Future evidence for extraterrestrial life might come from dying stars
Even dying stars could host planets with life—and if such life exists,
we might be able to detect it within the next decade. This encouraging
result comes from a new theoretical study of Earth-like planets orbiting
white dwarf stars. Researchers found that we could detect oxygen in the
atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star.
"In the quest for extraterrestrial biological signatures, the first
stars we study should be white dwarfs," said Avi Loeb, theorist at the
Harvard-Smithsonian Center for Astrophysics (CfA) and director of the
Institute for Theory and Computation. When a star like the Sun dies, it
puffs off its outer layers, leaving behind a hot core called a white
dwarf. A typical white dwarf is about the size of Earth.
It
slowly cools and fades over time, but it can retain heat long enough to
warm a nearby world for billions of years. Since a white dwarf is much
smaller and fainter than the Sun, a planet would have to be much closer
in to be habitable with liquid water on its surface. A habitable planet
would circle the white dwarf once every 10 hours at a distance of about a
million miles.
Read more at: http://bit.ly/13MAdKF
Image credit: David A. Aguilar
Future evidence for extraterrestrial life might come from dying stars
Even dying stars could host planets with life—and if such life exists, we might be able to detect it within the next decade. This encouraging result comes from a new theoretical study of Earth-like planets orbiting white dwarf stars. Researchers found that we could detect oxygen in the atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star.
"In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs," said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) and director of the Institute for Theory and Computation. When a star like the Sun dies, it puffs off its outer layers, leaving behind a hot core called a white dwarf. A typical white dwarf is about the size of Earth.
It slowly cools and fades over time, but it can retain heat long enough to warm a nearby world for billions of years. Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. A habitable planet would circle the white dwarf once every 10 hours at a distance of about a million miles.
Read more at: http://bit.ly/13MAdKF
Image credit: David A. Aguilar
Even dying stars could host planets with life—and if such life exists, we might be able to detect it within the next decade. This encouraging result comes from a new theoretical study of Earth-like planets orbiting white dwarf stars. Researchers found that we could detect oxygen in the atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star.
"In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs," said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) and director of the Institute for Theory and Computation. When a star like the Sun dies, it puffs off its outer layers, leaving behind a hot core called a white dwarf. A typical white dwarf is about the size of Earth.
It slowly cools and fades over time, but it can retain heat long enough to warm a nearby world for billions of years. Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. A habitable planet would circle the white dwarf once every 10 hours at a distance of about a million miles.
Read more at: http://bit.ly/13MAdKF
Image credit: David A. Aguilar
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