I am a mariner of Odysseus with heart of fire but with mind ruthless and clear

Chile’s Great Observatories are Searching for Earth’s Twin

In astronomy, extraterrestrial on March 2, 2010 at 10:44 am

Among the international astronomical observatories in Chile is the Gemini Observatory (South) at 2,700 meters (8,858 ft) elevation on Cerro Pachón (a mountain in the Chilean Andes) and the European Southern Observatory’s (ESO) Very Large Telescope (VLT) on Cerro Paranal, a 2,635 meter (8,645 ft) high mountain in the Atacama desert.

Gemini South is approximately 800 km (500 miles) north of the epicenter and the VLT is approximately 1,370 km (850 miles) north of the epicenter. Undoubtedly both locations would have experienced some seismic activity.

But as you would expect Chile’s observatories such as the VLT have some novel anti-earthquake safety measures in place, with the entire telescope is designed to swing during an earthquake, and securing the primary mirror prevents it from rattling against the metal tubes that surround it.

European astronomers based here recently discovered the smallest planet yet found orbiting another star. The discovery suggests that the Milky Way is full of small-mass planets and that with more time and improved instruments like NASA’s recently launched Kepler satellite, they would eventually find Earth-like planets in orbits suitable for life around other stars.

The newly found planet could be as little as only 1.9 times as massive as the Earth and belongs to a dim red star known as Gliese 581, which lies about 20 light-years from Earth in the constellation Libra.

“The holy grail of current exoplanet research is the detection of a rocky, Earth-like planet in the ‘habitable zone’ — a region around the host star with the right conditions for water to be liquid on a planet’s surface”, says Michel Mayor from the Geneva Observatory, who led the European team to this stunning breakthrough.

The Swiss, French and Portuguese astronomers manning the ESO’s La Silla 3.6m telescope were responsible for the original discovery of Gliese 581c, an exo-planet that revolves around Gliese 581. It is older than our solar system and its year lasts only 13 days, since it is 14 times closer to its star than the Earth is to the our Sun.  Astronomers also say—based on initial high-tech models and density-mass calculations—this quasi-Earth’s surface is either rocky or ocean-covered—both Earth-like geographical qualities.

ESO is the intergovernmental European Organization for Astronomical Research in the Southern Hemisphere. On behalf of its thirteen member states ESO operates a suite of the world’s most advanced ground-based astronomical telescopes located at the La Silla Paranal Observatory in the Atacama.

Planet Gliese 581 e orbits its host star – located only 20.5 light-years away in the constellation Libra  — in just 3.15 days. “With only 1.9 Earth-masses, it is the least massive exoplanet ever detected and is, very likely, a rocky planet”, says co-author Xavier Bonfils from Grenoble Observatory.

From previous observations — also obtained with the HARPS spectrograph at ESO’s La Silla Observatory -a suite of the world’s most advanced ground-based astronomical telescopes-  this star was known to harbor a system with a Neptune-sized planet b and two super-Earths. With the discovery of Gliese 581 e, the planetary system now has four known planets, with masses of about 1.9 (planet e), 16 (planet b), 5 (planet c), and 7 Earth-masses (planet d).

The planet farthest out, Gliese 581 d, orbits its host star in 66.8 days. “Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to the star,” says team member Stephane Udry. The new observations have revealed that this planet is in the habitable zone, where liquid water could exist. “‘d’ could even be covered by a large and deep ocean — it is the first serious ‘water world’ candidate,” continued Udry

“It is amazing to see how far we have come since we discovered the first exoplanet around a normal star in 1995 — the one around 51 Pegasi,” says Mayor. “The mass of Gliese 581 e is 80 times less than that of 51 Pegasi b. This is tremendous progress in just 14 years.”

The astronomers are confident that they can still do better. “With similar observing conditions an Earth-like planet located in the middle of the habitable zone of a red dwarf star could be detectable,” says Bonfils. “The hunt continues.”

La Silla is located in the epicenter of the Atacama Desert’s 5000 meter-high plateau of Chajnantor. Nearby, the European Southern Observatory’s  ALMA (Atacama Large Millimeter/submillimeter Array) Observatory project is under construction -a giant, international observatory composed initially of 66 high-precision telescopes, operating at wavelengths of 0.3 to 9.6 mm.

Alma_2 The ALMA antennas will be electronically combined and provide astronomical observations which are equivalent to a single large telescope of tremendous size and resolution, able to probe the Universe at millimeter and sub-millimeter wavelengths with unprecedented sensitivity and resolution, with an accuracy up to ten times better than the Hubble Space Telescope.

ALMA will be the forefront instrument for studying the cool universe – the relic radiation of the Big Bang, and the molecular gas and dust that constitute the very building blocks of stars, planetary systems, galaxies, and life itself.

In the meantime, odds are good that twin Earths with lukewarm temperatures will likely be discovered by the ESO team earthquke hazards notwithstanding..

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