerful objects. And there’s much we don’t understand about how black holes distort space-time around them, or how magnetars affect their surroundings, or how cosmic rays are accelerated by shocks in supernova remnants. A proposed new NASA mission called Gravity and Extreme Magnetism (GEMS), will use a new technique to study what has been unattainable until now. GEMS won’t study the X-ray emission of these objects directly, but will build up a picture indirectly by measuring the polarization of X-rays emitted from these violent regions.


No current mission has resolution to do this, or in the case of magnetic field imaging, simply can’t do this because magnetic fields are invisible.

X-rays are very powerful, and like all light, X-rays have a vibrating electric field. When light travels freely through space, it can vibrate in any direction. However, under certain conditions, it becomes polarized, meaning it is forced to vibrate in only one direction. This happens when light scatters off of a surface, for example.

In a similar manner, we use polarized glasses to reduce road glare. The glare is simply light that has become polarized by scattering off the road. The glasses are made to block polarized light, so they eliminate the glare.

“GEMS will be the first mission designed just to measure the polarization of these X-rays, which will enable us to explore these exotic places in an unprecedented way,” said GEMS Principal Investigator Dr. Jean Swank of NASA’s Goddard Space Flight Center in Greenbelt, Md.
GEMS was proposed as part of NASA’s Explorer program, and was selected as one of six missions for a detailed concept study. NASA will select two of the six for development in the spring of 2009. One selected mission is scheduled to launch in 2012, and the other is planned for launch in 2015.

“GEMS will be able to tell the shapes of the X-ray-emitting matter trapped near black holes better than existing missions can — in particular, whether matter around a black hole is confined to a flat disk or puffed into a sphere or squirting out in a jet,” said Swank.

“Since X-rays are polarized by the space swirling around a spinning black hole, GEMS also provides a method of determining black hole spin independent of other techniques, which is needed to check their accuracy,” said Swank.

The heart of GEMS will be a small chamber filled with gas. As X-rays travel through the gas, they release a cloud of electrons along their path. Since the electrons tend to move in the same direction as the electric field produced by the X-ray, the instrument will measure the electron cloud to get the direction of the X-ray’s electric field, which is the same as its polarization.

Original News Source: PhysOrg

Posted on by Nancy Atkinson

Hubble Does Independence Day With Stars and Stripe

Back in 1006 A.D, observers from Africa to Europe to the Far East witnessed and recorded the arrival of light from what is now called SN 1006, a tremendous supernova explosion caused by the final death throes of a white dwarf star nearly 7,000 light-years away. One Egyptian astronomer recorded the object was 2 – 3 times as large as the disc of Venus and about one quarter the brightness of the moon. The supernova was probably the brightest star ever seen by humans, visible even during the day for weeks, and it remained visible to the naked eye for at least two and a half years before fading away. Remnants of this supernova are still visible to telescopes, and the Hubble Space Telescope captured this close-up a filament of the shock wave of the explosion, still reverberating through space, seen here against the grid of background stars. The full image of SN 1006 is pretty impressive, too…

SN 1006 has a diameter of nearly 60 light-years, and it is still expanding at roughly 6 million miles per hour. Even at this tremendous speed, however, it takes observations typically separated by years to see significant outward motion of the shock wave against the grid of background stars. In the Hubble image shown here, the supernova would have occurred far off the lower right corner of the image, and the motion would be toward the upper left.

It wasn’t until the mid-1960s that radio astronomers first detected a nearly circular ring of material at the recorded position of the supernova. The ring was almost 30 arcminutes across, the same angular diameter as the full moon. The size of the remnant implied that the blast wave from the supernova had expanded at nearly 20 million miles per hour over the nearly 1,000 years since the explosion occurred.

In 1976, the first detection of exceedingly faint optical emission of the supernova remnant was reported, but only for a filament located on the northwest edge of the radio ring. A tiny portion of this filament is revealed in detail by the Hubble observation. The twisting ribbon of light seen by Hubble corresponds to locations where the expanding blast wave from the supernova is now sweeping into very tenuous surrounding gas.

The hydrogen gas heated by this fast shock wave emits radiation in visible light. Hence, the optical emission provides astronomers with a detailed “snapshot” of the actual position and geometry of the shock front at any given time. Bright edges within the ribbon correspond to places where the shock wave is seen exactly edge on to our line of sight.

Original News Source: HubbleSite

Posted on by Nancy Atkinson

Solar Sail To Launch This Summer

NanoSail D. Image credit NASA

NASA’s Marshall and Ames Research Centers will team up with the commercial space company SpaceX to launch and deploy a solar sail this summer. A bread-box sized payload called NanoSail-D will travel to space onboard a SpaceX Falcon 1 Rocket and if all goes well, it will be the first fully deployed solar sail in space, and the first spacecraft to use a solar sail as a primary means of orbital maneuvering. The first launch window is from July 29th to August 6th, with a back-up window extending from August 29th to September 5th. Weighing less than 4.5 kilograms (10 pounds) the aluminum and plastic sail has about 9.3 m² (100 square feet) of light-catching surface which researchers hope will successfully propel the spacecraft.

Solar sails have been the stuff of dreams for years. Because there’s no friction in space, once a solar sail starts moving, it can go on forever. While rockets would run out of gas and begin to coast, a spaceship powered by solar sails would continue accelerating as long as there is a solar wind, reaching faster speeds and covering distances far greater than any rocket. No rocket has been invented that could carry enough fuel to reach the outer solar system in as short a time. And like a marine sail, a solar sail could also bring you home. You could use the solar sail to travel “against the wind,” back to Earth.

“It’s not so much about how far a sail will go compared to a rocket; the key is how fast,” says Edward “Sandy” Montgomery of NASA’s Marshall Space Flight Center. “The Voyagers have escaped the solar system, and they were sent by rockets, but it’s taken more than three decades to do it. A sail launched today would probably catch up with them in a single decade. Sails are slower to get started though. So, for example, between the Earth and the moon, rockets might be preferred for missions with a short timeline. It’s a trip of days for rockets, but months for a solar sail. The rule of thumb, therefore, would be to use rockets for short hops and solar sails for the long hauls.”

Previous attempts to launch and deploy a solar sail in space have met limited success. In 2004 Japan launched prototype solar sails that deployed, but they weren’t used for propulsion. The Planetary Society attempted a solar sail launch in 2005, called Cosmos 1, but the Russian launch vehicle failed to reach orbit. NASA did successfully deploy a solar sail in a vacuum chamber in 2004, but of course, its propulsive capability wasn’t able to be tested.

Montgomery believes a successful mission would be huge for the future of spaceflight. If successful, solar sails could potentially help with a growing problem of space debris.

“Currently, micro-satellites in orbit above a few hundred kilometers can stay in orbit for decades after completing their mission,” Montgomery said. “This creates an orbital debris collision risk for other spacecraft. NanoSail-D will demonstrate the feasibility of using a drag sail to decrease the time satellites clutter up Earth’s orbit. Although our sail looks like a kite, it will act like a parachute (or like a drag sail) in the very thin upper atmosphere around Earth. It will slow the spacecraft and make it lose altitude, re-enter the Earth’s atmosphere and burn off in a relatively short period of time. A drag sail is a lighter alternative to carrying a propulsion system to de-orbit a satellite.”

Movie of how NanoSail D will unfurl.

Original News Source: Science at NASA