1. Headline
  1. Headline
layered rock on Mars
NASA / JPL / Cornell
An image from NASA’s Opportunity rover shows an intriguing stretch of layered rock on Mars. Geologists can analyze the pattern of layering for insights into the Red Planet’s watery past.
updated 11/5/2004 8:18:42 PM ET 2004-11-06T01:18:42

As NASA's Mars rovers keep rolling past all expectations of their useful lives, scientists have a happy mystery: For some reason one of the vehicles has actually gained power recently.

Opportunity recently experienced an unexplained rejuvenation from what can so far be described only as two or three significant "cleaning events," said Jim Erickson, the rover project manager at NASA's Jet Propulsion Laboratory in Pasadena.

"Now we're assuming they're cleaning, but all we can really say is that overnight the solar panels produced between 2 and 5 percent additional power immediately," he said.  "We're surmising that for some reason dust is being removed from the solar panel and that's increasing the efficiency of the sunlight being converted to electricity."

The rover team has been bandying about theories, but hasn't figured out the cause.

"One favorite is that a dust devil happened to pick the vehicle to go through and go over the surface of it and clean it off a little bit," Erickson said.

Opportunity and its twin, Spirit, parachuted to opposite sides of Mars back in January, but they remain in good shape after enduring the worst of the Martian winter, which cut down on the amount of energy reaching their solar panels.

Both six-wheeled rovers have discovered geologic evidence of past water activity on the Red Planet and are continuing to send valuable data.

Pushing the limits
"We are pushing these vehicles to their very limits," said Steve Squyres, the rover principal investigator from Cornell University in Ithaca, N.Y.  "In many ways they are performing better in some sense just because we've gotten better at operating them and we are in this much more challenging and geologically rich terrain."

Spirit has had several minor problems, indicating that various parts may be showing their age, Erickson said.

Spirit, having trekked nearly two miles across the flat terrain of the vast Gusev Crater region where it set down, is zigzagging up the rugged Columbia Hills and is now nearly 200 feet above the surrounding plain.

The intriguing layered rocks of the hills are much different than the plain below, and scientists are working on multiple hypotheses to explain how they formed.

  1. More from TODAY.com
    1. Play nice: 4 ways to teach kindness and raise kids who aren't jerks

      Every parent has probably said, “play nicely” or “be kind to your sister.” And most of us agree that we want to raise cari...

    2. Natalie and Jenna: We can be the next Thelma and Louise — 'minus the ending'
    3. Renee Zellweger selling Connecticut country home
    4. 5 things I wish my boss knew about fatherhood
    5. Tying the knot

The leading theory is that the rocks began as volcanic ash that fell out of the sky or moved along the ground in ash flows, and minerals inside them were subsequently altered by ground water, said Ray Arvidson, the rover deputy principal investigator from Washington University in St. Louis, Mo.

Opportunity is nearing the end of its exploration of stadium-size Endurance Crater in the Meridiani Planum region and may claw its way over the rim.

The rovers had available about 1,000 watt-hours a day when they arrived on Mars, but dust on their solar panels and the seasonal decrease in solar energy have limited their power, and therefore their activities.

Opportunity is now at about 820 watt-hours and remains very close to full capability. Spirit, which is in a less advantageous position to point its arrays toward the sun, has 350 to 400 watt-hours daily.

Copyright 2004 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


Discussion comments


Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments

More on TODAY.com

  1. Monkey Business Images / Shutterstock

    Play nice: 4 ways to teach kindness and raise kids who aren't jerks

    7/24/2014 7:05:14 PM +00:00 2014-07-24T19:05:14
  1. Watch the full ‘Fifty Shades of Grey’ trailer: What we couldn’t show on TV

    “Fifty Shades of Grey” fans, you’ve come to the right place. 

    7/24/2014 12:30:07 PM +00:00 2014-07-24T12:30:07
  2. video ‘Fifty Shades’ stars give first look at steamy film

    video Stars Jamie Dornan and Dakota Johnson offer TODAY viewers a sneak peek at the highly anticipated film. When Savannah Guthrie told Dornan that viewers had asked if he'd do the interview shirtless, he said, “I would have considered it.” 

    7/24/2014 5:22:44 PM +00:00 2014-07-24T17:22:44
  3. Not a date movie: Why ‘Fifty Shades’ a girls’ night hit

    Even though the film is opening on Valentine's Day — the biggest date night of the year — women are likely to turn the movie into a social event.

    7/24/2014 1:22:41 PM +00:00 2014-07-24T13:22:41
  4. Universal Pictures
  1. Air Algerie flight remains missing 

    After reports that the commercial jet that went missing on Thursday over western Africa had been found, French President Francois Hollande stated that “no trace of plane has been found yet." 

    7/24/2014 2:47:05 PM +00:00 2014-07-24T14:47:05