The Tarantula Nebula is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud, about 180 thousand light-years away. The […]

Found among the rich starfields of the Milky Way, star cluster NGC 7789 lies about 8,000 light-years away toward the constellation Cassiopeia. A late 18th century deep sky discovery of […]

Why is Comet Maccholz so depleted of carbon-containing chemicals? Comet 96P/Machholz’s original fame derives from its getting closer to the Sun than any other short period comet — half as […]

Chaotic in appearance, these tangled filaments of shocked, glowing gas are spread across planet Earth’s sky toward the constellation of Cygnus as part of the Veil Nebula. The Veil Nebula […]

Big, beautiful spiral galaxy NGC 1055 is a dominant member of a small galaxy group a mere 60 million light-years away toward the aquatically intimidating constellation Cetus. Seen edge-on, the […]

What causes Hubble’s Variable Nebula to vary? The unusual nebula featured here changes its appearance noticeably in just a few weeks. Discovered over 200 years ago and subsequently cataloged as […]

In the center of Prague there’s a clock the size of a building. During the day, crowds gather to watch the show when it chimes in a new hour. The […]

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. Last year, though, ESA’s Rosetta […]

Do all full moons look the same? No. To see the slight differences, consider this grid of twelve full moons. From upper left to lower right, the images represent every […]

Traveling at high velocity along an extreme hyperbolic orbit and making a hairpin turn as it swung past the Sun, the now designated A/2017 U1 is the first known small […]