Circumpolar Star Trails
17.01.2019

As Earth spins on its axis, the stars appear to rotate around an observatory in this well-composed image from the Canary Island of Tenerife. Of course, the colorful concentric arcs traced out by the stars are really centered on the planet's North Celestial Pole.

Earth, Clouds, Sky, Comet
3.04.1997

Does a comet's dust tail always orbit behind it? Since comets rotate, they shed gas and dust in all directions equally. Small ice and dust particles expelled by the comet, however, are literally pushed around by sunlight. The smaller the particle, the greater the effect.

Night on Venus in Infrared from Orbiting Akatsuki
6.06.2016

Why is Venus so different from Earth? To help find out, Japan launched the robotic Akatsuki spacecraft which entered orbit around Venus late last year after an unplanned five-year adventure around the inner Solar System.

The Shadow of Phobos
28.03.2003

Hurtling through space above the Red Planet, potato-shaped Phobos completes an orbit of Mars in less than eight hours. In fact, since its orbital period is shorter than the planet's rotation period, Mars-based...

Jupiters Clouds from Cassini
11.09.2005

Gas giant Jupiter is the solar system's largest world with about 320 times the mass of planet Earth. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible in very modest sized telescopes.

Shadow Of Phobos
4.11.1999

Hurtling through space above the Red Planet, potato-shaped Phobos completes an orbit of Mars in less than eight hours. In fact, since its orbital period is shorter than the planet's rotation period, Mars-based...

The Shadow of Phobos
17.09.2005

(xxxedit and linkxxx) Hurtling through space above the Red Planet, potato-shaped Phobos completes an orbit of Mars in less than eight hours. In fact, since its orbital period is shorter than the planet...

Jupiter s Brain
31.01.2001

Gas giant Jupiter is the solar system's largest world with about 320 times the mass of planet Earth. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible in very modest sized telescopes.

WIRO at Jupiter
12.03.2003

Gazing out over the mountaintops from the Wyoming InfraRed Observatory (WIRO), astronomers recently recorded this bizarre looking image of the solar system's ruling planet, gas giant Jupiter. The false-color picture is a composite...

Julius Caesar and Leap Days
28.02.2020

In 46 BC Julius Caesar reformed the calendar system. Based on advice by astronomer Sosigenes of Alexandria, the Julian calendar included one leap day every four years to account for the fact that an Earth year is slightly more than 365 days long.