Curiosity: New evidence of a formerly wet Mars

Photo: Conglomerate rock outcrop on Mars. Image credit: NASA/JPL-Caltech/MSSS
In this image from NASA’s Curiosity rover, a rock outcrop called Link pops out from a Martian surface that is elsewhere blanketed by reddish-brown dust. Image credit: NASA/JPL-Caltech/MSSS

PASADENA, Calif. — NASA’s Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence — images of rocks containing ancient streambed gravels — is the first of its kind.

Scientists are studying the images of stones cemented into a layer of conglomerate rock. The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow.

“From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep,” said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. “Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”

The finding site lies between the north rim of Gale Crater and the base of Mount Sharp, a mountain inside the crater. Earlier imaging of the region from Mars orbit allows for additional interpretation of the gravel-bearing conglomerate. The imagery shows an alluvial fan of material washed down from the rim, streaked by many apparent channels, sitting uphill of the new finds.

The rounded shape of some stones in the conglomerate indicates long-distance transport from above the rim, where a channel named Peace Vallis feeds into the alluvial fan. The abundance of channels in the fan between the rim and conglomerate suggests flows continued or repeated over a long time, not just once or for a few years.

The discovery comes from examining two outcrops, called “Hottah” and “Link,” with the telephoto capability of Curiosity’s mast camera during the first 40 days after landing. Those observations followed up on earlier hints from another outcrop, which was exposed by thruster exhaust as Curiosity, the Mars Science Laboratory Project’s rover, touched down.

“Hottah looks like someone jack-hammered up a slab of city sidewalk, but it’s really a tilted block of an ancient streambed,” said Mars Science Laboratory Project Scientist John Grotzinger of the California Institute of Technology in Pasadena.

The gravels in conglomerates at both outcrops range in size from a grain of sand to a golf ball. Some are angular, but many are rounded.

“The shapes tell you they were transported and the sizes tell you they couldn’t be transported by wind. They were transported by water flow,” said Curiosity science co-investigator Rebecca Williams of the Planetary Science Institute in Tucson, Ariz.

The science team may use Curiosity to learn the elemental composition of the material, which holds the conglomerate together, revealing more characteristics of the wet environment that formed these deposits. The stones in the conglomerate provide a sampling from above the crater rim, so the team may also examine several of them to learn about broader regional geology.

The slope of Mount Sharp in Gale Crater remains the rover’s main destination. Clay and sulfate minerals detected there from orbit can be good preservers of carbon-based organic chemicals that are potential ingredients for life.

“A long-flowing stream can be a habitable environment,” said Grotzinger. “It is not our top choice as an environment for preservation of organics, though. We’re still going to Mount Sharp, but this is insurance that we have already found our first potentially habitable environment.”

During the two-year prime mission of the Mars Science Laboratory, researchers will use Curiosity’s 10 instruments to investigate whether areas in Gale Crater have ever offered environmental conditions favorable for microbial life.

NASA’s Jet Propulsion Laboratory, a division of Caltech, built Curiosity and manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington.

For more about Curiosity, visit: http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl .

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“Head’s up” and Curiosity begins looking around

Photo: First two images of Martian surroundings from Curiosity's mast cam. Image credit: NASA/JPL-Caltech
The first two full-resolution images of the Martian surface from the Navigation cameras on NASA’s Curiosity rover. These are full-resolution images, 1024 by 1024 pixels in size. Image credit: NASA/JPL-Caltech

These are the first two full-resolution images of the Martian surface from the Navigation cameras on NASA’s Curiosity rover, which are located on the rover’s “head” or mast. The rim of Gale Crater can be seen in the distance beyond the pebbly ground.

The topography of the rim is very mountainous due to erosion. The ground seen in the middle shows low-relief scarps and plains. The foreground shows two distinct zones of excavation likely carved out by blasts from the rover’s descent stage thrusters.

Wednesday, Aug. 8, the team deployed the 3.6 foot-tall (1.1-meter) camera mast, activated and gathered surface radiation data from the rover’s Radiation Assessment Detector and concluded testing of the rover’s high-gain antenna.

Curiosity carries 10 science instruments with a total mass 15 times as large as the science payloads on NASA’s Mars rovers Spirit and Opportunity. Some of the tools, such as a laser-firing instrument for checking rocks’ elemental composition from a distance, are the first of their kind on Mars. Curiosity will use a drill and scoop, which are located at the end of its robotic arm, to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into the rover’s analytical laboratory instruments.

To handle this science toolkit, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. The Gale Crater landing site places the rover within driving distance of layers of the crater’s interior mountain. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.

Curiosity lands safely, is spied by HiRISE in descent to Mars

Photo: Mars Rover "Curiosity" hangs from its supersonic parachute. Credit: NASA/JPL-Caltech/Univ. of Arizona
Plummeting through the thin atmosphere of Mars, Mars rover “Curiosity” (still inside its protective enclosure) hangs from its supersonic parachute. White square indicates parachute (above) and protective aeroshell, below. This image captured by the “Mars Reconnaissance Orbiter” spacecraft in orbit around the Red Planet. Credit: NASA/JPL-Caltech/Univ. of Arizona

PASADENA, Calif. — NASA’s most advanced Mars rover Curiosity has landed on the Red Planet. The one-ton rover, hanging by ropes from a rocket backpack, touched down onto Mars Sunday to end a 36-week flight and begin a two-year investigation.

Photo: Heavily-cropped MRO image of Curiosity on its parachute. Credit: NASA/JPL-Caltech/Univ. of Arizona
This is a tight crop of the full image showing the remarkable detail produced by the MRO’s HiRISE instrument – Curiosity in its aeroshell suspended from its supersonic parachute (about 50 ft. in diameter). Credit: NASA/JPL-Caltech/Univ. of Arizona

The Mars Science Laboratory (MSL) spacecraft that carried Curiosity succeeded in every step of the most complex landing ever attempted on Mars, including the final severing of the bridle cords and flyaway maneuver of the rocket backpack.

Curiosity landed at 10:32 p.m. PDT Aug. 5, (1:32 a.m. EDT Aug. 6) near the foot of a mountain three miles tall and 96 miles in diameter inside Gale Crater.

During a nearly two-year prime mission, the rover will investigate whether the region ever offered conditions favorable for microbial life.

The rover, powered by a radioactive heat source rather than solar cells, is expected to last at least two Earth years and can continue to operate through the incredibly cold and dark Martian winter. Winter was and is a danger for solar-powered rovers like Opportunity, still operating on the surface of Mars, as is accumulation of light-blocking dust.

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The four main pieces of hardware that arrived on Mars with NASA’s Curiosity rover were spotted by NASA’s Mars Reconnaissance Orbiter (MRO). The High-Resolution Imaging Science Experiment (HiRISE) camera captured this image about 24 hours after landing. Credit: NASA/JPL-Caltech/Univ. of Arizona

Asteroid is just passin’ through

Tuesday, Nov. 8 at about 6:28 PM, a space rock a little over 1,300 feet in diameter will pass within about 202,000 miles of Earth. It will not hit our home planet nor will it have any other effect on us; it’s just passin’ through. Designated 2005 YU55, it is a potentially hazardous asteroid because of its size and near-Earth orbit. It was discovered on December 28, 2005 by Robert S. McMillan at Steward Observatory, Kitt Peak, Ariz.

Spotting chart for asteroid 2005 YU55 in November 2011. WikiPedia
Spotting chart for asteroid 2005 YU55 in November 2011. Source: Wikipedia

The main reason the flyby is known to the public is that this large asteroid will be closer to us than is our own Moon and that’s a neat science headline. When good-sized asteroids come close to Earth, news of the event has different effects in different quarters.

Amongst astronomers asteroid fly-bys offer an excellent opportunity to study small “worlds” usually too far away to see clearly with telescopes. NASA and other agencies are already scanning the space rock with high-powered radar systems in an effort to learn more about the object. The data can be used to learn something about the texture and composition of the object and a bit about its history. The asteroid’s orbit will also be highly refined through tracking by observers from around the world allowing improved prediction of its future movements.

Amongst conspiracy and doomsday fanatics, the close passage is another opportunity to spread FUD (Fear, Uncertainty, and Doubt) through pseudoscience and false prophesy. The Web is abuzz with gloom, doom, and gobs of misinformation already. What will they be saying Wednesday morning after 2005 YU55 has floated clean by Earth and left us unscathed? Those folks do have rich imaginations.

Here are some facts about our visitor from space and asteroids in general:

  • The word asteroid literally means “star-like object.”
  • Asteroids come in sizes ranging from small stones to a body about 3,300 feet in diameter: Ceres, the largest known object of that type.
  • The last time a space rock as large as 2005 YU55 came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next known approach of an asteroid this size will be in 2028.
  • Asteroid 2005 YU55 will pass through the constellations Aquila and Pegasus glowing like an 11th magnitude star (very dim) when closest, not visible to the unaided eye. You’d need a good-sized telescope and clear dark skies to see the tiny star-like object.
  • This asteroid orbits the Sun, roughly as close as Venus to as far away as Mars. Along the way it crosses Earth’s orbital path, one factor that makes it potentially hazardous.
  • Large asteroids pass closer to Earth than the Moon about every five years; smaller ones pass close more frequently and often enter Earth’s atmosphere.
  • Asteroids nearly the size of a house collide with Earth about once a year with no harmful effects to us — they ordinarily explode in the upper atmosphere and the fragments burn up.
  • Though a good-sized ball of rock, 2005 YU55 does not have enough mass to have any gravitational effect on Earth.
  • Asteroid close-encounters do not cause earthquakes, high tides, or any other geological or weather events.
  • Asteroids are cataloged, their orbits calculated, and the objects tracked regularly both for scientific study and planetary protection ends. Those data are publicly available and often incorporated into home astronomy software.
  • The approach of asteroids cannot be kept secret. They are “out there” and potentially visible to all who care to look. Any truly dangerous situation would quickly be confirmed by scientific authorities from around the world.

Asteroids are but one small part of our fascinating solar system. Enjoy the real adventure and wonder of our corner of the universe that is yours through astronomy!

Oppy reaches Endeavour Crater

Photo: Edge of Endeavour Crater on planet Mars.
NASA's Mars Exploration Rover Opportunity arrived at the rim of Endeavour crater on Aug. 9, 2011, after a trek of more than 13 miles (21 kilometers) lasting nearly three years. Image Credit: NASA/JPL-Caltech/Cornell/ASU. (Click on image to see full-size.)

PASADENA, Calif. – After a journey of almost three years, NASA’s Mars Exploration Rover Opportunity has reached the Red Planet’s Endeavour Crater to study rocks never seen before.

On Aug. 9, the golf cart-sized rover relayed its arrival at a location named Spirit Point on the crater’s rim. Opportunity drove approximately 13 miles (21 kilometers) since climbing out of the Victoria Crater.

“NASA is continuing to write remarkable chapters in our nation’s story of exploration with discoveries on Mars and trips to an array of challenging new destinations,” NASA Administrator Charles Bolden said. “Opportunity’s findings and data from the upcoming Mars Science Laboratory will play a key role in making possible future human missions to Mars and other places where humans have not yet been.”

Endeavour Crater, which is more than 25 times wider than Victoria Crater, is 14 miles (22 kilometers) in diameter. At Endeavour, scientists expect to see much older rocks and terrains than those examined by Opportunity during its first seven years on Mars. Endeavour became a tantalizing destination after NASA’s Mars Reconnaissance Orbiter detected clay minerals that may have formed in an early warmer and wetter period.

“We’re soon going to get the opportunity to sample a rock type the rovers haven’t seen yet,” said Matthew Golombek, Mars Exploration Rover science team member, at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “Clay minerals form in wet conditions so we may learn about a potentially habitable environment that appears to have been very different from those responsible for the rocks comprising the plains.”

The name Spirit Point informally commemorates Opportunity’s twin rover, which stopped communicating in March 2010. Spirit’s mission officially concluded in May.

Target Mars: Gale Crater selected for Mars Science Laboratory

Gale crater is 96 miles (154 kilometers) in diameter and holds a layered mountain rising about 3 miles (5 kilometers) above the crater floor. Image Credit: NASA/JPL-Caltech/ASU/UA

PASADENA, Calif. — NASA’s next Mars rover will land at the foot of a layered mountain inside the planet’s Gale Crater. The US space agency made the announcement Friday, July 22.

The car-sized MSL (Mars Science Laboratory), or “Curiosity,” is scheduled to launch late this year and land in August 2012. The target crater spans 96 miles (154 kilometers) in diameter and holds a mountain rising higher from the crater floor than Mount Rainier rises above Seattle. Gale is about the combined area of Connecticut and Rhode Island. Layering in the mound suggests it is the surviving remnant of an extensive sequence of deposits. The crater is named for Australian astronomer Walter F. Gale.

“Mars is firmly in our sights,” said NASA Administrator Charles Bolden. “Curiosity not only will return a wealth of important science data, but it will serve as a precursor mission for human exploration to the Red Planet.”

During a prime mission lasting one Martian year — nearly two Earth years — researchers will use the rover’s tools to study whether the landing region had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed.

“Scientists identified Gale as their top choice to pursue the ambitious goals of this new rover mission,” said Jim Green, director for the Planetary Science Division at NASA Headquarters in Washington. “The site offers a visually dramatic landscape and also great potential for significant science findings.”

In 2006, more than 100 scientists began to consider about 30 potential landing sites during worldwide workshops. Four candidates were selected in 2008. An abundance of targeted images enabled thorough analysis of the safety concerns and scientific attractions of each site. A team of senior NASA science officials then conducted a detailed review and unanimously agreed to move forward with the MSL Science Team’s recommendation. The team is comprised of a host of principal and co-investigators on the project.

Curiosity is about twice as long and more than five times as heavy as any previous Mars rover. Its 10 science instruments include two for ingesting and analyzing samples of powdered rock that the rover’s robotic arm collects. A radioisotope power source will provide heat and electric power to the rover. A rocket-powered sky crane suspending Curiosity on tethers will lower the rover directly to the Martian surface.

The portion of the crater where Curiosity will land has an alluvial fan likely formed by water-carried sediments. The layers at the base of the mountain contain clays and sulfates, both known to form in water.

May’s planetary dance

From SpaceWeather.com…

PLANETS AT DAWN: No coffee? No problem! To wake up any morning this week, all you need to do is look out the window. Mars, Jupiter, Venus and Mercury are aligning in the eastern sky for a spectacular dawn conjunction. Mariano Ribas observed the gathering on May 9 from his home in Buenos Aires, Argentina and wrote, “It was an awesome morning with an unforgettable view: four planets packed in just a 7º piece of sky.”

“The very compact Venus-Mercury-Jupiter triangle was simply hypnotic,” Ribas said. “And Mars, below them, was faint but still clearly visible to naked eye. Marvelous planetary gathering, but the best is yet to come.”

Indeed, on May 11th, Venus and Jupiter, the two brightest planets in the Solar System, will converge to form a pair less than 1/2 degree apart. Set your alarm for Wednesday morning and begin the day with an eye-opener–no caffeine required.

See the full story NASA Science News: http://1.usa.gov/kao0Oy