Venus: Earth's Cloudy Twin
23.09.1996

If Venus weren't so cloudy it would be more similar to Earth. This picture by the Galileo spacecraft shows just how cloudy Venus is. Venus is very similar to Earth in size and mass - and so is sometimes referred to as Earth's sister planet - but Venus has a quite different climate.

A Lucky Lunar Eclipse
3.04.1996

Tonight's full moon would normally washout the spectacle of Comet Hyakutake's lovely tail, even for those far from light polluted skies. Except that tonight comet observers are in luck - the dance of the planets calls for a total lunar eclipse! Lunar eclipses are caused when the Moon passes through the Earth's shadow.

Opportunity at Santa Maria Crater
29.01.2011

Celebrating 7 years on the surface of the Red Planet, Mars exploration rover Opportunity now stands near the rim of 90 meter wide Santa Maria crater. Remarkably, Opportunity and its fellow rover Spirit were initially intended for a 3 month long primary mission.

Equinox on a Spinning Earth
19.03.2014

When does the line between day and night become vertical? Tomorrow. Tomorrow is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator -- the dividing line between day and night -- becomes vertical and connects the north and south poles.

Retrograde Mars and Saturn
15.09.2016

Wandering Mars and Saturn have spent much of this year remarkably close in planet Earth's night sky. In a sequence of exposures spanning mid-December 2015 through the beginning of this week, this composited...

M27: Not a Comet
5.10.2024

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things encountered during his telescopic expeditions that were definitely not comets. This is number 27 on his now famous not-a-comet list.

Ancient Volcanos of Mars
8.08.2002

Findings of ancient martian microbial fossils in meteorites and liquid water related features on Mars' surface are currently controversial issues. But one thing long established by space-based observations of the Red Planet is the presence of volcanos, as Mars supports some of the largest volcanos in the solar system.

Dark Belt Reappearing on Jupiter
29.11.2010

Why are planet-circling clouds disappearing and reappearing on Jupiter? Although the ultimate cause remains unknown, planetary meteorologists are beginning to better understand what is happening. Earlier this year, unexpectedly, Jupiter's dark Southern Equatorial Belt (SEB) disappeared. The changes were first noted by amateurs dedicated to watching Jupiter full time.

Curiosity s Dusty Self
23.06.2018

Winds on Mars can't actually blow spacecraft over. But in the low gravity, martian winds can loft fine dust particles in planet-wide storms, like the dust storm now raging on the Red Planet.

The Seasons of Saturn
5.04.2003

Since Saturn's axis is tilted as it orbits the Sun, Saturn has seasons, like those of planet Earth ... but Saturn's seasons last for over seven years. So what season is it on Saturn now? Orbiting the equator, the tilt of the rings of Saturn provides quite a graphic seasonal display.