Posted on by Nancy Atkinson

Google Sky Takes You There

OK, I think I have my feet back on the ground now. But I may have gotten lost in the Small Magellanic Cloud’s Open Star Cluster. I’ve just been playing around with Google Sky, and have traveled around the universe, seeing dramatic astronomical images as never before. Anyone interested in astronomy, or those of you who just like awe-inspiring images will enjoy Google Sky. Just like Google Earth, Google Sky allows you to search for specific locations, zoom in and out of images, and pan around areas to look at nearby features. But Google Sky teams up with some of the largest ground- and space-based astronomical surveys to allow you to explore the far reaches of the universe.

You can select from the thumbnail images at the bottom of the display to bring up planets, constellations, highlights from the Hubble Space Telescope, famous stars, galaxies and nebulae, and views of the universe in the x-ray, ultraviolet and infrared. There’s also podcasts about upcoming astronomical events, and plenty of information about the images, including direct links to the Hubble’s comprehensive website about the specific image you are viewing.

What I found most interesting is the infrared images, particularly the ones from Spitzer. Initially, you see them in the visible spectrum, but then it quickly changes to infrared. Being able to compare the two spectrums is one of my favorite aspects of Google Sky. And other features allow you to play with the transparency to blend between all the different wavelengths and see how different parts of the universe light up at different wavelengths.

There’s also a view of the microwave sky from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), which shows the universe as it was 380,000 years after the big bang.

Also very interesting is the “Historical” feature, seeing the sky as drawn by Giovanni Maria Cassini (printed in 1792) showing the constellations in their classical form.

You can also use Google Sky to observe your own view of the sky, and zoom in for a closer look.

Start gallivanting around the universe with Google Sky here.

Posted on by Nancy Atkinson

Cassini Survives Close Flyby of Enceladus

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The Cassini spacecraft’s audacious flyby of Saturn’s moon Enceladus on March 12 has provided scientists more information about the geyser-like jets of ice shooting from the moon’s southern hemisphere. It also highlighted the drastic geologic differences between the moon’s north and south pole. While the data collected from the geysers is still being analyzed, images from the flyby showed a north polar region that is older and pitted with fractured craters, compared to the relatively newer cracks in south pole area from which water jets are emanating. The spacecraft came within 50 kilometers (30 miles) of the surface at closest approach and 200 kilometers (120 miles) while flying through the plume.

“These new images are showing us in great detail how the moon’s north pole differs from the south, an important comparison for working out the moon’s obviously complex geological history,” said Carolyn Porco, Cassini imaging team leader. “And the success of yesterday’s daring and very low-altitude flyby means this coming summer’s very close encounter, when we get exquisitely detailed images of the surface sources of Enceladus’ south polar jets, should be an exciting ‘next big step’ in understanding just how the jets are powered.”

Cassini was traveling about 15 kilometers per second (32,000 mph) through plumes from the geysers. The flyby was designed so that Cassini’s particle analyzers could dissect the “body” of the plume for information on the density, size, composition and speed of the particles.

Cassini scientists are pouring over the data being returned, which will give them a better understanding of the unique plume environment of Enceladus and possibly how the geysers are being formed.

The images show the north polar region is much older and pitted with craters of various sizes. These craters are captured at different stages of disruption and alteration by tectonic activity, and probably from past heating from below. Many of the craters seem sliced by small parallel cracks that appear to be ubiquitous throughout the old cratered terrains on Enceladus.

Future close flybys may bring Cassini even closer to the surface of Enceladus. The spacecraft will come close to Enceladus again in August, and skim even closer to the moon’s surface in October.

Original News Source: JPL Press Release

Posted on by Nancy Atkinson

Endeavour’s Launch Lights Up the Night Sky

With a spectacular and rare nighttime launch, space shuttle Endeavour lit up the dark sky and rocketed flawlessly to orbit. The shuttle launched at 2:28 am EST to begin its chase of the International Space Station. During the planned 16-day mission, the crew’s two prime objectives are to deliver and attach to the ISS the first component of Japan’s new laboratory called Kibo, as well as Canada’s new robotics system, the Special Purpose Dexterous Manipulator, or Dextre. STS-123 is the 25th shuttle mission to the International Space Station.

The launch of the first section of the Kibo lab is Japan’s first contribution to the space station. For the first time since space station construction began nearly 10 years ago, all five major partners will have hardware as part of the orbiting complex.

NASA astronaut Dominic Gorie commands a crew of six, including Pilot Greg Johnson and Mission Specialists Rick Linnehan, Robert Behnken, Mike Foreman, Garrett Reisman and Japanese astronaut Takao Doi. Johnson, Behnken and Foreman are making their first spaceflight. The crew has a busy flight, with five spacewalks for station construction. They will also test different repair techniques for damaged shuttle tiles.

Reisman will stay on board the station, replacing Expedition 16 Flight Engineer Leopold Eyharts, who arrived at the ISS aboard Atlantis in February, and he will return to Earth with the Endeavour crew.

Original News Source: NASA

Posted on by Nancy Atkinson

South Korean Astronauts Switched After Rule Infraction

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When it comes to following space agency rules, Russia stands firm. The man who was going to be the first South Korean in space has now been grounded for violating Russian security protocol and will be replaced by a female biotechnology engineer, the South Korean science ministry said on Monday. Ko San, 31, was dropped from the April 2008 flight to the International Space Station on a Russian Soyuz spacecraft. He is now the backup for the mission after he removed sensitive material from a Russian space training center. Ko, a technology researcher is being replaced by Yi So-yeon, 29, who is finishing her doctorate in bioengineering.

“The Russians emphasized the importance of abiding by the rules, as even small mistakes can bring about grave consequences in space,” a South Koren official said at a news conference, adding Ko appeared to have made innocent mistakes.

The Russian authorities said Ko took a book out of the center without permission and sent it to his home in South Korea in September. Ko later returned the book, explaining he accidently sent it home together with other personal belongings.

In February, Ko again violated regulations by getting a book from the center through a Russian colleague, and it was material he was not supposed to read. Officials did not give details about the book’s contents, but South Korean officials portrayed both of his infractions as minor.

“The Russian space agency has stressed that a minor mistake and disobedience can cause serious consequences,” a south Korean official told reporters.

Ko will remain at the Russian space center and continue training. The official did not say if Ko would possibly go to space on a future flight.

Yi, 29, will work aboard the International Space Station for about 10 days with three other cosmonauts as well as American station commander Peggy Whitson and flight engineer Garrett Reisman. Yi will conduct scientific experiments, according to a ministry statement.

The mission will make South Korea the world’s 35th country and Asia’s sixth to send an astronaut into space.

The two South Koreans were selected from a list of more than 36,000 candidates.

Original News Source: Reuters, AP

Posted on by Nancy Atkinson

Rings Detected Around Saturn’s Moon Rhea

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Saturn is known for the spectacular rings that circle the planet, and the Cassini spacecraft has been exploring Saturn’s rings, as well as its moons since 2004. And now Cassini has found evidence that there may be rings around one of Saturn’s moons, too: Rhea, the second largest moon in Saturn’s system. This is the first time rings may have been found around a moon. While no images yet have been taken of the rings (the picture here is an artist’s rendering) an extensive debris disk and at least one ring appear to have been detected by a suite of six instruments on Cassini specifically designed to study the atmospheres and particles around Saturn and its moons.

“Until now, only planets were known to have rings, but now Rhea seems to have some family ties to its ringed parent Saturn,” said Geraint Jones, a Cassini scientist and lead author on a paper that appears in the March 7 issue of the journal Science.

Rhea is about 1,500 kilometers (950 miles) in diameter. The apparent debris disk measures several thousand miles from end to end. The particles that make up the disk and any embedded rings probably range from the size of small pebbles to boulders. An additional dust cloud may extend up to 5,900 kilometers (3,000 miles) from the moon’s center, almost eight times the radius of Rhea.

Since the discovery, Cassini scientists have done simulations to determine if Rhea can maintain rings. The models show that Rhea’s gravity field, in combination with its orbit around Saturn, could allow rings that form to remain in place for a very long time. The discovery was a result of a Cassini close flyby of Rhea in November 2005.

One possible explanation for these rings is that they are remnants from an asteroid or comet collision in Rhea’s distant past. Such a collision may have pitched large quantities of gas and solid particles around Rhea. Once the gas dissipated, all that remained were the ring particles. Other moons of Saturn, such as Mimas, show evidence of a catastrophic collision that almost tore the moon apart.

“The diversity in our solar system never fails to amaze us,” said Candy Hansen, Cassini scientist and co-author on the paper. “Many years ago we thought Saturn was the only planet with rings. Now we may have a moon of Saturn that is a miniature version of its even more elaborately decorated parent.”

Original News Source: JPL/Cassini Press Release

Posted on by Nancy Atkinson

Cassini To Fly Through Enceladus’ Plume March 12 (Video)

The venerable Cassini spacecraft will make an extremely close flyby of Saturn’s moon Enceladus, one of the most intriguing moons in the Saturn system. Earlier flybys by Cassini revealed a geyser-like plume of ice particles shooting up from Enceladus’ south pole region. This means there’s a water source on the moon, and of course, water on another body in our solar system is an intriguing mystery that we want to take a closer look at. And this look will be extremely close. At one point during the flyby, when Cassini is near the equator of Enceladus, the spacecraft will only be about 50 km from the moon’s surface.

Cassini will skim over moon on March 12, at 19:06 UT. When Cassini is near the south pole, however, the spacecraft will be about 200km from Enceladus’ surface– which is probably a good thing. Even a small particle hitting the spacecraft could do a lot of damage, and the scientists say Cassini should be flying well above where any ice particles should be.

Learn more about the flyby in this video that the Jet Propulsion Laboratory put together.

Also, this graphic shows the areas on Enceladus that will be observable to Cassini as it whizzes by. Cassini’s scientists are hoping this flyby will help us understand the interior of this moon and how extensive its water source may be.

Enceladus flyby overview. Image Credit: JPL Photojournal

Original News Source: Cassini website

Posted on by Nancy Atkinson

Run, Don’t Walk, To Your Nearest Moon Base

An 'exoskeleton' made of fiberglass rods and springs, developed by MIT. Image courtesy of Christopher Carr.

Running is more efficient than walking for humans wearing spacesuits on the moon, according to a new study. A laboratory simulation of moonwalking found that pressurized spacesuits act as springs for our legs, and on the moon this effect is most pronounced during activity where the knee is bending at a greater angle, such as running. These findings may help NASA develop more efficient and comfortable spacesuits for future moon explorers, while also assisting research in prostheses for amputees. And who knows, maybe it could even promote the first lunar marathon run.

Because of the constriction of spacesuits and lower gravity, human movement is different on the moon than on Earth. This was evident during the Apollo missions where astronauts had a hard time bending over to pick up rocks or labored as they walked, but ran or bunny-hopped across the lunar surface with relative ease.

To simulate these conditions, researchers Christopher Carr and Dava Newman from MIT used an “exoskeleton” made of fiberglass rods and springs and placed them on the legs of a research subject. This exoskeleton was developed in large part by another MIT researcher, Dr. Hugh Herr in his study of prosthetics for amputees.

“We demonstrated that exoskeleton legs are similar to space suit legs, and that space suit legs act like springs due to the pressure of the space suit,” Carr told Universe Today. “Because of this, space suits support their own weight, but are hard to bend, making it difficult to carry out basic actions like picking up a tool from the ground.”

Carr is looking at ways to optimize the balance between stiffness and weight support to help the locomotive abilities for space-suited lunar astronauts. Less stiff spacesuits would enable easier ground access, but if they aren’t stiff enough, the suit will not support its own weight. Carr said the balance might be achieved with a change in the geometry of the space suit legs.

What else does this mean for future lunar exploration? During the Apollo missions there was a requirement of a walk-back constraint. Imagine a circle with an astronaut at the center, with the radius of the circle determined by how far you could walk while using only an emergency oxygen supply. This radius would specify how far away an astronaut could travel from their ‘base’, so that if a failure occurred he would be able to return safely. Now that we know running is more efficient than walking, said Carr, we should be able to base this constraint on running, allowing astronauts to travel further from their ‘base’, whether that base is their main habitat, or a pressurized rover.

Carr said he was somewhat surprised by their findings using the exoskeleton.

“I had not expected the forces imposed on the body by the exoskeleton to be so similar to the space suit knee joint,” he said.

They also used a simulated lunar gravity (1/6th of Earth’s) where the research subject wearing the exoskeleton was supported by cords attached to the ceiling by springs. “In this case, the subjects were even more efficient using an exoskeleton than walking or running without the exoskeleton,” said Carr. “We knew this was a possibility, but the proof is in the pudding.”

From this research it’s interesting to speculate about future athletic endeavors on the Moon. Running might be the sport of choice for lunar inhabitants, and the possibilities abound for lunar basketball. “Lower gravity might mean big jumps,” said Carr. “Even though our muscles will contract really fast, and thus will not be very efficient, we should be able to jump with a higher vertical velocity on the moon, maybe 30-50% faster than on Earth based on prior studies. Because gravity is 1/6 of Earth, that velocity will allow us to jump many times higher. We had better design those lunar habitats with high ceilings.”

Journal Reference: Science Direct

Posted on by Nancy Atkinson

Traffic Jam at the Space Station

Space traffic control will be needed at the International Space Station as a busy timeframe of missions and resupply flights continue for our home port in space. In a choreographed ballet of spaceships, ESA’s first Automated Transfer Vehicle (ATV) resupply ship and NASA’s Space Shuttle Endeavour are scheduled to liftoff on March 9 and 11, respectively, to dock with the ISS, while a third – Russia’s Soyuz – is due to arrive early in April. The heavy traffic comes just a few weeks after Space Shuttle Atlantis left the ISS on February 18, delivering the Columbus science lab to the station. With Endeavour scheduled to be docked to the ISS from March 13 – 24, the ATV must patiently wait in a “parking orbit,” travelling in a holding pattern below the station, and will then dock after the shuttle leaves.

As of now, everything is “go” for all three flights. Endeavour will ferry Japan’s Kibo science lab to the ISS, along with the Canadian Space Agency’s two-armed robotic system called Dextre. STS-123 is commanded by Dominic Gorie with Greg Johnson serving as pilot. The crew also includes Mission Specialists Rick Linnehan, Robert Behnken, Mike Foreman, Garrett Reisman and Japanese astronaut Takao Doi. Reisman will stay aboard the station, trading places with ESA astronaut Léopold Eyharts, who has been on board since Atlantis’ February mission to the ISS.

But in the meantime, the ATV will be waiting in the wings to deliver its cache of supplies to the station. “After launch, we will have an opportunity to show and demonstrate to our ISS partners exactly what the ATV is capable of doing,” said Alberto Novelli, ESA’s Mission Director for the ATV. “And we can place ATV in a holding orbit for an extended period, if necessary, before doing the final, actual docking,”.

Space Traffic Control. Image Credit: ESA
The ATV is scheduled to dock on March 29. However, if there are any slips or technical issues to delay the ATV’s docking, there are only four subsequent days on which the actual docking can take place. One limitation causing this is illumination conditions: astronauts on board the station must not be blinded by sunlight while monitoring the approaching vehicle’s progress.

Another limitation is caused by more traffic: Russia’s Progress M-63, docked since February 7, will undock on April 7 and a new Soyuz arrival and docking is scheduled for April 10. Additional limitations on the ATV docking window could come about if Endeavour’s launch is delayed or if its docked phase extends past March 27. For example, last month, Atlantis’ docked phase was extended by one day to facilitate the installation of Columbus.

“It’s an extraordinary time. While we face a tight window, the intense activity at the ISS these weeks – with European, American, Russian, Canadian and Japanese payloads or vessels in flight – highlights the fantastic international character of the Station,” said Bob Chesson, ESA’s manager for Human Spaceflight Operations.

Check out the ATV blog to follow the mission live, and NASA’s STS-123 launch blog.

Original News Source: ESA Press Release

Posted on by Nancy Atkinson

That Dark Stuff, Matter and Energy

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Being a very hands-on-type person, I have a hard time wrapping my brain around the concepts of dark energy and dark matter. These are invisible, hypothetical stuffs that cosmologists tell us make up a combined 96% of the universe. These ubiquitous substances are unlike anything we’re familiar with. They don’t emit or reflect enough electromagnetic radiation to be detected directly, but their presence is inferred by the gravitational effect they have on everything we can see. So, scientists are trying to determine if dark energy and dark matter are really there, and if so, what they’re made of. A couple of studies have come out recently dealing with dark energy and dark matter. One study released says that what we think might be dark energy may only be tiny whiskers of carbon materials, formed in the early days of the universe. And a new experiment tried to determine if dark matter is made of particles called axions.

Andrew Steele and Marc Fries from the Carnegie Institution say that what we thought was dark energy may just be a haze of tiny whiskers of carbon, strewn across the universe and perhaps those whiskers — and not dark energy — would dim faraway objects such as supernovae. Scientists proposed the dark energy hypothesis a decade ago in part to explain the unexpected dimness of certain stellar explosions.

The researchers report discovering an unusual new form of carbon in minerals within meteorites dating from the formation of the solar system. They believe the “graphite whiskers� were likely produced from hot, carbon-rich gases that formed near stars and were blown into interstellar space by solar winds or supernovae. A thin haze of the whiskers in space would affect how light of different wave-lengths pass through space. The researchers postulated that light of near-infrared wavelengths would be particularly affected—the same wavelengths whose dimming first led to the dark energy model.

Things like these graphite whiskers have been proposed previously to possibly explain observations where dimming appeared, but the presence of any types of materials in space has never been confirmed previously, said Steele and Fries. With their discovery in the meteorite, the pair added, researchers can test the whiskers’ properties against theories and observations.

Dark matter: To make hypothetical matter, you might just need a little dash of hypothetical particles. How about axions? Axions are theoretical particles that have a small mass, about 500 million times lighter than an electron. Additionally, according to theory, an axion should have no spin. A group from the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois designed an experiment to try to find axions.

They set up a magnetic field and shot a lazer into it. A “wall� was placed in the middle of the magnetic field as well. It was thought that the magnetic field would possibly change some of the photons from the laser into axions. The wall would stop the photons, but the axions would emerge on the other side.

They tried four different configurations of their system, unfortunately, the experiment found no evidence of new particles. But, they were able to exclude some constraints or regions where this type of particle could or could not exist.

And the data from the Fermilab experiment is still being examined. Scientist William Wester is optimistic about the role he and his colleagues are playing. “We did a serious measurement and excluded a region,� he says. “If our small experiment helps heighten awareness and leads to more experimental efforts, even using other techniques as well, it will be a huge benefit that we have done this.�

The group believes that maybe with a stronger magnetic field, it might be worth trying their experiement again.

This brings to mind something that I heard cosmologist Michael Turner say: “If I succeed in confusing you about dark matter and dark energy, then I will have brought you up to where the experts are.â€?

Original News Sources:
World Science
Physorg.com release

Posted on by Nancy Atkinson

Earth and Moon, As Seen From Mars

This picture was released a couple of days ago, but since it’s so special, it deserves a post on Universe Today. And besides, everyone secretly likes to look at pictures of themselves. And this is a picture of us: it’s the Earth and the moon, as seen from Mars. From the Mars Reconnaissance Orbiter, to be exact, and it was taken by the HiRISE Instrument on board, the High Resolution Imaging Science Experiment. That’s the same camera that gave us the images of the avalanche on Mars, so the capabilities of this instrument are quite spectacular. This image was snapped back in October 2007, from a distance of 142 million kilometers, and if you look closely, you can make out a few features on Earth.

The west coast outline of South America is at lower right on Earth, although the clouds are the dominant features. In fact, the clouds were so bright, compared with the Moon, that they almost completely saturated the filters on the HiRISE camera. The people working on HiRISE say this image required a fair amount of processing to make a such a nice-looking picture. Yes, I agree, we are looking quite nice.

The phase angle is 98 degrees, which means that less than half of the disks of the Earth and Moon have direct illumination from the sun; that’s the reason we only see about half of each object. The scientists working on HiRISE say they would be able to image the Earth and moon when they are fully illuminated, but only when they are on the opposite side of the sun from Mars. However, then the distance would be much greater and the image would show less detail.

At this distance, this HiRISE image has a scale of 142 km/pixel, giving the Earth diameter about 90 pixels and the Moon diameter 24 pixels.

And now, back to the target that HiRISE was originally designed for: Mars. Here’s a very colorful (and false color) image that highlights the different minerals in Nili Fossae on Mars, one of the potential landing sites for the Mars Science Laboratory rover. From the CRISM instrument, the on-board spectrometer, scientists can discern that this area on Mars contains iron and magnesium, minerals that also contain water.
Nili Fossae on Mars. Image Credit: NASA/JPL/University of Arizona

Original News Source: HiRISE Web page