Posted on by Nancy Atkinson

Gravity Anomaly Challenges MESSENGER Mission

Scientists from the MESSENGER mission continue to analyze the data from the spacecraft’s first flyby of Mercury on January 14, 2008. Initial data about the planet’s gravity field grabbed the science team’s attention, as the actual gravity data differed from predictions based on the Mariner 10 flyby in 1975. Any unknowns in Mercury’s gravity will provide challenges for the spacecraft’s navigation during the next flyby in October, and especially when MESSENGER goes into orbit of Mercury in 2011. This in turn could affect quality and detail of science observations. “There indeed are residuals that we have not yet been able to explain fully,” said Ralph McNutt, MESSENGER Project Scientist. “While we believe we have resolved possible extraneous effects, we continue to work those as well.”

The new data about Mercury’s internal structure is different from what the scientists expected. McNutt said that while it was surprising that the tracking data did not fit all of their preconceived notions from Mariner 10, MESSENGER went much closer to Mercury than did Mariner, which could account for the differences in data. Scientists believe there may be a large concentration of mass (mascons) under Mercury’s surface about 10 degrees south of the equator at about 60 degrees longitude. A presentation by team member David Smith at the Lunar and Planetary conference in March showed that they were able to account for about 95% of the problem deviation using a single mass anomaly at that location.

“This also leads into the most important thing on flyby 2,” said McNutt, “as we will have closest approach on the other side of the planet, we will then be able to obtain a much better separation of global versus local (mascon) signatures. So we expect major advances in our understanding of the gravity field from the 2nd flyby as it will complement the information gleaned from the first.”

From MESSENGER Navigation Team Chief Ken Williams’ perspective, any new information and understanding of this issue is important. “We’re following very closely any developments in understanding the gravity field,” said Williams. “As we encounter Mercury each time, we’re trying to build up our knowledge of what the gravity field is going to be. It’s not critical that we know it in fine detail right now, but obviously when we settle into orbit we’re going to want to know a lot more about it because that will affect the design of the orbit trim maneuvers that we’ll have to do.”

McNutt said the initial the command loads for the second flyby are being delivered to Mission Operations this week.

But Williams said the first flyby provided good news as far as knowing Mercury’s actual location in space. “While we had a pretty good idea of Mercury’s ephemeris, that fact that it hadn’t been visited by a spacecraft for a long time, there was a chance it would be different than we thought,” said Williams. “We did some things with optical navigation as we were flying by and it confirmed that it was only 2 km away at most from the ephemerides that JPL publishes. That was a great relief. That takes away the uncertainty for future encounters.”

MESSENGER’s orbit around Mercury will be affected by another perturbation, known as third body gravity, from the Sun’s gravity field. At first this effect will draw MESSENGER away from Mercury, but later in the mission it will force the spacecraft towards the planet. Williams said one navigation analyst estimated that if the mission ended in 2012 and no further maneuvers were done by the spacecraft, MESSENGER would impact Mercury sometime in 2016.

McNutt was clearly pleased with the data from the first flyby, and looks forward to the second. “The first flyby provided humanity’s first closeup of 21% of Mercury’s surface as well as an amazing set of data on the Caloris basin. We have also made major advances in our understanding of Mercury’s exosphere, magnetosphere, and surface mineralogy. The second flyby will provide a similar close-up of another 33% of terra incognita, and only ~1% of Mercury will not have been viewed by a spacecraft when we enter orbit in 2011.”

Posted on by Nancy Atkinson

NASA Flips for Petaflops

NASA is collaborating with Intell and SGI to create one of the world’s fastest supercomputers whose power will be measured in petaflops. By 2009 the US space agency wants to develop a computational system that will be able to do 1,000 trillion calculations per second. And by 2012 it hopes to have boosted the power of this machine to 10 petaflops, to help with modelling and simulation. NASA’s Advanced Supercomputing Division is calling the new project Pleiades, and it will be installed at the Ames Research Center in California, the site of its current supercomputer, Columbia, pictured here. The new computer would put NASA on the list of the top five fastest number crunchers in the world.

“Throughout its history, NASA has sought to explore the most compelling questions about mankind, Earth, and the worlds that await our discovery,” said Robert “Bo” Ewald, chief executive officer of SGI. “These groundbreaking new systems powered by SGI and fueled by the latest multi-core Intel processors, offer a platform for new discoveries that will help us all achieve the most promising future for the human race. This effort is important to everyone on this planet.”

NASA uses its current supercomputer to examine the performance of hypersonic aircraft, simulate lander deployments and model fabrics for future spacesuits.

“This additional computational performance is necessary to help us achieve breakthrough scientific discoveries,” said Pete Worden, Director at Ames.

Currently, the most powerful supercomputer on Earth is BlueGene/L which has a top speed of 478.2 teraflops.

Columbia was turned on in 2004 and has a theoretical peak of 88.88 teraflops. This makes it the 20th most powerful supercomputer on the planet, according to the Top 500 Project which compiles a list of the relative performance of these machines.

Petaflop computers are expected to debut in the next release of the Top 500 list which is due in June.

Quasi-supercomputing, where multiple computers are used using the BOINC platform has already achieved petaflop status. Folding@home, reported nearly 1.3 Petaflops of processing power in late 2007.

The largest BOINC project, SETI@home, reported processing power of over 450 teraflops through almost 350,000 active computers.

Original News Sources: BBC, NASA

Posted on by Nancy Atkinson

Long-term Observations Reveal Patterns in Saturn’s Atmosphere

Reading something like this makes me hopeful that we’re no longer in the infant stage of our understanding of our solar system: we’ve been patient and observant while growing in our knowledge. Scientists have discovered a wave pattern, or oscillation, in Saturn’s atmosphere only visible from Earth every 15 years. This discovery was made only because we’ve been studying Saturn from ground based telescopes for about 22 years. Combined with the Cassini spacecraft’s observations of temperature changes in the giant planet’s atmosphere over time, we’re gaining a better understanding of Saturn and discovering not only how unique it is, but also that Saturn has something in common with Earth. Our own planet has these oscillations too, and so does Jupiter. “You could only make this discovery by observing Saturn over a long period of time,” said Glenn Orton, of JPL, lead author of the ground-based study. “It’s like putting together 22 years worth of puzzle pieces, collected by a hugely rewarding collaboration of students and scientists from around the world on various telescopes.”

The image above shows a pattern ripples back and forth like a wave within Saturn’s upper atmosphere. In this region, temperatures switch from one altitude to the next in a candy cane-like, striped, hot-cold pattern. The temperature “snapshot” shown in these two images captures two different phases of this wave oscillation: the temperature at Saturn’s equator switches from hot to cold, and temperatures on either side of the equator switch from cold to hot every Saturn half-year.

The image on the left was taken in 1997 and shows the temperature at the equator is colder than the temperature at 13 degrees south latitude. Conversely, the image on the right taken in 2006 shows the temperature at the equator is warmer.

Results from Cassini’s infrared camera indicate that Saturn’s wave pattern is similar to a pattern found in Earth’s upper atmosphere, which takes about two years. A similar pattern on Jupiter takes more than four Earth years. The new Saturn findings add a common link to the three planets.

Cassini scientists hope to find out why this phenomenon on Saturn changes with the seasons, and why the temperature switchover happens when the sun is directly over Saturn’s equator.

Original News Source: JPL Press Release

Posted on by Nancy Atkinson

Popular Space Elevator Video Not “News,” says LiftPort Founder

An online video that’s been circulating like wildfire on the internet recently is actually almost two years old, says Michael Laine, founder of LiftPort, a company looking to develop a space elevator. The video was taken in the fall of 2006, at least 20 months ago.

The video has been downloaded over 200,000 times in the past few days, and has been extremely popular on sites like Digg. “I find the whole thing kind of a farce, actually,” said Laine. “I’m glad people are seeing it and commenting on it, but if someone thinks this is news, its not.”

The only reason Laine could site for a possible resurgence of this video is that last Friday, the Conan O’Brien show featured a guest talking about space elevators. Laine wonders if that led to people doing searches about the subject, finding this old video on You Tube, and re-posting it as “new.” Laine says LiftPort has received slightly more email than normal the past couple of days, but until now no one has contacted him to check on the authenticity or timing of the video.

“Everything in it is true, except the timing is strange,” said Laine. “Those are my quotes, (listed along with the video) but I don’t know how someone obtained them, and got that wording. What’s ironic is that we’ve done a lot of experiments since then. That specific test was supposed to be a mile high test, but we had problems with the ribbon snapping. The FAA required that we put markers on it, and the acetone used to mark it weakened the ribbon substantially. The test turned out to be 1,000 feet. We actually were very happy about the test, although we almost lost the ribbon.”

Laine was especially surprise to hear of this new interest in Liftport, since the company has gone through some hard times over the past year, losing investors, a building, and other support. Laine said he will have some positive news to report soon, so stay tuned.

And OK, here’s the video. (You Tube’s version, not LiveLeak’s!) It is pretty amazing.

Click here for more information about LiftPort.

Posted on by Nancy Atkinson

Volunteers Sweat for NASA

For three weeks, 23 volunteers spent time helping NASA test a new life support system for the spacecraft that will replace the shuttle. Five volunteers at a time would squeeze into a special room the size of a walk-in closet for eight hours. Sweating and heavy breathing was encouraged, as scientists at Johnson Space Center wanted to measure the amount of moisture and carbon dioxide absorbed by a new system designed to control carbon dioxide and humidity inside a crew capsule in order to make air breathable and living space more comfortable. The tests took place from April 14 to May 1 of this year and are some of the first to use human subjects in support of NASA’s Orion crew capsule, Altair lunar lander and lunar rovers.

“We’re moving from paper studies to tests with hardware that will evolve and become part of the spacecraft that will fly back to the moon,” said test volunteer and NASA engineer Evan Thomas at Johnson.

Known as the Carbon-dioxide and Moisture Removal Amine Swing-bed, or CAMRAS, the new system will help sustain life on exploration vehicles and reduce the dependence on resupply from Earth.

“Our goal for CAMRAS is to develop a simple, regenerative, lightweight device that will work for both the Orion crew capsule and the Altair lunar lander,” said lead researcher Jeff Sweterlitsch.

The Exploration Life Support project also is developing technologies that will recover oxygen and water vapor, recycle spacecraft wastewater into drinking water and recover usable resources from wastes.

This series of tests put volunteers inside a test chamber scaled to be the size of the Orion crew capsule, about 570 cubic feet. The volunteers, who were selected and grouped to replicate a typical crew, were asked to sleep, eat and exercise during test sessions that lasted from a few hours to overnight.

“The air smelled a little artificial, like on a plane, and it was a little crowded,” said Aaron Hetherington, one of the volunteers and a director for the test. “But the air was fine; the temperature comfortable. My biggest observation is that it was unremarkable, which is good because that means the hardware was working.”

Two additional phases of testing on CAMRAS are planned.

Video of the tests are available on NASA TV

Original News Source: NASA Press Release

Posted on by Nancy Atkinson

The Space Traveler’s Guide to Surviving Without a Spacesuit (Part 1)

In a few decades from now, when we’ve got interplanetary space travel perfected and all of us Average Joes can hop in our own personal spacecraft or grab the local express line of the Milky Way Transport Service, visiting other planets and moons is going to be a blast. Just imagine it: kicking back for a relaxing weekend on Mars, or heading out for a diving expedition on Europa, or possibly week of mountain climbing on Titan. But there are a few safety rules we’ll need to know, especially in the event of a spacesuit failure. Unfortunately, unless someone is able to figure out how to do some serious terraforming, we’ll all be stuck wearing spacesuits in order to survive on the other worlds in our solar system. And just how bad would it be if your spacesuit malfunctioned? Well, let’s just say it wouldn’t be pretty. Here’s a look at some problems you might encounter without an operational spacesuit on other worlds.


We’ll start with Mercury. Lack of air is going to be a serious problem here if your spacesuit quits working. So far, no discernable atmosphere has been detected on Mercury, except for trace amounts of helium, so maybe you could amuse your companions by doing a Munchkin voice for a short while before you passed out. A spacesuit designed for Mercury would have to withstand high temperature fluctuations, as temperatures range from -150 C to 425 C. Without your spacesuit, you’d either freeze or instantly turn into a carbon briquette, depending on which side of the planet you were standing. Moving about on Mercury would be fairly easy, since the gravity is about 1/3 that of Earth, and Mercury has smooth plains, plentiful craters and high cliffs that would be fun to explore. But if you were stuck on Mercury with a malfunctioning spacesuit, it would be a very long bad day, since one day on Mercury is equal to 59 days on Earth.


Venus. Why anyone would want to visit Venus is a mystery. It’s too hot, too cloudy and the atmospheric pressure is downright depressing. A spacesuit designed for Venus would need to be constructed of titanium or some other material that could withstand Venus’ high surface pressure, which is 90 times that of Earth’s. Without a strong spacesuit, you’d be instantly squashed. The Russians tried several times to land a robotic spacecraft on Venus, and most never made it to the surface without being crushed. The Venera 8 lander, however, lasted 50 minutes. So, if your titanium-strength spacesuit was working, and you, too could survive for at least 50 minutes, there are 1600 major volcanoes, lots of mountains, large highland terrains, and vast lava plains to explore. Before landing on Venus, you’d want to do a thorough checkout of your spacesuit’s Primary Life Support Subsystem (PLSS) which contains oxygen tanks, carbon dioxide scrubbers, cooling water, communications, and ventilating fans. You’ll need all of those things to be working at peak efficiency. Venus’ atmosphere is mostly carbon dioxide (96%), with some carbon monoxide and sulfur dioxide thrown in just to keep the riffraff out. Suffice to say, without a spacesuit, you wouldn’t last long and you might not even make it to the surface. And a bad day on Venus would be even worse than on Mercury: it’s about 230 Earth days long.


If you plan just to take a day trip and visit our Moon, you’re probably going to be in pretty good shape, as we’ve had the chance to thoroughly test out spacesuits designed for the lunar surface. Again, you’re going to need your PLSS, since there’s no air on the moon. Just the opposite of Venus, there’s no air pressure on old Luna, so you’ll need your spacesuit to keep your innards inside your body. Surface temperatures can vary dramatically over the course of a day, from 100° C at noon to -173° C at night, so a malfunctioning spacesuit might cause a predicament. But hopefully there’ll be a moon base just around the corner if you run into any problems.

Let’s head back to the safety of Earth now before we head on out to the rest of our solar system.

Sources: (9) 8 Planets, Windows to the Universe

Posted on by Nancy Atkinson

Snow on Mercury?

No, not that kind of snow, but scientists say deep inside the planet Mercury, iron “snow” forms and falls toward the center of the planet, much like snowflakes form in Earth’s atmosphere and fall to the ground. The movement of this iron snow could be responsible for Mercury’s mysterious magnetic field, and Mercury may be the only body in our solar system where this occurs.

Mercury and Earth are the only local terrestrial planets that possess a global magnetic field. But Mercury’s is about 100 times weaker than Earth’s, which scientists have been unable to explain.

Made mostly of iron, Mercury’s core is also thought to contain sulfur, which lowers the melting point of iron and plays an important role in producing the planet’s magnetic field.

To better understand the physical state of Mercury’s core, the researchers in a lab recreated the conditions believed to exist at Mercury’s core, and melted an iron-sulfur mixture at high pressures and high temperatures.

In each experiment, an iron-sulfur sample was compressed to a specific pressure and heated to a specific temperature. The sample was then quenched, cut in two, and analyzed with a scanning electron microscope and an electron probe microanalyzer.

As the molten, iron-sulfur mixture in the outer core slowly cools, iron atoms condense into cubic “flakes” that fall toward the planet’s center, said Bin Chen, University of Illinois graduate student and lead author of a paper published in the April issue of Geophysical Research Letters. As the iron snow sinks and the lighter, sulfur-rich liquid rises, convection currents are created that power the dynamo and produce the planet’s weak magnetic field.

The researchers say their findings provide a new context for the data that will be obtained from NASA’s MESSENGER spacecraft, which will flyby Mercury for a second time on October 6, 2008. It will pass by the planet again in September of 2009, and go into orbit in March of 2011.

Original News Source: Eureka Alert

Here are some interesting facts about Mercury.

Posted on by Nancy Atkinson

Where In The Universe? #4

Here’s this week’s “Where In The Universe?” mystery image. Your mission, should you choose to accept, is to guess what location in the universe is depicted here. No peeking below before you make a guess. Give yourself an extra point if you can name the feature shown here, and another point or two if you can name the spacecraft that took this image. I have to admit, I was drawn to this image strictly by the color: blue is my favorite, and especially this shade of blue. Kind of electric, don’t you think? Let’s see, could this be a moon, or a planet, or even a portion of a planetary nebula, or perhaps a photo from somewhere on our home planet? Make your guesses now, or maybe you knew what this was the moment you saw it….

Have you made your guess?

This spectacular image was taken by the Hubble Space Telescope. It’s a close-up view of an electric-blue aurora that is eerily glowing on the planet Jupiter. It was taken by HST’s Space Telescope Imaging Spectrograph (STIS) using an ultraviolet filter.

Auroras are curtains of light resulting from high-energy electrons racing along the planet’s magnetic field into the upper atmosphere. The electrons excite atmospheric gases, causing them to glow. The aurora is centered on Jupiter’s magnetic north pole.

Although this aurora resembles the same phenomenon seen at Earth’s polar regions, this image shows unique emissions from the magnetic “footprints” of three of Jupiter’s largest moons. These points are reached by following Jupiter’s magnetic field from each satellite down to the planet.

Auroral footprints can be seen in this image from Io (along the left hand limb), Ganymede (near the center), and Europa (just below and to the right of Ganymede’s auroral footprint). These emissions, produced by electric currents generated by the satellites, flow along Jupiter’s magnetic field, bouncing in and out of the upper atmosphere. They are unlike anything seen on Earth.

This ultraviolet image of Jupiter was taken with the on November 26, 1998. In this ultraviolet view, the aurora stands out clearly, but Jupiter’s cloud structure is masked by haze.

So, how’d you do?

Image credit: NASA/ESA, John Clarke (University of Michigan)

Link to image on the Hubble Site.

Posted on by Nancy Atkinson

JAXA Releases Boomerang Experiment Video

During the STS-123 mission to the International Space Station in March 2008 Japanese astronaut Takeo Doi tested a special boomerang in space to see how it worked in the microgravity environment of the ISS. The boomerang used in the experiment was a “Roomerang,” a small, tri-blade boomerang intended for use indoors in a small area or outdoors in light winds. IT was designed by boomerang expert Gary Broadbent, and it travels 5 to 8 feet before returning to the thrower.

The Japanese Space Agency has now released the video of the event:

As you can see, it worked very well, even in the small space of the ISS module. Broadbent told Universe Today that in the pressurized environment of the ISS, “microgravity has very little effect on the boomerang flight. The boomerang is so versatile, it can be tuned to fly in a perfect path back to the thrower, with gyroscopic precession and angular momentum over-compensating the lack of gravity.”

But Broadbent also said that a boomerang would not work in the vacuum of space. “You need air molecules to generate the lift to make the boomerang turn,” he said.

Here’s our earlier article about the boomerang experiment.

Original News Source: You Tube

Posted on by Nancy Atkinson

Did Earth Have More Than One Moon?

Scientists looking at the various Lagrangian Points in our solar system noticed a pattern. Lagrange points, (named after their discoverer Josef Lagrange) are five special locations in the vicinity of two orbiting masses where a third, smaller mass can orbit at a fixed distance from the larger masses. Essentially, the gravity from each large mass is equal at that point and the smaller object can be “trapped” there. The 4th and 5th Largrange points, called L4 and L5, are stable points. Researchers Jack Lissauera, and John Chambers noticed that more than 2200 cataloged asteroids are located about the L4 and L5 points of the Sun–Jupiter system, and five bodies have been discovered around the L4 point of the Sun–Neptune system. Small satellites have also been found librating about the L4 and L5 points of two of Saturn’s moons. However, no objects have been discovered around the Earth–Moon L4 and L5 points. Their research led them to believe that other small moons may once have existed in these points.

The triangular Lagrange points, L4 and L5, form equilateral triangles with the two massive bodies (here, the Earth and the moon) and objects near L4 and L5 can remain close to these locations indefinitely.

Lissauera and Chambers say that using numerical integrations, they’ve shown that orbits near the Earth–Moon L4 and L5 points can survive for over a billion years even when the sun’s gravity is thrown into the mix. However, when the small perturbations from the other planets are present, that can destabilize the orbits at L4 and L5 within several million years. So, they deduced that even though there’s no objects at those points right now, that doesn’t mean there wasn’t something there in the past.

The leading candidate for the theory of the moon’s formation is that a Mars-sized object hit the Earth and the resulting debris formed the moon. The two researchers say other debris would have been present as well, and may have been trapped at the L4 and L5 points.

However, one has to wonder, with the moon, as well as Earth, in a state of flux following the collision, their gravitational fields may have been unstable enough to preclude any L points at the stage where the other debris or moons were in the area. Also, the moon used to be closer to Earth, and the L points would have changed over time, and this change also might have been enough to disengage any “trapped” moons.

But it’s interesting to consider the night sky with multiple moons.

Original News Sources: Icarus, New Scientist