A Zodiacal Sky over Horseshoe Bend
21.05.2017

What's causing the unusual ray of white light extending upward from the central horizon? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System rises prominently before sunrise and is called zodiacal light.

The N44 Superbubble
24.06.2017

What created this gigantic hole? The vast emission nebula N44 in our neighboring galaxy the Large Magellanic Cloud has a large, 250 light-year hole and astronomers are trying to figure out why. One possibility is particle winds expelled by massive stars in the bubble's interior that are pushing out the glowing gas.

APOD: 2023 December 17 Б Geminids over Chinas Nianhu Lake
16.12.2023

Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids -- because shower meteors all appear to come from a radiant toward Gemini.

A Polar Martian Dust Storm
9.10.2000

On August 29, a large dust storm was photographed erupting out from the north polar cap of Mars. Such dust storms are not uncommon as summer advances in the north. In the above picture...

Sun, Moon, Hot Air Balloon
6.06.2003

Anticipating the celestial shadow play of a solar eclipse, sky gazers across Germany watched the Sun rise on May 31. In Bonn, astrophotographer Thilo Kranz had set up his small refractor telescope and camera on the Kennedy Bridge across the Rhein river to get a good view to the northeast.

Venus: Earths Cloudy Twin
16.05.2004

This picture by the Galileo spacecraft shows just how cloudy Venus is. Venus is very similar to Earth in size and mass - and so is sometimes referred to as Earth's sister planet - but Venus has a quite different climate.

Trifid Pillars and Jets
8.06.1999

Dust pillars are like interstellar mountains. They survive because they are more dense than their surroundings, but they are being slowly eroded away by a hostile environment. Visible in the above picture...

The Milky Way in Infrared
29.01.2000

At night, from a dark location, part of the clear sky looks milky. This unusual swath of dim light is generally visible during any month and from any location. Until the invention of the telescope, nobody really knew what the "Milky Way" was.

An Active Sunspot Viewed Sideways
2.04.2007

Why are there dark spots on the sun? Although noted for thousands of years, sunspots have been known for decades to be regions of the Sun that are slightly depressed and cooled by the Sun's complex and changing magnetic field.

Astronomer s Moon
24.08.2007

Jupiter is an astronomer's planet -- its large size and contrasting global cloud belts and zones allow detailed studies with a range of earthbound telescopes. On the other hand, most telescopic views of Jupiter's moons usually show only featureless, tantalizing points of light hovering near the ruling gas giant.