How many habitable planets are there in the galaxy?
By now you may have heard the report that as many as 1/4 of all the sun-like stars in the Milky Way may have Earth-like worlds. Briefly, astronomers studied 166 stars within 80 light years of Earth, and did a survey of the planets they found orbiting them. What they found is that about 1.5% of the stars have Jupiter-mass planets, 6% have Neptune-mass ones, and about 12% have planets from 3 – 10 times the Earth’s mass.
Buckyballs Could Be Plentiful in the Universe
Earlier this year, astronomers using the Spitzer Space Telescope announced they had found – for the first time — carbon molecules, known as “buckyballs,” in space. They were detected in one planetary nebula, and even though they were predicted to be rather prevalent out in space, no one was really sure. Until now. They’ve now been found in the space between stars, and around four more planetary nebulae, with one dying star in a nearby galaxy holding a staggering quantity of buckyballs — the equivalent mass of 15 times that of Earth’s Moon.
62 Miles Beneath the Sea! Deepest Ocean in the Solar System Discovered on Jupiter’s Europa
The deepest ocean on Earth is the Pacific Ocean’s Marianas Trench, which reaches a depth of 6.8 miles awesomely trumped by the depth of the ocean on the Jupiter’s moon, Europa, which some measurements put at 62 miles. That’s deep! Although Europa is covered in a thick crust of scarred and cross-hatched ice, measurements made by NASA’s Galileo spacecraft and other probes strongly suggest that a liquid ocean lies beneath that surface. The interior is warmed, researchers believe, by the tidal stresses exerted on Europa by Jupiter and several other large moons, as well as by radioactivity.
Astronomers study the sound of stars
A comprehensive study of the vibrations – or ‘starquakes’ – of thousands of distant stars is giving astronomers new insight into how stars work. A team of scientists from Australia, Europe and the US, this week presents the results of a study using NASA’s space-based Kepler telescope which looks in detail at the way stars vibrate. The Kepler mission has “revolutionised” the study of star interiors, according to lead author on one of the studies, graduate student Daniel Huber from the University of Sydney. “It’s like playing in a giant sandbox – there is so much more data than we had even four to five years ago,” he told Australian Geographic.
25% of Sun-Like Stars Could Host Earth-Sized Worlds
A five-year survey of nearby solar-mass stars has provided astronomers with an estimate of how many stars of this type could have Earth-size planets. Andrew Howard and Geoffrey Marcy from the University of California Berkeley studied 166 G and K stars within 80 light-years of Earth, determining the number, mass and orbital distance of any of the stars’ planets. Since Earth-sized worlds have not yet been found, they extrapolated the number of that size of planets, based on the fraction of stars that host Neptune to super-Earth sized planets. Their findings are encouraging, since it means planets the size of Neptune and smaller are probably much more common than gas-giant planets, like Jupiter. But what they found also conflict with current models of planet formation and migration.
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