APOD: 2023 September 10 Б An Annular Solar Eclipse over New Mexico
10.09.2023

What is this person doing? In 2012, an annular eclipse of the Sun was visible over a narrow path that crossed the northern Pacific Ocean and several western US states. In an annular solar...

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.

Unusual Aurora During Solar Wind Dropout
23.12.1999

On May 10, for some unknown reason, the Solar Wind virtually stopped. Normally our Sun emits a wind of between five and ten energetic particles per cubic centimeter moving outward at about 500 kilometers per second.

Fly Me to the Moon
17.01.2017

No, this is not a good way to get to the Moon. What is pictured is a chance superposition of an airplane and the Moon. The contrail would normally appear white, but the large volume of air toward the setting Sun preferentially knocks away blue light, giving the reflected trail a bright red hue.

Gemini Stars Pollux and Castor
16.05.2017

Who are the twins of Gemini? It terms of astronomical objects, the famous constellation is dominated by two bright stars: Pollux (left) and Castor (right). Pictured, the two stars stand out because they are so bright, so close together both in angle and brightness, but so different in color.

Salt Pepper and Ice
18.09.2018

There's a "camera" comet now moving across the sky. Just a bit too dim to see with the unaided eye, Comet 21P / Giacobini-Zinner has developed a long tail that makes it a good sight for binoculars and sensitive cameras.

APOD: 2025 October 10 Б 50 Light-years to 51 Pegasi
10.10.2025

It's only 50 light-years to 51 Pegasi. That star's position is indicated in this snapshot from August 2025, taken on a night with mostly brighter stars visible above the dome at Observatoire de Haute-Provence in France.

The Belt of Venus
10.11.1999

Although you've surely seen it, you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly off-color, slightly pink.

Ring of Fire Revisited
30.05.2003

Early on Saturday, May 31 (UT) the new Moon will once again slide across the Sun's fiery disk, and once again an annular solar eclipse will be the result -- since the Moon's apparent diameter will be a little too small to completely cover the Sun.

Sunrise Shadows in the Sky
21.09.2024

The defining astronomical moment of this September's equinox is at 12:44 UTC on September 22, when the Sun crosses the celestial equator moving south in its yearly journey through planet Earth's sky.