Mars Rover Curiosity’s 5 Biggest Achievements (So Far)

Today marks exactly 10 years since NASA’s Curiosity rover touched down on Mars.

The one-tonne vehicle launched from Earth in November 2011 and – after an arduous nine-month journey which included the ‘seven minutes of terror’ down to the Martian surface – it set out to look for evidence that the Red Planet may once have supported life.

Since then, Curiosity has driven nearly 18 miles (29 kilometres) and ascended 2,050 feet (625 metres) as it explores Gale Crater and the foothills of Mount Sharp within it. 

The rover has analysed 41 rock and soil samples, relying on a suite of science instruments to learn what they reveal about Earth’s rocky sibling.

Such has been its success, what was originally intended to be a two-year mission was later extended indefinitely, leading to a rather busy decade.

Curiosity has studied the Red Planet’s skies – capturing images of shining clouds and drifting moons – while the rover’s radiation sensor has allowed scientists to measure the amount future astronauts would be exposed to on the Martian surface, helping NASA figure out how to keep them safe. 

Let’s look at some of the rover’s biggest achievements during its decade on Mars, including what it could yet discover as it powers into the future.

 Lakes were present for millions of years in ancient Gale crater.

Perspective view of Gale Crater today, sans lake, using data from NASA’s Mars Reconnaissance Orbiter and the European Space Agency’s Mars Express spacecraft. Curiosity’s landing ellipse is marked in black, and its initially planned traverse up the base of Mount Sharp (aka “Aeolis Mons”) is marked in teal. Image credit: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS.

Curiosity landed next to a three-mile-high mountain of sedimentary rock, says Vasavada. Like the Grand Canyon on Earth, the oldest rocks are at the bottom, younger ones are on top, and each layer is a record of the conditions from a particular time, he says.

Curiosity has now climbed over 1300 feet on the mountain and has found a nearly uninterrupted record of ancient lakes in Gale crater that likely lasted for millions, if not tens of millions of years. 

Even though the lakes are long gone, Curiosity can see bands in the rock that are the remnants of millimeter-thick layers of mud that settled out in the lakes, perhaps at a rate of one per year, says Vasavada.  And he says that there is some evidence that occasionally the lakes dried up, but then returned. 

Organic matter was present on ancient Mars and has even survived intact to this day.

Curiosity has found that ancient Mars had enough carbon in the rocks and soils to serve as raw material for life, if it ever existed, says Vasavada. Curiosity has found that the lakebed rocks in Gale crater had a diversity of organic molecules, he says. 

Most are simple, only a few carbon atoms in length. 

Yet it’s possible that these carbon-based molecules on Mars may be fragments of more complex organic molecules that have degraded over billions of years, Vasavada says. And he notes that it’s surprising that even these simple molecules survived. 

It’s possible they were long buried and only recently appeared on the surface through natural processes of erosion.

“[But] the fact that such molecules were available makes the ancient environment even more suitable for life,” says Vasavada.

Gale Crater
Curiosity inside Gale Crater. NASA/JPL-CALTECH/MSSS

There are occasional spikes in methane gas that so far have no explanation.

Telescopic observers on Earth claimed they saw methane gas (similar to natural gas on Earth) in Mars’ atmosphere in the years before the rover arrived, says Vasavada. It seemed to come and go in large plumes, he says. This was quite surprising because methane is thought to be destroyed quickly by other chemicals, and wasn’t thought to be present, he notes.

Curiosity, however, is equipped with a special sensor for methane and the rover has found a tiny background level of methane, averaging about 1 part methane per 2 billion parts of Mars air, says Vasavada. And a few times over the last eight years, he says, the rover has detected spikes of ten to twenty times as much. 

But Vasavada cautions that although the detection of methane on Mars is exciting because it can be produced by biology on Earth, there also are non-biological explanations. Yet to date, the source of Mars’ methane remains a mystery.

“Either way, it’s very interesting because it means that it is being produced somehow, and seems to vary quite a bit for reasons we don’t yet understand,” said Vasavada.

The methane signal detected by Curiosity has been observed for nearly three Martian years (nearly six Earth years), peaking each summer. Credit: NASA/JPL-Caltech

Curiosity witnessed and made measurements through a planetary-wide dust storm.

Like in deserts on Earth, wind is constantly blowing and grinding away at the geology, says Vasavada. This leaves a lot of dust behind, which occasionally gets whipped up into huge clouds, he notes. Clouds absorb sunlight and heat up, making the winds even more intense, he says. 

With no rain or oceans on Mars, every few years the dust storms will grow until they wrap around the entire planet, says Vasavada. In 2018, such a storm occurred, and Curiosity was able to witness it from the ground, he says.

Although Mars has an atmosphere less than one percent of Earth’s, the most dramatic effect of the storm was that the sunlight in Gale Crater decreased by 97 percent. 

Even with a thin atmosphere, the wind is capable of moving sand around, says Vasavada. Sand dunes were discovered on Mars in the 1970s, but Curiosity is, actually, the first landed mission to watch sand move in the wind, he says.

Mars Curiosity
Overview of Curiosity at Gale Crater. NASA/JPL-CALTECH.

Engaging the Public

Curiosity has helped bring planetary science to the masses, inspiring a tremendous level of interest in Mars exploration.

Some of the intrigue was doubtless generated by Curiosity’s daring landing strategy, which seemed to be pulled from the pages of a sci-fi novel. Indeed, crowds gathered in places such as New York’s Times Square on the night of Aug. 5 to see if Curiosity would survive its harrowing “seven minutes of terror” plunge through the Martian atmosphere.

But the interest has remained strong in the months after the rover’s touchdown, thanks in part to Curiosity’s strong social media and Internet presence. 

As of late July, the robot’s official Twitter feed has more than 4 million followers, and Curiosity has posted more than 2,900 tweets. The rover has also returned to Earth more than 49,000 images, which are viewable by the public at Curiosity’s mission page.

Milestone moment: Today marks exactly 10 years since NASA’s Curiosity rover (pictured) touched down on the Red Planet

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