Venus and the Triply Ultraviolet Sun
3.02.2018

An unusual type of solar eclipse occurred in 2012. Usually it is the Earth's Moon that eclipses the Sun. That year, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.

The Suns Spectrum with its Missing Colors
25.09.2018

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

North of Orion s Belt
4.11.2020

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 wide field view spans just under 5 degrees or about 10 full moons on the sky.

APOD: 2023 December 11 Б Solar Minimum versus Solar Maximum
10.12.2023

The surface of our Sun is constantly changing. Some years it is quiet, showing relatively few sunspots and active regions. Other years it is churning, showing many sunspots and throwing frequent Coronal Mass Ejections (CMEs) and flares.

The Crab Nebula Pulsar Shrugs
20.09.2002

How does a city-sized neutron star power the vast Crab Nebula? The expulsion of wisps of hot gas at high speeds appears to be at least part of the answer. Yesterday time-lapse movies taken...

72.6: Oxygen Supply
28.05.2003

A supernova explosion, a massive star's inevitable and spectacular demise, blasts back into space debris enriched in the heavy elements forged in its stellar core. Incorporated into future stars and planets, these are the elements ultimately necessary for life.

Pelican Nebula Ionization Front
13.10.2003

What's happening to the Pelican Nebula? The light from young energetic stars is slowly transforming the Pelican's cold gas to hot gas, with the advancing boundary between the two known as an ionization front.

X Ray Triple Jet
16.07.1998

Recorded on July 7, this animation using X-ray images of the Sun shows an amazing event - three nearly simultaneous jets connected with solar active regions. The two frames were taken several hours apart by the Soft X-ray Telescope on board the orbiting Yohkoh observatory.

M27: Not A Comet
24.04.2004

While searching the skies above 18th century France for comets, astronomer Charles Messier diligently recorded this object as number 27 on his list of things which are definitely not comets. So what is it?

An Inner Neptune for 55 Cancri
1.09.2004

Is our Solar System unique? The discovery of a Neptune-mass planet in an sub-Mercury orbit around nearby Sun-like star 55 Cancri, announced yesterday along with the discovery of other similar systems, gives a new indication that planetary systems as complex as our own Solar System likely exist elsewhere.