US stepping up efforts to defend Earth from incoming asteroids
Print Edition
The US government is stepping up efforts to protect the planet from incoming asteroids that could wipe out entire regions or even continents.
The National Science and Technology Council released a report Wednesday calling for improved asteroid detection, tracking and deflection. NASA is participating, along with federal emergency, military, White House and other officials.
For now, scientists know of no asteroids or comets heading our way. But one could sneak up on us, and that’s why the government wants a better plan.
NASA’s planetary defense officer, Lindley Johnson, said scientists have found 95 percent of all these near-Earth objects measuring 1 kilometer or bigger. But the hunt is still on for the remaining 5 percent and smaller rocks that could still inflict big damage.
There’s no quick solution if a space rock is suddenly days, weeks or even months from striking, according to Johnson. But such short notice would give the world time, at least, to evacuate the area it might hit, he said.
Ground telescopes are good at picking up asteroids zooming into the inner solar system and approaching from the night side of Earth, Johnson said. What’s difficult to detect are rocks that have already zipped past the sun and are heading out of the solar system, approaching from the day side. That’s apparently what happened in 2013 when an asteroid about 20 meters in size suddenly appeared and exploded over Chelyabinsk, Russia, damaging thousands of buildings and causing widespread injuries.
An asteroid double or even triple in size exploded over Tunguska, Russia, in 1908, leveling 2,000 square kilometers of forest.
A giant space rock wiped out the dinosaurs when it smacked into Mexico’s Yucatan peninsula some 65 million years ago.
Johnson stressed it would take years to attempt to turn away a potential killer asteroid — several years to build a spacecraft then another few years to get it to the target. Ideally, he’d like at least 10 years’ notice.
A mission to defend planet Earth could involve hitting the asteroid or comet with big, fast-moving robotic spacecraft in hopes of changing its path; or worst case, launching a nuclear device and blow off enough material to divert it.
All that involves current technology, Johnson said.
Most of the extra work can be done with existing funds, said Aaron Miles of the White House Office of Science and Technology Policy.
“This is more about figuring out how to use those resources smartly,” he said.
The bottom line, officials said, is the US government wants to be prepared to decide which action is best if needed.
Scientists hope to learn a lot more about asteroids from a pair of missions currently underway. NASA’s Osiris-Rex spacecraft will reach the asteroid Bennu later this year and return samples in 2023, and Japan’s Hyabusa 2 is closing in on the asteroid Ryugu, with samples to be returned in 2020.
- About Us
- |
- Terms of Use
- |
-
RSS - |
- Privacy Policy
- |
- Contact Us
- |
- Shanghai Call Center: 962288
- |
- Tip-off hotline: 52920043
- 沪ICP证：沪ICP备05050403号-1
- |
- 互联网新闻信息服务许可证：31120180004
- |
- 网络视听许可证：0909346
- |
- 广播电视节目制作许可证：沪字第354号
- |
- 增值电信业务经营许可证：沪B2-20120012
Copyright © 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.
