A meteor explosion over Russia injured hundreds of people today (Feb. 15), just hours before an asteroid about half the size of a football field gave Earth an extremely close shave, catapulting the need to protect our home planet from hazardous space rocks into the spotlight.
The two events raise questions about our preparedness for dangerous encounters with asteroids, and by sheer coincidence one group of scientists has just unveiled plans for a novel system to vaporize asteroids in space that threaten Earth.
"We have to come to grips with discussing these issues in a logical and rational way," UC Santa Barbara physicist Philip M. Lubin said in a statement Thursday (Feb. 14), the day before the Russian meteor explosion.
"We need to be proactive rather than reactive in dealing with threats. Duck and cover is not an option," Lubin added. "We can actually do something about it, and it's credible to do something. So let's begin along this path. Let's start small and work our way up. There is no need to break the bank to start."
The hazards of asteroid impacts are starkly clear in Russia, where more than 900 people were injured and hundreds of buildings damaged by the shockwave from the meteor's explosion in the atmosphere, according to press reports. [Russian Meteor Explosion Injures Hundreds (Video)]
Lubin and his colleagues have conceived of a system they call DE-STAR, or Directed Energy Solar Targeting of Asteroids and exploration. The concept: harness power from the sun and convert it into a massive phased array of laser beams that can deflect or evaporate asteroids hazardous to Earth.
"This system is not some far-out idea from Star Trek," Gary B. Hughes, a researcher at California Polytechnic State University, said in a statement. "All the components of this system pretty much exist today. Maybe not quite at the scale that we'd need — scaling up would be the challenge — but the basic elements are all there and ready to go."
The scale the team has in mind is quite astounding — ranging from one system the size of a desktop device to one measuring 6 miles (10 kilometers) in diameter — and the capabilities would improve with each expansion.
DE-STAR 2, for example, would be about 330 feet (100 meters) in diameter, or about the size of the International Space Station, and could nudge comets or asteroids out of their orbits, the team said. Such a system would cost hundreds of millions of dollars, as it would need to be constructed in orbit from smaller pieces, Hughes said in an email to SPACE.com.
Taking a modular approach, the orbital system would keep getting bigger. The researchers envision DE-STAR 4 to be 100 times as big as DE-STAR 2 and say it would be capable of vaporizing a menacing 1,640-foot-wide (500-m) asteroid within a year by beaming it with 1.4 megatons of energy each day.
Hughes added that today's events — the Russian meteor blast and the unprecedented close approach of asteroid 2102 DA14 — "should remind us that there are asteroids and comets that cross Earth's orbit which pose a credible risk of impact."
"If we acknowledge the threat of impact, and the potential for severe disturbances to Earth and society, we should be compelled to investigate realistic approaches for mitigating the risk of impact," Hughes said in an email to SPACE.com. "DE-STAR is one such realistic approach, being based on sound concepts and an existing technological base. An orbiting DE-STAR 2 system would allow rapid reaction to smaller threats. A larger system could defuse any threat if detected sufficiently in advance."
The team thinks their ideas could have implications for asteroid mining and deep space travel, too. The DE-STAR systems could be a valuable tool for evaluating an asteroid's composition and figuring out which lucrative, rare elements it might hold, such as lanthanum, which is used in the batteries of hybrid cars. And a gigantic system that the team has imagined, DE-STAR 6, could serve as a massive orbiting power source, allowing interstellar travel without a warp drive.
"The ability to focus energy on a distant target would allow acceleration of interplanetary spacecraft," Hughes said. "Our calculations indicate that a 1,000-kg (2,200-pound) spacecraft could be accelerated to Mars and arrive in 15 days. Continuous acceleration could send a spacecraft to relativistic speeds, a tantalizing prospect for interstellar travel."
The team is currently preparing a manuscript on DE-STAR to submit for peer review.