Tag Archives: size

The Most Precise Measurement of an Alien World’s Size

Thanks to NASA’s Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the radius of a planet outside our solar system. The size of the exoplanet, dubbed Kepler-93b, is now known to an uncertainty of just 74 miles (119 kilometers) on either side of the planetary body.

The findings confirm Kepler-93b as a “super-Earth” that is about one-and-a-half times the size of our planet. Although super-Earths are common in the galaxy, none exist in our solar system. Exoplanets like Kepler-93b are therefore our only laboratories to study this major class of planet. (more…)

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NASA Releases Radar Movie of Asteroid 2012 DA14

An initial sequence of radar images of asteroid 2012 DA14 was obtained on the night of Feb. 15/16, 2013, by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif. Each of the 72 frames required 320 seconds of data collection by the Goldstone radar.

The observations were made as the asteroid was moving away from Earth. The asteroid’s distance from the radar dish increased from 74,000 miles (120,000 kilometers) to 195,000 miles (314,000 kilometers). The resolution is 13 feet (four meters) per pixel. The images span close to eight hours and clearly show an elongated object undergoing roughly one full rotation. The images suggest that the asteroid has a long axis of about 130 feet (40 meters). The radar observations were led by scientists Lance Benner and Marina Brozovic of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. Additional Goldstone radar observations are scheduled on February 18, 19 and 20. (more…)

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Russia Meteor Not Linked to Asteroid Flyby

New information provided by a worldwide network of sensors has allowed scientists to refine their estimates for the size of the object that entered that atmosphere and disintegrated in the skies over Chelyabinsk, Russia, at 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15).

The estimated size of the object, prior to entering Earth’s atmosphere, has been revised upward from 49 feet (15 meters) to 55 feet (17 meters), and its estimated mass has increased from 7,000 to 10,000 tons. Also, the estimate for energy released during the event has increased by 30 kilotons to nearly 500 kilotons of energy released. These new estimates were generated using new data that had been collected by five additional infrasound stations located around the world – the first recording of the event being in Alaska, over 6,500 kilometers away from Chelyabinsk. The infrasound data indicates that the event, from atmospheric entry to the meteor’s airborne disintegration took 32.5 seconds. The calculations using the infrasound data were performed by Peter Brown at the University of Western Ontario, Canada. (more…)

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Nearby Super-Earth Likely a Diamond Planet

New research led by Yale University scientists suggests that a rocky planet twice Earth’s size orbiting a nearby star is a diamond planet.

“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” said lead researcher Nikku Madhusudhan, a Yale postdoctoral researcher in physics and astronomy. “The surface of this planet is likely covered in graphite and diamond rather than water and granite.”

The paper reporting the findings has been accepted for publication in the journal Astrophysical Journal Letters. (more…)

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