Re-thinking an Alien World

Forty light years as of Earth, a rocky world name "55 Cancri e" circles dangerously close to a stellar inferno.  Implementation one orbit in only 18 hours, the alien planet is 26 times closer to its close relative star than Mercury is to the Sun. If soil were in the same position, the soil beneath our feet would heat up to about 3200 F.  Researchers have extended thought that 55 Cancri e must be a wasteland of dry rock.

Now they’re thoughts again.  New comments by NASA's Spitzer Space Telescope suggest that 55 Cancri e may be wetter and weirder than anyone imagined.

Spitzer recently deliberates the extremely small amount of light 55 Cancri e blocks when it crosses in front of its star. These transits occur every 18 hours, giving researchers repeated opportunity to gather the data they need to approximation the width, quantity and density of the planet.

According to the new observations, 55 Cancri e has a mass 7.8 times and a radius just over twice that of Earth. Those property place 55 Cancri e in the "super-Earth" class of exoplanets, a few dozen of which have been found. Only a handful of known super-Earths, on the other hand, cross the face of their stars as view from our vantage point in the cosmos, so 55 Cancri e is better understood than most.

When 55 Cancri e was discovered in 2004, initial estimate of its size and mass were consistent with a dense planet of solid rock.  Spitzer data suggest otherwise: About a fifth of the planet's mass must be made of light rudiments and compounds--including water. Given the intense heat and high pressure these materials likely experience, researchers think the compounds likely exist in a "supercritical" fluid state.

A supercritical fluid is a high-pressure, high-temperature state of matter best describe as a liquid-like gas, and a marvelous in the black. Water become supercritical in some steam turbines--and it tends to melt the tips of the turbine blades. Supercritical carbon dioxide is used to remove caffeine from coffee beans, and sometimes to dry-clean clothes. Liquid-fueled rocket propellant is also supercritical when it emerges from the tail of a spacecraft.

On 55 Cancri e, this material may be literally oozing--or is it sweltering?--out of the rocks.

With supercritical solvents rising from the planet’s surface, a star of terrifying proportions filling much of the daytime sky, and whole years rushing past in a matter of hours, 55 Cancri e teaches a valuable lesson: Just because a planet is similar in size to Earth does not mean the planet is like Earth.

0 Response to "Re-thinking an Alien World"