Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds — mostly. On the third night of returning to same peaks, though, […]

Why is Phobos so dark? Phobos, the largest and innermost of two Martian moons, is the darkest moon in the entire Solar System. Its unusual orbit and color indicate that […]

These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and […]

Completing one orbit of our fair planet in 90 minutes the International Space Station can easily be spotted by eye as a very bright star moving through the night sky. […]

Bright stars, interstellar clouds of dust and glowing nebulae fill this cosmic scene, a skyscape just north of Orion’s belt. Close to the plane of our Milky Way Galaxy, the […]

Over fifty gravitational wave events have now been detected. These events mark the distant, violent collisions of two black holes, a black hole and a neutron star, or two neutron […]

This is what it looks like to punch an asteroid. Last month, NASA’s robotic spacecraft OSIRIS-REx descended toward, thumped into, and then quickly moved away from the small near-Earth asteroid […]

What’s happening to the Sun? Clearly, the Sun’s lower half is hidden behind a thick cloud. Averaging over the entire Earth, clouds block the Sun about 2/3rds of the time, […]

What’s happening at the center of the Trifid Nebula? Three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear near the bottom, […]

Explore extreme and terrifying realms of the Universe tonight. If you dare to look, mysterious dark matter, a graveyard galaxy, zombie worlds, and gamma-ray bursts of doom are not all […]