A Halo Around the Moon
15.05.2000

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

Yosemite Winter Night
25.12.2012

In this evocative night skyscape a starry band of the Milky Way climbs over Yosemite Valley, Sierra Nevada Range, planet Earth. Jupiter is the brightest celestial beacon on the wintry scene, though. Standing nearly opposite the Sun in the constellation Taurus, the wandering planet joins yellowish Aldebaran and the Hyades star cluster.

APOD: 2023 May 28 Б Ida and Dactyl: Asteroid and Moon
27.05.2023

This asteroid has a moon. The robot spacecraft Galileo on route to Jupiter in 1993 encountered and photographed two asteroids during its long interplanetary voyage. The second minor planet it photographed, 243 Ida, was unexpectedly discovered to have a moon.

Leonids and Leica
26.11.2002

This lovely view from northern Spain, at Cape Creus on the easternmost point of the Iberian peninsula, looks out across the Mediteranean and up into the stream of the 2002 Leonid meteor shower.

Stars and Planets in the Halo of the Moon
20.03.2003

Photographed on March 13th from Caledon, Ontario, Canada, a bright Moon was surrounded by this lovely halo. Planet Jupiter and stars Procyon, Castor, and Pollux also appear within the circle of lunar light. Castor...

Explorer I
12.02.1998

Inaugurating the era of space exploration for the US, the First Explorer was launched into Earth orbit forty years ago (February 1, 1958) by the Army Ballistic Missle Agency. The Explorer I satellite weighed...

Lightning on Earth
18.08.2004

Nobody knows what causes lightning. It is known that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research.

A Prominence on the Sun
18.09.2015

This eerie landscape of incandescent plasma suspended in looping and twisted magnetic fields stretched toward the Sun's eastern horizon on September 16. Captured through a backyard telescope and narrowband filter in light from ionized hydrogen, the scene reveals a gigantic prominence lofted above the solar limb.

Cirrus over Paris
21.06.2016

What's that over Paris? Cirrus. Typically, cirrus clouds appear white or gray when reflecting sunlight, can appear dark at sunset (or sunrise) against a better lit sky. Cirrus are among the highest types of clouds and are usually thin enough to see stars through.

A Halo Around the Moon
6.12.2008

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.