Category: Mars

Image credit: NASA

With only a few months to go before NASA launches its next two rovers to Mars, mission planners need to pin down exactly where they want the robot explorers to touch down. The twin Mars Exploration Rovers are scheduled for launch in May and June of 2003, and they currently have four candidate landing locations picked out – each of which offers unique terrain to explore. The final decision will be made in April.

The launch dates for the two Mars Exploration Rovers are getting closer and so is the need to pick a place for them to land.

Adventurous travelers might spin a globe and pick a vacation based on whichever spot their finger finds. But scientists and engineers working on NASA’s newest rover mission cannot be as casual about landing site choices for the twin rovers that will launch in May and June of this year.

Last week, team members and others from the scientific community met for a final chance to discuss and fine-tune the pros and cons of each of the four landing site contenders.

Images and data from two other NASA spacecraft currently orbiting the red planet — Mars Global Surveyor and Mars Odyssey — have provided invaluable information on possible landing sites.

“This is a unique period where we have orbital missions that can help us make the selection,” said Dr. Matt Golombek, JPL landing site scientist. “We want to go to sites with terrains that will challenge our minds but not the safety of the rovers.”

Since the rovers do not have the luxury of landing on a well-paved runway, JPL geologists and engineers must carefully choose an area without large rocks that could damage the rovers’ airbag landing system. Also, an area that is too densely populated with rocks of any size could prevent the rover from moving freely. Winds in the lower atmosphere are also an important consideration, as are the slopes the airbag-clad lander impact against.

Adequate exposure to the sun is vital for the solar-powered rovers. Geologists have chosen sites near the equator where there is sufficient sunlight. The sites are also relatively free of accumulations of iron-oxide dust particles that can coat solar panels and interfere with the rovers’ mobility.

Like the final four in any competition, each of the four Mars candidates is a potential winner.

“Three of the sites, Terra Meridiani, known as the Hematite site, Gusev, and Isidis show evidence for surface processes involving water. These sites appear capable of addressing the science objectives of the rover missions: to determine if water was present on Mars and whether there are conditions favorable to the preservation of evidence for ancient life,” said Golombek.

The fourth site, Elysium, appears to contain ancient terrain, which may hold clues to Mars’ early climate when conditions may have been wetter.

Over the next several months, geologists and engineers will continue to analyze the viability of each site. The final decision will be made by NASA in April, shortly before the rovers begin their journey to Mars.

Original Source: NASA/JPL News Release

Gullies on Mars were discovered in 2001 that seemed to show evidence that liquid water had been on the surface of the planet very recently. But a theory from a University of Melbourne geologist examines the possibility that the gullies were carved by an avalanche of carbon dioxide changing directly from a solid to a gas. This theory has been met with skepticism from other Mars researchers, who are hoping that liquid water might someday be found on Mars, increasing the possibility of finding life.

An Australian geologist has identified what could be the first ever active flow of fluids through gullies on Mars.

University of Melbourne geologist, Dr Nick Hoffman, identified recent gully and channel development near the polar regions of Mars from images taken by the Mars Global Surveyor spacecraft. But contrary to the majority of scientific opinion which suggests that such features were carved by liquid water, Hoffman says the flow is most likely frozen carbon dioxide.

NASA is desperate to find signs of liquid water on Mars so they have a target for the next generation of Mars landers and rovers to go and search for life, but their search could prove fruitless if Hoffman’s analysis of the images is correct.

In the latest edition of the journal Astrobiology, Hoffman presents evidence for the flow events on Mars and demonstrates that there are substances other than water that can flow on Mars and that water is probably the least likely substance to do this. Hoffman says the channels he identified from the Surveyor images are more likely being carved by avalanches of carbon dioxide and associated debris.

“The consequences of this for life on Mars are shattering. If similar mechanisms are responsible for all the recent gullies on Mars then the near surface life NASA is so desperately searching for may not exist,” says Hoffman.

“Without liquid water there cannot be life and despite recent reports of more and more ice on the Red Planet, NASA has yet to find liquid water,” he says.

Many NASA scientists are doubtful about Hoffman’s observations, but at a meeting of the American Geophysical Union held last month, Hoffman says they struggled to find arguments against the evidence he presented.

The Mars Gullies were discovered in 2001. Hoffman’s analysis of the recent images shows that a patch of gullies near the South Pole shows signs of annual flow activity each Martian Spring.

“In itself the observation of active flows is a dramatic discovery since no movement has yet been seen on Mars, except for some dry dust avalanches. The gullies are thought to be the most promising candidates for liquid water flows on modern Mars and many NASA researchers are suggesting ways in which they might be formed by liquid water, but nobody has yet seen the gullies in action,” says Hoffman.

Hoffman suggests NASA researchers missed these most exciting events happening in the gullies as they have been focussed on looking for liquid water in late summer.

“In the Martian Spring, when carbon dioxide frost and snow at temperatures of minus130 degrees Centigrade still fill the valleys, flow events are occurring. The flows cut through the frost at temperatures that would turn battery acid into building stone,” he says.

“Nothing based on water can flow at these temperatures, so the culprit must be defrosting carbon dioxide.

“But carbon dioxide doesn’t melt on Mars; it boils directly from the solid (a process called ‘sublimation’). Instead of a trickle or gush of liquid pouring down the gully, the flow appears to be a flurry of boiling dry ice avalanching down the gully. The boiling dry ice acts like a amarda of miniature hovercraft carrying a shower of sand, dust, and tumbling rocks down the slope, carving out the gullies as it goes.

Original Source: University of Melbourne News Release

Image credit: ESA

One concern engineers have when designing space missions is how to ensure our spacecraft don’t bring along unexpected microorganisms when they reach a distant planet. There are strict international rules to avoid contamination, so engineers use several techniques to keep their spacecraft clean: sterilization through heat, vacuum, alcohol, irradiation with ultraviolet light and other kinds of radiation. Once they’re done, engineers hope to have less than 300,000 microorganisms in the Beagle 2, due for launch in 2003. That sounds like a lot, but there are several billion wee beasties on even the cleanest kitchen floor.

When packing for a trip towards another planet, there are some things, such as microorganisms, that you do not want to include in your ‘luggage’. For example, what if extraterrestial life is finally detected on Mars, and scientists realise afterwards that such life is actually terrestrial?

Fortunately, there are strict international rules to avoid the contamination of Solar System bodies with biological material from Earth. Landers, for example, may present a special danger to the objects they set down on. The European Space Agency (ESA) is well aware of this. ESA’s missions, such as Mars Express, with its lander Beagle 2, Rosetta, which will land on a comet, and Cassini-Huygens, headed towards Saturn and its moon Titan, will be ‘clean’ and responsible visitors. The strictest of procedures will ensure that they carry only highly sterilised landers.

Cassini (with Huygens on-board) left Earth in 1997 and is travelling towards the planet Saturn. In 2004, Huygens will separate from the spacecraft and land on its own on Saturn’s largest moon, Titan. Titan is a highly promising site for the scientists because its atmosphere very much resembles that of primitive Earth. It is a very cold place, with temperatures down to -180?C. Many scientists think such freezing temperatures are precisely the reason why life never arose on Titan. However, Huygens may well give them reasons to reconsider.

Rosetta and Mars Express will be launched in 2003. Rosetta is ESA’s comet-chaser. It will spend 8 years travelling through the Solar System and in 2011 it will land on Comet 46 P/Wirtanen, making Rosetta the first spacecraft ever to land on a comet. Mars Express is the next mission to Mars and the first European one. It will arrive on the Red Planet in December 2003 and release its lander Beagle 2, whose task, among others, is to search for evidences of Martian life.

These diverse projects all have something in common. They have all had to take into account the ‘planetary protection’ requirements set by the international scientific organisation, Committee on Space Research (COSPAR).

“We don’t want to contaminate the planets we go to,” says John Bennett, of ESA’s Mars Express team and one of the scientists responsible for ‘protecting’ the Red Planet from an undesired terrestrial invasion. “We don’t want future missions to detect contamination, instead of life.”

COSPAR rules determine a spacecraft’s degree of cleanliness. Standards vary depending on both the type of mission and its ‘destiny’. For example, from a contamination point of view, landers are obviously more ‘dangerous’ than orbiters. Moreover, the more likely a planet is considered to bear life, the stricter the requirements are.

For these reasons, rules are especially tough for Mars Express’s lander, Beagle 2. Scientists set sterilisation criteria of 300 microorganisms per square metre for missions to Mars in the past. At this level, no life was detected and they concluded that this sterilisation level would not compromise or affect biological measurements. Beagle 2 will have to be sterilised to contain less than 300 microorganisms per square metre at launch, and no more than 300 000 inside the whole launcher. By comparison, the floor of even the cleanest kitchen inside a house on Earth has several thousands of millions of microorganisms present.

The sterilisation process is quite complicated. Many of the instruments’ components are very delicate and would not withstand very high temperatures, so scientists use different techniques. They will heat most of the components of Beagle 2 to 120?C and clean other components chemically. For the solar panels, for example, an alcohol will be used. The microelectronics components will be placed in a vacuum chamber with a special gas, hydrogen peroxide plasma, that oxidises biological material, making it harmless. Scientists will also use another sterilising technique, irradiation with ultraviolet light and other kinds of radiation. Sterilisation will affect all parts of the lander, even the airbags and the parachute system the lander uses to reach the ground safely.

For Beagle, the process will take place in several facilities in the United Kingdom. Special transportation systems will take each component to a specially built clean room where they will be assembled on location at the Open University site in the United Kingdom. Assembly will begin this summer. Once finished, the ultraclean Beagle 2 will be ‘sealed’ within its own front-shield and back-cover, and made ready to be mounted on Mars Express.

Requirements for Rosetta and Huygens are less strict. When Cassini-Huygens was launched in 1997, scientists thought that life was simply too unlikely to exist on the cold Titan. They therefore labelled the project low risk, with no sterilisation procedures considered necessary. However, according to COSPAR rules, the spacecraft was assembled in a clean room, that is, with less than 100 000 particles per unit of volume.

Rosetta is a similar case. “Sterilisation is generally not crucial since comets are usually regarded as objects where you can find prebiotic molecules, that is, molecules that are precursors of life, but not living microorganisms,” explains Gerhard Schwehm, Rosetta’s Project Scientist. On the other hand, Rosetta has to perform delicate experiments on the comet and scientists do not want the results to be spoiled, so cleanliness is required.

Original Source: ESA News Release

Image credit: ESA

In a silly publicity stunt, Ferrari engineers have decided to see just how fast their paint can go. When the European Space Agency’s Mars Express spacecraft launches in May/June 2003, it may be carrying a tiny glass ball painted with Ferrari’s signature red paint. When Mars Express arrives at the Red Planet in December, the whole spacecraft (including the paint) will endure tremendous heat as it aerobrakes in the planet’s atmosphere.

What is the fastest Ferrari’s distinctive red paint has ever travelled? Next year it will be 10800 km/h! Mars Express, to be launched in May/June 2003, the first European spacecraft to visit the Red Planet, will be speeding on its way accompanied by the very essence of Ferrari: a sample of its distinctive red paint.

Mars has always fascinated us here on Earth. The European Space Agency’s Mars Express mission, due to arrive at its destination by December 2003, aims to solve many of the planet’s age-old mysteries. It will ultimately be looking for the presence of water on Mars, but might also find evidence of life, both past and present. And, of course, it will be studying the red soil in depth.

Following the outstanding success of the Scuderia Ferrari with the victory of Michael Schumacher’s fifth Formula 1 driver championship title, the Ferrari team has agreed to fly the symbol of that success on the Mars Express mission. Ferrari’s high-tech red paint is recognised all over the world as being synonymous with the record-breaking marque.

When Mars Express is launched next May/June, the Ferrari red paint will be on board in a specially constructed glass globe measuring 2cm in diameter, designed to withstand the extremes of temperature it will encounter on its trip to Mars. The spacecraft will be launched on a Soyuz/Fregat launcher, reaching speeds of roughly 10800 kilometres per hour, nearly 10 times the speed of sound!

The paint is currently undergoing rigorous tests at ESA’s test centre in the Netherlands to discover how it will withstand space conditions on the journey. Once it has been officially “space-qualified”, it is due to be installed on the spacecraft at a formal ceremony in September.

Original Source: ESA News Release

Russian space officials have announced their intentions to send human explorers to Mars by 2015. Hoping for International support to help fund the $20 billion budget, managers have already planned out the mission basics. They’re estimating that two ships would travel to Mars and deliver three people to the surface for 440 days while three others would remain in orbit. Obviously this is completely preliminary in nature, and officials from NASA or the ESA have yet to comment if they would support this Russian initiative.

Image credit: NASA

As predicted last week, NASA scientists announced that they have discovered evidence of vast deposits of water ice under the rocky surface of Mars. Special detectors on the Mars Odyssey spacecraft have found strong signals of enough ice to fill up Lake Michigan. As we’ve found on Earth, wherever there’s water and heat, there’s life, so this is encouraging for the search for life on Mars. This is also encouraging for possible future human missions to the Red Planet, as astronauts will have easy access to water for drinking, as well as hydrogen and oxygen.

Using instruments on NASA’s 2001 Mars Odyssey spacecraft, surprised scientists have found enormous quantities of buried treasure lying just under the surface of Mars — enough water ice to fill Lake Michigan twice over. And that may just be the tip of the iceberg.

Images are available at http://www.jpl.nasa.gov/images/mars and http://mars.jpl.nasa.gov/odyssey.

“This is really amazing. This is the best direct evidence we have of subsurface water ice on Mars. We were hopeful that we could find evidence of ice, but what we have found is much more ice than we ever expected,” said Dr. William Boynton, principal investigator for Odyssey’s gamma ray spectrometer suite at the University of Arizona, Tucson.

Scientists used Odyssey’s gamma ray spectrometer instrument suite to detect hydrogen, which indicated the presence of water ice in the upper meter (three feet) of soil in a large region surrounding the planet’s south pole. “It may be better to characterize this layer as dirty ice rather than as dirt containing ice,” added Boynton. The detection of hydrogen is based both on the intensity of gamma rays emitted by hydrogen, and by the intensity of neutrons that are affected by hydrogen. The spacecraft’s high-energy neutron detector and the neutron spectrometer observed the neutron intensity.

The amount of hydrogen detected indicates 20 to 50 percent ice by mass in the lower layer. Because rock has a greater density than ice, this amount is more than 50 percent water ice by volume. This means that if one heated a full bucket of this ice-rich polar soil it would result in more than half a bucket of water.

The gamma ray spectrometer suite is unique in that it senses the composition below the surface to a depth as great as one meter. By combining the different type of data from the instrument, the team has concluded the hydrogen is not distributed uniformly over the upper meter but is much more concentrated in a lower layer beneath the top-most surface.

The team also found that the hydrogen-rich regions are located in areas that are known to be very cold and where ice should be stable. This relationship between high hydrogen content with regions of predicted ice stability led the team to conclude that the hydrogen is, in fact, in the form of ice. The ice-rich layer is about 60 centimeters (two feet) beneath the surface at 60 degrees south latitude, and gets to within about 30 centimeters (one foot) of the surface at 75 degrees south latitude.

“Mars has surprised us again. The early results from the gamma ray spectrometer team are better than we ever expected,” said Dr. R. Stephen Saunders, Odyssey’s project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “In a few months, as we get into martian summer in the northern hemisphere, it will be exciting to see what lies beneath the cover of carbon dioxide dry-ice as it disappears.”

“The signature of buried hydrogen seen in the south polar area is also seen in the north, but not in the areas close to the pole. This is because the seasonal carbon dioxide (dry ice) frost covers the polar areas in winter. As northern spring approaches, the latest neutron data indicate that the frost is receding, revealing hydrogen-rich soil below,” said Dr. William Feldman, principal investigator for the neutron spectrometer at Los Alamos National Laboratories, New Mexico.

“We have suspected for some time that Mars once had large amounts of water near the surface. The big questions we are trying to answer are, ‘where did all that water go?’ and ‘what are the implications for life?’ Measuring and mapping the icy soils in the polar regions of Mars, as the Odyssey team has done, is an important piece of this puzzle, but we need to continue searching, perhaps much deeper underground, for what happened to the rest of the water we think Mars once had,” said Dr. Jim Garvin, Mars Program Scientist, NASA Headquarters, Washington, D.C.

Another new result from the neutron data is that large areas of Mars at low to middle latitudes contain slightly enhanced amounts of hydrogen, equivalent to several percent water by mass. Interpretation of this finding is ongoing, but the team’s preliminary hypothesis is that this relatively small amount of hydrogen is more likely to be chemically bound to the minerals in the soil, than to be in the form of water ice.

JPL manages the 2001 Mars Odyssey mission for NASA’s Office of Space Science, Washington, D.C. Investigators at Arizona State University, Tempe; the University of Arizona, Tucson; and NASA’s Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Additional information about the 2001 Mars Odyssey and the gamma-ray spectrometer is available on the Internet at: http://mars.jpl.nasa.gov/odyssey/ and http://grs.lpl.arizona.edu.

Original Source: NASA/JPL News Release

Space agency watchdog Keith Cowing is reporting that NASA is due to announce the discovery of large amounts of water ice on the surface of Mars. The speculation is that data from one or several instruments on board the Mars Odyssey spacecraft have confirmed the presence of underground ice, and that NASA will announce the findings at a press conference on Thursday, May 30. If true, the discovery of this much water ice will have tremendous implications on the search for life on the Red Planet. It’s all very preliminary right now, so stay tuned for some actual confirmation by NASA.

Although he was the second human to walk on the moon, astronaut Buzz Aldrin isn’t getting out the space race yet. He’s working on plans to develop a massive shuttle that would travel between the Earth and Mars, transferring people and supplies to and from the Red Planet. The shuttle wouldn’t actually stop at Mars, it would just drop off people and then use gravity to make a return voyage back to Earth to pick up more people. And although the idea sounds way off, Aldrin, and researchers from Purdue University believe something could be developed by 2018.

Scientists believe there may be chlorophyll, a substance used by plants to extract energy from sunlight, located near the landing site for the 1997 Mars Pathfinder mission. Scientists analyzed the spectral signature of the area surrounding Pathfinder’s landing site. Although the researchers have stressed that their findings are preliminary, they believe they’ve found two areas that appear to contain chlorophyll – it could be significant, or it just could be a patch of coloured soil.

Image credit: NASA

Now in its final orbit, Mars Odyssey is getting to work searching for water on the surface of the planet. The most recent set of images returned are of a network of channels taken by the Thermal Emission Imaging System (THEMIS). The Nirgal Vallis is a channel 500 km long and 6 km wide at this point – astronomers believe that gullies on the side of the channel were formed when water erupted to the surface.

This THEMIS image shows a sinuous valley network channel with sharp bends cutting across the cratered highlands of the southern hemisphere of Mars. The channel is named Nirgal Vallis, which is from the Babylonian word for “Mars”. Nirgal Vallis is a channel with a total length of approximately 500 km. It is approximately 6 km wide in this region. Gullies and alluvial deposits discovered by Mars Global Surveyor are clearly visible on the polar-facing (south) wall and floor of Nirgal Vallis. These gullies appear to emanate from a specific layer in the walls. There is a pronounced sparsity of gullies on the equator-ward facing slopes. The gullies have been proposed to have formed by the subsurface release of water. Patches of dunes are also seen on the channel floor, notably along the edges of the channel floor near the canyon walls. There is still debate within the scientific community as to how valley networks themselves form: surface runoff (rainfall/snowmelt) or headward erosion via groundwater sapping. This image is approximately 22 km wide and 60 km in length; north is toward the top.

Original Source: ASU News Release