LAST week, a new study of the surface of Mars by US scientists revealed strong evidence there may once have been a vast ocean covering more than a third of the Red Planet.
There would have been rivers, clouds, rainstorms and glaciers: Mars would have looked like the earth's smaller, wetter twin.
It is now widely accepted that there was once flowing water on Mars, and at least some of that water is still there - locked up as ice at the polar caps and in the shaded rims of deep craters.
But why did the Red Planet lose its oceans? Could liquid water still be there today? And what do these discoveries mean in the search for life on Mars?
1. A SHORT HISTORY OF MARS
MARS, along with earth and all the other planets in the solar system, formed around 4.5billion years ago out of a cloud of dust orbiting around our new-born sun.
Four billion years ago, Mars would have had a thick atmosphere which kept the surface warm enough for water to flow.
The atmosphere would have been fed with gases from giant volcanoes like Olympus Mons - the biggest mountain in the solar system at over three times the height of Everest.
Because Mars is only half the diameter of earth, it would have been born with less internal heat than our planet and would have lost that heat much more quickly to space.
This meant that its molten iron core cooled and solidified.
Our planet, earth, still has a molten core which produces its magnetic field. This isn't just useful for compasses, it protects us from the violence of the solar wind, a stream of ultra-high energy pieces of the sun that blasts our planet every day.
Without our protective magnetic field, our atmosphere would soon be blown off into space, and this is what we think happened to Mars.
Without an atmosphere, Mars quickly lost its oceans as they boiled away into space, and the remaining water froze solid as temperatures fell. The giant volcanoes lost their power source and Mars died with them.
2. THE MYSTERY OF THE NEW DISCOVERIES
THIS standard story of a long-dead Mars is being challenged by new discoveries from the army of spacecraft currently in orbit around Mars and roaming over its surface.
Researchers from London's Imperial College recently found evidence for flowing water as little as three billion years ago.
And NASA's incredibly successful Mars rovers, Spirit and Opportunity, recently discovered on the surface of Mars the mineral gypsum - which back on earth can only be formed in areas of standing water. Along with the new find of a possible Martian ocean, this all adds up to a tantalising picture of a Mars that was warmer and wetter in its much more recent past.
3. WHAT DOES THIS MEAN FOR LIFE?
HERE, on earth, there is one general rule - wherever there is water, there is life.
In the darkest depths of the oceans, in the deepest caves and mines and even buried within glacial ice, we find microbes eking out an existence.
One of the scientists who worked on the Martian gypsum discovery recently described it as "compelling" evidence that there must have been life on Mars at some point in the past.
He pointed to the Mediterranean, where gypsum is found side by side with enormous numbers of ancient fossils.
4. WILL WE EVER FIND LIFE ON MARS?
EMBOLDENED by these tantalising glimpses into Mars' warmer, wetter past, NASA and the European Space Agency are planning a fleet of new robotic missions to the Red Planet.
Top of the list is the complex ExoMars mission (from the term exobiology, meaning life beyond earth).
The plan is for four spacecraft, including a large Mars rover, to be launched between 2016 and 2018 - with dedicated experiments to search for signs of life, whether alive or extinct.
5. WHAT WOULD IT MEAN IF WE DID?
FINDING life in another world would, in my view, be the greatest discovery in human history.
Life is the most baffling and valuable part of our universe.
Without it, the universe might as well not exist because there would be nobody around to marvel at its beauty.
As far as we know for sure, tiny earth is the only place in the cosmos that supports life.
We must find out whether we are an impossibly unlikely accident or a part of a giant universal community.
If we discover life on our nearest planetary neighbour, we will have our answer. This is why the exploration of the Red Planet is so vital and valuable.
view the pictures at this link.
New evidence of oceans on Mars | The Sun |Features
HubbleSite - The Telescope - Hubble Essentials - Quick Facts
:Jester:
There would have been rivers, clouds, rainstorms and glaciers: Mars would have looked like the earth's smaller, wetter twin.
It is now widely accepted that there was once flowing water on Mars, and at least some of that water is still there - locked up as ice at the polar caps and in the shaded rims of deep craters.
But why did the Red Planet lose its oceans? Could liquid water still be there today? And what do these discoveries mean in the search for life on Mars?
1. A SHORT HISTORY OF MARS
MARS, along with earth and all the other planets in the solar system, formed around 4.5billion years ago out of a cloud of dust orbiting around our new-born sun.
Four billion years ago, Mars would have had a thick atmosphere which kept the surface warm enough for water to flow.
The atmosphere would have been fed with gases from giant volcanoes like Olympus Mons - the biggest mountain in the solar system at over three times the height of Everest.
Because Mars is only half the diameter of earth, it would have been born with less internal heat than our planet and would have lost that heat much more quickly to space.
This meant that its molten iron core cooled and solidified.
Our planet, earth, still has a molten core which produces its magnetic field. This isn't just useful for compasses, it protects us from the violence of the solar wind, a stream of ultra-high energy pieces of the sun that blasts our planet every day.
Without our protective magnetic field, our atmosphere would soon be blown off into space, and this is what we think happened to Mars.
Without an atmosphere, Mars quickly lost its oceans as they boiled away into space, and the remaining water froze solid as temperatures fell. The giant volcanoes lost their power source and Mars died with them.
2. THE MYSTERY OF THE NEW DISCOVERIES
THIS standard story of a long-dead Mars is being challenged by new discoveries from the army of spacecraft currently in orbit around Mars and roaming over its surface.
Researchers from London's Imperial College recently found evidence for flowing water as little as three billion years ago.
And NASA's incredibly successful Mars rovers, Spirit and Opportunity, recently discovered on the surface of Mars the mineral gypsum - which back on earth can only be formed in areas of standing water. Along with the new find of a possible Martian ocean, this all adds up to a tantalising picture of a Mars that was warmer and wetter in its much more recent past.
3. WHAT DOES THIS MEAN FOR LIFE?
HERE, on earth, there is one general rule - wherever there is water, there is life.
In the darkest depths of the oceans, in the deepest caves and mines and even buried within glacial ice, we find microbes eking out an existence.
One of the scientists who worked on the Martian gypsum discovery recently described it as "compelling" evidence that there must have been life on Mars at some point in the past.
He pointed to the Mediterranean, where gypsum is found side by side with enormous numbers of ancient fossils.
4. WILL WE EVER FIND LIFE ON MARS?
EMBOLDENED by these tantalising glimpses into Mars' warmer, wetter past, NASA and the European Space Agency are planning a fleet of new robotic missions to the Red Planet.
Top of the list is the complex ExoMars mission (from the term exobiology, meaning life beyond earth).
The plan is for four spacecraft, including a large Mars rover, to be launched between 2016 and 2018 - with dedicated experiments to search for signs of life, whether alive or extinct.
5. WHAT WOULD IT MEAN IF WE DID?
FINDING life in another world would, in my view, be the greatest discovery in human history.
Life is the most baffling and valuable part of our universe.
Without it, the universe might as well not exist because there would be nobody around to marvel at its beauty.
As far as we know for sure, tiny earth is the only place in the cosmos that supports life.
We must find out whether we are an impossibly unlikely accident or a part of a giant universal community.
If we discover life on our nearest planetary neighbour, we will have our answer. This is why the exploration of the Red Planet is so vital and valuable.
view the pictures at this link.
New evidence of oceans on Mars | The Sun |Features
HubbleSite - The Telescope - Hubble Essentials - Quick Facts
:Jester:
