Tail Wags of Comet Ikeya Zhang
15.05.2002

As Comet Ikeya-Zhang approached the Sun two months ago, it developed a complex blue ion tail. The tail was composed of ions that boiled off the nucleus and were pushed away from the Sun by the out-flowing fast-moving particles of the solar wind.

Phases of Venus
21.05.2004

Venus is currently falling out of the western evening sky. Second planet from the Sun and third brightest celestial object after the Sun and Moon, Venus has been appreciated by casual sky gazers as a brilliant beacon above the horizon after sunset. But telescopic images have also revealed its dramatic phases.

Venus and the Chromosphere
11.06.2004

Enjoying the 2004 Transit of Venus from Stuttgart, Germany, astronomer Stefan Seip recorded this fascinating, detailed image of the Sun. Revealing a network of cells and dark filaments against a bright solar disk with spicules and prominences along the Sun's limb, his telescopic picture was taken through an H-alpha filter.

East to West, Light and Shadow
25.11.2016

On this November morning an old crescent Moon and morning star rise just before the Sun in a wide panoramic skyscape from Kenya's Amboseli National Park. Still below the limbs of an acacia tree and the eastern horizon, the Sun's position is easy to find though.

Large Sunspot Groups 10484 and 10486
26.10.2003

Two unusually large sunspot groups are now crossing the face of the Sun. Each group, roughly the size of Jupiter, is unusual not only for its size but because it is appearing over three years after solar maximum, the peak of solar surface activity.

Opportunity s Mars Analemma
16.05.2014

Staring up into the martian sky, the Opportunity rover captured an image at 11:02 AM local mean time nearly every 3rd sol, or martian day, for 1 martian year. Of course, the result...

Analemma 2010
30.12.2010

Looking back on the year, have you wondered where the Sun was in the sky each day during 2010 at exacty 9am UT? Of course you have. Search no further for the answer! It was somewhere along this celestial figure 8 curve known as an analemma.

Violent Sunspot Group AR 1302 Unleashes a Flare
28.09.2011

One of the most active sunspot groups in years is currently crossing the Sun. AR 1302 first came around the Sun's edge last week and is so large it can be seen without a telescope.

Analemma over the Callanish Stones
17.09.2022

If you went outside at the same time every day and took a picture that included the Sun, how would the Sun's position change? A more visual answer to that question is an analemma, a composite image taken from the same spot at the same time over the course of a year.

Comet Hyakutake's Orbit
13.03.1996

Where did Comet Hyakutake come from? The orbits of the Earth and this brightening comet are shown in the above diagram. The blue disk is bounded by the circular orbit of the Earth about the central Sun. The comet's path outlines the green shape.