Sunspot Group AR 2339 Crosses the Sun
29.06.2015

How do sunspots evolve? Large dark sunspots -- and the active regions that contain them -- may last for weeks, but all during that time they are constantly changing. Such variations were particularly apparent...

Kepler Discovers How Planets Move
13.09.1997

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Philadelphia Perigee Full Moon
18.11.2016

A supermoon sets over the metropolis of Philadelphia in this twilight snapshot captured on November 14 at 6:21am Eastern Standard Time. Within hours of the Moon's exact full phase, that time does correspond to a lunar perigee or the closest point in the Moon's elliptical orbit around our fair planet.

Kepler Discovers How Planets Move
31.08.1996

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Comet PANSTARRS and the Andromeda Galaxy
3.04.2013

Currently, comet PANSTARRS is passing nearly in front of the galaxy Andromeda. Coincidentally, both comet and galaxy appear now to be just about the same angular size. In physical size, even though Comet PANSTARRS...

Alpha Cam: Runaway Star
24.11.2006

Runaway stars are massive stars traveling rapidly through interstellar space. Like a ship plowing through cosmic seas, runaway star Alpha Cam has produced this graceful arcing bow wave or bow shock - moving at over 60 kilometers per second and compressing the interstellar material in its path.

The Veil Nebula Unveiled
6.12.2005

These wisps of gas are all that remain visible of a Milky Way star. Many thousands of years ago that star exploded in a supernova leaving the Veil Nebula, pictured above. At the time...

Help Aldebaran Map the Moon
28.07.1997

Turn on your camcorder, go outside, and become an astronomer. How?. Tomorrow morning, our Moon will pass directly in front of Aldebaran, the brightest star in this picture and in entire constellation of Taurus.

Kepler Discovers How Planets Move
6.06.1999

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Apollo s Analemma
22.09.2013

Today, the Sun crosses the celestial equator heading south at 20:44 Universal Time. An equinox (equal night), this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south.