Mars’ Family of Rovers

In this week's post, Grace discusses the different rovers that have been to Mars in response to a query from her sister. One of the most important things we can do as scientists is to translate the excitement and meaning of what we do for the public. (above) Image credit NASA/JPL-Caltech.

By Grace Bischof

A few days ago, I received a text message from my sister asking for a fun space fact to tell the 5-year-olds she teaches who are “super into space”. I thought about all of the interesting things I’ve learned since joining PVL, from both my own and other lab members’ work, but was pretty certain that the seasonal variation of methane on Mars might not be very interesting to young children. Having just finished shadowing my first MSL shift, I had the Curiosity rover on my mind. I realized that Curiosity has been roaming the Martian surface for longer than the kids in her class have been alive. I told my sister to explain to the students that Curiosity is older than them; they might not have found it a very fun fact, but I sure did.

 

So what other rovers are there on Mars, and how old are they? Let’s work from youngest to oldest.

 

Assuming the landing goes to plan, the Perseverance rover should touch down in Jezero Crater on February 18th of 2021 as part of the Mars 2020 mission. If the age of the rover starts at landing, Perseverance might still be considered a zygote rover. Regardless of its infant age, Perseverance is set to be the largest rover to touch down on the Martian surface. Weighing in at 2260 lbs, Perseverance is approximately the size of an SUV. Perseverance is equipped with 7 instruments and has the ultimate goal of searching for signs of past or present life on MArs.

 

Curiosity is the second youngest rover that is currently on Mars. Landing on the red planet in 2012, Curiosity is set to reach its 3000^th sol in early 2021. Curiosity resides in Gale Crater and has traveled more than 21 km in its 8 years of operation. The MSL mission had 8 main objectives, which largely centered around determining if Mars was ever hospitable to life. The rover is equipped with 10 instruments, including the Rover Environmental Monitoring System and the Sample Analysis at Mars, which help to understand the meteorology and atmospheric gases on Mars, respectively. Curiosity’s many cameras have captured interesting Martian features, such as the major dust storm in Martian Year 34. In its 8 years on the planet, Curiosity has been an indispensable asset to understanding the habitability of Mars.

 

Leaping back 17 years, the twin rovers, Spirit and Opportunity, landed at separate locations on Mars in January 2003. Smaller than Perseverance and Curiosity, the twins are about the size of a golf cart. Spirit and Opportunity are the fastest rovers to roam mars, moving at a neck-breaking speed of 0.16 km/hour. Primarily, Spirit and Opportunity were to identify rocks and soil from the Martian surface. Though originally planned as a 90-sol mission, Spirit traveled the dusty plains of Mars until May 2009, when it became stuck in soft soil. Attempts to free Spirit from the soil were carried out for 9 months, but were eventually abandoned. Spirit acted as a stationary instrument until it lost connection to Earth in March 2010. Opportunity stayed active until June 2018, losing its signal to Earth after its solar panels were covered in dust from the MY 34 dust storm. Opportunity holds the record for most distance traveled on a non-Earth world, having driven a total of 42.2 km during its 11 active years. 

 

 

Opportunity: Planetary Marathoner. The Opportunity rover has covered more ground than any other rover on an extraterrestrial surface.
Credit: NASA/JPL-Caltech - https://mars.nasa.gov/resources/6471/driving-distances-on-mars-and-the-moon/

 

The oldest rover to land on Mars is called Sojourner, and landed on the planet in July 1997 (which makes Sojourner older than me by one year). Sojourner is much smaller than its younger siblings, resembling a microwave-oven in size. Carrying only 2 instruments, Sojourner took hundreds of pictures of the Martian surface, and sampled Martian rocks and dirt. Sojourner operated for 83 sols, surpassing its original mission by 53 sols. By the end of its lifetime, Sojourner had traveled 100 m.

 

The family of Mars rovers has been growing since 1997 and is set to become a family of 5 once Perseverance arrives early next year. Through incredible science and engineering feats, we have been able to explore the surface of an entirely different planet from Earth for the past 23 years. I, for one, am excited for the next 23 years of Mars exploration – and maybe by then I can think of a cooler space fact to tell a bunch of 5-year-olds.

 

For more interesting information on the rovers, see: https://spaceplace.nasa.gov/mars-rovers