Scientist Works Out There Is Over 15,000 Pounds of Human Trash on Mars

There are over 15,000 pounds of space junk on the surface of Mars, which was left over the past 50 years.

Cagri Kilic, a postdoctoral research fellow in robotics at West Virginia University, calculated a figure of 15,694 pounds of trash, according to an online article on The Conversation. Kilic, who specializes in Mars and moon rovers, added up the mass of all spacecraft that have been sent to Mars (22,000 pounds) and subtracted the weight of the currently operational craft on the surface (6,306 pounds).

Humankind has now sent 18 human-made objects to Mars over the course of 14 missions, according to the United Nations Office for Outer Space Affairs. The first mission landing an object on the red planet occurred in 1971 when the Soviet Union crash-landed its Mars 2 orbiter.

A stock illustration shows the Earth as viewed from Mars' surface. Debris scattered across Mars from past landings may affect future missions to the planet. iStock / Getty Images Plus

Since then, several spacecraft have landed on Mars' surface, successfully and unsuccessfully. All of these missions have inadvertently left scraps of debris scattered across the planet, which are now being spotted by rovers on the surface. In mid-August, the Mars rover Perseverance came across multiple pieces of junk jettisoned during its landing.

According to Kilic, the debris comes from three distinct sources: discarded hardware, inactive spacecraft and crashed spacecraft.

"It would be really hard to get an average number [of pieces of debris per spacecraft] since all spacecraft have their own specific requirements," Kilic told Newsweek. "For this reason, the total mass would be different. However, it can be said that the crashed spacecraft on the surface would create more numbers of junk."

Spacecraft that land on Mars discard pieces of their module as they descend toward the surface, with pieces of the heat shield and parachute breaking off and soaring significant distances in the Martian wind. Additionally, crashed craft may burn up on entry or hit the ground at immense speeds, again sending debris flying off in various directions.

There are also several inactive spacecraft on Mars' surface, which ran out of power or were broken in some way. One example is the NASA Pathfinder lander and Sojourner rover, which landed in July 1997 and lost contact with Earth in September 1997, likely because its battery died, Other spacecraft relics on Mars are the Mars 3 lander, Mars 6 lander, Viking 1 lander, Viking 2 lander, the formerly lost Beagle 2 lander, the Phoenix lander, the Spirit rover and the Opportunity rover.

The scattered debris on Mars' surface could have an impact on future Mars missions, according to Kilic. There is concern that the junk may contaminate samples collected by the rovers or even get tangled in the debris.

"Since Perseverance collects the samples for bringing back to Earth, the imaging teams at NASA are reviewing the images of the terrain for possible sources of discarded hardware debris," Kilic said.

He continued: "Monitoring the potential sources of contamination to ensure the integrity of the returned sample cache is also handled by the sampling teams at NASA. Martian winds can carry some of the debris, but the current imaging technology will help us to identify these. I believe contamination and entanglement with the rovers are low-risk. However, it is still a risk."

Space junk can come crashing down to Earth at very high speeds after being ejected from ascending spacecraft or de-orbiting from space. It's thought that up to 27,000 small pieces of debris are traveling at speeds of up to 15,700 mph in low-Earth orbit.

Update 9/21/22, 10:45 a.m. ET: This story has been updated with comments from Cagri Kilic.