Criar uma Loja Virtual Grátis
ONLINE
39


http://USAcomment.com




Total de visitas: 691838

Ancient Mars Liveable, Milder And Warmer, Fresh Ma

Ancient Mars Liveable, Milder And Warmer, Fresh Ma

Ancient Mars Liveable, Milder And Warmer, Fresh Martian Water Could Have Supported Life

 

New findings from rock samples collected and examined by NASA’s Mars Exploration Rover Opportunity have confirmed an ancient wet environment that was milder and older than the acidic and oxidizing conditions told by rocks the rover examined previously.

In this week’s edition of the journal Science, Opportunity Deputy Principal Investigator Ray Arvidson, a professor at Washington University in St. Louis, writes in detail about the discoveries made by the rover and how these discoveries have shaped our knowledge of the planet. According to Arvidson and others on the team, the latest evidence from Opportunity is landmark.
NASA’s Mars Exploration Rover Opportunity has been working on Mars since landing inside Eagle Crater on Jan. 25, 2004 (Universal Time; evening of Jan. 24, Pacific Standard Time).

 

* Image Credit: NASA/JPL-Caltech/MSSS/NMMNHS

 

“These rocks are older than any we examined earlier in the mission, and they reveal more favorable conditions for microbial life than any evidence previously examined by investigations with Opportunity,” said Arvidson.

While the Opportunity team celebrates the rover’s 10th anniversary on Mars, they also look forward to what discoveries lie ahead and how a better understanding of Mars will help advance plans for human missions to the planet in the 2030s.

Researchers used NASA’s Mars Exploration Rover Opportunity to find a water-related mineral on the ground that had been detected from orbit, and found it in the dark veneer of rocks on the rim of Endeavour Crater.

 

* Image Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State University

 

Opportunity’s original mission was to last only three months. On the day of its 10th anniversary on the Red Planet, Opportunity is examining the rim of the Endeavour Crater. It has driven 24 miles (38.7 kilometers) from where it landed on Jan. 24, 2004. The site is about halfway around the planet from NASA’s latest Mars rover, Curiosity.

To find rocks for examination, the rover team at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., steered Opportunity in a loop, scanning the ground for promising rocks in an area of Endeavour’s rim called Matijevic Hill. The search was guided by a mineral-mapping instrument on NASA’s Mars Reconnaissance Orbiter (MRO), which did not arrive at Mars until 2006, long after Opportunity’s mission was expected to end.

Beginning in 2010, the mapping instrument, called the Compact Reconnaissance Imaging Spectrometer for Mars, detected evidence on Matijevic Hill of a clay mineral known as iron-rich smectite. The Opportunity team set a goal to examine this mineral in its natural context — where it is found, how it is situated with respect to other minerals and the area’s geological layers — a valuable method for gathering more information about this ancient environment. Researchers believe the wet conditions that produced the iron-rich smectite preceded the formation of the Endeavor Crater about 4 billion years ago.

“The more we explore Mars, the more interesting it becomes. These latest findings present yet another kind of gift that just happens to coincide with Opportunity’s 10th anniversary on Mars,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program. “We’re finding more places where Mars reveals a warmer and wetter planet in its history. This gives us greater incentive to continue seeking evidence of past life on Mars.”

Opportunity has not experienced much change in health in the past year and the vehicle remains a capable research partner for the team of scientists and engineers who plot each day’s activities to be carried out on Mars.

“We’re looking at the legacy of Opportunity’s first decade this week, but there’s more good stuff ahead,” said Steve Squyres of Cornell University, Ithaca, N.Y., the mission’s principal investigator. “We are examining a rock right in front of the rover that is unlike anything we’ve seen before. Mars keeps surprising us, just like in the very first week of the mission.”

JPL manages the Mars Exploration Rover Project for NASA’s Science Mission Directorate in Washington. Opportunity’s twin, Spirit, which worked for six years, and their successor, Curiosity, also contributed valuable information about the diverse watery environments of ancient Mars, from hot springs to flowing streams. NASA’s Mars orbiters Odyssey and MRO study the whole planet and assist the rovers.
NASA’s Mars Rover Spirit’s View Southward from Husband Hill: This section from a panorama that NASA’s Mars Exploration Rover Spirit acquired in October 2005 from the top of “Husband Hill” presents the view toward the south from that summit.

 

 

“Over the past decade, Mars rovers have made the Red Planet our workplace, our neighborhood,” said John Callas, manager of NASA’s Mars Exploration Rover Project, which built and operates Opportunity. “The longevity and the distances driven are remarkable. But even more important are the discoveries that are made and the generation that has been inspired.”

A team of researchers has found what may once have been the most liveable mud on Mars.

Some of the oldest minerals ever analysed by NASA’s Mars Opportunity Rover show that around four billion years ago Mars had liquid water so fresh it could have supported life.This before-and-after pair of images of the same patch of ground in front of NASA’s Mars Exploration Rover Opportunity 13 days apart documents the arrival of a bright rock onto the scene. The rover had completed a short drive just before taking the second image, and one of its wheels likely knocked the rock — dubbed “Pinnacle Island” — to this position. The rock is about the size of a doughnut.

 

 

The findings were announced in a special ‘Exploring Mars Habitability’ edition of the journal Science released today to coincide with the 10th anniversary of the Mars Opportunity Rover and its twin, Spirit, landing on the red planet.

CSIRO’s Dr Paulo de Souza, who is on the science team led by Cornell University’s Professor Steven Squyres, said a major focus on NASA’s decade of research on Mars surface was whether the planet may ever have been habitable.

“While Mars is too cold now to have the liquid water needed for life, we’ve had evidence for past water activity on the planet from satellite images of valleys and analysis of rocks by the Rovers,” Dr de Souza said.

“But the water that once shaped those landscapes and minerals was as acidic as vinegar.

“Our latest research has found not only the earliest episode of water activity documented yet by the Opportunity Rover, but that the geochemistry of the 4 billion year old rocks indicates extensive deposits of past water that’s among the freshest, most life-sustaining found so far anywhere on Mars.

“If there was ever life on Mars, then this would have been the mud for it to live in.”

Dr de Souza is a Science Leader at CSIRO in micro-sensors and has worked with NASA since the Mars Exploration Rover Program began, having collaborated with NASA’s research teams for many years.

Dr de Souza is very proud of the Opportunity Rover, a golf buggy-sized all-terrain vehicle also known as ‘Oppy’, whose tenth birthday is today.

“She’s a brave little Rover and she’s way past warranty,” he said.

“Opportunity’s Mars mission was expected to last just months but she’s still going strong 10 years on with no signs of stopping. She’s travelled 38km instead of the few hundred metres planned.

“Along the way, Oppy’s collected invaluable information about Mars’ surface with her high tech toolkit of rock scrapers, chemical sensors, and spectral analysers.”

Oppy’s been beaming a decade’s worth of data back to space receiving stations on Earth, including the Canberra Deep Space Communication Centre outside Canberra at Tidbinbilla managed by CSIRO.

“Thanks to the Rovers, we now have a much richer knowledge of our nearest planet and where to focus our future search for microfossils, present water and other signs of life,” Dr de Souza said.

Dr de Souza is giving three public lectures on 23-24 January at CSIRO Discovery in Canberra to celebrate the 10th Anniversary of the NASA Mars Exploration Rover Program. The lectures are suitable for all ages.