Fireball, Smoke Trail, Meteor Storm
21.11.2001

Returning from orbit, space shuttles enter the atmosphere at about 8 kilometers per second as friction heats their protective ceramic tiles to over 1,400 degrees Celsius. By contrast, the bits of comet dust...

Blue Stragglers in NGC 6397
8.08.2003

In our neck of the Galaxy stars are too far apart to be in danger of colliding, but in the dense cores of globular star clusters star collisions may be relatively common. In fact...

Hubble Floats Free
25.05.2009

Why put observatories in space? Most telescopes are on the ground. On the ground, you can deploy a heavier telescope and fix it more easily. The trouble is that Earth-bound telescopes must look through the Earth's atmosphere.

The North America Nebula in Infrared
14.02.2011

The North America Nebula can do what most North Americans cannot -- form stars. Precisely where in the nebula these stars are forming has been mostly obscured by some of the nebula's thick dust that is opaque to visible light.

APOD: 2024 October 20 Б Dark Matter in a Simulated Universe
19.10.2024

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

The Nebula And The Neutron Star
25.10.2000

The lonely RX J1856.5-3754 was formed from the collapsed core of an exploding star. At a distance of 180 light-years it is the closest known neutron star. More massive than...

Magnetar
27.05.1998

What do you call a neutron star with a super-strong magnetic field? You guessed it ... a Magnetar. Imagine a star with more mass than the sun, the density of a neutron, and a magnetic field about a thousand trillion (a one followed by 15 zeroes) times stronger than Earth's.

Schwassmann Wachmann 3: Fragment B
4.05.2006

Periodic comet 73P/Schwassmann-Wachmann 3 has fallen apart before. A cosmic souffle of ice and dust left over from the early solar system, this comet was seen to split into several large pieces during the close-in part of its orbit in 1995.

Comet Schwassmann Wachmann 3 Passes the Earth
23.05.2006

Rarely does a comet pass this close to Earth. Last week, dedicated astrofilmographers were able to take advantage of the close approach of crumbling 73P / Comet Schwassmann-Wachmann 3 to make time-lapse movies of the fast-moving comet. Large comet fragments passed about 25 times the Moon's distance from the Earth.

Nix and Hydra
24.06.2006

Discovered in mid-2005, Pluto's small moons were provisionally designated S/2005 P1 and S/2005 P2. They have now been officially christened Nix and Hydra. Compared to Pluto and its large moon Charon...