Solar System Family Portrait
29.06.2022

Yes, but have you ever seen all of the planets at once? A rare roll-call of planets has been occurring in the morning sky for much of June. The featured fisheye all-sky image, taken...

Jupiter Rotates as Moons Orbit
25.10.2022

Jupiter and its moons move like our Sun and its planets. Similarly, Jupiter spins while its moons circle around. JupiterБs rotation can be observed by tracking circulating dark belts and light zones. The Great Red Spot, the largest storm known, rotates to become visible after about 15 seconds in the 48-second time lapse video.

The Perseus Cluster of Galaxies
5.04.1996

Here is one of the largest objects that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies.

Moonrise Over Turkey
16.06.2009

Is the Moon larger when near the horizon? No -- as shown above, the Moon appears to be very nearly the same size no matter its location on the sky. Oddly, the cause or causes for the common Moon Illusion are still being debated.

A Fading Moonset Over Hong Kong
15.12.2009

Do stars appear dimmer when nearer the horizon? Yes -- atmospheric air absorbs and reradiates light, so that the greater the airmass through which one peers, the fainter an object will appear. Pictured above in a multi-frame image, stars, the planet Jupiter, and even the Moon show the horizon-dimming effects of Earth's nearly-transparent atmosphere.

The Spotty Surface of Betelgeuse
6.01.2010

Betelgeuse really is a big star. If placed at the center of our Solar System it would extend to the orbit of Jupiter. But like all stars except the Sun, Betelgeuse is so distant it usually appears as a single point of light, even in large telescopes.

Tyrrhenian Sea and Solstice Sky
21.12.2010

Today the solstice occurs at 23:38 Universal Time, the Sun reaching its southernmost declination in planet Earth's sky. Of course, the December solstice marks the beginning of winter in the northern hemisphere and summer in the south.

Celestial Trails over Greece
4.05.2011

If you watch the horizon at just the right place and at just the right time, you can witness some spectacular juxtapositions between Earth and sky. In the above video, stars, the Moon, and even a partially eclipsed Sun were recorded rising and setting over photogenic landmarks in Greece.

Pleiades Deep Field
21.09.2011

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it like this: all dusty. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city.

Comet ISON Rising
27.11.2013

Will Comet ISON survive tomorrow's close encounter with the Sun? Approaching to within a solar diameter of the Sun's surface, the fate of one of the most unusual comets of modern times will finally be determined.