People are too complacent about theasteroid threat因为Bill Nye喜欢。
The former TV "Science Guy," who currently serves as CEO of the nonprofit Planetary Society,warned that catastrophic impacts like the one thatoffed the dinosaurs 66 million years agoare not confined to the past.
"The Earth is going to get hit with another [big]asteroid," Nye said May 2 at the International Academy of Astronautics' 2019 Planetary Defense Conference in College Park,Maryland.
"The problem is,we don't know when," he added.“这在任何人的一生中都是很低的概率，but it's a very high-consequence event.If it happens,it would be like control-alt-delete for everything."
Unlike the dinosaurs,however,we don't just have to sit around and wait for doom to rain down on us.We can do something about the asteroid threat — and we should start prepping for it now,Nye强调。
第一步是找到危险的太空岩石。There's good 徳赢时时彩news on this front: NASA scientists think they've already discovered more than 90% of the potential civilization-enders — near-Earth asteroids at least 0.6 miles (1 kilometers) wide — and none of these mountain-size space rocks pose a threat for the foreseeable future.
但是，有许多未被发现的小行星在地球附近的空间快速移动，可能会在局部范围内造成严重的破坏——摧毁一个州大小的区域，for example.所以，我们应该在网上找到更好的检测工具，Nye said.
这样的帮助即将到来，很快。例如，the Large Synoptic Survey Telescope,a big instrument set to start observing the heavens next year from Chile,will likely be able to discover and catalog 80% to 90% of potentially hazardous asteroids at least 460 feet (140 meters) wide,项目组成员说.
美国国家航空航天局正在考虑发射一种被称为近地天体照相机的小行星猎手。This proposed mission would scan for space rocks in infrared light,spotting their heat signatures in the darkness.
Coordination is the next step after detection,Nye said.A big asteroid hurtling toward Earth would be a global issue,so the international community would have to work together to deal with it.
And we'd haveseveral options at our disposal.If we had enough warning time — years or,preferably,decades — we could launch a probe to fly alongside the asteroid,gradually nudging the rock off course via a gravitational tug.This "gravity tractor" craft would ideally boost its pull by plucking a big boulder off the asteroid,美国宇航局首席科学家吉姆·格林说，who participated in yesterday's event with Nye.
If we were pressed for time,we could slam one or more spacecraft into the asteroid,knocking it onto a benign trajectory through brute force.或者我们可以引爆核武器near the rock,vaporizing much of its surface.The resulting mass loss,and the flow of material off the asteroid,would change the rock's path,experts say.And the shock wave from the blast might do the trick by itself,Nye said.
Nye还提到了Laser Bees" strategy,which involves sending a swarm of small spacecraft out to the potentially dangerous asteroid.Each little probe would focus a laser beam on the same spot on the rock,vaporizing material and causing a jet to erupt.This jet would serve as a sort of engine that would push the asteroid onto a different path.
During his portion of the presentation,Green highlighted the many things we can learn from asteroids — they're time capsules from the dawn of the solar system,after all,而且富含碳的岩石可能有助于地球上的生命开始——以及它们对勘探的潜在好处。利用小行星资源可以使宇宙飞船和宇航员更加自给自足，并改善地球上的生活，他说。
"It's not a matter of if;it's only a matter of when," Green said.
- Deflecting Killer Asteroids Away From Earth: How We Could Do It
- Humanity Will Slam a Spacecraft into an Asteroid in a Few Years to Help Save Us All
- This Is NASA's New Plan to Detect and Destroy Asteroids Before They Hit Earth