For decades, Uranus and Neptune have been filed neatly into the “ice giant” drawer, shorthand for worlds built mostly from ...

Astronomers have spotted a large and mysterious dark spot within Neptune’s atmosphere, and it has an unexpectedly bright companion. The observation was made using the European Southern Observatory’s ...

A day on Neptune lasts precisely 15 hours, 57 minutes and 59 seconds, according to the first accurate measurement of its rotational period made by University of Arizona planetary scientist Erich ...