How do clusters of galaxies form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. A recent effort is TNG50 from IllustrisTNG, […]

What are those red filaments in the sky? It is a rarely seen form of lightning confirmed only about 30 years ago: red sprites. Recent research has shown that following […]

Can you find supernova 1987A? It isn’t hard — it occurred at the center of the expanding bullseye pattern. Although this stellar detonation was first seen in 1987, light from […]

Like grains of sand on a cosmic beach, stars of the Triangulum Galaxy are resolved in this sharp mosaic from the Hubble Space Telescope’s Advanced Camera for Surveys (ACS). The […]

Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic […]

Centered in a well-composed celestial still life, pretty, blue vdB 9 is the 9th object in Sidney van den Bergh’s 1966 catalog of reflection nebulae. It shares this telescopic field […]

It isn’t every night that a comet passes a galaxy. Last Thursday, though, binocular comet C/2018 Y1 (Iwamoto) moved nearly in front of a spiral galaxy of approximately the same […]

Have you ever seen a dragon in the sky? Although real flying dragons don’t exist, a huge dragon-shaped aurora developed in the sky over Iceland earlier this month. The aurora […]

What if you saw your shadow on Mars and it wasn’t human? Then you might be the Opportunity rover currently exploring Mars. Opportunity explored the red planet from 2004 to […]

NGC 2359 is a helmet-shaped cosmic cloud with wing-like appendages popularly called Thor’s Helmet. Heroically sized even for a Norse god, Thor’s Helmet is about 30 light-years across. In fact, […]