Young Martian Terrain
1.08.2001

What caused the pits, ridges, and gullies on otherwise smooth Martian terrain? One hypothesis is water. The lack of craters at this mid-latitude location indicates that the terrain is quite young by geological standards, perhaps only 100,000 years old.

La Nina Earth
15.02.1999

La Niña is a temporary climate change caused by unusually cold water in the central Pacific Ocean. Cold water topping an unusually low sea level is shown as purple in the above false-color picture taken by the orbiting TOPEX/Poseidon satellite in mid-January.

Old Faithful Meets Hale-Bopp
26.05.1997

As Comet Hale-Bopp leaves our Northern Skies, it provides us with yet another burst of joy. On May 11th the fading comet was photographed behind the famous "Old Faithful" water geyser of Yellowstone National Park, Wyoming, USA, Planet Earth.

High Cliffs Surrounding Echus Chasma on Mars
23.07.2008

What created this great cliff on Mars? Did giant waterfalls once plummet through its grooves? With a four-kilometer drop, this high cliff surrounding Echus Chasma, near an impressive impact crater, was carved by either water or lava.

Tardigrade in Moss
26.03.2017

Is this an alien? Probably not, but of all the animals on Earth, the tardigrade might be the best candidate. That's because tardigrades are known to be able to go for decades without...

Infrared Mars
3.03.1999

Was Mars wetter and more Earth-like in its distant past? This false-color composite image of Mars is part of the mounting evidence that liquid water once did play a significant role in Martian surface geology.

Layers of the South Pole of Mars
31.07.2018

What lies beneath the layered south pole of Mars? A recent measurement with ground-penetrating radar from ESA's Mars Express satellite has detected a bright reflection layer consistent with an underground lake of salty water. The reflection comes from about 1.5-km down but covers an area 200-km across.

A Year of Extraterrestrial Fountains and Flows
31.12.2006

The past year was extraordinary for the discovery of extraterrestrial fountains and flows -- some offering new potential in the search for liquid water and the origin of life beyond planet Earth.. Increased evidence was uncovered that fountains spurt not only from Saturn's moon Enceladus, but from the dunes of Mars as well.

Mammatus Clouds Over Mexico
7.06.2004

When do cloud bottoms appear like bubbles? Normal cloud bottoms are flat because moist warm air that rises and cools will condense into water droplets at a very specific temperature, which usually corresponds to a very specific height. After water droplets form that air becomes an opaque cloud.

El Nino Earth
12.11.1997

El Niño is a temporary global climate change resulting from unusually warm water in the central Pacific Ocean. El Niño can cause unusual or severe weather for some locations over the next few months.