The rover Spirit’s stuck wheel in the Martian surface, while it moved across the landscape, turned out to be a lucky accident. It made an important discovery for scientists searching for evidence of life on the Red Planet.

When the crippled wheel dragged along, it dug up a trench revealing a white layer of silica, which is apparently similar to the one produced by hydrothermal vents like the famous hot springs at Yellowstone. So, if there were hot springs on Mars, there might have been life.

Reported in Science Magazine, the discovery was made by a team of researchers led by Steven Squyres of Cornell University. The news was also announced by Arizona State University.

Steven Ruff of A.S.U., one of the co-authors of the report, said the hot springs were indicated by the type of silica found as well as by other evidence of volcanic activity in the area. Dr. Ruff said, who noted that this part of Mars (dubbed Home Plate by the researchers) was a logical spot for the water, said, “On Earth, the only way to have this kind of silica enrichment is by hot water reacting with rocks. Home Plate came from an explosive volcanic event with water or ice being involved. We saw where rocks were thrown into the air and landed to make small indentations in the soft, wet ash sediment around the vent.”

The co-authors of the report, Jack Farmer of A.S.U., said, “On Earth, hydrothermal deposits teem with life and the associated silica deposits typically contain fossil remains of microbes.” The researchers aren’t sure if that’s the case on Mars, because the Spirit rover doesn’t carry instruments that can detect microscopic life. “What we can say,” Dr. Farmer added, “is that this was once a habitable environment where liquid water and the energy needed for life were present.”

According to the scientists, it looks like a spot where a future rover with the right equipment — which is already being developed — should go looking for signs of that microscopic life.