Well, of course there is.... Though I think "mollusc" is probably even more insulting to the guy than "pointy-eared half-breed."
Posted on 10/31/2002 9:23:26 AM PST by RightWhale
Astronomers Find Life on Earth
PRESS RELEASE
Harvard-Smithsonian Center for Astrophysics
Wednesday, October 30, 2002
Cambridge, MA -- Now that the discovery of extrasolar planets, or planets around distant stars, has become relatively routine, scientists are now tackling the next step: finding life-bearing worlds. To do this, observers must know what signs to look for in the feeble light from these faraway planets.
Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA), in collaboration with researchers at the University of Arizona's Steward Observatory, have identified key signatures of life by studying Earthshine-the light of the Earth reflected off the dark side of the Moon. They found clear signs of water and an oxygen atmosphere, as well as tentative signs of plant life. Their findings give a clear indication of what "fingerprints" to search for when seeking life on Earth-like worlds orbiting distant stars.
"Our research is paving the way for future missions like the Terrestrial Planet Finder," says Smithsonian astronomer Wes Traub. "Hopefully, within the next 10 years astronomers will be able to confidently say that some as-yet-undiscovered planet is a living world like our own."
Archetypal Earth
So far, astronomers can only detect Jupiter-like planets around other stars because such planets are large and create strong gravitational signals. However, as technology continues to improve, astronomers soon will be able to locate Earth-like extrasolar planets and study their dim light to search for signs of life. To know what to look for, they must use the example of the one planet where life is known to exist: the Earth.
To replicate the view that a distant astronomer would have if studying the Earth from another planet, Traub and his colleagues used the nearby Moon as a mirror. Using the Steward Observatory 90-inch telescope at Kitt Peak, Arizona, they measured both the light of Earthshine from the Moon and the light of the Moon itself, then corrected the Earthshine to determine how the Earth would appear to a faraway observer. They compared this measured spectrum to a model created by Traub and CfA's Ken Jucks.
The team found that Earthlight shows strong evidence for water- a necessary ingredient for life as we know it- and for molecular oxygen, which must be continually replenished by the processes of life to remain in the atmosphere. They also found features that suggested the presence of chlorophyll, indicating the existence of land plants.
The latter showed up as bright reflections in the far-red region of the visible spectrum. This "red edge" is a well-known signature of chlorophyll, which appears green to us only because our eyes aren't very sensitive at the red end of the visible spectrum.
The team also suggests that changes for finding life-bearing worlds are improved because the signatures can develop early in a planet's history and last for a long time. Our home planet has maintained an oxygen atmosphere for the past two billion years, and has shown a "red edge" since the first land plants evolved 500 million years ago.
"If someone out there is watching our solar system," Traub points out, "they could have detected plant life here long before any intelligent life appeared."
Findings Match Galileo
These measurements complement those made by the Galileo spacecraft during a 1990 fly-by of Earth. As reported in the October 21, 1993 issue of Nature, instruments aboard the spacecraft also found evidence of gaseous oxygen and land plants.
However, the Galileo measurements were made while it was close to the Earth and show conditions only in limited areas of the planet's surface. Studying Earthlight, on the other hand, yields a spectrum integrated over the entire visible surface of the planet, which matches the view that would be available to a distant astronomer in another star system.
The measurements by Traub and his colleagues, reported in the July 20, 2002 issue of The Astrophysical Journal, were taken over two nights. The astronomers suggest that follow-up studies be conducted over a longer period of time to see how Earthlight changes as different areas of the planet rotate into view, and as cloud cover changes.
I'm reminded of the blind men who encountered the elephant. The man holding the tail, thought the elephant was like a rope. The man who bumped into the side thought an elephant was like a wall. The man holding the trunk thought an elephant was like a snake.
If you look only for the stuff you already know, you run the risk of not learning new things. But, as I said, you have to start somewhere.
It's becoming a large program at NASA, not compared to the International Space Station, the OWE, but significantly big bucks for science projects.
This is true of the magnesium centered porphyrin, chlorophyll, that we know on most of the Earth. Interestingly, if an iron atom is swapped for the Mg, then we have hemoglobin, so this is an important molecule for _our_ biosystem.
However,some seaweeds have a manganese analog that serves them just fine, and its IR spectral properties are different. (Playing with Infrared Ektachrome along the shore is more educational than simply using it to penetrate Orlon bathing suits!)
So just because we understand Life to use Mg.chlorophyll does not mean other life does. The organisms that live near black smoker discharges in the deep do well enough with a sulfur redox chemistry.
That ruined their future. Their brains are more advanced,
and have more lobes than ours BTW, and their eyes...
just forget it ... but they lost because they use copper
and it is generally not available beyond the shore's edge.
BUMP FOR HEMOGLOBIN. (at least the ferrous form. ;-)X
The man holding the gonads thought an elephant was like identical democRAT twins!
D'ya figure that proves there's intelligent life on earth? ;-))
Horseshoe crabs. They are really primitive. I do not know what the oxygen transport mechanism or compound is, but I believe it is BLUE!
So we cannot look for Life based on a few critical compounds, because even here, there are so many exceptions.
Quite right. If such a characteristic spectrum is found it is bonus time.
Well, of course there is.... Though I think "mollusc" is probably even more insulting to the guy than "pointy-eared half-breed."
IMO, conscious beings exist in a million or more locations elsewhere in the Universe.
In our 14 billion year old Universe many of those civilizations would be millions of years more advanced in their technologies than conscious beings on Earth have achieved in a few thousand years. Curing conscious death by achieving biologic immortality in prime health is the norm. The nature of conscious beings free of mysticism, irrationality, dishonesty and criminality is to preserve the most valuable entity in the Universe: the conscious being -- the one entity that can alter nature's course.
On Earth, man has altered nature in many ways -- the Hover dam that created Lake Meade from the Colorado River and CPU made from silicon and copper are but two examples from a very long list. Conscious beings with million year advanced technologies may be altering nature's course of solar systems, black holes, galaxies and our Universe.
Chapter 6, A Cosmology of Infinite Riches
| This chapter is going to take you on a journey. A journey into realms you never knew existed. By the time you finish this journey, your thinking will change about you, this world, the universe, the future. That metamorphosis will occur on putting together 25 pieces of a puzzle. ...When the last piece snaps into place, your thinking will change forever. More specifically, after reading this 25-part chapter, an array of new concepts will jell into a matrix on the final page. That matrix will eventually end all mysticism and deliver endless riches to this world. |
No, it's completely expected. Such man-made objects are below the limits of resolution for the optical systems under discussion.
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