Feb. 1 (UPI) -- Mars may be home to some of the oldest volcanoes in the solar system. New evidence suggests the Red Planet has been home to volcanic activity for at least 2 billion years.
The evidence is a small Martian meteorite discovered in Africa in 2012. The rock was named Northwest Africa 7635.
Scientists has studied many Martian meteorites over the years. Most arrived on Earth's surface roughly 1 million years ago, when a large object collided with Mars, dislodging significant amounts of rock -- much of it volcanic.
The researchers who analyzed Northwest Africa 7635 determined it to be shergottite, a kind of volcanic rock. They also estimated that it was forged some 2.4 billion years ago.
Scientists have previously found 11 other Martian meteorites with a similar chemical composition. The fragments were all found within the same strata on Earth, suggesting they were dislodged from Mars and fell to Earth at the same time.
"We see that they came from a similar volcanic source," Tom Lapen, a geology professor at the University of Houston, said in a news release. "Given that they also have the same ejection time, we can conclude that these come from the same location on Mars."
Lapen and his colleagues detailed their analysis of Northwest Africa 7635 in the journal Science Advances.