http://www.upi.com/view.cfm?StoryID=20040416-041840-4139rA few days ago, on its slow roll across the Martian terrain at its landing site at Meridiani Planum, an iron-oxide-rich area near the planet's equator, Opportunity's controllers noticed an odd-looking, football-shaped rock lying in the red dust. They named the rock "Bounce," because the lander most likely hit it as it bounced along the surface, cushioned by its airbags, before coming to rest inside the little crater called Eagle.
Controllers considered Bounce an odd find because it did not resemble any of the other rocks in the crater's vicinity -- nor did it resemble anything seen before on Mars, they said.
So they ordered Opportunity to train its formidable instruments on the rock, including the tool NASA engineers affectionately called the "RAT," for rock abrasion tool, which grinds away surface impurities to expose the undisturbed, primordial composition below.
The results stunned the NASA team.
"We think we have a rock similar to something found on Earth," said Benton Clark of Lockheed Martin Space Systems in Denver, a science-team member for the missions of both Opportunity and its twin, Spirit.
Rather more than that. Bounce's chemical composition exactly matches that of a meteorite that hit the ground in Shergotty, India, on Aug. 25, 1865."We think we have a rock similar to something found on Earth," said Benton Clark of Lockheed Martin Space Systems in Denver, a science-team member for the missions of both Opportunity and its twin, Spirit.
So far, no one has broached the bigger implication: Bounce provides conclusive evidence not only of Martian meteorites on Earth, but also of the possibility of cross-seeding.
During the early eons of the solar system, planetary impacts were downright common. Given the relative proximity of Earth and Mars, it is easy to accept the possibility that materials propelled upward from one planet eventually could make their way to the other.
The first organisms on Earth originated around 3.5 billion years ago and maybe earlier. Back then, impacts from asteroids and comets still were common. It is conceivable that material ejected from Earth by those impacts could have landed on Mars carrying some of those organisms -- or their raw ingredients. The converse also is possible -- early organisms from Mars could have landed on Earth.
The discovery of Bounce raises the distinct possibility that life arising from a common source could have existed for a time on both worlds.