Martian meteorite mysteries resolved New Scientist - Nov. 2002

Martian meteorite mysteries resolved 

Martian rock 'does contain life'  BBC - October 2002 
The strange shapes seen in a rock from Mars that
some researchers say are fossilised bacteria really are
tiny micro organisms, say American researchers. 

Mars Climate Clues Found in Slice of Ice October 2002 -

Martian 'wobbles' shift climate September 2002 - BBC

Giant Martian lake traced  June 2002 - BBC

New maps show that Ma'adim Vallis, one of the biggest valleys on Mars, formed when a large lake overflowed over a low point in its perimeter. Harvesting the water beneath the surface of Mars June 2002 - Mars Daily Updates - Reuters News June 2002 There's Far More to Mars Than Red June 2002 - NY Times UK Scientists Recreate Martian Environment - May 2002 - Reuters Martian Southern Hemisphere Ground Images May 2002 - Cosminiverse Mars ice could flood planet BBC - May 2002

NASA report on this story NASA May 2002 Mars Global Surveyor observes volcanoes Space Flight - May 2002 Digital data puts Mars on map BBC - Feb. 2002 Water Gushed 'Recently' on Mars, Experts Say Reuters - Feb. 2002 Scientist Urges Alien Life Search - Feb. 2002 There's a strange spiral cloud above Mars! Feb. 2002

Hubble's best view of Mars

July 6, 2001 - BBC

The Hubble Space Telescope (HST) has taken its best ever image of Mars.

The picture shows frosty, white, water-ice clouds and swirling orange dust storms above a vivid rusty landscape.

The image was taken on 26 June when Mars was approximately 68 million kilometres (43 million miles) from Earth - the closest the Red Planet has been to Earth since 1988.

Hubble can see details as small as 16 km (10 miles) across. Unlike the orbiting Mars Global Surveyor, which takes detailed images of small regions, Hubble can provide an instant global view of the planet.

Storm activity

Astronomers say the large amount of seasonal dust-storm activity is especially striking. One large storm system can be seen churning high above the northern polar cap, with a smaller dust-storm cloud nearby. Another large dust storm is spilling out of the giant Hellas impact basin in the southern hemisphere.

Although Hubble has observed Mars before, it has never seen such detail because the Red Planet has never been so close since the HST was launched in 1990.

The biennial close approaches of Mars and Earth are not all the same. Mars' orbit around the Sun is markedly elliptical; the close approaches to Earth can range from 56 million km (35 million miles) to 101 million km (63 million miles).

The Mars opposition of 2001 (this event sees the Earth lie directly between the Sun and the Red Planet) serves as a prelude for 2003 when Mars and Earth will come within 56 million km (35 million miles) of each other. That will be the closest they been since 1924 and will not be matched again until 2287.

Frosty craters on Mars

The frosty region in this unnamed crater might stay there all year round

December 3, 2000 - BBC

The Mars Global Surveyor spacecraft has taken a series of images showing frost moving across the Martian surface.

As spring thaws the northern hemisphere, and winter starts to grip the southern, scientists can see the frost-line migrate, changing the appearance of craters as it passes over them.

Mars has the most extreme seasons of any planet. It is always cold and, at its warmest, temperatures rarely exceed freezing.

It is currently spring in the northern hemisphere, and frost that accumulated during the recent winter has been retreating since May.

Of particular interest to experts is a frosty patch seen in an unnamed crater. In 1976, the Viking Orbiter saw a region of frost in the same place and scientists suspect that it persists throughout the Martian summer.

Mars Barnard Crater turns frosty

followed by the Lowell Crater

More evidence of flowing water on Mars

Small gullies can be seen on the slopes of some of the peaks to the upper left of the picture

November 20, 2000 - BBC

New images taken from space show further evidence of gullies on the surface of Mars that may have been carved by water.

The pictures reveal channels in the peaks of sand dunes within one of the planet's southern craters.

Wide angle view of the area depicted in close-up

The pictures come from Nasa's Mars Global Surveyor (MGS) spacecraft, which is currently in orbit around the Red Planet.

Earlier this year, scientists at the US space agency and Malin Space Science Systems, who operate MGS, presented photographic evidence pointing towards the presence of recent, running water on Mars. "Recent" in this sense means within the last two million years.

The announcement, which ran counter to prevailing theories about the presence of water on the Red Planet, caused a sensation. The "discovery" gave fresh impetus to Nasa exploration plans that were under threat at the time because of the loss of two probes.

Hale crater

What is happening on Mars?

Compared with the rest of the Martian surface, the pictured channels appear to be extremely young

Some of the channels are free of dust, suggesting they were only recently washed clean.

Scientists suggest that sudden floods have cut the grooves.

Atmospheric pressure is so low on Mars that liquid water will rapidly boil away.

Any evaporating seepage would likely freeze the ground and damn waters building up behind.

These waters might burst out, flooding down the side of cliffs and cutting gullies.

Each flood could contain as much as 2,500 cubic metres of water - enough water to fill seven community-sized swimming pools

Volcanic heating could be driving the whole process.

The new pictures are of the 136-kilometre- (85-mile-) wide Hale crater in the planet's southern hemisphere.

The Mars Global Surveyor made the observations on 10 November. The top of the picture shows peaks up to 630 metres (2,070 feet) above the crater floor.

Small gullies can be seen on the slopes of some of the largest peaks. Nasa scientists believe these channels may have been carved by running water.

The new pictures add to a growing body of evidence gleaned by the MGS which suggests that water could exist in a porous layer of rock buried just below the Martian surface.

If liquid water does still flow on Mars, and some experts remain sceptical, the planet's southern hemisphere would be a good place to look. More than 90% of the gullies are located there, in the cooler areas away from sunlight.

Martian autumn

Winter in the Martian southern hemisphere begins in mid-December. Over the next few months, Nasa scientists will examine closely new pictures of the planet in an attempt to bolster their evidence.

Liquid water is the key ingredient for supporting life. If the discovery were confirmed, it would have profound implications for the chance of finding existing, microbial extra-terrestrial life.

But some experts are cautious about the findings. It had been thought that water on Mars was in the form of ice below the surface and unlikely to run free on the surface.

Mars enthusiasts will be awaiting eagerly the opportunity, in the next few years, to place a lander on the surface of the planet in an attempt to resolve the question one way or the other.

Mars may still rumble

The lava flows are a mere 20 million years old

Mars may not be volcanically dead. Lava may have flowed over its surface just a few tens of millions of years ago.

The planet apparently continues to have at least some localised, sporadic activity.

Geologists say this is so recent that they cannot rule out the possibility that the Red Planet may burst into life again.

A team of US scientists have identified young lava flows on the flanks of two of Mars' largest, thought to be extinct, volcanoes.

They say that to settle the issue a lander will be required to visit the sites and analyse the surface rocks.

So young

The evidence that Mars could still be active comes from the Mars Global Surveyor (MGS) spacecraft in orbit around the planet.

Elysium Mons rises 13 km (8 miles) above the surrounding plains

Dr William Hartmann, from the Planetary Science Institute in Tucson, Arizona, US, together with Dr Alfred McEwen, from the University of Arizona, and colleagues, have used images from the MGS camera to estimate the age of lava flows on the slopes of an extinct volcano called Elysium Mons.

These flows are a mere 20 million years old. Elysium Mons is one of three large volcanoes on Elysium Planitia, the second largest volcanic region on Mars. It is 1,700 by 2,400 km (1060 by 1490 miles) in size.

Elysium Mons is the largest volcano in this region, measuring 700 km (435 miles) across and rising 13 km (8 miles) above the surrounding plains.

Counting craters

"Some individual flow units could be as young as 10 million years or less," says Dr Hartmann. "In geological terms, that's so recent that volcanic activity might start up again at any time somewhere on the Red Planet."

The suggestion comes just a few months after scientists found convincing evidence that water may have flowed on the surface of Mars in the past few million years.

The scientists say that the clue lies with the numbers of craters.

They counted the number of impact craters of various sizes on lava flows on the planet. The reasoning is that the older a surface, the more impact craters it will have because it has been exposed for longer.

Olympus Mons volcano: The Solar System's biggest

But the method of estimating the age of a lava flow is uncertain by a factor of up to four and the team's conclusions have yet to be universally accepted.

"If I tell you I have an area with an age of 20 million years and I'm out by a factor of four, then the true age could be as much as 80 million years. But that's still within the last few per cent of Martian history," said Dr Hartmann.

"This means volcanism did not shut off in the first 2.5 billion years, as some early scientific papers proposed. Rather, the planet apparently continues to have at least some localised, sporadic activity."

The researchers have also found evidence for flows less than 100 million years old on the slopes of Olympus Mons, the Solar System's largest volcano, thought to be long extinct.

Definitive answers could only come from a robotic mission to sample surface conditions.

New view of giant martian volcano

Olympus Mons, the largest volcano in the Solar System

October 23, 2000 - BBC

Laser beams bounced off the surface of Mars have produced this unique view of the largest volcano in the Solar System.

Called Olympus Mons, it is 27 km (17 miles) tall, three times the height of Mt Everest, and twenty times wider than it is high.

Looking down from Viking orbiter

Images mapped by the Mars Global Surveyor spacecraft have enabled a profile of unprecedented accuracy of Olympus Mons to be produced.

Astronomers say it is raising many questions about the still poorly-understood extinct volcano.

Mars mission

Since it started its mapping mission around Mars in 1998 the Mars Global Surveyor has sent back thousands of high quality images.

It has also scanned the surface of the planet using Mola (Mars Orbiter Laser Altimeter), which beams an infrared laser pulse towards Mars ten times a second. Mola then measures how long it takes for a reflection to return to the spacecraft.

A profile of the surface can be obtained to an accuracy of 37 cm (15 inches), with this data. The measurements have been used to construct a precise topographical map of Mars with many applications in geophysics, geology and atmospheric circulation.

The volcano data has been merged with an image of Olympus Mons taken by the Viking Orbiter spacecraft of the 1970s and vertically exaggerated by a factor of ten.

Astronomers say that Mola's data is giving them a new view of the volcano. It shows that it sits off to the west of the main Tharsis rise rather than on its western flank as was thought.

The topography also clearly shows the relationship between the scarp of the volcano, unique on Mars, and structures produced by the collapse of the flanks of Olympus Mons.