Blue Marble Earth
5.02.2022

Welcome to planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen.

Barred Spiral Galaxy NGC 1300
15.10.2022

Across the center of this spiral galaxy is a bar. And at the center of this bar is smaller spiral. And at the center of that spiralбis a supermassiveбblack hole.б This all happens...

Structure in the Tail of Comet 12P/Pons Brooks
15.02.2024

Heading for its next perihelion passage on April 21, Comet 12P/Pons-Brooks is growing brighter. The greenish coma of this periodic Halley-type comet has become relatively easy to observe in small telescopes. But the bluish...

Tycho Brahe Measures the Sky
6.01.2001

Tycho Brahe was the most meticulous astronomical observer of his time. Brahe, who lived between 1546 and 1601, set out to solve the day's most pressing astronomical problem: to determine whether the Earth or the Sun was at the center of the Solar System.

Gamma-ray Burster
17.12.1997

Gamma-ray bursts seem to be the most powerful explosions in the Universe. Yet their sources continue to elude researchers who stand in awe and frustration at the bursts' transient, enigmatic behavior. The blinking gif above illustrates the latest hard-won result in the quest to identify and understand the nature of the bursters.

IC 4628: The Prawn Nebula
20.10.2006

South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, radiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow.

Comet Hale-Bopp Over Val Parola Pass
8.08.1999

Comet Hale-Bopp became much brighter than any surrounding stars. It was seen even over bright city lights. Out away from city lights, however, it put on quite a spectacular show. Here Comet Hale-Bopp was photographed above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy.

Markarian s Eyes
8.06.2007

Across the heart of the Virgo Galaxy Cluster lies a string of galaxies known as Markarian's Chain. Prominent in Markarian's Chain are these two interacting galaxies, NGC 4438 (left) and NGC 4435 - also known as The Eyes.

Equinox and Harvest Moon
24.09.2010

Did you enjoy the moonlight last night? The Full Moon closest to autumnal equinox and the beginning of Fall is traditionally known as the Harvest Moon, rising opposite the Sun and illuminating fields at harvest time after sunset. This year's northern hemisphere autumnal equinox occurred yesterday, September 23rd, at 03:09 Universal Time.

Comet Lovejoy over Paranal
28.12.2011

Comet Lovejoy (C/2011 W3) survived its close encounter with the Sun earlier this month, taking its place among wonders of the southern skies just in time for Christmas. Seen here before sunrise from Paranal Observatory in Chile, the sungrazing comet's tails stretch far above the eastern horizon.