+ - First Earth-Size Exoplanet Already Found?->
New Scientist is reporting the extrasolar planet MOA-2007-BLG-192Lb — whose discovery was announced just last summer — may actually be the first truly Earth-sized exoplanet to be identified.
According to New Scientist, a new analysis suggests the planet weighs less than half the original estimate of 3.3 Earth masses. The new estimate — which scientists hope to confirm with more observations in the near future — peg the planet's size at 1.4 Earth masses.
The new estimate is the result of recent observations suggesting the planet's host star is more massive than originally thought, meaning the planet must be smaller than scientists originally estimated. Astronomers first thought the host star was a tiny brown dwarf , but now realize it is actually a red dwarf.
The planet orbits a small red dwarf star some 3,000 light-years distant and orbits its host star at a distance of 0.62 astronomical units (an astronomical unit is the distance from the Earth to the Sun, or about 93 million miles) — about the same distance as Venus from our Sun. One significance of the planet's discovery is that it points to the probable ubiquity of smaller terrestrial planets in somewhat Earth-like orbits — at least when it comes to red dwarf stars, the oldest and most numerous stars in the galaxy. Scientists don't think MOA-2007-BLG-192Lb is likely to harbor life but concede it may be habitable due to a probably thick atmosphere and possible oceans.
Astronomers first discovered the planet using a technique called gravitational microlensing, a technique that may be sensitive enough to detect planets with masses one-tenth that of Earth.
You can view a video report from the discoverers here.
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First Earth-Size Exoplanet Already Found? More Login
First Earth-Size Exoplanet Already Found?