NASA: Astronomy Picture of the Day(2022-05-03)

lalaloo 입니다.

This photo is the Astronomy Picture of the Day provided by NASA.

나사에서 매일 업데이트하는 오늘의 우주 모습입니다.

 

Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

이 사진의 제목은 <Mercury's Sodium Tail> 입니다.

해당 작품의 소유권은 Sebastian Voltmer 에게 있습니다.

 

That's no comet. Below the Pleiades star cluster is actually a planet: Mercury. Long exposures of our Solar System's innermost planet may reveal something unexpected: a tail. Mercury's thin atmosphere contains small amounts of sodium that glow when excited by light from the Sun. Sunlight also liberates these molecules from Mercury's surface and pushes them away. The yellow glow from sodium, in particular, is relatively bright. Pictured, Mercury and its sodium tail are visible in a deep image taken last week from La Palma, Spain through a filter that primarily transmits yellow light emitted by sodium. First predicted in the 1980s, Mercury's tail was first discovered in 2001. Many tail details were revealed in multiple observations by NASA's robotic MESSENGER spacecraft that orbited Mercury between 2011 and 2015. Tails, of course, are usually associated with comets.