APOD: 2023 August 23 Б The Meteor and the Galaxy
23.08.2023

It came from outer space. It -- in this case a sand-sized bit of a comet nucleus -- was likely ejected many years ago from Sun-orbiting Comet Swift-Tuttle, but then continued to orbit the Sun alone.

A Quasar Portrait Gallery
9.03.2002

Quasars (QUASi-stellAR objects) lie near the edge of the observable Universe. Discovered in 1963, astronomers were astounded that such objects could be visible across billions of light-years, as this implies they must emit prodigious amounts of energy. Where does the energy come from?

Southern Lights and Shuttle Glow
6.05.1996

A background of distant stars, sinuous and spiky bands of Southern Lights (Aurora Australis), and the faint glow of charged plasma (ionized atomic gas) surrounding the Space Shuttle Discovery's engines give this photo from the STS-39 mission an eerie, otherworldly look.

Watch Galaxies Form
5.09.1996

Snips and snails and puppy dog tails, is that what galaxies were made of? In a report released yesterday and soon to be published in Nature, astronomers have imaged an interesting distant patch of sky with the orbiting Hubble Space Telescope.

Asteroid 253 Mathilde's Large Craters
1.07.1997

You're zipping through the Solar System when you pass ... asteroid 253 Mathilde. This actually happened to NASA's NEAR spacecraft just last Friday. The above picture of the previously unresolved asteroid was released just yesterday.

Lunokhod: Moon Robot
9.01.1999

On November 17, 1970 the Soviet Luna 17 spacecraft landed the first roving remote-controlled robot on the Moon. Known as Lunokhod 1, it weighed just under 2,000 pounds and was designed to operate...

Spiral Galaxies in Collision
9.11.1999

Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars.

The Solar Wind Emerges
8.02.1999

Winds of fast particles blow out from the Sun, but why? Astronomers came a step closer to answering this question recently by making detailed observations of the high-speed wind source with the space-borne Solar and Heliospheric Observatory (SOHO).

Stars of the Galactic Center
13.01.2006

The center of our Milky Way Galaxy is hidden from the prying eyes of optical telescopes by clouds of obscuring dust and gas. But in this stunning vista, the Spitzer Space Telescope's infrared cameras, penetrate much of the dust revealing the stars of the crowded galactic center region.

The Big Dipper Cluster
17.03.2006

A well-known asterism in northern skies, The Big Dipper is easy to recognize even when viewed upside down. Part of the larger constellation of Ursa Major, the bright dipper stars above are named (left to right along the dipper) Dubhe, Merak, Phecda, Megrez, Alioth, Mizar/Alcor, and Alkaid.