28 June 2008

45 New Planets! Phoenix confirms water on Mars and Genetic Material on Meteorite!

Researchers discover forty five new planets.
USA Today (6/17, Vergano) reports, "Nearby stars probably abound with planets only slightly larger than our own," according to researchers from of Switzerland's University of Geneva Observatory, which "reported the discovery of 45 of these 'super-Earth" planets" through two studies. However, "[a]ll of the planets, including a solar system of three super-Earths reported by team leader Michel Mayor of Switzerland's University of Geneva Observatory, orbit too close to their stars to harbor life." Still, said Mayor, "what is exciting is that we can say about one-third of stars have these kind of low-mass planets."
The New York Times (6/17, Overbye) notes that, according to Mayor, "[t]heories of planet formation...hold that smaller planets like super-Earths and Neptunes should be numerous." And, some astronomers say, "the new results indicated that when their instruments got sensitive enough to detect even smaller planets, such planets would be there to be found." The Times noted that "Dr. Mayor and his team discovered the first so-called exoplanet orbiting a regular star, known as Pegasi 51, in 1995." Since that time, "some 270 exoplanets have been discovered, many of them like the original, so-called hot Jupiters in lethal scorching embraces of their stars."

The AFP (6/17) adds, "The recent batch of exoplanets were all spotted with the High-Accuracy Radial-Velocity Planet Searcher (HARPS), a 3.6-meter telescope and spectograph perched atop La Scilla mountain at the southern edge of Chile's Atacama Desert." The instrument "has uncovered 45 super-Earths since it began operation in 2004."
Reuters (6/17, Fox) points out that none of the planets "can be imaged directly at such distances but can be spotted indirectly using radio waves or, in the case of HARPS, spectrographic measurements. As a planet orbits, it makes the star wobble very slightly and this can be measured." Stephane Udry, a contributing researcher, said, "With the advent of much more precise instruments such as the HARPS spectrograph...we can now discover smaller planets, with masses between 2 and 10 times the Earth's mass." The AP (6/17, Borenstein), Space.com (6/16, Bryner), National Geographic (6/16, Minard), the BBC (6/17) and the Tech Herald (6/17, Bowden) also report the story.

Earth-size planets give some researchers hope for finding alien life.
On the front page of its Science Times section, the New York Times (6/24, F1, Angier) continues reporting on the Geneva Observatory's recent finding "that many Sun-size stars in our galaxy are girdled with Earth-size planets." Although the 45 planets discovered are likely too close to their stars to harbor life, "researchers are confident that other rocky planets remain to be found at Earthier distances from their suns." Planetary theorist Sara Seager noted, "As soon as astronomers started looking for low-mass planets, they found a whole bunch, and that's a real breakthrough." As a result, some researchers "suspect that life abounds" in the universe, "at least of the microbial kind." The Times notes that "astronomers have high hopes for the Kepler spacecraft to be launched in February." The spacecraft will search "for 'tiny drops in brightness,' possible signs of a planet transiting across [a] distant Sun's face," focusing on "100,000 stars for four years." With this information, scientists "can pick out the places most worthy of follow-up probes."

Astronomers on verge of finding Earth's twin
Planet hunters say doppelgänger is almost surely hiding in our galaxy

Planet hunters say it's just a matter of time before they lasso Earth's twin, which almost surely is hiding somewhere in our star-studded galaxy.
Momentum is building: Just last week, astronomers announced they had discovered three super-Earths — worlds more massive than ours but small enough to most likely be rocky — orbiting a single star. And dozens of other worlds suspected of having masses in that same range were found around other stars.
"Being able to find three Earth-mass planets around a single star really makes the point that not only may many stars have one Earth, but they may very well have a couple of Earths," said Alan Boss, a planet formation theorist at the Carnegie Institution of Washington in Washington, D.C.

Since the early 1990s, when the first planets outside of our solar system were detected orbiting the pulsar PSR 1257, astronomers have identified nearly 300 such worlds. However, most of them are gas giants called hot Jupiters that orbit close to their stars because, simply, they are easier to find.
"So far we've found Jupiters and Saturns, and now our technology is becoming good enough to detect planets smaller, more like the size of Uranus and Neptune, and even smaller," said one of the top planet hunters on this world, Geoff Marcy of the University of California, Berkeley....With upgrades in spectrometers and digital cameras attached to telescopes, astronomers' eyes have become more sensitive to relatively tiny stellar wobbles (measured by changes in certain wavelengths of light) and dips in starlight from ever smaller planets.
The discovery of super-Earths announced last week reflects this technological leap. ...The ultimate goal of planet-hunting projects is to find Earth twins.
"We are looking for twins of the Earth, analogs that walk and talk and smell like our own Earth," Marcy said during a telephone interview. He is currently looking for super-Earths using the W.M. Keck Observatory in Hawaii. ..."I suspect there are Earth-like planets with lakes and rivers and waterfalls and deep glacial gorges and that are spectacularly beautiful," Marcy said.
Finding a planet ...The James Webb Space Telescope (JWST), scheduled for launch in 2013, could do just that. ...But first things first. "There's no doubt that other Earths exist, simply due to the sheer vast numbers of other stars and galaxies in our universe," Marcy said. "There's a deeper question — how common are Earth-like planets? Are Earth-like planets a dime a dozen, or are they quite rare, quirky precious planets that are one in a thousand or one in a million?"

NASA Phoenix Lander finds Water Ice! (From NSS Downlink)

Scientists have confirmed that the substance from just beneath the surface of Mars, dug up by the Phoenix lander, is water ice. This find has scientists excited about other big discoveries that are possible in the upcoming weeks.Phoenix has the capability to analyze the soil and ice to see whether Mars has ever been accommodating for microbial life. Project scientists will look for evidence of water in liquid form and organic compounds that could have provided chemical building blocks and energy for life.

PARIS (AFP) - Genetic material from outer space found in a meteorite in Australia may well have played a key role in the origin of life on Earth, according to a study to be published Sunday.

European and US scientists have proved for the first time that two bits of genetic coding, called nucleobases, contained in the meteor fragment, are truly extraterrestrial. Previous studies had suggested that the space rocks, which hit Earth some 40 years ago, might have been contaminated upon impact. Both of the molecules identified, uracil and xanthine, "are present in our DNA and RNA," said lead author Zita Martins, a researcher at Imperial College London. RNA, or ribonucleic acid, is another key part of the genetic coding that makes up our bodies. These molecules would also have been essential to the still-mysterious alchemy that somehow gave rise, some four billion years ago, to life itself. "We know that meteorites very similar to the Murchison meteorite, which is the one we analysed, were delivering the building blocks of life to Earth 3.8 to 4.5 billion years ago," Martins told AFP in an interview. Competing theories suggest that nucleobases were synthesised closer to home, but Martins counters that the atmospheric conditions of early Earth would have rendered that process difficult or impossible. A team of European and US scientists showed that the two types of molecules in the Australian meteorite contained a heavy form of carbon -- carbon 13 -- which could only have been formed in space. "We believe early life may have adopted nucleobases from meteoric fragments for use in genetic coding, enabling them to pass on their successful features to subsequent generations," Martins said. If so, this would have been the start of an evolutionary process leading over billions of years to all the flora and fauna -- including human beings -- in existence today. The study, published in Earth Planetary Science Letters, also has implications for life on other planets. "Because meteorities represent leftover materials from the formation of the solar system, the key components of life -- including nucleobases -- could be widespread in the cosmos," said co-author Mark Sephton, also at Imperial College London. "As more and more of life's raw materials are discovered in objects from space, the possibility of life springing forth wherever the right chemistry is present becomes more likely," he said. Uracil is an organic compound found in RNA, where it binds in a genetic base pair with another molecule, adenine. Xanthine is not directly part of RNA or DNA, but participates in a series of chemical reactions inside the RNA of cells. The two types of nucleobases and the ratio of light-to-heavy carbon molecules were identified through gas chromatography and mass spectrometry, technologies that were not available during earlier analyses of the now-famous meteorite. Even so, said Martins, the process was extremely laborious and time-consuming, one reason it had not be carried out up to now by other scientists.

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