APOD: 2023 October 31 Б Halloween and the Wizard Nebula
31.10.2023

Halloween's origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere).

A Particle Beam Jet forms HH 24
4.02.2014

If you visit HH 24, don't go near the particle beam jet. This potential future travel advisory might be issued because the powerful jet likely contains electrons and protons moving hundreds of kilometers per second.

NGC 3310: A Starburst Spiral Galaxy
1.03.2016

The party is still going on in spiral galaxy NGC 3310. Roughly 100 million years ago, NGC 3310 likely collided with a smaller galaxy causing the large spiral galaxy to light up with a tremendous burst of star formation.

A Close Up of Aurora on Jupiter
19.12.2000

Jupiter has aurorae. Like Earth, the magnetic field of the gas giant funnels charged particles released from the Sun onto the poles. As these particles strike the atmosphere, electrons are temporarily knocked away from existing gas molecules. Electric force attracts these electrons back. As the electrons recombine to remake neutral molecules, auroral light is emitted.

Vela Supernova Remnant in X-ray
12.06.1996

What happens when a star explodes? A huge fireball of hot gas shoots out in all directions. When this gas slams into the existing interstellar medium, it heats up so much it glows in X-rays.

Infrared Helix
12.01.2006

Over six hundred light years from Earth, in the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution.

Filaments In The Cygnus Loop
26.04.2000

Subtle and delicate in appearance, these are filaments of shocked interstellar gas -- part of the expanding blast wave from a violent stellar explosion. Recorded in November 1997 with the Wide Field and Planetary Camera 2 onboard the Hubble Space Telescope, the picture is a closeup of a supernova remnant known as the Cygnus Loop.

All the Colors of the Sun
24.06.2007

It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

The Dark Tower in Scorpius
8.05.2008

In silhouette against a crowded star field toward the constellation Scorpius, this dusty cosmic cloud evokes for some the image of an ominous dark tower. In fact, clumps of dust and molecular gas collapsing...

Inside the Eagle Nebula
8.02.2009

From afar, the whole thing looks like an Eagle. A closer look at the Eagle Nebula, however, shows the bright region is actually a window into the center of a larger dark shell of dust. Through this window, a brightly-lit workshop appears where a whole open cluster of stars is being formed.