NASA's Amazing Discovery: WATER ON MERCURY!

July 05, 2008
If There's Water on Mercury, Can Fish Be Far Behind? NASA's Amazing Discovery

Most media attention may be on Mars these days, but luckily for us (and the species as a whole) NASA is smarter than the average news network, and can actually look at more than one thing at a time. As well as the "red planet" they've got a probe surveying the "insanely roasted by the sun planet" (aka Mercury) and have found the last thing they expected: water.

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission detected this most precious of liquids in the Mercurian atmosphere, very surprising because to even call what the planet has an "atmosphere" is like calling the morning dew an ocean. The thin layer of material that clings to the planet comes from high energy solar radiation directly vaporizing the surface rocks. Not the sort of thing you'd expect to get wet.

This exosphere (as it's normally termed) is so thin that the MESSENGER can fly directly through it without burning up (though if it had been worried about burning it wouldn't have flown to Mercury in the first place). On the way through its Fast Imaging Plasma Spectrometer detected an awful lot of rock elements, as you might expect, but also signals indicating water element groups. To the general reactions of "What the Hell?" "Check it AGAIN!" and eventually "Wow!" back at mission control.

One explanation for this momentous moisture is that charged hydrogen atoms from the solar wind (which constantly flays the surface) can combine with oxygen from the vaporized crust of the planet to form the essential H2O. Sun radiation combined with blasted rocks on another planet - it makes Evian look like tap water in a council flat.

Water is normally exciting for astro-observers because it's a necessary condition for Earth-type life. While a study of extremophiles shows it never pays to underestimate organic ingenuity, saying that water makes Mercurians possible is like throwing a carpet into an active volcano and calling it a sitting room.

This likely lack of life doesn't make the news any less awesome. It's a pure and simple "Wow, we totally didn't expect that" moment, one of the best times in any field of research. And this is just on MESSENGER's first flyby - it will doubtless reveal much more, but unless it spots Elvis on a subsequent run it's unlikely to find anything more exciting.

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Mercury's surface was shaped by volcanoes - and it's shrinking, Nasa probe finds
By Daily Mail Reporter
Last updated at 12:54 PM on 04th July 2008

Volcanic activity forged the surface of Mercury while also making it shrink, scientists revealed today.

A NASA spacecraft discovered the smallest planet in the solar system has lost 3 miles of its 3,032 mile diameter. This is far more than scientists had expected.

Messenger has begun to resolve some of the mysteries of Mercury, a sun-baked world about a third the diameter of Earth and only slightly larger than the moon. The car-sized spacecraft has seven scientific instruments on board and has measured magnetic activity.

In 1975, Mariner 10, the last spacecraft to fly past heavily cratered Mercury, sent back images showing smooth plains covering large parts of its surface.

But scientists have debated whether these plains were created by volcanic activity or by debris settling back onto the surface after space rocks collided with the planet.

But Messenger images from its January 14 fly-by provide strong evidence that volcanoes played a critical role in forming the planet's surface, according to geologist James Head of Brown University in Providence, Rhode Island.

The dramatic and large-scale volcanism probably took the form both of huge lava flows and violent eruptions, based on surface features seen in the images, Dr Head said.

He estimated that the volcanic activity occurred between three billion and four billion years ago, adding that there is no evidence of ongoing volcanism on the planet’s surface.

‘Everything we’ve seen so far would suggest that the activity on the surface dates from the first half of solar system history rather than the last half,’ Dr Head said.

The Caloris basin, with a diameter of 960 miles, is one of the solar system’s biggest impact craters, formed more than 3.8 billion years ago when a large space rock hit.

Messenger sent back images of a shield volcano with a distinct orange color about 60 miles wide on the southwestern edge of this basin that may be a source for the lava that formed smooth plains inside the basin.

These deposits look similar to basalt flows on the moon, but are very low in iron, representing an unusual rock type. The size of the plains imply the existence of large sources of magma in Mercury’s upper mantle, the scientists said.

Inside the shield volcano they detected a kidney-shaped vent with a bright halo around it very similar to halos formed by explosive eruptions on Earth and the moon.

In other findings also published in the journal Science, scientists said Mercury’s magnetic field originates in the planet’s outer core and is powered by the core’s cooling.

Messenger, which stands for Mercury Surface, Space Environment, Geochemistry and Ranging, was launched in 2004.

Nasa’s Mariner 10 flew past Mercury three times, mapping 45 per cent of its surface. Messenger has imaged about 20 per cent more and is due to fly by Mercury again this October and in September 2009 before starting a yearlong orbit in 2011.

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