Asteroid heading for Earth? Heat it up!

William Atkins
Sunday, 30 January 2011 01:29

Science - Space

A New York professor has an idea that may help to deflect any asteroid that is on a head-on collision with Earth. He is testing his idea, which includes a solar sail, sunlight, and a warmed up asteroid, with the help of NASA.

Dr. Gregory L. Matloff is an associate professor of physics at New York City College of Technology (City Tech).

He is working with NASA on an idea of heating up an asteroid with the use of a solar sail (which produces a concentrated stream of sunlight) so that a jet stream could be created on the asteroid to alter its course away from Earth.

Earth is always in jeopardy of being hit by an asteroid and other space objects. Small ones - meteorites - hit Earth all of the time and still smaller ones - meteors - enter Earth's atmosphere but burn up before reaching the ground. However, larger ones still out in space - meteoroids and even larger ones called asteroids -- are of concern to astronomers because of their potential to do great harm to our planet if they should collide with us.

Some of them are of greater concern to these asteroid trackers because they travel close to Earth. They are called Near-Earth Objects (NEOs) - those meteoroids and asteroids that travel less than 120 million miles (195 million kilometers) from Earth on their orbits about the Sun.

Thus, they are traveling about 1.3 astronomical units (AU) or less from Earth. One AU is the average distance that Earth and Sun are apart, which is around 93 million miles (150 million kilometers).

According to the January 26, 2011 City University of New York (CUNY) article 'City Tech Research Team Casts Light on Asteroid Deflection,' the team headed by Dr. Matloff is working on analysis of what would happen if, for example, a 25-million-ton NEO, traveling at 30,000 to 40,000 miles per hour, was heading straight toward Earth and it could somehow be diverted by a concentrated beam of sunlight.

Sound impossible? It's not!

The January 25, 2011  iTWire article 'Surprise! NanoSail-D solar sail does its thing!' talks about the NanoSail-D spacecraft, which recently deployed its solar sail out in space.

Such a spacecraft is being tested to help remove space junk from orbit about Earth. The NanoSail-D has a 100-square-foot (9.2-square-meter) sail -- made of a thin polymer sheet of reflective material -- that unfurls. It could be used to add extra atmospheric drag on old satellites in orbit, so that they de-orbit faster. And, thus, less junk in space.

However, such a solar sail could also be used to divert asteroids and large meteoroids from a head-on collision with Earth.

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