David Kirkpatrick

February 23, 2010

Metal-free carbon nanotube production

Via KurzweilAI.net — I’ll just let the quoted bit below do all the explaining …

A Stellar, Metal-Free Way to Make Carbon Nanotubes
Physorg.com, Feb. 22, 2010

A new method of growing carbon nanotubes without requiring platinum or another metal as a catalyst has been developed by researchers at NASA‘s Goddard  Center.

The carbon nanotubes are produced when graphite dust particles are exposed to a mixture of carbon monoxide and hydrogen gases.

The method was suggested by a 2008 discovery that the long, thin carbon structures known as graphite whiskers — essentially, bigger cousins of carbon nanotubes — were identified in three meteorites. Researchers suspect that it could have produced at least some of the simple carbon-based compounds in the early solar system.

The work also could help researchers understand puzzling observations about some supernovas.


Nanotubes grown on graphite (Yuki Kimura, Tohoku University)


Read Original Article>>

June 18, 2009

NASA’s heading back to the moon

A release hot from the inbox:

NASA Returning to the Moon With First Lunar Launch In A Decade

GREENBELT, Md., June 18 /PRNewswire-USNewswire/ — NASA’s Lunar Reconnaissance Orbiter launched at 5:32 p.m. EDT Thursday aboard an Atlas V rocket from Cape Canaveral Air Force Station in Florida. The satellite will relay more information about the lunar environment than any other previous mission to the moon.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

The orbiter, known as LRO, separated from the Atlas V rocket carrying it and a companion mission, the Lunar Crater Observation and Sensing Satellite, or LCROSS, and immediately began powering up the components necessary to control the spacecraft. The flight operations team established communication with LRO and commanded the successful deployment of the solar array at 7:40 p.m. The operations team continues to check out the spacecraft subsystems and prepare for the first mid-course correction maneuver. NASA scientists expect to establish communications with LCROSS about four hours after launch, at approximately 9:30 p.m.

“This is a very important day for NASA,” said Doug Cooke, associate administrator for NASA’s Exploration Systems Mission Directorate in Washington, which designed and developed both the LRO and LCROSS missions. “We look forward to an extraordinary period of discovery at the moon and the information LRO will give us for future exploration missions.”

The spacecraft will be placed in low polar orbit about 31 miles, or 50 kilometers, above the moon for a one year primary mission. LRO’s instruments will help scientists compile high resolution three-dimensional maps of the lunar surface and also survey it at many spectral wavelengths. The satellite will explore the moon’s deepest craters, exploring permanently sunlit and shadowed regions, and provide understanding of the effects of lunar radiation on humans.

“Our job is to perform reconnaissance of the moon’s surface using a suite of seven powerful instruments,” said Craig Tooley, LRO project manager at NASA’s Goddard Space Flight Center in Greenbelt, Md. “NASA will use the data LRO collects to design the vehicles and systems for returning humans to the moon and selecting the landing sites that will be their destinations.”

High resolution imagery from LRO’s camera will help identify landing sites for future explorers and characterize the moon’s topography and composition. The hydrogen concentrations at the moon’s poles will be mapped in detail, pinpointing the locations of possible water ice. A miniaturized radar system will image the poles and test communication capabilities.

“During the 60 day commissioning period, we will turn on spacecraft components and science instruments,” explained Cathy Peddie, LRO deputy project manager at Goddard. “All instruments will be turned on within two weeks of launch, and we should start seeing the moon in new and greater detail within the next month.”

“We learned much about the moon from the Apollo program, but now it is time to return to the moon for intensive study, and we will do just that with LRO,” said Richard Vondrak, LRO project scientist at Goddard.

All LRO initial data sets will be deposited in the Planetary Data System, a publicly accessible repository of planetary science information, within six months of launch.

Goddard built and manages LRO. LRO is a NASA mission with international participation from the Institute for Space Research in Moscow. Russia provides the neutron detector aboard the spacecraft.

The LRO mission is providing updates via @LRO_NASA on Twitter. To follow, visit:

http://www.twitter.com/lro_nasa

  For more information about the LRO mission, visit:

  http://www.nasa.gov/lro

March 17, 2009

Did life arrive from space?

Looks like this research from NASA lends a lot of credence to the idea life on Earth arrived via rocks from space. Very interesting.

The release fresh from the inbox:

NASA Researchers Find Clues to a Secret of Life

GREENBELT, Md., March 17 /PRNewswire-USNewswire/ — NASA scientists analyzing the dust of meteorites have discovered new clues to a long-standing mystery about how life works on its most basic, molecular level.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

“We found more support for the idea that biological molecules, like amino acids, created in space and brought to Earth by meteorite impacts help explain why life is left-handed,” said Dr. Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md. “By that I mean why all known life uses only left-handed versions of amino acids to build proteins.” Glavin is lead author of a paper on this research appearing in the Proceedings of the National Academy of Sciences March 16.

Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes, the catalysts that speed up or regulate chemical reactions. Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acids in a huge variety of arrangements to build millions of different proteins. Amino acid molecules can be built in two ways that are mirror images of each other, like your hands. Although life based on right-handed amino acids would presumably work fine, “you can’t mix them,” says Dr. Jason Dworkin of NASA Goddard, co-author of the study. “If you do, life turns to something resembling scrambled eggs — it’s a mess. Since life doesn’t work with a mixture of left-handed and right-handed amino acids, the mystery is: how did life decide — what made life choose left-handed amino acids over right-handed ones?”

Over the last four years, the team carefully analyzed samples of meteorites with an abundance of carbon, called carbonaceous chondrites. The researchers looked for the amino acid isovaline and discovered that three types of carbonaceous meteorites had more of the left-handed version than the right-handed variety — as much as a record 18 percent more in the often-studied Murchison meteorite. “Finding more left-handed isovaline in a variety of meteorites supports the theory that amino acids brought to the early Earth by asteroids and comets contributed to the origin of only left-handed based protein life on Earth,” said Glavin.

All amino acids can switch from left-handed to right, or the reverse, by chemical reactions energized with radiation or temperature, according to the team. The scientists looked for isovaline because it has the ability to preserve its handedness for billions of years, and it is extremely rarely used by life, so its presence in meteorites is unlikely to be from contamination by terrestrial life. “The meteorites we studied are from before Earth formed, over 4.5 billion years ago,” said Glavin. “We believe the same process that created extra left-handed isovaline would have created more left-handed versions of the other amino acids found in these meteorites, but the bias toward left-handed versions has been mostly erased after all this time.”

The team’s discovery validates and extends the research first reported a decade ago by Drs. John Cronin and Sandra Pizzarello of Arizona State University, who were first to discover excess isovaline in the Murchison meteorite, believed to be a piece of an asteroid. “We used a different technique to find the excess, and discovered it for the first time in the Orgueil meteorite, which belongs to another meteorite group believed to be from an extinct comet,” said Glavin.

The team also found a pattern to the excess. Different types of meteorites had different amounts of water, as determined by the clays and water-bearing minerals found in the meteorites. The team discovered meteorites with more water also had greater amounts of left-handed isovaline. “This gives us a hint that the creation of extra left-handed amino acids had something to do with alteration by water,” said Dworkin. “Since there are many ways to make extra left-handed amino acids, this discovery considerably narrows down the search.”

If the bias toward left-handedness originated in space, it makes the search for extraterrestrial life in our solar system more difficult, while also making its origin a bit more likely, according to the team. “If we find life anywhere else in our solar system, it will probably be microscopic, since microbes can survive in extreme environments,” said Dworkin. “One of the biggest problems in determining if microscopic life is truly extra-terrestrial is making sure the sample wasn’t contaminated by microbes brought from Earth. If we find the life is based on right-handed amino acids, then we know for sure it isn’t from Earth. However, if the bias toward left-handed amino acids began in space, it likely extends across the solar system, so any life we may find on Mars, for example, will also be left-handed. On the other hand, if there is a mechanism to choose handedness before life emerges, it is one less problem prebiotic chemistry has to solve before making life. If it was solved for Earth, it probably has been solved for the other places in our solar system where the recipe for life might exist, such as beneath the surface of Mars, or in potential oceans under the icy crust of Europa and Enceladus, or on Titan.”

The research was funded by the NASA Astrobiology Institute, the NASA Cosmochemistry program, and the NASA Astrobiology: Exobiology, and Evolutionary Biology program. For an image, refer to:

http://www.nasa.gov/centers/goddard/news/topstory/2009/left_hand_life.html

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   

Web Site:  http://www.nasa.gov/

December 10, 2008

James Webb Telescope news

The latest on the James Webb Telescope from NASA.

The release:

James Webb Telescope Mirrors Chill Out at NASA’s Marshall Space Flight Center

HUNSTVILLE, Ala., Dec. 10 /PRNewswire-USNewswire/ — The first of 18 mirror segments that will fly on NASA’s James Webb Space Telescope arrived this week at the Marshall Space Flight Center, Huntsville, Ala., to prepare it to meet the extreme temperatures it will encounter in space.

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The X-ray & Cryogenic Facility (XRCF) at the Marshall Center is the world’s largest X-ray telescope test facility and a unique, cryogenic, clean room optical test facility. Cryogenic testing will take place in a 7,600 cubic foot helium cooled vacuum chamber, chilling the Webb flight mirror from room temperature down to frigid -414 degrees Fahrenheit. While the mirrors change temperature, test engineers will precisely measure their structural stability to ensure they will perform as designed once they are operating in the extreme temperatures of space.

“Getting the best performance requires conditioning and testing the mirrors in the XRCF at temperatures just as cold as in space,” said Helen Cole, project manager for Webb Telescope mirror activities at XRCF. “Optical measurements of the 18 mirror segments at cold temperatures will be made and used to create mirrors that will focus crisply in space. This will allow us to see new wonders in our Universe.”

NASA’s James Webb Space Telescope is a large, infrared-optimized space telescope that will be the premier observatory of the next decade. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System. Its instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range.

The Webb Telescope will have a large mirror, 6.5 meters (21.3 feet) in diameter, made up of 18 segments about 1.5 meters (4.9 feet) in size. The telescope’s home in space will be about one million miles from Earth. The completed primary mirror will be over 2.5 times larger than the diameter of the Hubble Space Telescope’s primary mirror, which is 2.4 meters (7.8 feet) in diameter, but will weigh roughly half as much because it is made of beryllium, one of the lightest applicable metals known to man.

The amount of detail a space telescope can see is directly related to the size of the mirror area that collects light from the universe. A larger area collects more light and can see deeper into space and at a much higher resolution than a smaller mirror. That’s why the telescope’s primary mirror is made up of 18 mirror segments that form a total area of 25 square-meters (almost 30 square yards) when they all come together.

What’s unique about the large primary mirror is that each of the 18 mirrors will have the ability to be moved individually, so that they can be aligned together to act as a single large mirror. Scientists and engineers can also correct for imperfections after the telescope opens in space, or if any changes occur in the mirror during the life of the mission. Precision testing, like this test cycle in the X-ray & Cryogenic Facility, provides detailed measurements to fabricate and deliver a high resolution mirror.

“Beginning today, we kick off exclusive testing of the James Webb Space Telescope mirrors which will run though 2011. Our one-of-a-kind facility can provide the environment which allows us to optically measure infinitesimally small changes in the mirrors as they cool,” said Jeff Kegley, XRCF testing manager.

The James Webb Space Telescope is expected to launch in 2013. NASA’s Goddard Space Flight Center in Greenbelt, Md., is managing the overall development effort for the Webb telescope. The telescope is a joint project of NASA and many U.S. partners, the European Space Agency and the Canadian Space Agency.

  For related images to this story, please visit:

  http://www.nasa.gov/topics/universe/features/mirror_chill.html

  For more information about the James Webb Space Telescope, please visit:

  http://jwst.gsfc.nasa.gov/

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   
Web Site:  http://www.nasa.gov/

October 10, 2008

Extrasolar planets and dust rings

An interesting press release from NASA today:

NASA Supercomputer Shows How Dust Rings Point to Exo-Earths

GREENBELT, Md., Oct. 10 /PRNewswire-USNewswire/ — Supercomputer simulations of dusty disks around sunlike stars show that planets nearly as small as Mars can create patterns that future telescopes may be able to detect. The research points to a new avenue in the search for habitable planets.

(Logo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO )

“It may be a while before we can directly image earthlike planets around other stars but, before then, we’ll be able to detect the ornate and beautiful rings they carve in interplanetary dust,” says Christopher Stark, the study’s lead researcher at the University of Maryland, College Park.

Working with Marc Kuchner at NASA’s Goddard Space Flight Center in Greenbelt, Md., Stark modeled how 25,000 dust particles responded to the presence of a single planet — ranging from the mass of Mars to five times Earth’s — orbiting a sunlike star. Using NASA’s Thunderhead supercomputer at Goddard, the scientists ran 120 different simulations that varied the size of the dust particles and the planet’s mass and orbital distance.

“Our models use ten times as many particles as previous simulations. This allows us to study the contrast and shapes of ring structures,” Kuchner adds. From this data, the researchers mapped the density, brightness, and heat signature resulting from each set of parameters.

“It isn’t widely appreciated that planetary systems — including our own — contain lots of dust,” Stark adds. “We’re going to put that dust to work for us.”

Much of the dust in our solar system forms inward of Jupiter’s orbit, as comets crumble near the sun and asteroids of all sizes collide. The dust reflects sunlight and sometimes can be seen as a wedge-shaped sky glow — called the zodiacal light — before sunrise or after sunset.

The computer models account for the dust’s response to gravity and other forces, including the star’s light. Starlight exerts a slight drag on small particles that makes them lose orbital energy and drift closer to the star.

“The particles spiral inward and then become temporarily trapped in resonances with the planet,” Kuchner explains. A resonance occurs whenever a particle’s orbital period is a small-number ratio — such as two-thirds or five-sixths — of the planet’s.

For example, if a dust particle makes three orbits around its star every time the planet completes one, the particle repeatedly will feel an extra gravitational tug at the same point in its orbit. For a time, this extra nudge can offset the drag force from starlight and the dust can settle into subtle ring-like structures.

“The particles spiral in toward the star, get trapped in one resonance, fall out of it, spiral in some more, become trapped in another resonance, and so on,” Kuchner says. Accounting for the complex interplay of forces on tens of thousands of particles required the mathematical horsepower of a supercomputer.

Some scientists note that the presence of large amounts of dust could present an obstacle to directly imaging earthlike planets. Future space missions — such as NASA’s James Webb Space Telescope, now under construction and scheduled for launch in 2013, and the proposed Terrestrial Planet Finder — will study nearby stars with dusty disks. The models created by Stark and Kuchner give astronomers a preview of dust structures that signal the presence of otherwise hidden worlds.

“Our catalog will help others infer a planet’s mass and orbital distance, as well as the dominant particle sizes in the rings,” Stark says.

Stark and Kuchner published their results in the October 10 issue of The Astrophysical Journal. Stark has made his atlas of exo-zodiacal dust simulations available online.

  For images related to this release, please visit:

  http://www.nasa.gov/centers/goddard/news/topstory/2008/dust_rings.html

  To explore the Exozodi Simulation Catalog, please visit:

  http://asd.gsfc.nasa.gov/Christopher.Stark/catalog.php

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   

Web Site:  http://www.nasa.gov/