WASHINGTON, Oct. 15 (Xinhua) -- Hot, young planets
may be easier to spot because they stay that way longer than astronomers have
thought, according to new work by scientists at Massachusetts Institute of
Technology.
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A view of the earth's solar system is
shown on a giant screen at the all-digital planetarium at
the California Academy of Sciences building in Golden Gate Park in San
Francisco, California Sept. 18, 2008.(Xinhua/Reuters Photo) Photo Gallery>>> |
For a few million years after their initial
formation, planets like Earth may maintain a hot surface of molten rock that
would glow brightly enough to make them stand out as they orbit neighboring
stars.
MIT scientist Linda Elkins-Tanton says the "magma
ocean" stage for Earth-sized planets may last a few million years, much longer
than previously estimated. "That means we may actually see them elsewhere, as
detection systems get better," she said.
The findings were presented this week at the annual
meeting of the American Astronomical Society's Division for Planetary Sciences.
The research shows that even after the surface magma
solidifies, within about 5 million years, it could stay hot enough to glow
brightly in infrared light for tens of millions of years, providing a relatively
long window for detectability.
The big problem for astronomers hoping to detect
planets around other stars is the vast difference in brightness between the star
and the planet, which shines only by reflecting light from its parent star. But
the difference in brightness in infrared wavelengths for a glowing, molten
planetary surface would be much less, making the detection more feasible. ¡¡