Named for the southern constellation toward which most of its galaxies can be found, the Fornax Cluster is one of the closest clusters of galaxies. About 62 million light-years away, […]

Part of the Sun disappeared earlier this month, but few people were worried. The missing part, which included the center from some locations, just went behind the Moon in what […]

What’s happened to the Moon? Within the last day, part of the Moon moved through the Earth’s shadow. This happens about once or twice a year, but not every month […]

Gamma Cassiopeiae shines high in northern autumn evening skies. It’s the brightest spiky star in this telescopic field of view toward the constellation Cassiopeia. Gamma Cas shares the ethereal-looking scene […]

History’s second known periodic comet is Comet Encke (2P/Encke). As it swings through the inner Solar System, Encke’s orbit takes it from an aphelion, its greatest distance from the Sun, […]

History’s first known periodic comet, Comet Halley (1P/Halley), returns to the inner Solar System every 76 years or so. The famous comet made its last appearance to the naked-eye in […]

In 60 seconds, this setting Sun will turn green. Actually, the top of the Sun already appears not only green, but wavey — along with all of its edges. The […]

This dance is to the death. As these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge […]

There goes another one! Volcanoes on Jupiter’s moon Io keep erupting. To investigate, NASA’s robotic Juno spacecraft has begun a series of visits to this very strange moon. Io is […]

What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared. The […]