Opportunity Finds Beachfront Property on Mars
NASA scientists have determined that the bedrock outcrop in Eagle Crater, where Opportunity landed, formed in liquid water. The new discovery makes Meridiani Planum a prime target for future exploration.

Martian Salty Sea
Did Mars once have a salty sea? Two new lines of evidence suggest that layered rocks have embedded ripples (called crossbedding), along with high salt concentrations. These hints point to what may once have been a shoreline to a salty sea, according to mission scientists, and the finding has implications for the global climate which today likely could not support such standing water for long.

Mars Berries Once Rich in Iron-Water
The BB-sized spheres found at the Opportunity landing site have a composition rich in iron, according to mineralogical tests. Their origins now appear intimately tied to the presence of water, sulfate-rich salts, and the finely layered rocks.

The Case for Spirit's Water
If the Opportunity site was 'drenched' in water, the Spirit site also has revealed the interior of a volcanic rock called Humphrey, which shows evidence of perhaps bringing up subsurface water with magma. The last stages of crystallization point to some fluid erosion, which suggests further that water may have a role to play globally as well as locally on Mars.

Evidence of Water Found on Mars
Opportunity has found definitive evidence that liquid water was once present in Meridiani Planum - enough water to provide a habitat suitable for life as we know it. The evidence comes from a detailed study of El Capitan, a narrow section of the rock outcrop that is exposed in the crater where the rover landed. Scientists are now certain that underground water percolated through the rocks at some point in the past. They remain unsure, however, about whether it was ever present on the surface.

Meridiani Planum Was Wet
Opportunity scientists now believe that the landing site near the martian equator was once 'an area where liquid water once drenched the rocks'. In places, up to forty percent of the outcrop can be composed of sulfate-rich salts, akin to magnesium sulfate like epsom salts. The presence of bromine also suggests that the region may have formed by slow evaporation and percolation by water.

Divining Water: The Plot Thickens?
One of the fascinating mysteries unraveling on Mars is the origin of the tiny spherules which dot the crater floor at Opportunity's Meridiani Planum. If these tiny balls turn out to show significant layering, a theory of their watery past would likely rise in prominence. A planned briefing on Tuesday in Washington is anticipated to present new 'significant' evidence related to the rovers' primary mission: to follow the water.

Into the Briny Deep - Perhaps
Spirit has discovered irregular patterns in a small patch of fine-grained soil at Gusev Crater. One possible explanation is that there is liquid brine -salty water - below the surface. Scientists plan to use one of the rover's wheels to dig a trench, so they can find out what's going on there. If brine is present, it could mean that Mars has the potential to support microscopic life.

Born Bone Dry
Mars has polar ice caps, and pockets of liquid water are suspected to exist beneath the martian surface. Yet compared to Earth, Mars is a very dry place. Why is Mars so arid? The answer may lie in the random nature of planetary birth.

Opportunity Finds 'Blueberry Muffins'
Small spheres of rock are embedded within the layered bedrock outcrop that Opportunity has begun to explore. Scientists said the rock looked a bit like a blueberry muffin.