It has been over four decades since NASA left the moon, but now the space agency is at it again.

NASA is launching a small rocket to investigate an unusual discovery made by the crew on Apollo 17 – moon dust.

Crews reported seeing an odd glow on the lunar horizon just before sunrise, an unexpected sight as the airless moon lacked atmosphere for reflecting sunlight.

Read more: http://www.dailymail.co.uk/news/article-2412461/NASA-launch-rocket-30-day-mission-investigate-moon-dust.html#ixzz2e81HDg1t
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the moon does have a very thin atmosphere which causes the glow

this article mentions an airless moon

NASA set to launch robot spacecraft on moon dust mission

The phenomenon, which Apollo 17 Commander Eugene Cernan sketched in a notebook, was unexpected because the airless moon lacked atmosphere for reflecting sunlight.

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while this article mentions a thin lunar atmosphere.

NASA set to explore moon’s mysterious glow with LADEE mission

An unmanned rocket is scheduled to blast off late Friday night (11:27 p.m. EDT) from Virginia’s Eastern Shore with a robotic explorer that will study the lunar atmosphere and dust. Called LADEE (LA’-dee), the moon-orbiting craft will measure the thin lunar atmosphere.

maybe not all atmospheres are air. air is specific to earth atmosphere.

also the moon’s atmosphere is for all intents and purposes non-existant.

For most practical purposes, the Moon is considered to be surrounded by vacuum. The elevated presence of atomic and molecular particles in its vicinity (compared to interplanetary medium), referred to as ‘lunar atmosphere’ for scientific objectives, is negligible in comparison with the gaseous envelope surrounding Earth and most planets of the Solar system – less than one hundred trillionth of Earth’s atmospheric density at sea level. Otherwise the Moon is considered to not have an atmosphere as it cannot absorb measurable quantities of radiation, does not appear layered or self-circulating, and requires constant replenishment given the high rate at which the atmosphere is lost to space. The solar wind and outgassing are not primary sources of the Earth’s atmosphere, or of any stable atmosphere.

http://en.wikipedia.org/wiki/Atmosphere_of_the_Moon

I have a book here that gives the composition of the Moon’s atmosphere. Just a sec.

The Moon’s atmosphere is dominated by helium and argon, with traces of sodium and potassium. Its atmosphere is 2.2 times as dense during the night as it is during the day. The Moon’s atmosphere is only fractionally less dense at night than the atmosphere of Mercury.

Moon dust is easily electrostatically charged, which allows it to levitate above the surface. “The Moon’s atmosphere is in part formed from sputtering by micrometeorites and energetic particles, and by capturing particles from the solar wind.”

As you can imagine, a meteorite impact would have a very big effect on the amount of dust in the Moon’s atmosphere. About 300 meteorites with a mass of 1 kg or more will hit the Moon each year. And 3,000 meteorites with a mass of 10 g or more. Give or take a factor of two or three.