Category: Mars

Image credit: NASA

Since it arrived at Mars in 1997, the Mars Global Surveyor has been searching the surface of the Red Planet for carbonate minerals. Large quantities of this substance would be evidence that the planet was once warm and wet, with large oceans and seas on the surface. Surveyor has found trace quantities of the mineral spread evenly in the dust of the planet, but no deposits, indicating that the planet was probably always icy and cold.

After a decades-long quest, scientists analyzing data from NASA’s Mars Global Surveyor spacecraft have at last found critical evidence the spacecraft’s infrared spectrometer instrument was built to search for: the presence of water-related carbonate minerals on the surface of Mars.

However, the discovery also potentially contradicts what scientists had hoped to prove: the past existence of large bodies of liquid water on Mars, such as oceans. How this discovery relates to the possibility of ephemeral lakes on Mars is not known at this time.

The thermal emission spectrometer on Global Surveyor found no detectable carbonate signature in surface materials at scales ranging from three to 10 kilometers (two to six miles) during its six-year Mars mapping mission. However, the sensitive instrument has detected the mineral’s ubiquitous presence in martian dust in quantities between two and five percent. Planetary geologists Timothy Glotch Dr. Joshua Bandfield, and Dr. Philip Christensen of Arizona State University, Tempe, analyze the data from dust-covered areas of Mars in a report to be published Aug. 22 in the journal Science.

“We have finally found carbonate, but we’ve only found trace amounts in dust, not in the form of outcroppings as originally suspected. This shows that the thermal emission spectrometer can see carbonates — if they are there ? and that carbonates can exist on the surface today,” said Christensen, principal investigator for the instrument.

“We believe that the trace amounts that we see probably did not come from marine deposits derived from ancient martian oceans, but from the atmosphere interacting directly with dust,” Christensen said. “Tiny amounts of water in Mars’ atmosphere can interact with the ubiquitous dust to form the small amounts of carbonate that we see. This seems to be the result of a thin atmosphere interacting with dust, not oceans interacting with the big, thick atmosphere that many people have thought once existed there.”

“What we don’t see is massive regional concentrations of carbonates, like limestone,” said Bandfield, who spent a year refining the techniques that allowed the group to separate carbonate’s distinctive infrared signature from the spectrometer’s extensive database of infrared spectra, despite the mineral’s low concentrations and the masking effects of the martian atmosphere.

“We’re not seeing the white cliffs of Dover or anything like that,” he said. “We’re not seeing high concentrations, we’re just seeing ubiquitously low levels. Wherever we see the dust, we see the signature that is due to the carbonate.”

Because there are known to be deposits of frozen water on Mars, the findings have important implications for Mars’ past climate history.

“This really points to a cold, frozen, icy Mars that has always been that way, as opposed to a warm, humid, ocean-bearing Mars sometime in the past,” said Christensen. “People have argued that early in Mars history, maybe the climate was warmer and oceans may have formed and produced extensive carbonate rock layers. If that was the case, the rocks formed in those purported oceans should be somewhere.”

Although ancient carbonate rock deposits might have been buried by later layers of dust, Christensen pointed out that the global survey found no strong carbonate signatures anywhere on the planet, despite clear evidence of geological processes that have exposed ancient rocks.

Bandfield said that carbonate deposits in dust could be partially responsible for Mars’ atmosphere growing even colder, to become as cold, thin and dry as it is today.

“If you store just a couple percent of carbonate in the upper crust, you can easily account for several times the Earth’s atmospheric pressure,” Bandfield said. “You can store a lot of carbon dioxide in a little bit of rock. If you form enough carbonates, pretty soon your atmosphere goes away. If that happens, you can no longer have liquid water on the surface because you get to the point where liquid water is not stable.”

“The significance of these dramatic results may have to wait for the discoveries to be made by the Mars Exploration Rovers in 2004 and the Mars Reconnaissance Orbiter in 2006 and beyond,” stated Dr. Jim Garvin, NASA’s lead scientist for Mars exploration. What’s important is that we have found carbon-bearing minerals at Mars, which may be linked to the history of liquid water and hence to our quest to understand whether Mars has ever been an abode for life.”

The Mars Global Surveyor mission is managed for NASA’s Office of Space Science, Washington, D.C. by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Arizona State University built and operates the Thermal Emission Spectrometer on Mars Global Surveyor. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft.

Original Source: NASA/JPL News Release

Image credit: NASA/MSSS

To celebrate the closest approach of Mars in 60,000 years, NASA is looking for suggestions for where it should point the cameras on the Mars Global Surveyor. The spacecraft has been orbiting Mars since 1997, and taken more than 120,000 photos of the Red Planet which a resolution high enough to show a school bus on the surface. But the high resolution camera has only covered about 3% of the planet’s surface. The NASA Mars Global Surveyor team will review suggestions from the public and then catch pictures when the spacecraft is above the right locations.

Earth comes closer to Mars this month than it has in nearly 60,000 years, but one new opportunity for seeing details on the red planet comes from a vantage point much closer.

The public has an unprecedented opportunity to suggest places on Mars that should be photographed from a spacecraft orbiting that planet. Camera operators for NASA’s Mars Global Surveyor spacecraft are ready to take suggestions online for new places for images from the Mars Orbiter Camera.

The spacecraft, managed by NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., has been orbiting Mars since 1997, with more than 20,000 orbits so far. The Mars Orbiter Camera has already taken more than 120,000 pictures of Mars. Many of the camera’s images have sharp enough resolution to show features as small as a school bus. The images have revealed relatively recent gully erosion, ancient sedimentary rocks and many other spectacular scientific surprises.

“We’ve only covered about three percent of the surface area of Mars with the high-resolution camera. We want to be sure we’re not missing some place that could be important, so we’re casting a wide net for new suggestions,” said Dr. Ken Edgett, staff scientist at Malin Space Science Systems, the San Diego firm that supplied and operates the camera for NASA. “We’re looking for excellent suggestions of areas on Mars that we have not already imaged,” Edgett said. “We’ll look at every request that comes in.”

“NASA’s Mars Global Surveyor spacecraft team will examine each request to ensure the safety of this priceless ‘eye in the sky’ above Mars,” said Dr. Jim Garvin, NASA’s Lead Scientist for Mars Exploration at NASA Headquarters, Washington.

Information about how to submit requests is online at the new Mars Orbiter Camera Target Request Site, at:

http://www.msss.com/plan/intro
Requesters should describe the purpose for the suggested image. Suggestions for target sites already imaged by the camera will be disqualified unless there is a convincing reason for repeating the target. An online gallery of pictures taken by the camera is at:

http://www.msss.com/moc_gallery/
“Some of the best requests may be places nowhere near any site the Mars Orbiter Camera has imaged before,” Edgett said. As with pictures desired by Mars scientists working with the camera every day, new suggestions will need to wait until the Mars Global Surveyor flies directly over the selected target, which could be several months or longer. The first images from this public suggestion program will probably be released this fall.

JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA’s Office of Space Science in Washington. JPL’s industrial partner is Lockheed Martin Space Systems, Denver, which developed and operates the spacecraft. Malin Space Science Systems and the California Institute of Technology built the Mars Orbiter Camera. Malin Space Science Systems operates the camera from facilities in San Diego.

For information about NASA on the Internet, visit:

Home Page

Information about Mars Global Surveyor is available on the Internet at:

http://mars.jpl.nasa.gov/mgs

Original Source: NASA News Release

As I mentioned in the newsletter a couple of weeks ago, I’m hard at work collecting details about events around the world that will be celebrating the Mars 2003 opposition. I’ve got a few hundred included so far, with most states in the USA represented as well as a few countries outside that.

Click here to access the worldwide list of Mars 2003 events.

If you’re interested in attending, check out the list and see if there’s something in your neighbourhood. If not, bookmark the page and then come back as we get closer to August 27, as I’m adding dozens every day. I suspect they’re really going to pour in as the word gets out. If you’re involved with a group that’s planning an event, let me know about it.

But you don’t need a big party. If you’ve got a reasonable telescope, just pick a public place that you think will have a lot of people wandering by and invite them to look at Mars. Let me know the location and I’ll incorporate it into the list. This is one of the best ways to share the wonder of astronomy.

Please don’t send me an email asking if there’s going to be an event in your area. Every event I know about has already been added to the list. If you don’t see something, why don’t you contact your local planetarium, museum, library, observatory, university, or astronomy club and ask them if they’ve got something planned? Let them know about this list. Anything you can do to get the word out would be much appreciated. 🙂

Finally, Bad Astronomy has a great page that explains the opposition and debunks some of the crazy rumours. Check it out.

Fraser Cain
Publisher
Universe Today

P.S. Thanks to John Chumack for his great picture of Mars. He snapped this on August 15 with an 11″ telescope.

An instrument on board Spirit, one of NASA’s Mars Exploration Rovers, has malfunctioned, potentially limiting the amount of data that can be retrieved from the surface of Mars. The instrument is called a Mossbauer spectrometer, and it’s designed to determine the presence and abundance of iron-bearing minerals in the rocks of Mars. If the glitch can’t be worked out, it will still be able to detect the mineral, just not its quantity. Engineers still have several months to get this fixed before Spirit arrives at Mars on January 3.

Image credit: NASA/JPL

NASA announced on Monday that it has selected the University of Arizona’s “Phoenix” mission to launch to Mars in 2007 as part of its new, low-cost Scout mission. NASA has granted the university $325 million to build the spacecraft, which will land on the planet’s northern pole, which is rich in water ice. The mission will have two goals: to study the geologic history of water, and to search for evidence of a habitable zone that may exist in the ice-soil boundary.

In May 2008, the progeny of two promising U.S. missions to Mars will deploy a lander to the water-ice-rich northern polar region, dig with a robotic arm into arctic terrain for clues on the history of water, and search for environments suitable for microbes.

NASA today announced that it has selected the University of Arizona “Phoenix” mission for launch in 2007 as what is hoped will be the first in a new line of smaller competed “Scout” missions in the agency’s Mars Exploration Program.

Dr. Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory heads the Phoenix mission, named for the mythological bird that is repeatedly reborn of ashes. The $325 million NASA award is more than six times larger than any other single research grant in University of Arizona history.

“The selection of Phoenix completes almost two years of intense competition with other institutions,” Smith said. “I am overjoyed that we can now begin the real work that will lead to a successful mission to Mars.”

Phoenix is a partnership of universities, NASA centers, and the aerospace industry. The science instruments and operations will be a University of Arizona responsibility. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., will manage the project and provide mission design. Lockheed Martin Space Systems, Denver, will build and test the spacecraft. Canadian partners will provide the meteorological instrumentation, including an innovative laser-based sensor.

Phoenix has the scientific capability “to change our thinking about the origins of life on other worlds,” Smith said. “Even though the northern plains are thought to be too cold now for water to exist as a liquid, periodic variations in the martian orbit allow a warmer climate to develop every 50,000 years. During these periods the ice can melt, dormant organisms could come back to life, (if there are indeed any), and evolution can proceed. Our mission will verify whether the northern plains are indeed a last viable habitat on Mars.”

The lander for Phoenix was built and was being tested to fly as part of the 2001 Mars Surveyor Program, but the program was canceled after the Mars Polar Lander was lost upon landing near Mars’ south pole in December 1999. Since then, the 2001 lander has been stored in a clean room at Lockheed Martin in Denver, managed by NASA’s new Mars Exploration Program as a flight asset.

Renamed Phoenix, it will carry improved versions of University of Arizona panoramic cameras and volatiles-analysis instrument from the ill-fated Mars Polar Lander, as well as experiments that had been built for the 2001 Mars Surveyor Program, including a JPL trench-digging robot arm and a chemistry-microscopy instrument. The science payload also includes a descent imager and a suite of meteorological instruments.

The mission has two goals. One is to study the geologic history of water, the key to unlocking the story of past climate change. Two is to search for evidence of a habitable zone that may exist in the ice-soil boundary, the “biological paydirt.”

The Phoenix robotic arm will scoop up martian soil samples and deliver them for heating into tiny ovens of the volatiles-analysis instrument so team members can measure how much water vapor and carbon dioxide gas are given off, how much water ice the samples contain, and what minerals are present that may have formed during a wetter, warmer past climate. The instrument, called thermal evolved gas analyzer, will also measure any organic volatiles.

Using another instrument, researchers will examine soil particles as small as 16 microns across. They will measure electrical and thermal conductivity of soil particles using a probe on the robotic arm scoop. One of the most interesting experiments is the wet chemistry laboratory, Smith said.

“We plan to scoop up some soil, put it in a cell, add water, shake it up, and measure the impurities dissolved in the water that have leached out from the soil. This is important, because if the soil ever gets wet, we’ll know if microbes could survive. We’ll know if the wet soil is super acidic or alkaline and salty, or full of oxidants that can destroy life. We’ll test the environment that microbes might have had to live and grow in,” Smith said.

Information is available online about NASA’s Mars exploration at http://mars.jpl.nasa.gov and about Phoenix at http://phoenix.lpl.arizona.edu .

Original Source: NASA News Release

Image credit: Hubble

On August 27, 2003 the Planet Mars will be a mere 55.76 million kilometres away from the Earth – the closest it’s been in 50,000 years. Visible in the early morning, Mars is the brightest object in the sky, after the Moon and Venus, and almost any small telescope will be able to show details on the planet’s surface. Make sure you enjoy Mars’ close approach this summer, as it won’t make another visit this close for nearly 300 years.

Living too close to a neighbor may not be very appealing, but when Earth?s neighboring red planet moves closer than it?s been in 60,000 years, observers expect nothing but acclaim.

This August, scientists and amateur astronomers will benefit from the spectacular view of Mars as it appears bigger and brighter than ever before, revealing its reflective south polar cap and whirling dust clouds.

On August 27, 2003, the fourth rock from the sun will be less than 55.76 million kilometers (34.65 million miles) away from the Earth. In comparison to the space between your house and your neighbor?s yard, that may seem like a large distance, but Mars was about five times that distance from Earth only six months ago.

“Think of Earth and Mars as two race cars going around a track,” said Dr. Myles Standish, an astronomer from NASA?s Jet Propulsion Laboratory, Pasadena, Calif. “Earth is on a race track that is inside the track that Mars goes around, and neither track is perfectly circular. There is one place where the two race tracks are closest together. When Earth and Mars are at that place simultaneously, it is an unusually close approach, referred to as a ‘perihelic opposition’.”

Opposition is a term used when Earth and another planet are lined up in the same direction from the Sun. The term perihelic comes from perihelion, the point of orbit in which a celestial body is closest to the Sun. This August, Mars will reach its perihelion and be in line with Earth and the Sun at the same time.

The average opposition occurs about every two years, when Earth laps Mars on its orbit around the Sun. In 1995, the opposition brought Mars 101.1 million kilometers (62.8 million miles) from the Earth, twice as far as this most recent approach.

“It gets more complicated as the race tracks are changing shape and size and are rotating, changing their orientation,” Standish explains. “So this place where the two tracks are closest together constantly changes, changing the opposition closeness as well. This is why a ‘great’ approach, like the one this month, hasn?t happened in 60,000 years. But with the tracks closer together now, there will be even closer approaches in the relatively near future.”

Aside from visiting a local observatory, peering through a telescope is the best way to take advantage of this unique opportunity. Since June, Mars has been noticeably bright in the night?s sky, only outshined by Venus and the Moon. Observers in the Northern Hemisphere will see it glowing remarkably in the southern sky in the constellation Aquarius, best seen just before dawn.

“You’re not going to go outside and see some big red ball in the sky. It will look like a bright red star,” said Standish.

The word ‘planet’ is derived from the Greek expression for ?wanderer.? At such a close distance, Mars remains true to this expectation as it consistently wanders across the night?s sky. Tracking the “red star?s” movement from week to week is yet another way to appreciate the opposition as Mars appears to dart across the sky in comparison to more distant planets, such as Jupiter.

Although Mars will be closest on August 27, astronomers suggest viewing the planet earlier, as dust storm season is just beginning on the red planet and can obstruct a more detailed view.

Whether you are viewing through a telescope, glancing through a pair of binoculars, or star-gazing outside the city, be sure to take advantage of this once-in-a-lifetime opportunity, for Mars will not make another neighborly visit this close until 2287.

Original Source: NASA/JPL News Release

Image credit: Hubble

Now that Mars is closer than ever, amateur astronomers with regular backyard telescopes can see incredible details on the planet’s surface. On July 1, astronomers were able to see a dust storm in the Hellas Basin; four days later it was 1,800 kilometres wide, obscuring nearly a quarter of the planet. Two years ago a similar storm grew in the same region and ended up obscuring the entire planet for months. Earth and Mars will reach their closest point in 60,000 years on August 27, 2003, and the Red Planet should offer up some tremendous views.

Something is happening on Mars and it’s so big you can see it through an ordinary backyard telescope.

On July 1st a bright dust cloud spilled out of Hellas Basin, a giant impact crater on Mars’ southern hemisphere. The cloud quickly spread and by the Fourth of July was 1100 miles wide–about one-fourth the diameter of Mars itself.

“The cloud can be seen now through a telescope as small as 6 inches,” says Donald Parker, executive director of the Association of Lunar and Planetary Observers (ALPO). “Its core is quite bright.”

Parker has been tracking the cloud through his own 16-inch telescope. “A red filter helps,” he notes. “Even a piece of red or orange gelatin held between the eye and ocular will improve the visibility of the dust.”

Two years ago, a similar cloud from Hellas Basin grew until it circled the entire planet. Features on Mars long familiar to amateur astronomers–the dark volcanic terrain of Syrtis Major, for example–were hidden for months. “The planet looked like an orange billiard ball,” recalls Parker.

Will it happen again?

“No one knows,” says astronomer James Bell of Cornell University who studied the dust storm of 2001 using the Hubble telescope. “We don’t yet understand the mechanism that causes regional clouds to self-assemble into giant dust storms.”

Mars Global Surveyor and Mars Odyssey, two NASA spacecraft circling Mars, have seen many “regional storms” like the cloud near Hellas Basin now. They persist for a few days or weeks, then dissipate. Rarely do they become a planet-wide event.

“Only 10 global or planet-encircling dust storms have been reported since 1877,” notes Parker.

All dust storms on Mars, no matter what size, are powered by sunshine. Solar heating warms the martian atmosphere and causes the air to move, lifting dust off the ground.

Because the martian atmosphere is thin–about 1% as dense as Earth’s at sea level–only the smallest dust grains hang in the air. “Airborne dust on Mars is about as fine as cigarette smoke,” says Bell. These fine grains reflect 20% to 25% of the sunlight that hits them; that’s why the clouds look bright. (For comparison, the reflectivity of typical martian terrain is 10% to 15%.)

Sunlight on Mars is about to become unusually intense. The planet goes around the sun in a 9%-elliptical orbit with one end 40 million km closer to the sun than the other. Mars reaches perihelion–its closest approach to the sun–on August 30th. During the weeks around perihelion, sunlight striking Mars will be 20% more intense than the annual average.

“This means the season for dust storms is just beginning,” says Bell.

A total of four spacecraft from NASA, the European Space Agency and Japan are en route to Mars now. They include three landers and two orbiters. Will dust storms cause problems for those missions?

Probably not. NASA spacecraft have encountered Mars dust before. The Viking landers of 1976, for instance, weathered two big dust storms without being damaged. As far as researchers were concerned, it was a good opportunity to study such storms from the inside–something Mars colonists may do again one day for themselves. Viking data will give them a head start.

Five years earlier, in 1971, the Mariner 9 spacecraft reached Mars during the biggest dust storm ever recorded. The planet was completely obscured; not even the polar caps were visible. Mission controllers simply waited a few weeks for the storm to subside. Then they carried on with Mariner 9’s mission: to photograph the entire surface of the planet. It was a complete success.

As 2003 unfolds, Earth and Mars are drawing together for their closest approach in some 60,000 years on August 27th. Already in July Mars is a pleasing sight. Step outside before dawn anytime this month. Mars will be there in the southern sky, a remarkably bright red star. (If you live in the southern hemisphere, look northeast instead.)

Right: John Nemy and Carol Legate took this recent picture of bright Mars and a meteor above their campsite on Blackcomb Mountain, Whistler, British Columbia.

Even a small telescope will reveal the planet’s orange disk and its icy south polar cap. And if “seeing is good” you might catch a glimpse of some dust clouds. Swirling, surging, merging with others … building the next global dust storm? “They’re fun to watch,” says Parker. Now is a great time to see for yourself.

Original Source: NASA Science Story

Image credit: NASA/JPL

Opportunity, NASA’s second Mars Exploration rover, has been in space for a few days now and everything seems to be going according to plan. The spacecraft has reduced its spin rate from 12 rotations a minute to just 2; enabling it to switch to celestial navigation using its star scanner. In fact, one of the first reference points Opportunity used was Mars – already one of the brightest objects in view. It’s already over 7 million kilometres away from the Earth and on track to arrive at Mars on January 25.

NASA’s Opportunity spacecraft, the second of twin Mars Exploration Rovers, has successfully reduced its spin rate as planned and switched to celestial navigation using a star scanner.

Prior to today?s maneuver, Opportunity was spinning 12.13 rotations per minute. Onboard thrusters were used to reduce the spin rate to approximately 2 rotations per minute, the designed rate for the cruise to Mars. After the spinning slowed, Opportunity’s star scanner found stars that are being used as reference points for spacecraft attitude. One of the bright points in the star scanner’s first field of view was Mars.

All systems on the spacecraft are in good health. As of 6 a.m. Pacific Daylight Time July 10, Opportunity will have traveled 6.6 million kilometers (4.1 million miles) since its July 7 launch. The Mars Exploration Rover flight team at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., is preparing to command Opportunity’s first trajectory-correction maneuver, scheduled for July 18.

Opportunity will arrive at Mars on Jan. 25, 2004, Universal Time (evening of Jan. 24, 2004, Eastern and Pacific times). The rover will examine its landing area in Mars’ Meridiani Planum area for geological evidence about the history of water on Mars.

Opportunity’s twin, Spirit, also continues in good health on its cruise to Mars. As of 6 a.m. Pacific Daylight Time July 10, it will have traveled 82.6 million kilometers (51.3 million miles) since its June 10 launch.

JPL, a division of the California Institute of Technology, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington, D.C. Additional information about the project is available from JPL at http://mars.jpl.nasa.gov/mer or and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Image credit: ESA

The European Space Agency has been testing all aspects of the Mars Express spacecraft to ensure that it’s ready for its encounter with Mars. This week they put the UK-built Beagle 2 lander through its paces. The tests included uploading software and turning various instruments on and off, and everything seems to be working properly. A final series of tests will be done in mid-July. Mars Express is expected to reach the Red Planet on December 19 – Beagle 2 will land on the surface on December 25.

On Friday 4 July, and Saturday 5 July 2003, engineers successfully carried out overnight tests on the Mars Express lander, Beagle 2.

Ground controllers at the European Space Agency’s Operations Centre in Darmstadt, Germany, contacted Mars Express at the weekend to carry out the tests on the lander, which were rescheduled from two weeks ago. These functional tests included uploading software and switching units on and off.

With these tests, the near-Earth phase of the Mars Express payload check-outs is almost complete. All instruments, including the lander, have performed as expected. Star calibration of some instruments is scheduled for mid-July, which marks the first attempt to make scientific measurements. This will also be done in the same way when nearer to Mars.

Rudi Schmidt, ESA Mars Express Project Manager, said: “This check-out was a marvellous example of complete cooperation between ESA?s Mars Express and the Beagle lander teams Another major milestone has been achieved successfully. What a fantastic feeling!”

Original Source: ESA News Release

NASA’s second Mars Exploration Rover, Opportunity, successfully lifted off from Florida early Tuesday morning after several delays. The launch was halted only seven seconds away from liftoff during the first window because of a problem with a valve on the rocket, but during the second window at 0318 GMT (11:18 pm EDT Monday) the Delta II successfully blasted off. Opportunity will reach Mars on January 25.