MarsNews.com
July 15th, 2014

Curiosity Finds Iron Meteorite on Mars NASA

This rock encountered by NASA’s Curiosity Mars rover is an iron meteorite called “Lebanon,” similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers, Spirit and Opportunity. Lebanon is about 2 yards or 2 meters wide (left to right, from this angle). The smaller piece in the foreground is called “Lebanon B.”
This view combines a series of high-resolution circular images taken by the Remote Micro-Imager (RMI) of Curiosity’s Chemistry and Camera (ChemCam) instrument with color and context from rover’s Mast Camera (Mastcam). The component images were taken during the 640th Martian day, or sol, of Curiosity’s work on Mars (May 25, 2014).
The imaging shows angular shaped cavities on the surface of the rock. One possible explanation is that they resulted from preferential erosion along crystalline boundaries within the metal of the rock. Another possibility is that these cavities once contained olivine crystals, which can be found in a rare type of stony-iron meteorites called pallasites, thought to have been formed near the core-mantle boundary within an asteroid.

March 6th, 2014

Big Mars Impact Gave Earth Most of Its Martian Meteorites Space.com

A huge meteorite impact on Mars five million years ago blasted toward Earth many of the rocks that scientists scrutinize to learn more about the Red Planet, a new study reveals.
The cosmic crash left a 34-mile-wide (55 kilometers) gouge on Mars called Mojave Crater and is the source of all “shergottite” or igneous rock Martian meteorites found on Earth, researchers say. Examining the crater and the meteorites also led to new revelations about how old the rocks are.

October 22nd, 2013

Meteorite may explain ‘how Mars turned to stone’ BBC

A meteorite reveals clues to how Mars lost its thick, carbon dioxide-rich atmosphere and became a cold, rocky desert, researchers say.
They say the Lafayette meteorite shows signs of carbonation – where minerals absorb CO2 in a reaction with water.
Mars lost its protective blanket about 4 billion years ago, perhaps because of the loss of its magnetic field, space impacts, or chemical processes.
Carbonation may be the key factor, they write in Nature Communications.

October 17th, 2013

Curiosity proves that bits of Mars fall to Earth as meteorites Geek.com

Case closed. After several decades of speculation and the gathering of imperfect evidence, Mars rover Curiosity has positively identified hundreds of meteorites found all over the Earth as Martians. The discovery is not unexpected, but it allows the science to go forward with renewed confidence in conjectures about the Red Planet. In particular, Curiosity’s findings could help scientists figure out exactly how Mars lost the vast majority of its atmosphere, why, and how long ago it happened.

January 18th, 2012

Morocco fireball yields rare Mars meteorites Nature

A meteorite that fell to Earth last July in Morocco has proven to be a rare chunk of Mars. Only a handful of Martian meteorites are known, and only five (counting the new find) come from meteorites whose fall was witnessed. That’s important because it tells scientists how long it has been lying on the ground, and therefore how much contamination it might have picked up. In this case, about a dozen pieces (such as the one shown, right), totalling several kilograms, were recovered from Morocco in late December.
“Because it’s only been on the ground for six months or less, it hasn’t been exposed to much contamination,” says Chris Herd, a planetary geologist specializing in meteorites at the University of Alberta, Edmonton, Canada. Herd chairs an international meteoritics committee that yesterday certified the rocks as coming from Mars and approved their name – Tissint – in honour of the village near which they were found.

January 18th, 2012

ASU’s Center for Meteorite Studies acquires exotic piece of Mars Arizona State University

Arizona State University’s Center for Meteorite Studies has acquired a significant new sample for its collection, a rare martian meteorite that fell in southern Morocco in July 2011. It is the first martian fall in around fifty years.
Since the observed fall of the famed Ensisheim meteorite in 1492, there have been around 1,200 recovered meteorite falls. A “fall” is a meteorite that was witnessed by someone as it fell from the sky, whereas a “find” is a meteorite that was not observed to fall but was later found and collected. Only a handful of witnessed meteorite falls occur each year.
The chance of finding a meteorite is exceedingly small. The chance of witnessing a meteorite fall and finding it is even smaller – and the probability that the fall is a martian meteorite is smaller yet.

June 28th, 2011

100 Years Ago, a Chunk of Mars Hit Egypt (and a Dog) Discovery News

Exactly a century ago, on June 28, 1911, an explosion shook the Nakhla region of Alexandria in Egypt at 9 a.m. Soon after, around 40 chunks of meteorite debris from the high altitude blast rained down. 22 pounds (10 kilograms) of the bolide were recovered by witnesses of this cosmic event.
The Smithsonian received two samples of the Nakhla meteorite the following August and then acquired a larger 480 gram (one pound) piece in 1962 (pictured top). By the 1970’s, the Smithsonian had collected 650 grams (1.4 pounds) of the meteorite.

April 17th, 2010

Oldest Mars Meteorite Younger Than Thought Space.com

The oldest known Martian meteorite – a space rock that fell to Earth – is some 400 million years younger than originally thought. It formed about 4.091 billion years ago, a time when the red planet was wet and had a magnetic field, a new study suggests.
Studying this chunk of ancient Mars, which reflects the volcanic processes and bombardment by space debris, could help scientists better understand Mars’ early evolution, as well as Earth’s.
The meteorite, dubbed ALH84001, was found during a snowmobile ride on Dec. 27, 1984 in the Far Western Icefield of Allan Hills in Antarctica.

December 9th, 2009

Mars methane ‘not from meteors’ BBC

The methane found on Mars is not brought to the planet by meteor strikes, scientists say.
Meteoritic material subjected to high temperatures did not release enough methane to account for the amount believed to be released on Mars.
The researchers argue that the methane must therefore be created by geologic or chemical processes, or it is a by-product of microbial life.
The work appears in Earth and Planetary Science Letters.
The origin of the methane on Mars has remained a mystery since it was first detected in 2004.
Because methane has a limited lifetime in the Martian atmosphere before degrading, some process must be pumping hundreds of tonnes of it into the Martian atmosphere annually to keep it at the levels that have been detected.

December 1st, 2009

NASA: compelling evidence of life on Mars The Daily Telegraph

A research team at Johnson Space Centre in Houston has been re-examining a meteorite that hit Antarctica 13,000 years ago, and found the most compelling evidence yet that the planet once harboured bacterial life.
The team says that microscopic crystals found in the rock are almost certainly fossilised bacteria that have many characteristics in common with bacteria found on Earth.
“The evidence supporting the possibility of past life on Mars has been slowly building up during the past decade,” said David McKay, NASA chief scientist for exploration and astrobiology.
“This evidence includes signs of past surface water including remains of rivers, lakes and possibly oceans and signs of current water near or at the surface.”