Rare Water-Rich Mars Meteorite Discovered 71
astroengine writes "A rare Martian meteorite recently found in Morocco contains minerals with 10 times more water than previously discovered Mars meteorites, a finding that raises new questions about when and how long the planet most like Earth in the solar system had conditions suitable for life. The meteorite, known as Northwest Africa (NWA) 7034, is the second-oldest of 110 named stones originating from Mars that have been retrieved on Earth. Purchased from a Moroccan meteorite dealer in 2011, the black, baseball-sized stone, which weighs less than 1 pound, is 2.1 billion years old, meaning it formed during what is known as the early Amazonian era in Mars' geologic history. 'It's from a time on Mars that we actually don't know much about,' geologist Carl Agee, with the University of New Mexico in Albuquerque, told Discovery News."
Re:Ironic (Score:3, Informative)
Firstly, we probe for much much more than just water.
Secondly, we don't get more information from looking at a rock in Africa. We get some information, and it's different from the information we get from Mars itself.
Thirdly, this is from very early Mars history. It's very different to current Mars.
Re:Ironic (Score:5, Informative)
Without the money spent on probes (and, in particular, without the Apollo Lunar samples and the Viking Mars descent mass spectrometer), we wouldn't know that this was a Martian rock.
Re:So (Score:4, Informative)
Re:Two questions... (Score:5, Informative)
1. How do we know that a rock is from Mars, especially when its composition is different from what we've found on Mars to date.
Isotope ratios and certain element ratios. These depend on the history of a planetary body, and you can rule out every planet / asteroid but Mars. I always liked the conclusion in this paper [sciencedirect.com] :
There seems little likelihood that the SNCs are not from Mars. If they were from another planetary body, it would have to be substantially identical to Mars
Of course, there is no such other Mars in the solar system.
The existence and composition of little atmospheric inclusions (i.e., tiny little bits of Martian air trapped in the rock) were another convincing piece of evidence for the Mars meteorites, as was the evidence of alteration by water.
2. How do rocks leave Mars' gravity well in the first place? Are they shrapnel from Mars being hit by big meteorites?
In a way. Suppose you have a big meteor hit (the size of the one that formed the Baringer Meteor Crater, or bigger). The meteor drills into the body and goes beneath the surface. At some point, it is stopped, and it dumps its kinetic energy into the body of the planet (i.e., for big impacts the meteorite explodes at depth). The shock wave is roughly spherical, and so the part directed upwards lifts up the surface above where the meteorite hit. Most of this material is lifted not much more than the depth of the explosion, forming the characteristic lip of the crater, and typically turning the layers in the rock upside down at the lip. Some of this material can be accelerated to much higher velocities, however, forming (for example) the rays of the new craters on the Moon. If the meteorite is really big, some of the surface material is accelerated to escape velocity and away it goes. After a little while (a few dozen to no more than a million years), some material will hit another planet. Mars and Earth have been trading material like this for the life of the solar system.
The really amazing thing is that some of the material ejected is not treated too roughly. Spores and seeds etc. could definitely survive the trip.
Re:Some questions (Score:4, Informative)
Funny that you can find a link to something that implies the claim is false... but that you can't be bothered to google on "martian meteorite [google.com]"... and if you did do so, you'd see one of the related searches is "how do martian meteorites get to earth [google.com]".
Skepticism is useful, but get off your dead ass and be an informed skeptic rather than an ignoramus.