Scientists are building a mini DEATH STAR to protect Earth from killer asteroids
Scientists at the University of California claim a spacecraft loaded with lasers could be our best hope for deflecting a killer asteroid
It sounds like something straight out of Star Wars, but scientists are reportedly planning to build a mini "Death Star" to protect Earth from asteroids, comets, and other space objects.
The idea is to put a spacecraft into orbit around the Earth, armed with high-energy lasers that could vaporise any asteroids that look like they might collide with our planet.
The process, known as sublimation, would create a blast of gas that would push the object into a new path.
The concept is being developed by researchers at the University of California, who claim that - unlike some of the ideas that have been proposed involving "kinetic impactors", "robotic mining" and "gravity tractors" - this could actually work.
The so-called DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) would have a 330ft-wide laser array that could divert asteroids 330ft in diameter from a distance of two million miles.
A similar, much smaller system called DE-STARLITE is also being considered, which would travel alongside asteroids, slowly deflecting them over a long period of time.
The scientists claim that a 20 kW version of DE-STARLITE operating for 15 years could deflect a 1,066ft asteroid at a distance equal to Earth's diameter.
A 1 MW version could deflect all known threats up to 1,640ft in diameter with five-year laser activity.
Although DE-STARLITE would be much less expensive, it would be ineffective at deflecting targets on short notice due to the time required for it to deflect the target asteroid.
The DE-STAR system would therefore be a last line of defense on short notice.
"Generally speaking, the technology is available today," said Qicheng Zhang of the University of California, Santa Barbara, told Astrowatch.net .
"The main challenge with building a full DE-STAR is the necessary scale to be effective."
The scientists have tested the technique on earth, by using lasers to blast a piece of basalt – an igneous rock similar in composition to some asteroids. They found that when it glowed white-hot, it began to lose mass.
However, the researchers note that the effectiveness of a deflection mission would depend strongly on the target.
"If, say, a 100-metre-wide asteroid were found today on a collision course with Earth next week, directed energy would not be a viable solution as that would require a very large laser array that would be far bigger than an equally effective single-use impactor or explosive," Zhang explained.
"If, on the other hand, we find that same asteroid 30 years before impact, directed energy would be very effective, even with 10 kW lasers which are far below the power of many lasers in possession by the US military today.”
The news comes as an asteroid is indeed headed for Earth. The space rock, dubbed 2013 TX68, is expected to speed by our planet on Tuesday March 8.
The asteroid is hidden by the sun's glare , which makes it very difficult to track accurately.
Calculations show that 2013 TX68 could shoot past the Earth well within the ring of geostationary communications and GPS satellites stationed 22,300 miles above sea level.
At the other limit of its predicted range it could remain as far out as 40 times the distance to the moon.
No comments: