Texarkana, TX 60° View Live Radar Thu H 73° L 52° Fri H 76° L 62° Sat H 77° L 60° Weather Sponsored By:

Erosion is revealing surprising amounts of ice on Red Planet

Erosion is revealing surprising amounts of ice on Red Planet

January 13th, 2018 by Los Angeles Times in National News

Thanks to erosion wearing away surface rock on Mars, scientists using NASA's Mars Reconnaissance Orbiter have spotted thick deposits of ice in the planet's mid-latitudes that extend hundreds of feet deep.

The discovery, described in the journal Science, could offer researchers a tantalizing new spot to sample our dusty, rusty neighbor. "This ice is a critical target for science and exploration: it affects modern geomorphology, is expected to preserve a record of climate history, influences the planet's habitability, and may be a potential resource for future exploration," the study authors wrote.

In spite of its dry appearance, about a third of the Red Planet actually holds shallow ground ice. But while that frozen water's extent is fairly well known, other crucial details—how thick it is, what its layers look like, and how pure it is—largely remain unknown. If future explorers want to be able to draw down these water sources, scientists are going to have to learn much more about them.

The deposits described in this new paper offer a potential window into some of those mysteries. The researchers examined eight different exposed ice deposits on the planet spotted by the orbiter's HiRISE camera. Seven of them are pole-facing scarps (that is, steep banks or slopes) in the southern hemisphere; one is a cluster of scarps in the northern hemisphere, in Milankovic Crater.

"The scarps are sharply defined and nearly straight, up to (about 3.7 miles) long, and face slightly east of poleward," the scientists wrote.

These ice deposits could start just 1 to 2 meters beneath the surface but extend more than 100 meters (or more than 328 feet) deep. They're capped with a layer of rock and dust that's been cemented with ice. These deposits seem to be pretty pure in terms of composition—not a lot of dust or dirt mixed in—which was not what scientists originally expected.

On one of the scarps, a number of boulders have fallen out as the ice retreats. Those boulders actually allowed scientists to compare before-and-after images to calculate how fast the ice was shrinking back (a few millimeters every summer).

The researchers think the ice deposits started out as snow or frost that fell, was compacted and then recrystallized.

"This interpretation is consistent with the high ice content and the mantling appearance of the host unit," the study authors wrote.

That's not all that different from glaciers on Earth, which form from snow being compacted over hundreds, thousands and even millions of years. Here, glaciers are a crucial tool for understanding our planet's atmospheric history. Each layer of snow laid down over time records a different epoch—and the deeper the layers, the older the epoch. Air pockets trapped in the ice provide tiny, prehistoric samples of air that can be analyzed.

Similarly, these Martian ice deposits could offer scientists a frozen trove of information just waiting to be sampled and studied up close. And because they've already been excavated by erosion, they're much easier to access. "These shallow depths make the ice sheets potentially accessible to future exploration," the authors wrote, "and the scarps present cross-sections of these ices that record past episodes of ice deposition on Mars."

Getting Started/Comments Policy

Getting started

  1. 1. If you frequently comment on news websites then you may already have a Disqus account. If so, click the "Login" button at the top right of the comment widget and choose whether you'd rather log in with Facebook, Twitter, Google, or a Disqus account.
  2. 2. If you've forgotten your password, Disqus will email you a link that will allow you to create a new one. Easy!
  3. 3. If you're not a member yet, Disqus will go ahead and register you. It's seamless and takes about 10 seconds.
  4. 4. To register, either go through the login process or just click in the box that says "join the discussion," type your comment, and either choose a social media platform to log you in or create a Disqus account with your email address.
  5. 5. If you use Twitter, Facebook or Google to log in, you will need to stay logged into that platform in order to comment. If you create a Disqus account instead, you'll need to remember your Disqus password. Either way, you can change your display name if you'd rather not show off your real name.
  6. 6. Don't be a huge jerk or do anything illegal, and you'll be fine.

Texarkana Gazette Comments Policy

The Texarkana Gazette web sites include interactive areas in which users can express opinions and share ideas and information. We cannot and do not monitor all of the material submitted to the website. Additionally, we do not control, and are not responsible for, content submitted by users. By using the web sites, you may be exposed to content that you may find offensive, indecent, inaccurate, misleading, or otherwise objectionable. You agree that you must evaluate, and bear all risks associated with, the use of the Gazette web sites and any content on the Gazette web sites, including, but not limited to, whether you should rely on such content. Notwithstanding the foregoing, you acknowledge that we shall have the right (but not the obligation) to review any content that you have submitted to the Gazette, and to reject, delete, disable, or remove any content that we determine, in our sole discretion, (a) does not comply with the terms and conditions of this agreement; (b) might violate any law, infringe upon the rights of third parties, or subject us to liability for any reason; or (c) might adversely affect our public image, reputation or goodwill. Moreover, we reserve the right to reject, delete, disable, or remove any content at any time, for the reasons set forth above, for any other reason, or for no reason. If you believe that any content on any of the Gazette web sites infringes upon any copyrights that you own, please contact us pursuant to the procedures outlined in the Digital Millennium Copyright Act (Title 17 U.S.C. § 512) at the following address:

Copyright Agent
The Texarkana Gazette
15 Pine Street
Texarkana, TX 75501
Phone: 903-794-3311
Email: webeditor@texarkanagazette.com