Mercury has made a rare transit, where the planet passes across the face of the Sun as seen from Earth. During the transit, Mercury appeared as a dark silhouetted disc against the bright surface ...

Mercury is the closest planet to the Sun and Mercury retrograde is an optical illusion which occurs three or four times a year, making the planet appear to move in the opposite direction than it ...

Narrator: As the solar system grew, four rocky planets: Mercury, Venus, Earth and Mars, were created closest to the Sun. Made of rocks and metals, they have solid surfaces and a central core of ...