Welcome to the International Year of Astronomy
1.01.2009

Astronomers all over planet Earth invite you to experience the night sky as part of the International Year of Astronomy 2009. This year was picked by the International Astronomical Union and the United Nations Educational, Scientific, and Cultural Organization because it occurs 400 years after Galileo turned one of the first telescopes toward the heavens.

M33: Triangulum Galaxy
3.12.2010

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.

Tutulemma: Solar Eclipse Analemma
22.12.2013

If you went outside at exactly the same time every day and took a picture that included the Sun, how would the Sun's position change? With great planning and effort, such a series of images can be taken. The figure-8 path the Sun follows over the course of a year is called an analemma.

Dark Skies: Turn on the Night
16.05.2019

Have you ever experienced a really dark night sky? One common and amazing feature is the glowing band of our Milky Way galaxy stretching from horizon to horizon. If you live in or near...

Apollo 11 Launches Humans to the Moon
16.07.2019

Everybody saw the Moon. Nobody had ever been there. Humans across planet Earth watched in awe 50 years ago today as a powerful Saturn V rocket attempted to launch humans -- to the Moon. Some...

Churning Clouds on Jupiter
11.08.2020

Where is Jupiter's ammonia? Gaseous ammonia was expected to be seen in Jupiter's upper atmosphere by the orbiting Juno spacecraft -- but in many clouds is almost absent. Recent Juno data, however, gives some clues: some high-level clouds appear to be home to an unexpected type of electrical discharge dubbed shallow lightning.

APOD: 2023 January 30 Б Globular Star Cluster NGC 6355 from Hubble
30.01.2023

Globular clusters once ruled the Milky Way. Back in the old days, back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy. Today, there are less than 200 left. Over the eons, many globular clusters were destroyed by repeated fateful encounters with each other or the Galactic center.

APOD: 2023 October 17 Б PDS 70: Disk, Planets, and Moons
17.10.2023

It's not the big ring that's attracting the most attention. Although the big planet-forming ring around the star PDS 70 is clearly imaged and itself quite interesting. It's also not the planet on the right, just inside the big disk, thatБs being talked about the most.

APOD: 2024 August 28 Б Tulip Nebula and Black Hole Cygnus X 1
28.08.2024

When can you see a black hole, a tulip, and a swan all at once? At night -- if the timing is right, and if your telescope is pointed in the right direction. The complex and beautiful Tulip Nebula blossoms about 8,000 light-years away toward the constellation of Cygnus the Swan.

Venus Evening Loop
1.06.2001

From September 2000 through March 2001, astronomer Tunc Tezel patiently photographed the planet Venus on 25 different dates as it wandered through the evening twilight. The pictures were taken from the same spot...