WASHINGTON, D.C. - Representatives of NASA are planning a news conference Tuesday afternoon to announce the latest discoveries from the Curiosity rover.
The mobile Martian science lab has been collecting soil samples for the past several weeks, searching for signs of life.
It uses special on-board sensors to analyze the soil and determine its origins.
Today's announcement is expected to be made at 1 p.m. at the agency's headquarters in Washington, D.C.
The rock results come seven months after Curiosity made a dramatic landing in an ancient crater near the equator. It has been slow going since then as engineers learn to handle the car-size rover.
Scientists are thrilled with the latest achievement - a first on Mars. It involved boring a hole, scooping the powder and running it through Curiosity's instruments.
By analyzing the rock's interior, researchers hope to determine whether the landing spot was habitable. They already have one hint - an ancient streambed that Curiosity crossed to get to the rock.