Jupiter, long known for its high radiation and spectacular atmospheric storms, is still a relatively cool planet compared with similar-sized worlds
astronomers have spotted. But not forever. In several billion years, our sun, entering its so-called red giant phase (artist's impression above), will
expand to roughly 100 times its present size, shrinking its distance from Jupiter from 765 million to roughly 500 million kilometers and causing the giant planet to glow like "faint red coils" on a hot electric stove. That's according to a new
study to be published in the 10 September issue of The Astrophysical Journal. Once the sun exhausts its hydrogen fuel, its outward expansion will heat Jupiter's surface beyond 1000 K, not unlike the plethora of "hot Jupiters" elsewhere in the galaxy known to
circle their own sunlike stars on orbits of sometimes only a few hours. As for our own fate in all of this? If the sun does expand to 100 times its present
size, and Earth stays in its current orbit, the sun would easily overtake it. That's a point not lost on the paper's lead author David Spiegel, an
astrophysicist at the Institute for Advanced Study in Princeton, New Jersey: "My best guess is that Earth will be swallowed and Jupiter will not."
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