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.

APOD: 2023 July 4 Б Aurora over Icelandic Waterfall
4.07.2023

It seemed like the sky exploded. The original idea was to photograph an aurora over a waterfall. After waiting for hours under opaque clouds, though, hope was running out. Others left. Then, unexpectedly, the clouds moved away.

Goldilocks Zones and Stars
31.01.2020

The Goldilocks zone is the habitable zone around a star where it's not too hot and not too cold for liquid water to exist on the surface of orbiting planets. This intriguing infographic...

CME, Comet, and Planet Earth
15.03.2013

After appearing in a popular photo opportunity with a young crescent Moon near sunset, naked-eye Comet PanSTARRS continues to rise in northern hemisphere skies. But this remarkable interplanetary perspective from March 13, finds the comet posing with our fair planet itself - as seen from the STEREO Behind spacecraft.

Halo of the Cat s Eye
31.08.2012

The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this tantalizing image, processed to reveal the enormous but extremely faint halo of gaseous material, about 6 light-years across, which surrounds the brighter, familiar planetary nebula.

Sunspot Metamorphosis: From Bottom to Top
16.02.2005

Sunspots -- magnets the size of the Earth -- are normally seen flat on the Sun. The above digital metamorphosis, however, shows a sunspot as it appears at increasing heights, effectively in three dimensions. The above...

A Winter Solstice
21.12.1997

Today is the Winter Solstice, the shortest day of the year in the Northern Hemisphere. The yearly cycle of Seasons on planet Earth once again finds the Sun at its lowest point in the Northern Sky.

Aurora over Maine
17.09.2014

It has been a good week for auroras. Earlier this month active sunspot region 2158 rotated into view and unleashed a series of flares and plasma ejections into the Solar System during its journey across the Sun's disk.

A Brighter Comet LINEAR
25.06.2001

Brighter than ever expected, comet LINEAR -- you know, the one designated C/2001 A2 -- is a sight to see in southern skies. This comet LINEAR first brightened impressively in late March as its active nucleus began to fragment, prompting some speculation that the comet might soon break up completely.

Halo of the Cat s Eye
20.10.2018

Not a Falcon 9 rocket launch after sunset, the Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very...