This was because they saw the black-drop effect in a transit of Mercury, a planet that has no atmosphere.
ECONOMIST: Transits of Venus
During such a transit, the observed brightness of the star drops slightly because the planet blocks a part of the starlight.
BBC: New robotic telescope in Chile set for planet hunt
The transit method for finding planets searches for the small drop in brightness of a star that occurs when a planet passes in front of it and blocks some of its light.
ENGADGET: 9-gigapixel image of the Milky Way reminds us just how small we truly are
应用推荐
模块上移
模块下移
不移动