Mars has been a mystery to man for ages. Many questions shroud the Red Planet; namely, has there ever been life on Mars? But scientists think that a decade-old accidental discovery may hold the key to unlocking the planet's secrets.
In 2007, NASA's Spirit rover uncovered silica deposits in what is believed to be an ancient hot springs on Mars. Because the silica deposits are similar to deposits found here on Earth, they've got scientists scratching their heads.
The deposits were found when Spirit was exploring near an eroded deposit of volcanic ash known as Home Plate in the Columbia Hills of the Gusev Crater, which is three to four billion years old. One of the rover's wheels failed and it dragged along, digging up material, which included the deposits.
But the findings have come up again as scientists recently discovered that the deposits found on Mars resemble deposits found here on Earth in the hot springs in El Tatio, Chile. El Tatio is located on the edge of the Atacama Desert, one of the most Mars-like locales on our planet.
The similarity of the silica deposits found on Mars to the deposits found in El Tatio suggests that the deposits on Mars were created through a similar process to the one on Earth —through microbial organisms. Should the conjecture be true, the deposits would be evidence that life once existed on the Red Planet.
Biosignatures are indicators of a past life. On Earth, they can take the form of fossils. Biosignatures can be as subtle as organic molecules trapped in rocks. However, since no fossils have been detected on Mars as of yet, scientists feel that any Martian biosignature found would be microscopic. The fossils would be difficult to both find and identify as the surface area of Mars is vast.
“We went to El Tatio looking for comparisons with the features found by Spirit at Home Plate. Our results show that the conditions at El Tatio produce silica deposits with characteristics that are among the most Mars-like of any silica deposits on Earth," said Steve Ruff of Arizona State University's School of Earth and Space Exploration. Ruff is one of the co-authors of a report on the findings.
"The fact that microbes play a role in producing the distinctive silica structures at El Tatio raises the possibility that the Martian silica structures formed in a comparable manner — in other words, with the help of organisms that were alive at the time," said Ruff.
Because of the findings, NASA is considering the location as a potential landing site for their 2020 Mars rover, provided that the potential for biosignatures has been preserved. The rover will serve as an attempt to discover if life once existed on Mars.