On March 25, the MESSENGER spacecraft completed its 4,000th orbit of Mercury, and the lowest point in its orbit continues to move closer to the planet than ever before. The orbital phase of the ...

Turns out, it's as tough to drop inward into the inner solar system, as it is to head outward. The problem stems from losing momentum from a launch starting point on Earth. It can take missions ...

Mercury, often considered the “elusive planet,” is notoriously difficult to observe due to its proximity to the Sun. However, December 2025 brings a rare opportunity for skywatchers to spot this ...

CAPE CANAVERAL, Fla. (AP) – The only spacecraft ever to orbit Mercury ended its four-year tour with a crash landing Thursday. NASA’s Messenger plunged from orbit as planned and slammed into the sun’s ...

Of the eight known planets in the Solar System, Mercury is the smallest and closest to our star, the Sun. Mercury has been known since the time of ancient Babylon, in the 14th century BC. Its name ...