Celebrating 10 Years of the Curiosity Mars Rover

When a jetpack first lowered Curiosity onto Mars, she was only setting out on a two-year mission to discover whether the Red Planet could have homed ancient microbial life. Fast forward 10 years – the car-sized rover is still exploring with no signs of stopping.

Since landing, Curiosity has travelled 17.5 miles and climbed over 2000ft in elevation. You can even track her live location! The rover still has practically full capabilities, with all science instruments said to be working almost just as they were when they landed.

Curiosity has collected 41 material samples, had her data published in 883 scientific papers and captured 494,540 images - including a 1.8-billion-pixel panorama, her largest and highest resolution panorama ever.

A great way to keep up with Curiosity’s adventures is to follow her Twitter account. As of August 2022, she has 4.3 million followers cheering her on.

Launched in November 2011, Curiosity was designed to explore Gale Crater, a 96-mile-wide impact basin with a 3-mile-high rock-layered mountain called Mount Sharp in the centre. This particular landing site was chosen as it has several signs of the historic presence of water. Scientists back on Earth wanted to discover the history of this crater, how it came to be, and what it could teach us about the Red Planet’s history.

After years of exploration, experts concluded the crater was formed around 3.7 billion years ago when a large meteor hit the planet, annihilating the rock below while forming the mountain peak in the middle.

In alignment with NASA’s Mars Exploration Program, Curiosity’s main science goals are divided into four categories:

• determine whether life ever arose on Mars

• characterize the climate of Mars

• characterize the geology of Mars

• prepare for human exploration

To mark 10 incredible years of exploration and discovery, we’re looking back over Curiosity’s achievements as one of the largest and most powerful rovers ever sent to Mars.

Discovering an Ancient Streambed

Only seven weeks after landing, Curiosity discovered smooth, rounded pebbles that experts believe likely rolled downstream for miles on an ancient streambed. The varying sizes and shapes of these rocks allowed experts to calculate the speed and depth of the water that once flowed there.

“At a minimum, the stream was flowing at a speed equivalent to a walking pace - a meter, or three feet, per second - and it was ankle-deep to hip-deep,” said Rebecca Williams of the Planetary Science Institute.

Since life thrives around water on Earth, this first discovery suggested that parts of Mars may well have been habitable billions of years ago.

Drilling Samples from Martian Rock

Curiosity later drilled her first sample from an ancient network of streams flowing from the rim of Gale Crater. Vital chemical ingredients for life such as nitrogen, sulphur, oxygen, carbon, hydrogen and phosphorus were discovered in powder from the sedimentary rock. Layers of mudstone, nodules, and veins were also found in the ancient bedrock, indicating that the planet experienced multiple periods of wet conditions. After studying the sample further, scientists found that clay minerals made up at least 20% of its composition – these minerals form when fresh water reacts with igneous materials. Experts concluded that rivers and lakes existed in Gale Crater for a million years, if not longer.

"The range of chemical ingredients we have identified in the sample is impressive, and it suggests pairings such as sulphates and sulphides that indicate a possible chemical energy source for micro-organisms," said Paul Mahaffy, principal investigator of the SAM suite of instruments at NASA's Goddard Space Flight Center.

Detecting Active and Ancient Organic Chemicals

After discovering the historic presence of water and life-supporting chemistry, Curiosity went on to measure a tenfold increase of methane – an organic chemical – in Mars’ atmosphere over a two-month period. This was a huge discovery as methane is produced both by chemical reactions and by living organisms – this means that present-day Mars is an active environment.

"This temporary increase in methane - sharply up and then back down - tells us there must be some relatively localized source," commented Sushil Atreya of the University of Michigan, a member of the Curiosity rover science team. "There are many possible sources, biological or non-biological, such as interaction of water and rock."

          

Assessing Radiation Levels

Aside from discovering about Mars’ past, Curiosity has taught us about our potential future on the planet. The rover has been measuring and assessing the planet’s radiation levels with her Radiation Assessment Detector (RAD), helping scientists understand potential risks to human visitors.

While Earth has a magnetic field to shield it from high-energy particles, Mars does not. This kind of radiation can cause serious problems both for health and for astronaut’s life support systems. However, data from Curiosity’s RAD suggests that natural Martian elements like sediment and rock could shield astronauts from this harmful radiation.  

In 2019, Curiosity was parked by a cliff in Murray Buttes from September 9th to 12th. During this time, RAD reported a decrease in overall radiation of 4%, and a decrease in neutral particle radiation of 7.5%. These findings sparked new areas of research, one of which involved Curiosity’s counterpart, Perseverance, being sent to Mars with spacesuit samples to see how they fare against the planet’s radiation.

So, there you have it. After 6686 Martian days, Curiosity’s incredible journey and discoveries like these have led to some ground-breaking conclusions about the Red Planet’s history, as well as our future there.

"A fundamental question for this mission is whether Mars could have supported a habitable environment," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the agency's headquarters in Washington. "From what we know now, the answer is yes."

Thanks to Curiosity, scientists have pieced together the history of Mars’ evolution. Now we’ve answered this essential question, it seems we still have a lot to learn.

On her 10th birthday, we’re wishing this curious robot many more on Martian soil as she continues to fuel our understanding of the planet.