英語時差：危險的月球塵埃

Don: Hey Ya?l, I was wondering–why don't we hear much about the moon anymore?

Ya?l: Whadya mean, Don?

D: It's just that back in the 1960s and '70s, sending astronauts to the moon was a big deal, but nobody talks much about it anymore.

Y: Well, actually NASA is planning to send astronauts back to the moon.

D: Really?

Y: Yep. And this time there's talk of building a lunar base where astronauts can stay for weeks and months at a time to conduct experiments in low gravity.

D: Cool.

Y: But there are a few kinks to work out–like what to do about moon dust.

D: Wait. Why is moon dust a problem?

Y: Well, for one thing, it has chemical properties that resemble fresh fractured quartz, which is pretty toxic. And moon dust is clingy; it gets all over spacesuits and inside space capsules. Astronauts from the '60s and '70s used to complain that there was so much dust inside the capsule that they could smell it.

D: So is the dust actually dangerous? What happens if it gets in the lungs?

Y: That's what scientists are studying now. One issue is that the moon's weak gravity could allow dust particles to float around in an astronaut's airway, which could let moon dust penetrate deeper into the lungs.

D: Which increases the health risks. So what can astronauts do to breath in less dust? High-tech feather dusters?

Y: Funny. But it's a good question–one that scientists are busy looking into before sending astronauts up there to set up house on our very dusty moon.