Featured Research

from universities, journals, and other organizations

Dramatic Wind Action Detailed On Mars

Date:
January 28, 2008
Source:
NASA/Jet Propulsion Laboratory
Summary:
Mars has an ethereal, tenuous atmosphere with less than one-percent the surface pressure of Earth, which challenges scientists to explain complex, wind-sculpted landforms seen with unprecedented detail in images from NASA's Mars Reconnaissance Orbiter. One of the main questions has been if winds on present-day Mars are strong enough to form and change geological features, or if wind-constructed formations were made in the past, perhaps when winds speeds and atmospheric pressures were higher.

Dust-devils are vortices of wind that form when air rising from a warm surface encounters shear in the above atmosphere.
Credit: NASA/JPL/University of Arizona

Mars has an ethereal, tenuous atmosphere with less than one-percent the surface pressure of Earth, which challenges scientists to explain complex, wind-sculpted landforms seen with unprecedented detail in images from NASA's Mars Reconnaissance Orbiter.

Related Articles


One of the main questions has been if winds on present-day Mars are strong enough to form and change geological features, or if wind-constructed formations were made in the past, perhaps when winds speeds and atmospheric pressures were higher.

The eye-opening new views of wind-driven Mars geology come from the University of Arizona's High Resolution Imaging Science Experiment camera (HiRISE). As the orbiter flies at about 3,400 meters per second (7,500 mph) between 250 and 315 kilometers (155 to 196 miles) above the Martian surface, this camera can see features as small as half a meter (20 inches).

"We're seeing what look like smaller sand bedforms on the tops of larger dunes, and, when we zoom in more, a third set of bedforms topping those," said HiRISE co-investigator Nathan Bridges of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "On Earth, small bedforms can form and change on time scales as short as a day."

There are two kinds of "bedforms," or wind-deposited landforms. They can be sand dunes, which are typically larger and have distinct shapes. Or they can be ripples, in which sand is mixed with coarser particles. Ripples are typically smaller and more linear.

HiRISE also shows detail in sediments deposited by winds on the downwind side of rocks. Such "windtails" show which way the most current winds have blown, Bridges said. They have been seen before, but only by rovers and landers, never by an orbiter. Researchers can now use HiRISE images to infer wind directions over the entire planet.

Scientists discovered miles-long, wind-scoured ridges called "yardangs" with the first Mars orbiter, Mariner 9, in the early 1970s. New HiRISE images reveal surface texture and fine-scale features that are giving scientists insight into how yardangs form. "HiRISE is showing us just how interesting layers in yardangs are," Bridges said. "For example, we see one layer that appears to have rocks in it. You can actually see rocks in the layer, and if you look downslope, you can see rocks that we think have eroded out from that rocky layer above."

New images show that some layers in the yardangs are made of softer materials that have been modified by wind, he added. The soft material could be volcanic ash deposits, or the dried-up remnants of what once were mixtures of ice and dust, or something else. "The fact that we see layers that appear to be rocky and layers that are obviously soft says that the process that formed yardangs is no simple process but a complicated sequence of processes," Bridges said.

"HiRISE keeps showing interesting things about terrains that I expected to be uninteresting," said Alfred McEwen of the University of Arizona Lunar and Planetary Laboratory, HiRISE principal investigator. "I was surprised by the diversity of morphology of the thick dust mantles. Instead of a uniform blanket of smooth dust, there are often intricate patterns due to the action of the wind and perhaps light cementation from atmospheric volatiles."

Paul Geissler of the U.S. Geological Survey, Flagstaff, Ariz., has discovered from HiRISE images that dark streaks coming from Victoria Crater probably consist of streaks of dark sand blown out from the crater onto the surface. Scientists had wondered if wind might have blown away lighter-colored surface material, exposing a darker underlying surface. Geissler is comparing HiRISE images to images taken by NASA's Mars Exploration Rover Opportunity rover at Victoria Crater.

Bridges is lead author and McEwen is a co-author on the paper titled "Windy Mars: A dynamic planet as seen by the HiRISE camera" in Geophysical Research Letters in December.


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Jet Propulsion Laboratory. "Dramatic Wind Action Detailed On Mars." ScienceDaily. ScienceDaily, 28 January 2008. <www.sciencedaily.com/releases/2008/01/080124191716.htm>.
NASA/Jet Propulsion Laboratory. (2008, January 28). Dramatic Wind Action Detailed On Mars. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2008/01/080124191716.htm
NASA/Jet Propulsion Laboratory. "Dramatic Wind Action Detailed On Mars." ScienceDaily. www.sciencedaily.com/releases/2008/01/080124191716.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Space & Time News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Mars Rover Opportunity Celebrates 11-Year Anniversary

Mars Rover Opportunity Celebrates 11-Year Anniversary

Rumble (Jan. 26, 2015) Eleven years ago NASA&apos;s Opportunity rover touched down on Mars for what was only supposed to be a 90-day mission. Since then it has traveled 25.9 miles (41.7 kilometers), further than any other off-Earth surface vehicle has ever driven. Credit to &apos;NASA&apos;. Video provided by Rumble
Powered by NewsLook.com
NASA's On Course To Take Pluto's Best Photo Ever

NASA's On Course To Take Pluto's Best Photo Ever

Newsy (Jan. 25, 2015) NASA&apos;s New Horizons probe is en route to snap a picture of Pluto this summer, but making sure it doesn&apos;t miss its one chance to do so starts now. Video provided by Newsy
Powered by NewsLook.com
Rosetta Captures Stunning Views, Diverse Data Of Comet 67P

Rosetta Captures Stunning Views, Diverse Data Of Comet 67P

Newsy (Jan. 23, 2015) The first images of the European Space Agency&apos;s Rosetta probe comet orbit could provide clues about its origin and how it got its unique shape. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins