Asteroid and Comet Deflection

Tightening the Focus on Near Earth Asteroids

December 15, 2014

The impact at Tunguska, Siberia on June 30,1908, evidently a small asteroid, devastated 1300 square kilometers, which works out to be the equivalent of a large metropolitan area. June 30, 2015 is thus an appropriate date to launch Asteroid Day, a global awareness campaign to put the issue of dangerous impacts in front of as […]

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Digging into the Late Heavy Bombardment

April 11, 2014

The Barberton greenstone belt is considered one of the oldest pieces of continental crust on the planet. About 100 kilometers long and 60 kilometers wide, the belt is in South Africa east of Johannesburg and not far from the border of Swaziland, a region where gold was first discovered in South Africa. Greenstone belts, however, […]

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Asteroid Re-Direct: Finding a Candidate

February 17, 2014

It was just a year ago, on February 15, 2013, that the 30-meter asteroid 2012 DA14 whisked past the Earth at a distance of well less than 30,000 kilometers, inside the orbits of our geosynchronous satellites. If you don’t recall 2012 DA14, it’s probably because it was later on the same day that the Chelyabinsk […]

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Shaking Up a ‘Snow Globe’ Solar System

January 30, 2014

The same issue of Nature that carried Ian Crossfield’s weather map of Luhman 16B, published yesterday, also featured a paper from Francesca DeMeo on planetary systems in chaos. Specifically, DeMeo (a Hubble postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics), looks at main belt asteroids in terms of their composition and history. Her findings reveal […]

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Spacecraft and Their Messages

January 16, 2014

Just over 8300 people have now signed the petition supporting the New Horizons Message Initiative. The approach of the 10,000 figure reminds me to jog those who haven’t to stop by the site to sign the petition. For those not yet aware of the NHMI, the idea is to upload a crowdsourced package of images […]

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What a Strange Asteroid Can Tell Us

November 14, 2013

The Pan-STARRS survey telescope in Hawaii has reminded us how much we still have to learn about asteroids. We saw yesterday that the Chelyabinsk impactor could be studied through physical evidence as well as the ample photographic records made by witnesses on the ground. But P/2013 P5, discovered by Pan-STARRS and then the object of […]

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Piecing Together the Chelyabinsk Event

November 13, 2013

We’re still trying to learn how frequently asteroid events like the spectacular fireball over Chelyabinsk occur. The Chelyabinsk object was the largest to fall to Earth since the Tunguska explosion in 1908, which leveled thousands of acres of forest in Siberia. This BBC story discusses Peter Brown (University of Western Ontario) and colleagues’ recent paper […]

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Riding on Comets’ Coat-tails

September 13, 2013

Voyager 1 is now an interstellar spacecraft, according to the latest reports (and I’ll have thoughts on Voyager, its progress and its implications, on Monday). For today, though, Keith Cooper is envisioning other ways of going interstellar, methods that take advantage of natural objects like comets. Can we harness their resources and change the paradigm […]

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‘Graveyard Comets’ in the Asteroid Belt

August 7, 2013

When we study extrasolar planetary systems, we’re seeing stars and planets in a wide variety of ages and configurations, helpful in making sense out of our own system’s past. New work out of the University of Antioquia (Medellin, Colombia) suggests changes to the main belt of asteroids between Mars and Jupiter of a kind that […]

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Into the Orion Arm

March 28, 2013

Although we have little observational data to go on, the existence of the Oort Cloud simply makes sense. We see new comets coming into the inner system that are breaking up as they approach the Sun, obviously not candidates for long survival. There has to be a source containing billions of comets to account for […]

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