The International Space Station. Credit: NASA

Saturday, November 26, 2011

THE NEW MOON MAP FROM NASA

The following excerpt is from the NASA website:

"NASA’s Lunar Reconnaissance Orbiter science team released the highest resolution near-global topographic map of the moon ever created. This new topographic map shows the surface shape and features over nearly the entire moon with a pixel scale close to 328 feet.

Although the moon is Earth's closest neighbor, knowledge of its morphology is still limited. Due to the limitations of previous missions, a global map of the moon’s topography at high resolution has not existed until now. With LRO's Wide Angle Camera and the Lunar Orbiter Laser Altimeter instrument, scientists can now accurately portray the shape of the entire moon at high resolution."

Friday, November 18, 2011

COLLAPSE OF MASSIVE STAR CREATES A STELLAR-MASS BLACK HOLE

The following excerpt is from the NASA website:

"On the left, an optical image from the Digitized Sky Survey shows Cygnus X-1, outlined in a red box. Cygnus X-1 is located near large active regions of star formation in the Milky Way, as seen in this image that spans some 700 light years across. An artist's illustration on the right depicts what astronomers think is happening within the Cygnus X-1 system. Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. The black hole pulls material from a massive, blue companion star toward it. This material forms a disk (shown in red and orange) that rotates around the black hole before falling into it or being redirected away from the black hole in the form of powerful jets.

A trio of papers with data from radio, optical and X-ray telescopes, including NASA's Chandra X-ray Observatory, has revealed new details about the birth of this famous black hole that took place millions of years ago. Using X-ray data from Chandra, the Rossi X-ray Timing Explorer, and the Advanced Satellite for Cosmology and Astrophysics, scientists were able to determine the spin of Cygnus X-1 with unprecedented accuracy, showing that the black hole is spinning at very close to its maximum rate. Its event horizon -- the point of no return for material falling towards a black hole -- is spinning around more than 800 times a second.

Using optical observations of the companion star and its motion around its unseen companion, the team also made the most precise determination ever for the mass of Cygnus X-1, of 14.8 times the mass of the Sun. It was likely to have been almost this massive at birth, because of lack of time for it to grow appreciably."

Tuesday, November 15, 2011

GALATIC ENCOUNTERS MAY CAUSE GROWTH OF HUGE BLACK HOLES

The following excerpt is from the NASA website:

"Astronomers have used a large survey to test a prediction that close encounters between galaxies can trigger the rapid growth of supermassive black holes. Key to this work was Chandra's unique ability to pinpoint actively growing black holes through the X-rays they generate.

The researchers looked at 562 pairs of galaxies ranging in distances from about 3 billion to 8 billion light years from Earth. They found that the galaxies in the early stages of an encounter with another were more likely than isolated, or "lonelier" galaxies to have actively growing black holes in their cores.

These two composite images show a sample of the pairs of galaxies that are undergoing close encounters in the survey. In these images, the data from NASA's Chandra X-ray Observatory are shown in purple and Hubble Space Telescope data are in gold. In both images, the point-like X-ray source near the center is generated by gas that has been heated to millions of degrees as it falls toward a supermassive black hole located in the middle of its host galaxy. The other faint X-ray emission may be caused by hot gas associated with the pair of galaxies.

The authors of the study estimate that nearly one-fifth of all moderately active black holes are found in galaxies undergoing the early stages of an interaction. This leaves open the question of what events are responsible for fueling the remaining 80% of growing black holes. Some of these may involve the late stages of mergers between two galaxies. Less violent events such as gas falling in from the halo of the galaxy, or the disruption of small satellite galaxies are also likely to play an important role.

The survey used in this research is called the Cosmic Evolution Survey (COSMOS), which covers two square degrees on the sky with observations from several major space-based observatories including Chandra and Hubble. Accurate distance information about the galaxies was also derived from optical observations with the European Southern Observatory's Very Large Telescope. The researchers compared a sample of 562 galaxies in pairs with 2726 solo galaxies to come to their conclusions.

A paper describing this work has been accepted for publication in The Astrophysical Journal. The study was led by John Silverman from the Institute for the Physics and Mathematics of the Universe (IPMU) at the University of Tokyo in Japan. There are 54 co-authors from various institutions around the world.

Credits: X-ray: NASA/CXC/IPMU/J.Silverman et al; Optical: NASA/STScI/Caltech/N.Scoville et al."

Monday, November 7, 2011

DAN TANI TALKS ABOUT BEING AN ASTRONAUT

The following excerpt is from the NASA website:

In Their Own Words
Dan Tani,
Astronaut

What made you want to become an astronaut?

When I was a little boy, I was not one of those astronauts, and there are some, that wanted to be an astronaut when they were four years old or six years old. But I loved, I thought aviation was incredibly exciting and I liked model rockets. I used to fly model rockets when I was in elementary school. Just making stuff go fast and high was really exciting. Of course, if you would have asked me if I wanted to be an astronaut, I would have said absolutely, but it wasn't something I carried as a goal since childhood.

And then in college I became an engineer and learned how stuff works, how to build things and I got a job in an aerospace company and we were building satellites and satellite parts and I got to meet a few astronauts and when I met them I realized, hey, it's a job and I never even thought of being an astronaut as a job. /// And then I heard they were taking applications for that job, so I thought, who doesn't want to be an astronaut? /// So, got the application, filled it in, mailed it off and almost forgot about it. I just felt like I bought the lottery ticket, stuck it in my pocket and forgot about it. I was really surprised when they gave me a call and asked me if I wanted to interview and equally surprised when I got selected for the class of '96.

What is astronaut training like?

It's fun. We sort of go back to school. For the first two years we're called astronaut candidates, or ASCANs for short and ASCAN training is learning everything you can about NASA so we go to all the centers, we learn about what they do. It's all about learning how the space station works, when I joined it was all about learning how the space shuttle works and then it's about all the skills you're going to need as an astronaut, so some robotics skills and some spacewalking skills and some fix-it skills and some speaking skills. And so it's sort of going to school for almost two years and then when you come out of it, you're an eligible astronaut for assignment and the lucky ones get picked first and the more normal ones like us have to wait a little bit and so it was five years, I guess it was four years after I joined that I got selected for my first mission.

What was adapting to space like?

It felt pretty normal pretty quickly. When we go up on the space shuttle, we don't dock until the third day and so that means we have two full days of living in the space shuttle to kind of get used to weightlessness, to get used to brushing your teeth in weightlessness, putting on your socks, which is comically difficult to do in weightlessness and so you've sort of adapted that, doing your everyday stuff in weightlessness. Now you get into the station and it's a real benefit, there's just a lot more room. There's more to, so you're not elbowing your buddy every time you want to move around, or, again, when you put on your socks or your shoes and so in that way it's a lot easier. And then we, space station is outfitted with lots of computers to provide you some entertainment, also some communication with home so you can talk to your family virtually every day and so that feels a lot more normal. So living on the space station I thought was a very fast adaptation.

Describe the view from space?

The two great things about going into space are floating and looking out the window, and they would flip-flop in priority day to day in my mind. Looking out the window is a spectacular privilege. We're two hundred something miles above the Earth, we're going 17,000 mph, we cover most of the populated land mass because of the inclination of our orbit.

To look down at the earth and see both very familiar sights like your hometown and unfamiliar sights like the middle of Australia, which is incredibly beautiful, the colors and textures of central Australia are just spectacular, that was a motivator every day for space for me. Even out the little window, it was amazing.

So now you put the helmet on, you put the spacesuit on, you get in the airlock, you close the door behind you, you open the door out into space and now your window has become a full, 180-degree mask view. And the thing about spacewalks is we're not out there for the view, we're there to do the work and I think every spacewalker would tell you, the view is great, we think, because as far as I remember, every spacewalk was stuff right here. And so my memory of the spacewalks really is what's here and I had to force myself to have moments where I would appreciate the setting, the view and take some pictures and remember it that way. It is spectacular. It's amazing to hold onto the International Space Station, you're going 17 and a half thousand miles an hour, and hold on and just sort of look down at your feet and 200 miles under your feet, there goes the coast of California and, oops, nine minutes later, there goes New York City as you're flying over and then on your way to Europe.

What was the biggest surprise of spaceflight?

The biggest surprise to me was that when you're in space, with the weightlessness, it is, I call weightlessness 75 percent enjoyable, 75 percent unbelievably fun, 25 percent just a pain in the neck. And the pain the neck aspect is you're used to, on the ground you're used to doing things without thinking, you're used to writing something down, putting the pen down. The pen stays there, the paper stays there and you can turn around and when you turn back, the pen's there, paper's there.

Well, since everything floats in space, you have to think about absolutely everything you touch and everything that you want to touch. When you're eating, in space, you have to, generally people will eat one thing at a time because to eat your meat and your potatoes and your drink, you have to hold down, tie down, find a fixture for each item between if you're going to pick something new. Otherwise you're just juggling stuff and it'll get out of control. So generally most people will eat one thing, all, fold it up, throw that away. Open up the next thing, eat that next thing and roll it up, throw that away. Deal with one thing at a time because it's just too complex to have more than two things, one thing in each hand, at any time. And one of the pleasures of coming back to the ground was not having to think about eating, not having to think about my utensils. I could put them down and it was magic, they just stayed right there."

Tuesday, November 1, 2011

NASA TO HOST A HUMAN SPACE EXPLORATION WORKSHOP IN NOVEMBER

The following excerpt is from the NASA website:

“WASHINGTON -- NASA will host a three-day Human Space Exploration Community Workshop in San Diego starting on Monday, Nov. 14. The agency will introduce the International Space Exploration Coordination Group's Global Exploration Roadmap during the event.

The workshop will frame the Global Exploration Roadmap, with overviews of NASA's plans for human spaceflight, including exploration missions to an asteroid and Mars. The goal is to review the work done developing international exploration scenarios while seeking community input on the long-term scenarios represented in the roadmap.

NASA is seeking industry and academia feedback to shape strategy, assist with investment priorities and refine international exploration scenarios for human exploration and operations through the 2020's. The agency has outlined an ambitious program moving forward that relies on private industry to assume transportation of cargo and crew to the International Space Station, while NASA focuses on deep space exploration.

The workshop is part of a continuing agency effort to engage the broader space community in appropriate forums. More events will follow as part of a series of "theme focused" opportunities for human spaceflight exploration planning and engagement.”

FLOWS ON THE SLOPES OF MARS

The following is from the NASA website:

This image, which combines orbital imagery with 3-D modeling, shows flows that appear in spring and summer on a slope inside Mars' Newton Crater. Sequences of observations recording the seasonal changes at this site and a few others with similar flows might be evidence of salty liquid water active on Mars today. Evidence for that possible interpretation is presented in a report by McEwen et al. in the Aug. 5, 2011, edition of Science. This image has been reprojected to show a view of a slope as it would be seen from a helicopter inside the crater, with a synthetic Mars-like sky. The source observation was made May 30, 2011, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Color has been enhanced. The season was summer at the location, 41.6 degrees south latitude, 202.3 degrees east longitude. The flow features are narrow (one-half to five yards or meters wide), relatively dark markings on steep (25 to 40 degree) slopes at several southern hemisphere locations. Repeat imaging by HiRISE shows the features appear and incrementally grow during warm seasons and fade in cold seasons. Image Credit: NASA/JPL-Caltech/Univ. of Arizona
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