VOA常速英语:NASA Readies Lunar Mission, Invites International Participation

The U.S. space agency is launching a mission to study the moon from NASA's Wallops Flight Facility in Virginia on September 7 around 0330 UTC.

The Lunar Atmosphere and Dust Environment Explorer, known as LADEE, is NASA's newest robotic mission. LADEE is the size of a small car, and it will collect data for 100 days as it orbits our moon.

Scientists want to learn more about the moon's thin atmosphere because they think it could be common in our solar system. That knowledge could help them better understand large asteroids and other planets, including Mercury.

Lunar Dust

LADEE also will collect data about lunar dust, such as its electric charge, density and mass.

LADEE project manager Butler Hine told reporters at a mission pre-launch briefing that lunar dust is "kind of evil." He said the moon's dust is very rough, not powdery like terrestrial dust.

"It works its way in equipment," Hine said. "So one of the questions about dust on the moon is an engineering question: How do you design things so that they can survive the dust environment?"

And there's another question scientists hope to answer. Astronauts who landed on the moon in the 1960s reported seeing a pre-sunrise glow, and NASA wants to know if electrically charged lunar dust was responsible for it.

Pristine Landscape

It's been decades since a manned mission, so the timing is right, says LADEE program scientist Sarah Noble.

"There's actually a number of countries, a number of private companies, that are planning landings on the moon in the upcoming years, so now is a really good time to go and take a look at it while it's still in its sort of pristine natural state," she said.

Noble says a landing disturbs the moon's delicate atmosphere more than other impacts do because of the fuel used when a craft lands on the lunar surface.

International Participation

NASA is urging amateur astronomers worldwide to watch for lunar impacts during the LADEE mission.

"There are impacts hitting the moon all the time, and we want to know what impact those impacts are having on the atmosphere and dust environment," said Noble.

She added that even skywatchers who don't have telescopes powerful enough to spot lunar impacts can take part. People with iPhones can download a free application called Meteor Counter, and when they observe meteorites here on Earth, they can share their observations with the space agency.

"As we go through a meteorite storm, a certain number of things are hitting the moon, and they're also hitting the Earth at roughly the same rates, so we actually are interested in acquiring data about how many things are hitting the Earth at any given time," Noble explained.

NASA's Noble says something the size of LADEE hits the moon about once a month, and LADEE will do just that, with a controlled crash at the end of its mission.