Featured Research

from universities, journals, and other organizations

Mars' Climate In Flux: Mid-latitude Glaciers

October 18, 2005
Geological Society of America
New high-resolution images of mid-latitude Mars are revealing glacier-formed landscapes far from the Martian poles, says a leading Mars researcher.

The fretted channel and lineated valleys of the central Deuteronilus-Protonilus Mensae region. 1. A Viking Orbiter mosaic and map. Boxes show locations of images in Fig. 2. 2. Color topographic map with each contour line showing 400-meter-elevation difference. 3. Map showing alcoves (narrow arrows) and broad flow trends of lineated valley fill on the valley floor (wide arrows). From Mars Express High Resolution Stereo Camera, THEMIS and MOC images. 4. Topographic profiles from north to south across the same region. From MOLA locations shown in b).
Credit: Image courtesy of Geological Society of America

New high-resolution images of mid-latitude Mars are revealingglacier-formed landscapes far from the Martian poles, says a leadingMars researcher.

Conspicuous trains of debris in valleys, arcs of debris on steepslopes and other features far from the polar ice caps bear strikingsimilarities to glacial landscapes of Earth, says Brown University'sJames Head III. When combined with the latest climate models andorbital calculation for Mars, the geological features make a compellingcase for Mars having ongoing climate shifts that allow ice to leave thepoles and accumulate at lower latitudes.

"The exciting thing is a real convergence of these things,"said Head, who presented the latest Mars climate discoveries on Sunday,16 October, at the Annual Meeting of the Geological Society of Americain Salt Lake City.

"For decades people have been saying that deposits at mid andequatorial latitudes look like they are ice-created," said Head. Butwithout better images, elevation data and some way of explaining it,ice outside of Mars' polar regions was a hard sell.

Now high-resolution images from the Mars Odyssey spacecraft'sThermal Emission Imaging System combined with images from the MarsGlobal Surveyor spacecraft's Mars Orbiter Camera and Mars Orbiter LaserAltimeter can be compared directly with glacier features in mountainand polar regions of Earth. The likenesses are hard to ignore.

For instance, consider what Head calls "lineated valley fill."These are lines of debris on valley floors that run downhill andparallel to the valley walls, as if they mark some sort of past flow.The same sorts of lines of debris are seen in aerial images of Earthglaciers. The difference is that on Mars the water ice sublimes away(goes directly from solid ice to gas, without any liquid phase between)and leaves the debris lines intact. On Earth the lines of debris areusually washed away as a glacier melts.

The lines of debris on Mars continue down valleys and convergeswith other lines of debris - again, just like what's seen on Earthwhere glaciers converge.

"There's so much topography and the debris is so thick (onMars) that it's possible some of the ice might still be there," saidHead. The evidence for present day ice includes unusually degradedrecent impact craters in these areas - just what you'd expect to see ifa lot of the material ejected from the impact was ice that quicklysublimed away.

Another peculiarly glacier-like feature seen in Martianmid-latitudes are concentric arcs of debris breaking away from steepmountain alcoves - just as they do at the heads of glaciers on Earth.

As for how ice could reach Mars lower latitudes, orbitalcalculations indicate that Mars may slowly wobble on its spin axis farmore than Earth does (the Moon minimizes Earth's wobble). This meansthat as Mars' axis tilted to the extremes - up to 60 degrees from theplane of Mars' orbit - the Martian poles get a whole lot more sunshinein the summertime than they do now. That extra sun would likely sublimewater from the polar ice caps, explains Head.

"When you do that you are mobilizing a lot of ice andredistributing it to the equator," Head said. "The climate models aresaying it's possible."

It's pure chance that we happen to be exploring Mars when itsaxis is at a lesser, more Earth-like tilt. This has led to the falseimpression of Mars being a place that's geologically and climaticallydead. In fact, says Head, Mars is turning out to be a place that isconstantly changing.


Lineated Valley Fill at the Dichotomy Boundary on Mars: Evidence for Regional Mid-Latitude GlaciationView abstract:http://gsa.confex.com/gsa/2005AM/finalprogram/abstract_94125.htm

Story Source:

The above story is based on materials provided by Geological Society of America. Note: Materials may be edited for content and length.

Cite This Page:

Geological Society of America. "Mars' Climate In Flux: Mid-latitude Glaciers." ScienceDaily. ScienceDaily, 18 October 2005. <www.sciencedaily.com/releases/2005/10/051018080323.htm>.
Geological Society of America. (2005, October 18). Mars' Climate In Flux: Mid-latitude Glaciers. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2005/10/051018080323.htm
Geological Society of America. "Mars' Climate In Flux: Mid-latitude Glaciers." ScienceDaily. www.sciencedaily.com/releases/2005/10/051018080323.htm (accessed September 17, 2014).

Share This

More Space & Time News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Boeing, SpaceX to Send Astronauts to Space Station

Boeing, SpaceX to Send Astronauts to Space Station

AFP (Sep. 17, 2014) — NASA selected Boeing and SpaceX on Tuesday to build America's next spacecraft to carry astronauts to the International Space Station (ISS) by 2017, opening the way to a new chapter in human spaceflight. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) — Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
NASA Picks Boeing and SpaceX to Ferry Astronauts

NASA Picks Boeing and SpaceX to Ferry Astronauts

AP (Sep. 16, 2014) — NASA is a giant step closer to launching Americans again from U.S. soil. It has announced it has picked Boeing and SpaceX to transport astronauts to the International Space Station in the next few years. (Sept. 16) Video provided by AP
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.


Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


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