APOD: 2025 September 24 Б GW250114: Rotating Black Holes Collide
24.09.2025

It was the strongest gravitational wave signal yet measured -- what did it show? GW250114 was detected by both arms of the Laser Interferometer Gravitational-wave Observatory (LIGO) in Washington and Louisiana USA earlier this year.

The Hubble Deep Field South
14.12.1998

Among the faintest objects are some of the most unusual objects. The Hubble Deep Field South was released after much anticipation earlier this month, delivering a unique view of some of the most distant parts of our universe. Part of this field is shown above.

Our Busy Solar System
24.07.2002

Our Solar System is a busy place. Although the major planets get the most press, a swarm of rocks, comets, and asteroids also exist. The above plot shows the placement of known inner Solar System objects on 2002 July 20. The light blue lines indicate the orbits of planets.

The Sun Spews X-rays
4.10.1995

Our Sun is really very hot. The Sun's outer atmosphere is so hot that it emits much light in the X-ray band, which was unexpected. X-rays are usually emitted from objects having a temperature in the millions of degrees, not the mere thousands of degrees of the Sun's surface.

NGC 6992: Filaments of the Veil Nebula
1.12.2009

Wisps like this are all that remain visible of a Milky Way star. About 7,500 years ago that star exploded in a supernova leaving the Veil Nebula, also known as the Cygnus Loop.

Prometheus Creating Saturn Ring Streamers
2.08.2010

What's causing those strange dark streaks in the rings of Saturn? Prometheus. Specifically, an orbital dance involving Saturn's moon Prometheus keeps creating unusual light and dark streamers in the F-Ring of Saturn. Now Prometheus orbits Saturn just inside the thin F-ring, but ventures into its inner edge about every 15 hours.

NGC 7331 and Beyond
12.08.2011

Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog.

Night of the Long Leonid
22.11.2012

A cosmic grain of sand left the long and colorful trail across this all-sky view. Its grazing impact with planet Earth's atmosphere began at 71 kilometers per second. With the Milky Way stretching...

Milky Way Over Quiver Tree Forest
12.12.2012

In front of a famous background of stars and galaxies lies some of Earth's more unusual trees. Known as quiver trees, they are actually succulent aloe plants that can grow to tree-like proportions. The quiver tree name is derived from the historical usefulness of their hollowed branches as dart holders.

Halley Dust and Milky Way
9.05.2014

The early morning hours of May 6 were moonless when grains of cosmic dust streaked through dark skies. Swept up as planet Earth plows through dusty debris streams left behind periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids.