APOD: 2025 August 6 Б Meteor before Galaxy
6.08.2025

What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a small pebble from deep space crossed right in front of our Milky Way Galaxy's far-distant companion.

Assembling The International Space Station
10.12.1998

Batteries and solar panels were included with this version of the International Space Station (ISS) but some assembly is still required. On Saturday, December 5th, the STS-88 crew of the Space Shuttle Endeavor achieved the in orbit docking of the Zarya and Unity (foreground) ISS modules.

Comet Hyakutake on a Starry Night
23.04.1996

It was a starry night in April (April 9th, 1996, 9:32 pm CDT to be exact) near Lone Jack, Missouri when Comet Hyakutake graced this astronomically rich field. Making an appearance as the brilliant evening star, Venus is overexposed at the far left.

Gamma Ray Burst: A Milestone Explosion
2.07.2000

Gamma-Ray Bursts (GRBs) were discovered by accident. Thirty three years ago today, satellites first recorded a GRB. The data plotted here show that the count rate of the satellite gamma-ray instrument abruptly jumped indicating a sudden flash of gamma-rays.

Alpha Centauri: The Closest Star System
23.03.2003

The closest star system to the Sun is the Alpha Centauri system. Of the three stars in the system, the dimmest -- called Proxima Centauri -- is actually the nearest star. The bright stars Alpha Centauri...

HET: The New Largest Optical Telescope
27.12.1996

Most of our universe is too dim to see. To peer into our cosmos' unknown depths, astronomers must deploy new tools - and the classic new tool is a larger telescope. Pictured above is the new Hobby-Eberly Telescope (HET) which recently declared "first light" in western Texas.

NGC 4565: Galaxy on the Edge
9.04.2004

Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many springtime telescopic tours of the northern sky as it lies in the faint but well-groomed constellation Coma Berenices.

Descent to Titan
14.01.2005

Today's descent to the surface of Titan by the European Space Agency's Huygens probe is the most distant landing ever attempted by a spacecraft from Earth. At 10:13 UT (5:13am...

An X Class Flare Region on the Sun
6.11.2007

Why does the Sun flare? Unpredictably, our Sun unleashes tremendous flares expelling hot gas into the Solar System that can affect satellites, astronauts, and power grids on Earth. This close up of an active region on the Sun that produced a powerful X-class flare was captured by the orbiting TRACE satellite.

Mercury on the Horizon
27.01.2008

Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset.