As Curiosity explored an area known as the Sulfate-Bearing Unit, scientists were hopeful that the rover would discover proof of there once being water on Mars. At best, researchers only expected to find evidence of “mere trickles of water.” However, Curiosity found much more proof than they anticipated that water once flowed freely on Mars.

“Scientists believed the rocks there formed as the surface of the red planet was drying out,” she wrote. “Instead, the rover found some of the clearest evidence yet of ancient waters.” Amazingly, Curiosity showed scientists evidence of wave-marked rocks that NASA experts believe were formed by a shallow lake that once covered the Sulfate-Bearing Unit.

Researchers are confident that there was once an ample water supply on the planet many years ago that created the wave-marked rocks. “Billions of years ago, waves on the surface of a shallow lake stirred up sediment at the lake bottom, over time creating rippled textures left in rock,” said NASA in a statement.

“The wave-marked rocks were found about one-half mile (800 meters) into Curiosity’s ascent of Mount Sharp,” wrote Wattles. Scientists were taken aback by what Curiosity was able to uncover on its remarkable mission. “As the rover climbed higher, it traveled over rocks that would have formed more recently. That’s why researchers didn’t expect to see such clear markers of a large body of water,” said Wattles. 

This discovery opens the door to a multitude of other possibilities about Mars. Knowing that there was once water could mean that the planet is a lot more habitable than scientists thought. While the presence of water doesn’t “necessarily mean that life exists on Mars,” it certainly shows that there is still a lot more to learn about the Red Planet.

The rover has been a helpful tool for scientists to learn more about the planet from millions of miles away. After many years of research, scientists are happy with the evidence gathered by Curiosity. According to NASA Senior Scientist Ashwin Vasavada, “This is the best evidence of water and waves that we’ve seen in the entire mission.”

It was originally intended to explore the Red Planet for two years but it continued to produce useful findings for scientists. As a result, Curiosity’s mission was extended. Curiosity has provided valuable insight about Mars to NASA, and they continue to utilize its abilities indefinitely. “We will continue to operate Curiosity as long as it’s scientifically viable,” said NASA’s Associate Administrator for Science John Grunsfled.

However, Vasavada revealed that researchers were surprised by the enlightening evidence, saying, “We climbed through thousands of feet of lake deposits and never saw evidence like this—and now we found it in a place we expected to be dry.”

“The wave ripples, debris flows, and rhythmic layers all tell us that the story of wet-to-dry on Mars wasn’t simple,” he said. He revealed that Mars and Earth were once much more similar in ancient times, saying, “Mars’ ancient climate had a wonderful complexity to it, much like Earth’s.”

The rover accomplished its goal by showing that there was once ample amounts of water on the Red Planet, making it livable to various life forms. “We’re finding evidence that Mars was likely a planet of rivers,” said Penn State University geoscientist Benjamin Cardenas.

“Our research indicates that Mars could have had far more rivers than previously believed, which certainly paints a more optimistic view of ancient life on Mars,” Cardenas said. “It offers a vision of Mars where most of the planet once had the right conditions for life.”

“In order to be liquid at such cold temperatures, the water beneath the south pole might need to be really salty, which would make it difficult for any microbial life to inhabit it,” he said. He further added, “However, it does give hope that there were more habitable environments in the past when the climate was less unforgiving.”