Jef's web files - Space

NASA's Griffin: 'Humans Will Colonize the Solar System'

Sun, 25 Sep 2005 16:42:40 -0400

NASA Administrator Michael D. Griffin met last week with reporters and editors at The Post. Here are some of the questions and answers:

What can humans learn in space that robots couldn't?

The thing that you can learn with humans in scientific enterprises are all of the things that you didn't send the robot to find out. With a human you're doing the opportunistic plan, the uncorrelated observation. You know, you see this over here and that over there, and you put them together.

When you know what question you want to ask and what measurement you want to make, it's almost always to your advantage to do that robotically or, at most, use the human to put the thing in place. There's no question about it. When you don't know what you don't know, when you don't know what the questions are, we do very poorly at attempting to figure out what those questions ought to be by using robots.

Astronomers find star-less galaxy

Thu, 24 Feb 2005 11:00:44 -0500

Astronomers have discovered an object that appears to be an invisible galaxy made almost entirely of dark matter.

The team, led by Cardiff University, UK, claims it is the first such object to be detected.

A dark galaxy is an area in the Universe containing a large amount of mass that rotates like a galaxy, but contains no stars.

It was found 50 million light-years away using radio telescopes in England and Puerto Rico.

Murchison meteorite

Wed, 23 Feb 2005 12:15:52 -0500

On September 28, 1969 fragments of a meteorite fell in and around the small town of Murchison, Victoria, about 100km north of Melbourne, Australia. The meteorite was found to contain a wide variety of organic compounds, including many of biological relevance such as amino acids.

Earth-like planets may be more rare than thought

Mon, 02 Aug 2004 12:38:17 -0400

We could be alone in the Universe after all. The discovery during the past decade of over a hundred planets around other stars has encouraged many scientists to think that habitable planets like ours might be common. But a recent study tells them to think again.

Martin Beer of the University of Leicester, UK, and co-workers argue that our Solar System may be highly unusual, compared with the planetary systems of other stars. In a preprint published on Arxiv1, they point out that the alien planets we have seen so far could have been formed by a completely different process from the one that formed ours. If that is so, says Beer, "there won't necessarily be lots of other Earths up there".

Life In The Universe Could Be Just About Everywhere

Fri, 07 May 2004 00:28:41 -0400

The chemistry that underlies life on Earth is abundant throughout the universe -- in comets, in the interstellar medium, in the atmospheres of planets, in the outer solar system bodies and in living organisms, an astrophysicist told United Press International.

"If these are made everywhere, perhaps life is everywhere," said Emma Bakes, a principal investigator with NASA's Ames Research Center in California and with the SETI Institute. SETI stands for the Search for Extra-Terrestrial Intelligence.

"You have the chemical foundation spread throughout the entire galaxy," she said. "We're not special. I would bet -- if I had a million dollars -- I would bet that life is widespread across the universe."

Ray burst may have wiped out life on Earth

Sun, 02 May 2004 11:25:32 -0400

A massive gamma-ray burst could have helped destroy much of life on Earth 440 million years ago, say a team of U.S. scientists.

Professor Adrian Melott of the University of Kansas and team argued their case in a paper accepted for publication in the International Journal of Astrobiology.

Asteroid protection plan proposed

Thu, 08 Apr 2004 14:46:03 -0400

They are out there, ready to smack into the Earth and wipe out human civilization, but astronomers said on Wednesday they are well on their way to finding every asteroid that poses a threat.

The next task will be to look for smaller objects that might just destroy, say, a city, the experts told the U.S. Senate's Subcommittee on Science, Technology and Space.

In an update on the Near Earth Object Observation Program, experts told the Senate subcommittee that they are on schedule to finding everything bigger than 1 kilometer in diameter that might approach the planet.

"The survey officially started in 1998 and to date more than 700 objects of an estimated population of about 1,100 have been discovered, so the effort is now believed to be over 70 percent complete and well on the way to meeting its objective by 2008," NASA's Lindley Johnson told the hearing.

Earth Impact Effects Program

Thu, 08 Apr 2004 10:31:03 -0400

Next time an asteroid or comet is on a collision course with Earth you can go to a web site to find out if you have time to finish lunch or need to jump in the car and DRIVE.

University of Arizona scientists are launching an easy-to-use, web-based program that tells you how the collision will affect your spot on the globe by calculating several environmental consequences of its impact.

Ancient Supernova May Have Caused Eco-Catastrophe

Thu, 08 Apr 2004 10:16:13 -0400

An exploding star may have destroyed part of Earth's protective ozone layer two million years ago, devastating some forms of ancient marine life, according to a new theory presented at this week's meeting of the American Astronomical Society.

The new theory brings together puzzling clues from several different fields of research, including paleontology, geology, and astronomy.

Narciso Benitez, an associate research scientist in astronomy at Johns Hopkins University, said the "missing smoking gun" that brought the clues together was the revelation that a stellar cluster with many large, short-lived stars prone to producing supernovae had passed near Earth's solar system several million years ago.

Astronomers Take Search For Earth-Threatening Space Rocks To Southern Skies

Thu, 08 Apr 2004 10:34:17 -0400

The hunt for space rocks on a collision course with Earth has so far been pretty much limited to the Northern Hemisphere. But last week astronomers took the search for Earth-threatening asteroids to southern skies.

Astronomers using a refurbished telescope at the Australian National University's Siding Spring Observatory discovered their first two near-Earth asteroids (NEAs) on March 29. NEAs are asteroids that pass near the Earth and may pose a threat of collision.

Shooting Stars: U.S. Military Takes First Step Towards Weapons in Space

Mon, 05 Apr 2004 11:07:05 -0400

For all of human history, people have looked at the stars with a sense of wonder. More recently, some U.S. military planners have looked skyward and seen something very different — the next battlefield.

While the military's presence in space stretches back decades, now there appears to be a new emphasis. Officials in the Bush administration and the Department of Defense are actively pursuing an agenda calling for the unprecedented weaponization of space.

The first real step in that direction appears to be coming in the form of a little-noticed weapons program at the U.S. Missile Defense Agency. The agency has now earmarked $68 million in 2005 for something called the Near Field Infrared Experiment.

The NFIRE satellite is primarily designed to gather data on exhaust plumes from rockets launched from earth, and defense officials claim it is therefore designed as a defensive, rather than offensive weapons.

But the satellite will also contain a smaller "kill vehicle," a projectile that takes advantage of the kinetic energy of objects traveling through low-Earth orbit (which move at several times the speed of a bullet) to disable or destroy an oncoming missile or another orbiting satellite.

Age of the Moon

Sun, 14 Mar 2004 12:19:13 -0500

Lee et al (Science 1997 278:1098) report a study of the age and
origin of the Moon with the hafnium-tungsten chronometric method.
The tungsten isotopic compositions of 21 lunar samples were found
to range from chondritic to slightly radiogenic. The authors
suggest this heterogeneity is probably the result of late
radioactive decay within the Moon itself, and that the Moon
formed 4.52 to 4.50 billion years ago and its mantle has since
remained poorly mixed.

Astronomers Unravel A Mystery From The Dark Ages

Thu, 08 Apr 2004 10:36:43 -0400

Scientists at Cardiff University, UK, believe they have discovered the cause of crop failures and summer frosts some 1,500 years ago – a comet colliding with Earth. The team has been studying evidence from tree rings, which suggests that the Earth underwent a series of very cold summers around 536-540 AD, indicating an effect rather like a nuclear winter.

The scientists in the School of Physics and Astronomy believe this was caused by a comet hitting the earth and exploding in the upper atmosphere. The debris from this giant explosion was such that it enveloped the earth in soot and ash, blocking out the sunlight and causing the very cold weather.

U.S. Eyes Space as Possible Battleground

Wed, 21 Jan 2004 10:00:24 -0500

President Bush's plan to expand the exploration of space parallels U.S. efforts to control the heavens for military, economic and strategic gain.

Defense Secretary Donald Rumsfeld long has pushed for technology that could be used to attack or defend orbiting satellites as well as a costly program, heavily reliant on space-based sensors, to thwart incoming warheads.

One tenth of stars may support life

Fri, 02 Jan 2004 15:39:12 -0500

One tenth of the stars in our galaxy might provide the right conditions to support complex life, according to a new analysis by Australian researchers. And most of these stars are on average one billion years older than the Sun, allowing much more time, in theory, for any life to evolve.

The concept of a "galactic habitable zone" (GHZ) for the Milky Way was first proposed in 2001. Now Charles Lineweaver of the University of New South Wales and colleagues have defined a life-friendly GHZ using a detailed model of the evolution of the Milky Way to map the distribution in space and time of four major factors thought essential for complex life.