An Evaporating Exoplanet?

(Artist rendering of an exoplanet atmosphere “evaporating” near its host star.  Credit: ESA / Alfred Vidal-Madjar, Institut d’Astrophysique de Paris, CNRS, France)

“There’s something strange obscuring the light from a cool, low-mass star observed by NASA’s Kepler mission. Every 15.685 Earth days, KIC 12557548’s light dims for about 1.5 hours. The dips in starlight aren’t always the same — some events block more light than others — so the occultations don’t look like the regular blip caused by a planet passing in front of the star. After considering various options, an international team of astronomers reported recently that the signal might be from debris thrown off by a small rocky planet as it disintegrates under the star’s glare.”

“Astronomers found what looks like an evaporating gas giant in 2003, but if real KIC 12557548’s world would be the first solid exoplanet seen dematerializing.”

“Spectral observations may be able to determine if the planet and its tail are there and what the tail is made of. The astronomers put their bet on pyroxene, a silicate mineral found in Earth’s crust and mantle (and in meteorites) that should survive close proximity to KIC 12557548 long enough to block starlight before the grains vaporize.”

We’re getting close to making firm detections of Earth-like exoplanets, not only in terms of size, density, and other physical properties, but in their compositions.  Astronomers are still novices in the business of understanding exoplanets’ detailed characteristics, and are not entirely sure what variety of possible planets exists.  The detection of silicate minerals around an exoplanet host star would lend support to the idea that some of these extraterrestrial worlds are of a rather similar composition to our own home.  The closer we come to finding planets like our own, the closer we may be to answering the ultimate question: do any of them harbor life? -JCB

Spectacular Photos of Monster Saturn Storm Snapped by NASA Spacecraft

(This false-color mosaic from NASA’s Cassini spacecraft shows the tail of Saturn’s huge northern storm.  CREDIT: NASA/JPL-Caltech/Space Science Institute )

“A NASA spacecraft has chronicled the birth, evolution and death of the biggest storm to hit Saturn in two decades.”

“The monster storm on Saturn emerged in the ringed planet’s northern hemisphere on Dec. 5, 2010. It started out as a tiny spot but grew rapidly, completely encircling the planet by late January 2011. It eventually extended about 9,000 miles (15,000 kilometers) from north to south before sputtering out in late June.”

“The storm’s 200-day active period makes it the longest-lived planet-encircling tempest ever observed on Saturn, researchers said. And NASA’s unmanned Cassini probe watched everything unfold, snapping pictures all the while.”

discoverynews: Titan’s Hazy History and the Potential for Life Saturn’s moon Titan is the only moon in our solar system known to possess an atmosphere of any significance. Ten times thicker than Earth’s, Titan’s atmosphere extends nearly 370 miles (600 km) above its frigid surface. It’s a literal chemical factory, where nitrogen and methane are zapped by the sun’s ultraviolet rays and transformed into organic molecules, some of which descend to the moon’s surface while others rise up above the clouds, creating a bluish high-level haze of hydrocarbons. Titan’s atmosphere forms an opaque orange shroud that covers it and hides many of its surface features from view, keeping much of its details a mystery until the arrival of the Cassini-Huygens spacecraft in 2004. Read more
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discoverynews:

Titan’s Hazy History and the Potential for Life

Saturn’s moon Titan is the only moon in our solar system known to possess an atmosphere of any significance.

Ten times thicker than Earth’s, Titan’s atmosphere extends nearly 370 miles (600 km) above its frigid surface. It’s a literal chemical factory, where nitrogen and methane are zapped by the sun’s ultraviolet rays and transformed into organic molecules, some of which descend to the moon’s surface while others rise up above the clouds, creating a bluish high-level haze of hydrocarbons.

Titan’s atmosphere forms an opaque orange shroud that covers it and hides many of its surface features from view, keeping much of its details a mystery until the arrival of the Cassini-Huygens spacecraft in 2004.

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A ‘Cometary Planet’ From nasa.gov: “Astronomers using NASA’s Hubble Space Telescope have confirmed the existence of a baked object that could be called a ‘cometary planet.’ Named HD 209458b, the gas giant is orbiting so close to its star that its heated atmosphere is escaping into space. Observations suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched body and shaping it into a comet-like tail. HD 209458b is located 153 light-years from Earth.” (image credit: NASA/ESA)
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A ‘Cometary Planet’

From nasa.gov: “Astronomers using NASA’s Hubble Space Telescope have confirmed the existence of a baked object that could be called a ‘cometary planet.’ Named HD 209458b, the gas giant is orbiting so close to its star that its heated atmosphere is escaping into space. Observations suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched body and shaping it into a comet-like tail. HD 209458b is located 153 light-years from Earth.” (image credit: NASA/ESA)