Sundogs over the VLA
23.08.1999

What if you woke up one morning and saw more than one Sun in the sky? Most probably, you would be seeing sundogs, extra-images of the Sun created by falling ice-crystals in the Earth's atmosphere. As water freezes in the atmosphere, small, flat, six-sided, ice crystals might be formed.

Mars in a Manger
30.04.2010

At opposition in late January, Mars shone very brightly in planet Earth's night sky, among the stars of the constellation Cancer the Crab. Since then the Red Planet has been fading, but still lingers in Cancer during April and May.

Meteor in the Milky Way
22.04.2015

Earth's April showers include the Lyrid Meteor Shower, observed for more than 2,000 years when the planet makes its annual passage through the dust stream of long-period Comet Thatcher. A grain...

Animation: Perseid Meteor Shower
7.08.2018

Where do Perseid meteors come from? Mostly small bits of stony grit, Perseid meteoroids were once expelled from Comet Swift-Tuttle and continue to follow this comet's orbit as they slowly disperse. The featured animation depicts the entire meteoroid stream as it orbits our Sun.

Geminids and the Mittens
24.12.2022

Asteroid 3200 Phaethon's annual gift to planet Earth always arrives in December. Otherwise known as the Geminid meteor shower, the source of the meteroid stream is dust shed along the orbit of the mysterious asteroid.

APOD: 2023 February 7 Б A Comet and Two Dippers
6.02.2023

Can you still see the comet? Yes. Even as C/2022 E3 (ZTF) fades, there is still time to see it if you know where and when to look. Geometrically, Comet ZTF has passed its closest to both the Sun and the Earth and is now headed back to the outer Solar System.

Downtown Auriga
13.02.2014

Rich in star clusters and nebulae, the ancient constellation of Auriga, the Charioteer, rides high in northern winter night skies. Spanning nearly 24 full moons (12 degrees) on the sky, this deep telescopic mosaic view recorded in January shows off some of Auriga's most popular sights for cosmic tourists.

Anticrepuscular Rays Over Colorado
29.10.2001

What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Pictured above are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds.

Analemma of the Moon
13.07.2005

An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. But the trick to imaging an analemma...

Z is for Mars
22.04.2006

This composite of images spaced about a week apart - from late July 2005 (bottom right) through February 2006 (top left) - traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky. On November 7th, 2005 the Red Planet was opposite the Sun in Earth's sky (at opposition).