M33: The Triangulum Galaxy
8.07.1996

The spiral galaxy M33 is a mid-sized member of our Local Group of galaxies. M33 is also called the Triangulum Galaxy for the constellation in which it resides. About four times smaller (in radius)...

Welcome to Planet Earth
4.02.2001

Welcome to Planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen.

Chamaeleon II Dark Cloud
2.08.2019

A small constellation hiding near the south celestial pole, The Chamaeleon boasts no bright stars. Stars are forming within its constellation boundaries though, in a complex of dark, dusty molecular clouds. Some 500 light-years...

Moon Over Andromeda
28.12.2006

The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small...

Moon Over Andromeda
1.08.2013

The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small...

APOD: 2024 June 10 Б Sh2 132: The Lion Nebula
10.06.2024

Is the Lion Nebula the real ruler of the constellation Cepheus? This powerful feline appearing nebula is powered by two massive stars, each with a mass over 20 times greater than our Sun. Formed...

Rampaging Fronts of the Veil Nebula
7.03.1996

A supernova explosion of a high-mass star results in fast moving blast waves. At the front of the waves shown above, ionized gas in the Veil Supernova Remnant rushes out from the explosion, sweeps up material, and breaks up many atoms into constituent ions and electrons.

A Total Eclipse of the Sun
11.03.1998

On February 26th, it was dark during the day. This total solar eclipse was the last visible from the Americas for this millennium. A total solar eclipse is exciting partly because it is so short.

Moon over Andromeda
25.09.2020

The Great Spiral Galaxy in Andromeda (also known as M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided...

APOD: 2024 January 8 Б The Phases of Venus
8.01.2024

Venus goes through phases. Just like our Moon, Venus can appear as a full circular disk, a thin crescent, or anything in between. Venus, frequently the brightest object in the post-sunset or pre-sunrise sky, appears so small, however, that it usually requires binoculars or a small telescope to clearly see its current phase.