Tag Archives: climate

Aeolis Serpens, Mars’ longest sinuous ridge, is an ancient riverbed

Posted on May 17, 2013 by rburnham

A linear ridge that winds for more than 200 kilometers (120 miles) through part of South Australia was a river channel roughly 10 million years ago. After the paleoriver stopped flowing, silica-rich groundwater seeped into the riverbed, cementing its sediments.

Posted in Reports | Tagged , , , , , , , , , , | Comments Off

Most deltas on Mars created by short, catastrophic floods

Posted on April 22, 2013 by rburnham

Rivers that run into lakes and other standing bodies of water drop sediment where the flow slackens as it enters the body of water. Over time, the accumulating material builds a delta — a wedge of sediment whose form can … Continue reading →

Posted in Reports | Tagged , , , , , , , | Comments Off

Are brines actually needed to make recurring slope lineae flow?

Posted on April 5, 2013 by rburnham

Recurring slope lineae (RSL) are finger-like dark lines on steep slopes that appear and grow longer during the warmest time of year, then fade and disappear over winter. They repeat the following Mars year in the same places. While scientists … Continue reading →

Posted in Reports | Tagged , , , , , , , , , , , , , , , , | Comments Off

‘Faint young Sun paradox’ a problem for Mars (and Earth, too)

Posted on April 3, 2013 by rburnham

Astronomers say that billions of years ago when the Sun was young, it shone with only 70 percent its current brightness, notes Robert Craddock (Smithsonian Institution). If that were true of today’s Sun,

Posted in Reports | Tagged , , , , , , , , , | Comments Off

Mars’ ancient climate had a “wet-pass” filter

Posted on January 17, 2013 by rburnham

Volcanic eruptions — and the rocks they produce — dominate the surface of the Red Planet. Mars also shows evidence for activity by liquid water — sediments, channels, and valley networks — through much of its history. While volcanos can … Continue reading →

Posted in Reports | Tagged , , , , , , , , , , | 1 Comment

Mars’ explosive childhood

Posted on December 14, 2012 by rburnham

Mars is widely understood to be a volcanic planet — its surface shows abundant evidence of volcanic activity, both ancient and more recent. Spacecraft detect lava flows in many locations, and spectroscopic evidence of volcanic rocks lies almost everywhere. The … Continue reading →

Posted in Reports | Tagged , , , , , , , , , | 1 Comment

Hesperian lava floods thicker than previously thought

Posted on October 23, 2012 by rburnham

A study examining layered “megablocks” of lava in the central parts of Mars craters concludes that flood lavas in the Hesperian epoch were at least 23 percent thicker than previously known. The research says this shows there has been more … Continue reading →

Posted in Reports | Tagged , , , , | Comments Off

Hidden valley at the north pole

Posted on March 28, 2012 by rburnham

The north polar cap of Mars has a wide, deep trough called Chasma Boreale that slices into the polar cap for 560 kilometers (350 miles). The floor of the chasma exposes a layer of sand and dust cemented with water … Continue reading →

Posted in Reports | Tagged , , , , , , , , | Comments Off

Home Plate’s volcanic bomb landed with a splat

Posted on January 11, 2012 by rburnham

One of the unusual features that Mars Exploration Rover Spirit discovered at Home Plate, a former hydrothermal vent in the Columbia Hills, was a “bomb sag,” complete with its partially embedded volcanic bomb. To geologists, volcanic bombs are rocks or … Continue reading →

Posted in Reports | Tagged , , , , , , , , | 1 Comment

No flow found in north polar ice layers

Posted on January 10, 2012 by rburnham

The northern polar ice cap of Mars contains a thick stack of layers rich in water ice. Under the right conditions ice can flow, as seen in ice sheets and glaciers on Earth. What about Mars? A group of scientists … Continue reading →

Posted in Reports | Tagged , , , | Comments Off