Active Comet ISON
16.11.2013

Falling through planet Earth's predawn skies toward its close encounter with the Sun on November 28, Comet ISON is coming to life. The much anticipated comet has now been reported to have substantially increased in brightness, surging to naked-eye visibility for dark sites and sprouting a more complex tail.

APOD: 2023 May 3 Б Centaurus A: A Peculiar Island of Stars
3.05.2023

Galaxies are fascinating. In galaxies, gravity alone holds together massive collections of stars, dust, interstellar gas, stellar remnants and dark matter. Pictured is NGC 5128, better known as Centaurus A. Cen A is the fifth brightest galaxy on the sky and is located at a distance of about 12 million light years from Earth.

Active Galaxy Centaurus A
10.01.2008

A mere 11 million light-years away, Centaurus A is a giant elliptical galaxy - the closest active galaxy to Earth. This remarkable composite view of the galaxy combines image data from the x-ray ( Chandra), optical(ESO), and radio(VLA) regimes.

Manhattanhenge: A New York Sunset
13.07.2007

Today, if it is clear, well placed New Yorkers can go outside at sunset and watch their city act like a modern version of Stonehenge. Manhattan will flood dramatically with sunlight just as the Sun sets precisely on the centerline of every street.

APOD: 2025 July 30 Б Coronal Loops on the Sun
30.07.2025

Our Sun frequently erupts in loops. Hot solar plasma jumps off the Sun's surface into prominences, with the most common type of prominence being a simple loop. The loop shape originates from the Sun's magnetic field, which is traced by spiraling electrons and protons.

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.

X-Ray Moon
4.10.2003

This x-ray image of the Moon was made by the orbiting ROSAT (Röntgensatellit) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray moon, the darker half of the moon, and the x-ray sky background.

X Ray Moon
14.09.2002

This x-ray image of the Moon was made by the orbiting ROSAT (Röntgensatellit) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray moon, the darker half of the moon, and the x-ray sky background.

50000 Kilometers over the Sun
19.09.2016

What's happening at the edge of the Sun? Although it may look like a monster is rampaging, what is pictured is actually only a monster prominence -- a sheath of thin gas held above the surface by the Sun's magnetic field.

A Green Flash from the Sun
9.09.1997

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.