Science Daily: Mars

MAVEN's top 10 discoveries at Mars

Since its launch in November 2013 and its orbit insertion in September 2014, MAVEN has been exploring the upper atmosphere of Mars. MAVEN is bringing insight to how the sun stripped Mars of most of its atmosphere, turning a planet once possibly habitable to microbial life into a barren desert world.

Hot rocks, not warm atmosphere, led to relatively recent water-carved valleys on Mars

Some scientists have interpreted water-carved valleys on Mars formed within the last few billion years as a sign of either an active groundwater system or of transient warm periods in the atmosphere. But new research shows that snow and ice melted by hot impact ejecta could have produced enough water to carve those valleys with no groundwater or heat wave required.

Collateral damage from cosmic rays increases cancer risks for Mars astronauts

The cancer risk for a human mission to Mars has effectively doubled following a study predicting a dramatic increase in the disease for astronauts traveling to the red planet or on long-term missions outside the protection of Earth's magnetic field. The new predictive model shows radiation from cosmic rays extends from damaged to otherwise healthy 'bystander' cells.

Study estimates amount of water needed to carve Martian valleys

A new study calculates the amount of water needed to carve the ancient network of valleys on Mars and concludes the planet's surface was once much more watery than previously thought. The study bolsters the idea that Mars had a warmer climate and active hydrologic cycle, with water evaporating from an ancient ocean, returning to the surface as rainfall and eroding the extensive network of valleys.

Rover findings indicate stratified lake on ancient Mars

A long-lasting lake on ancient Mars provided stable environmental conditions that differed significantly from one part of the lake to another, according to a comprehensive look at findings from the first three-and-a-half years of NASA's Curiosity rover mission.

'Halos' discovered on Mars widen time frame for potential life

Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica -- called "halos" -- has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed.

History of Titan's landscape resembles that of Mars, not Earth

In a paper published in Science, researchers report that Titan, like Mars but unlike Earth, has not undergone any active plate tectonics in its recent past. The upheaval of mountains by plate tectonics deflects the paths that rivers take. The team found that this telltale signature was missing from river networks on Mars and Titan.

How hard did it rain on Mars?

Heavy rain on Mars reshaped the planet's impact craters and carved out river-like channels in its surface billions of years ago, according to a new study. Scientists show that changes in the atmosphere on Mars made it rain harder and harder, which had a similar effect on the planet's surface as we see on Earth.

Lull in Mars' giant impact history

From the earliest days of our solar system's history, collisions between astronomical objects have shaped the planets and changed the course of their evolution. Studying the early bombardment history of Mars, scientists have discovered a 400-million-year lull in large impacts early in Martian history.

Detailed map of potential Mars rover landing site

Mineral deposits in a region on Mars called Northeast Syrtis Major suggest a plethora of once-habitable environments. By mapping those deposits in the region's larger geological context, the research could help set the stage for a possible rover mission.

NASA's MAVEN reveals Mars has metal in its atmosphere

Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results. The metal ions can reveal previously invisible activity in the mysterious electrically charged upper atmosphere (ionosphere) of Mars.

Solar wind stripped Martian atmosphere away

Solar wind and radiation are responsible for stripping the Martian atmosphere, transforming Mars from a planet that could have supported life billions of years ago into a frigid desert world, according to new results.

Mars volcano, Earth's dinosaurs went extinct about the same time

Arsia Mons produced one new lava flow at its summit every 1 to 3 million years during the final peak of activity, about 50 million years ago. The last volcanic activity there ceased about 50 million years ago -- around the time of Earth's Cretaceous-Paleogene extinction, when large numbers of our planet's plant and animal species (including dinosaurs) went extinct.

Does Mars have rings? Not right now, but maybe one day

Researchers have developed a model that suggests that debris that was pushed into space from an asteroid or other body slamming into Mars around 4.3 billion years ago and alternates between becoming a planetary ring and clumping up to form a moon.

Eruptions on the sun trigger surprising phenomenon near Earth

Eruptions on the Sun's surface not only send bursts of energetic particles into the Earth's atmosphere causing disturbances in our planet's magnetic field, they can also strangely decrease the number of free electrons over large areas in the polar region of the ionosphere, new research concludes.

NASA Mars Orbiter tracks back-to-back regional storms

A regional dust storm currently swelling on Mars follows unusually closely on one that blossomed less than two weeks earlier and is now dissipating, as seen in daily global weather monitoring by NASA's Mars Reconnaissance Orbiter.