By Mary O’KEEFE

It will be 13 years on Nov. 26 that the Mars Science Laboratory and its rover, Curiosity, were launched. It took a little less than nine months for it to arrive on the Martian surface. And, like most missions managed by the Jet Propulsion Laboratory/NASA, the discoveries are still coming in and continuing to surprise scientists.

On May 30, the Curiosity Mars rover drove over a rock, which cracked it open. It held yellow sulfur crystals. The rover didn’t reveal just a small amount of sulfur but a lot of sulfur.

The area that’s covered by these rocks, which measure about six inches in size, is about 50 yards across, said Dr. Ashwin Vasavada, project scientist for Curiosity.

“Something was creating quite a bit of sulfur,” he added. “Sulfur is a common element but it usually binds with other elements, like oxygen. We have found sulfur all throughout the mission as calcium sulfate or magnesium sulfate … We are climbing through a unit that has a lot of magnesium sulfate salts in it, so finding sulfur in that respect is not surprising at all.”

However, what Curiosity recently found was elemental, or pure, sulfur.

“What we know from Earth is that forming sulfur in a pure sense, without it being bound to anything else, requires a pretty special environment,” Vasavada said.

On Earth, pure sulfur is found to form in specific environments including those environments formed through volcanic activity or is near hot, and sometimes cold, springs.

“There’s actually a number of different ways [pure sulfur] could form, [however] the problem that we’re facing is that there’s no immediate answer to how it formed [on Mars],” Vasavada said.

He added there is no sign of volcanic activity in the area. Scientists are exploring all possibilities but Vasavada said they could be looking at a cold spring as the cause of pure sulfur deposits.

“We are talking about a spring that would have been in this location three billion years ago when the mountain was forming and the channel that we’re in might have had flowing water in it,” he added.

“[The discovery is] incredibly exciting especially after 12 years,” he said. “You think you’ve seen it all and then Mars surprises you.”

This discovery, along with the others made over the Mars exploration timeline, is needed in preparation for human flights to Mars and return flights to Earth. It has been discovered that ancient Mars had liquid water on it but now has “basically zero liquid water,” he said.

“Water is long gone, but three billion years ago it flowed down and we found that it created huge debris flow deposits further downhill,” Vasavada said.

Ancient debris flows on Earth are often what paleontologists use to peel back history; it’s the same on Mars as Curiosity continues to explore.

NASA’s goal is for humans to travel to the Moon and to Mars. NASA has launched from the Moon but not from Mars; the more information known of the planet the better it will be for future exploration, which is one of the reasons the Mars Sample Retrieval Lander is so important. According to NASA, “the Sample Retrieval Lander would touch down on Mars and remain in place to receive a diverse collection of scientifically curated samples of Martian rock collected and cached by NASA’s Perseverance rover.”

For Vasavada space exploration is something he has wanted to do for a long time.

“I was a fan … of missions like Voyager and the Viking spacecrafts that landed on Mars,” he said. “Just seeing pictures of Viking on Mars, on this whole other world that looked a lot like Earth in a lot of ways. It made you just want to walk on the surface and pick up a rock. I always wanted to do that.”

The Perseverance rover landed on Mars in February 2021 and began picking up specific rock samples from the Red Planet. Those samples are waiting for the Mars Sample Retrieval Lander to pick them up and bring them home, so even though Vasavada won’t be able to physically pick up those rocks, he may very well be able to hold one in his hand.