Leaning Tower, Active Sun
1.04.2022

The natural filter of a hazy atmosphere offered this recognizable architecture and sunset view on March 27. Dark against the solar disk, large sunspots in solar active regions 2975 and 2976 are wedged between the Duomo of Pisa and its famous Leaning Tower.

APOD: 2023 August 23 Б The Meteor and the Galaxy
23.08.2023

It came from outer space. It -- in this case a sand-sized bit of a comet nucleus -- was likely ejected many years ago from Sun-orbiting Comet Swift-Tuttle, but then continued to orbit the Sun alone.

The Moons of Earth
4.05.2002

While orbiting the planet during their June 1998 mission, the crew of the Space Shuttle Discovery photographed this view of two moons of Earth. Thick storm clouds are visible in the lovely blue planet...

Southern Lights and Shuttle Glow
6.05.1996

A background of distant stars, sinuous and spiky bands of Southern Lights (Aurora Australis), and the faint glow of charged plasma (ionized atomic gas) surrounding the Space Shuttle Discovery's engines give this photo from the STS-39 mission an eerie, otherworldly look.

A Sun Halo Over Tennessee
9.03.2005

Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.

The Surface of Titan
4.08.1999

If sailing the hydrocarbon seas of Titan, beware of gasoline rain. Such might be a travel advisory issued next millennium for adventurers visiting Titan, the largest moon of Saturn. Images of Titan's surface were released last week from the Keck 10-meter telescope featuring the finest details yet resolved.

The Horsehead Nebula
31.12.2013

The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula in the center of the above photograph. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright red emission nebula.

Total Lunar Eclipse from Sydney
28.05.2021

The reddened shadow of planet Earth plays across the lunar disk in this telescopic image taken on May 26 near Sydney, New South Wales, Australia. On that crisp, clear autumn night a Perigee Full Moon slid through the northern edge of the shadow's dark central umbra.

APOD: 2024 January 14 Б Dragon Aurora over Iceland
14.01.2024

Have you ever seen a dragon in the sky? Although real flying dragons don't exist, a huge dragon-shaped aurora developed in the sky over Iceland in 2019. The aurora was caused...

Uranus' Ring System
30.04.1996

The rings of Uranus are thin, narrow, and dark compared to other planetary ring systems. Brightened artificially by computer, the ring particles reflect as little light as charcoal, although they are really made of ice chucks darkened by rock.