What Are Robots Doing On Mars?

Mars, the fourth planet along from the sun in the solar system and a neighbor planet to Earth, has inspired stories for as long as humans have been on this planet. 

Other than the moon, the only other celestial bodies that we have landed on have been Venus, and, our beloved planetary neighbor, Mars.

Humans are curious creatures, and we’ll do everything we can to find out about the universe we live in.

Whilst any secret aliens hiding away on Mars may find us to be particularly nosey, sending robots such as rovers to Mars’ surface, in order to explore and conduct important experiments that give us an idea of Mars’ history, is the key to plenty of scientific advancements that can greatly benefit humans, and life, here on Earth.

The exploration of Mars, as well as the experiments conducted in order to find out even more about it, can help us to answer important and intriguing questions, such as whether it’s possible for life to exist within the universe outside of Earth – and even if life ever has existed within the universe outside of Earth. 

The Habitable Zone

There is an area within our Solar System, known as the ‘habitable zone’ – this zone, scientists believe, provides the best chance for life to exist within our Solar System, due to the zone being just far enough away from the Sun that liquid water may exist within this zone.

This is a result of the temperature – a little further away from the Sun and that liquid would become ice due to the coldness of space, any closer to the Sun and it would heat up to the point of evaporation; becoming steam.

In the search for extraterrestrial life, Mars, the closest planet to Earth in the solar system (and fellow inhabitant of the Habitable Zone), is probably one of the most logical places to look.

So, Why Send Robots To Mars?

Human-made robots, such as rovers and probes, were perfect for undertaking the seven-month journey. 

Human passengers would require supplies that would take up much-needed space that could be used for other, arguably more useful things – such as extra fuel, or equipment to do some more potentially groundbreaking experiments.

Not to mention, the heavier the craft, the more fuel it requires to reach its destination – so the more weight lost the better.

Another good reason for not sending humans is that Mars has an extremely volatile atmosphere – dust storms, a lack of oxygen and an abundance of space radiation all work together to make this planet pretty dangerous for humans to visit… at least until we have the science behind us to do so.

Rovers and probes can be equipped to undertake any number of measurements and experiments whilst learning about and exploring the red planet – not to mention, they provide us with some close-up pictures of this interesting planet, that we can learn from.

Missions To Mars

Both the Soviet Union and the United States of America started sending probes to do flybys of Mars in the ’60s. The Soviets attempted a number of landings from as early as 1962 but unfortunately, all of these resulted in failure.

In 1975 NASA launched their first probe to the red planet to see how the Martian atmosphere compared.

Both Mars and Earth have something in common when it comes to the fact that they both orbit the Sun. Complications arise, however, when it comes to journeys to Mars, as a result of those orbits – whilst they both orbit the Sun, Earth has a faster orbit than Mars.

This means that Earth speeds past Mars, leaving a small window in which both Earth and Mars’ orbits will sync up for just long enough that the distance between the two planets is short enough to make the journey feasible.

The Viking 1 And Viking 2 Landers

In 1976 Viking 1 and 2 Mars landers from NASA made the first successful touchdown on Martian soil. Their mission was to look for signs of life on the planet’s surface.

Viking 1 landed first, using its onboard equipment, it sent back the first images from the surface of Mars and discovered the atmosphere of Mars is made up of 95% carbon dioxide, 3% nitrogen, and 1.6% argon, which doesn’t really make life the easiest to sustain – but, they did show strong evidence of ancient riverbeds and mass flooding.

Viking 2 landed at the same time as Viking 1 but in a different location. From samples taken from the soil, it was determined that Mars has all the building blocks of life; sulfur, phosphorus, oxygen, nitrogen, carbon, and hydrogen.

Sojourner Rover

Sent by NASA this was the first rover to operate on an alien world. It landed on July 4th, 1997. It operated for 84 days on what was originally intended to be a 7-day mission and covered a distance of 330 feet, taking photographs along with chemical and atmospheric measurements.


One of two rovers launched in 2003, with the mission to explore Mars and search for signs of past life. With an original mission duration of 92 Earth days, the rover far outlasted that, being fully operational for a staggering 6 years and 2 months.

The extra time was due to the Martian wind, regularly cleaning the solar panels giving the rover more power. With this, Spirit was able to travel an extra 7.13 kilometers on top of the planned 600 meters it was originally tasked to do.

In 2009 the rover got stuck in a way the solar panels couldn’t be charged. The mission officially ended in 2011 after NASA exhausted all of its options to get it moving again.


Opportunity the rover was given the endearing nickname, ‘Oppie’, by NASA staff. They became well acquainted with this rover, as it lasted 57 times its original mission length – racking up a total of 14 years and 46 days on Mars after landing.

It was able to stay operational for that long by maintaining its power, hibernating during dust storms, and waiting for the Martian wind to clean its solar panels before powering back on.

On one of the most successful missions to Mars, Opportunity made some really major discoveries – one of which was the discovery of evidence suggesting that some areas of the planet had been wet for a long time in the past, meaning the red planet might have been able to support microbial life.

Its mission finally came to an end in 2019 after a planet-wide dust storm caused the rover to lose communication with Earth the previous year.

Phoenix Lander

The lander was launched on August 4th, 2007 with the mission of assessing its local habitability and researching the history of water on the planet. Landing in May 2008, the lander was able to dig half a meter deep into the soil and verified the presence of frozen water, just under the planet’s surface. 

Curiosity Rover

Exploring the Gale crater, Curiosity is a car-sized rover that launched in 2011 and is still operational today. Another rover with the assignment of searching the planet for evidence of microbial life, Gale crater was chosen as the landing spot for this rover.

This was because the crater appears to have once been a lake – out of all of the places the rovers had explored on the planet so far, the lake had the best chances of finding fossilized microbial life if any had ever existed on the planet. 

Curiosity is equipped with 17 cameras, a robotic arm, and a whole arsenal of specialized laboratory equipment that had the ability to prove that Mars once had the necessary conditions to support microbial life – and did.

It also discovered the presence of methane, a gas that is produced by living organisms, or as a result of a chemical reaction between rock and water.


NASA’s currently operational lander, InSight, landed in 2019 and was tasked to learn more about the interior of the red planet. InSight is an acronym for ‘Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport’.

The lander’s 3 primary science tools are the SEIS, HP3, and RISE. Using the trio of instruments, the lander has learned more about the interior of planets and may help unlock clues as to why the magnetic field of Mars is so weak.


China was the second nation to successfully land and operate a robot on Mars. In 2021 the Tianwen-1 mission sent a rover to the surface and, at the same time, put a satellite in orbit to send back the data the rover collects.

The rover’s landing site was chosen as it’s suspected to have once been a sea bed, and as a result, the rover was aimed to see if it could find evidence of this.

Zhurong has six scientific instruments, a ground-penetrating radar, a magnetometer, a climate station, a surface compound detector, a multi-spectrum camera, and navigation cameras.


Designed to prepare for future human exploration, the rover landed on Mars in February 2021 in the Jazzero crater, which once was thought to have been filled with water.

Perseverance is the evolved form of its predecessor, Curiosity. On top of the 7 scientific instruments, 19 cameras, two microphones it also carries a solar-powered drone helicopter named Ingenuity.

Upon successfully demonstrating flight is possible in the Martian atmosphere, the drone can explore and help scout ahead for Perseverance through tricky terrain. A future mission is planned to collect rock core samples taken by Perseverance in 2031.

Final Thoughts

The universe is a vast, seemingly endless void, full of loads of secrets, still waiting to be found out.

A lot of those secrets may be unlocked as a result of rover’s being deployed to planets such as Mars, helping us to learn more about how our solar system was formed and the history of the planet, all the while potentially helping us to find out more about our closest neighbor – and maybe, one day, second home.

Gordon Watts