The Earth finds an unlikely saviour. So charge your guns, and wait for the command!
In the event that a gaint asteroid is headed toward Earth, you'd better hope that it's blindingly white. A pale asteroid would reflect dunlight - and over time, this bouncing of photons off its surface could create enough of a force to push off its course.
How might one encourage such a deflection? The answer, according to an MIT student: with a volley or two of paintballs.
Sung Wook Paek, a student at MIT, says if timed just right, pellets full of paint powder, launched in two rounds from a spacecraft at relatively close distance, would cover the front and back of an asteroid, more than doubling its reflectivity. The initial force from the pellets would bump an asteroid off course; over time, the sun's photons would deflect it even more.
Paek's paper won the 2012 Move an Asteroid Technical Paper Competition, sponsored by the UN's Space Generation Advisory Council.
Paek's paintball strategy builds on a solution submitted by last year's winner, who proposed deflecting an asteroid with a cloud of solid pellets. Paek came up with a similar proposal, adding paint to the pellets to take advantage of solar radiation pressure - the force exerted on objects by the sun's photons. Researchers have observed that pressure from sunlight can alter the orbits of satellites, while others have proposed equipping spacecraft with sails to catch solar radiation, much like a sailboat catches wind.
In his proposal, Paek used the asteroid Apophis as a theoretical test case. According to astronomical observations, this 27-gigaton rock may come close to Earth in 2029, and then again in 2036. Paek determined that five tons of paint would be required to cover the massive asteroid, which has a diameter of 1,480 feet. He used the asteroid's period of rotation to determine the timing of pellets, launching a first round to cover the front of the asteroid, and firing a second round once the asteroid's surface, they would burst apart, splattering the space rock with a fine, five-micrometer-layer of paint.
Paek estimates that it would take up to 20 years for the cumulative effect of solar radiation pressure to successfully pull the asteroid off its Earthbound trajectory. He says launching pellets with rockets may not be an ideal option, as the violent take off may rupture the payload. Instead, he envisions paintballs may be made in space, in ports such as the ISS, where a spacecraft could pick up pellets to deliver to the asteroid.
In the event that a gaint asteroid is headed toward Earth, you'd better hope that it's blindingly white. A pale asteroid would reflect dunlight - and over time, this bouncing of photons off its surface could create enough of a force to push off its course.
Sung Wook Paek, a student at MIT, says if timed just right, pellets full of paint powder, launched in two rounds from a spacecraft at relatively close distance, would cover the front and back of an asteroid, more than doubling its reflectivity. The initial force from the pellets would bump an asteroid off course; over time, the sun's photons would deflect it even more.
Paek's paper won the 2012 Move an Asteroid Technical Paper Competition, sponsored by the UN's Space Generation Advisory Council.
Paek's paintball strategy builds on a solution submitted by last year's winner, who proposed deflecting an asteroid with a cloud of solid pellets. Paek came up with a similar proposal, adding paint to the pellets to take advantage of solar radiation pressure - the force exerted on objects by the sun's photons. Researchers have observed that pressure from sunlight can alter the orbits of satellites, while others have proposed equipping spacecraft with sails to catch solar radiation, much like a sailboat catches wind.
In his proposal, Paek used the asteroid Apophis as a theoretical test case. According to astronomical observations, this 27-gigaton rock may come close to Earth in 2029, and then again in 2036. Paek determined that five tons of paint would be required to cover the massive asteroid, which has a diameter of 1,480 feet. He used the asteroid's period of rotation to determine the timing of pellets, launching a first round to cover the front of the asteroid, and firing a second round once the asteroid's surface, they would burst apart, splattering the space rock with a fine, five-micrometer-layer of paint.
Paek estimates that it would take up to 20 years for the cumulative effect of solar radiation pressure to successfully pull the asteroid off its Earthbound trajectory. He says launching pellets with rockets may not be an ideal option, as the violent take off may rupture the payload. Instead, he envisions paintballs may be made in space, in ports such as the ISS, where a spacecraft could pick up pellets to deliver to the asteroid.
No comments:
Post a Comment