An Iridescent Cloud Over France
13.04.2004

Why would a cloud appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. These clouds are formed of small water droplets of nearly uniform size.

Vega
23.08.1998

Vega is a bright blue star 25 light years away. Vega is the brightest star in the Summer Triangle, a group of stars easily visible summer evenings in the northern hemisphere. The name Vega...

Sharp Silhouette
21.09.2006

Though it's 93 million miles away, the Sun still hurts your eyes when you look at it. But bright sunlight (along with accurate planning and proper equipment!) resulted in this sharp silhouette of spaceship and space station.

Moon and Mars Tonight
23.12.2007

The Full Moon and a brilliant, ruddy Mars will share the sky tonight. Skygazers can easily enjoy the celestial pairing as the two are separated by a degree or even less. In fact, seen from parts of northern North America and Europe, the Moon will actually occult (pass in front of) the Red Planet.

Manhattan Moonrise
16.06.2017

A Full Moon rose as the Sun set on June 9, known to some as a Strawberry Moon. Close to the horizon and taking on the warm color of reflected sunlight filtered through...

APOD: 2024 April 23 Б Contrail Shadow X
23.04.2024

What created this giant X in the clouds? It was the shadow of contrails illuminated from below. When airplanes fly, humid engine exhaust may form water droplets that might freeze in Earth's cold upper atmosphere. These persistent streams of water and ice scatter light from the Sun above and so appear bright from below.

Jupiter with the Great Red Spot
10.01.2026

Jupiter reaches its 2026 opposition today, January 10. That puts our Solar System's most massive planet opposite the Sun and near its closest and brightest for viewing from planet Earth. In fact, captured...

Sunspot Region 30
18.07.2002

The solar active region designated number 0030 is now appearing on the visible hemisphere of the closest star. Dwarfed by the Sun's disk, the group of sunspots which make up region 30 actually cover an enormous area -- nearly 10 times the size of Earth.

The Long Shadow of the Moon
27.11.2003

The long shadow of the Moon fell across the continent of Antarctica on November 23rd, during the second total solar eclipse of 2003. In this view from orbit, based on data from the MODIS instrument on board the Earth observing Aqua satellite, the Moon's shadow stretches for almost 500 kilometers.

The Big Corona
15.09.1999

Most photographs don't adequately portray the magnificence of the Sun's corona. Seeing the corona first-hand during a total solar eclipse is best. The human eye can adapt to see features and extent that photographic film usually cannot. Welcome, however, to the digital age.