There’s too much garbage on Mars

There’s too much garbage on Mars

This article was originally featured on The Conversation.

People have been exploring the surface of Mars for over 50 years. According to the United Nations Office for Outer Space Affairs, nations have sent 18 human-made objects to Mars over 14 separate missions. While many of these missions are still ongoing over the decades of Martian exploration and exploration, many pieces of debris have been left behind by humankind.

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I am a postdoctoral research fellow who studies ways to track Mars and Moon rovers. In mid-August 2022, NASA confirmed that the Mars rover Perseverance had spotted a piece of trash jettisoned during its landing, this time a tangled mess of netting. This is not the first time that scientists have found trash on Mars. Because there is so much there.

There’s too much garbage on Mars
All spacecraft that land on Mars eject equipment-like this protective shell-on their way to the Martian surface. NASA/JPL-Caltech

Where does the debris come from?

Mars debris comes from three main sources: discarded hardware and inactive spacecraft.

Every mission to the Martian surface requires a module that protects the spacecraft. This module contains a heat shield to protect the craft from the planet’s atmosphere, as well as landing hardware and parachute so it can land softly.

The craft throws away pieces of the module when it descends. These pieces can land in various locations on the planet’s surface. There may be a lower heat protection in one location and a parachute at another. When this debris crashes to the ground, it can break into smaller pieces, as happened during the Perseverance rover landing in 2021. Martian winds can blow these small pieces around.

There’s too much garbage on Mars
The Perseverance rover came across this piece of netting on July 12, 2022, more than a year after landing on Mars. NASA/JPL-Caltech

A lot of small, windblown trash has been found over the years-like the netting material found recently. Earlier in the year, on June 13, 2022, Perseverance rover spotted a large, shiny thermal blanket wedged in some rocks 1. 25 miles (2 km) from where the rover landed. Both Curiosity in 2012 and Opportunity in 2005 also came across debris from their landing vehicles.

Dead and crashed spacecraft

The nine inactive spacecraft on the surface of Mars make up the next type of debris. These craft are the Mars 3 lander, Mars 6 lander, Viking 1 lander, Viking 2 lander, the Sojourner rover, the formerly lost Beagle 2 lander, the Phoenix lander, the Spirit rover and the most recently deceased spacecraft, the Opportunity rover. These are mostly intact and can be considered historical relics rather than trash.

Wear and tear take their toll upon everything on the Martian surface. Some parts of Curiosity’s aluminum wheels have broken off and are presumably scattered along the rover’s track. Some of the litter is purposeful, with Perseverance having dropped a drill bit onto the surface in July 2021, allowing it to swap in a new, pristine bit so that it could keep collecting samples.

Crashed spacecraft and their parts are another source of trash. At least two spacecraft have been lost contact, and four more have lost contact shortly after landing. Safely descending to the planet’s surface is the hardest part of any Mars landing mission-and it doesn’t always end well.

When you add up the mass of all spacecraft that have ever been sent to Mars, you get about 22,000 pounds (9979 kilograms). Subtract the weight of the currently operational craft on the surface-6,306 pounds (2,860 kilograms)-and you are left with 15,694 pounds (7,119 kilograms) of human debris on Mars.

Why does trash matter?

Today’s main concern about trash on Mars is its potential impact on future and current missions. Perseverance teams are currently documenting any debris found and checking to see whether it could contaminate samples being collected by the rover. NASA engineers have also considered whether Perseverance could get tangled in debris from the landing but have concluded the risk is low.

The real reason that debris from Mars is so important is its historical significance. The early milestones in human exploration of Mars are represented by the spacecraft and their parts.

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