Mars is the current Holy Grail for space missions, and humanity has been throwing everything we can at it.
With each new mission to the Red Planet, alongside the hope of loads of interesting data and samples for our scientists to study, there comes a slightly depressing cost.
A diagram shows all the locations of debris left behind on Mars by these missions or their failures - an amount of leftover waste that is probably way heavier than you might think.
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Indeed, reports suggest that over the whole surface of Mars we've so far spread around seven tonnes of waste, which is a pretty big total considering how we've only managed to send probes to the planet on relatively few occasions.
Of course, since so many of those missions are designed to establish whether Mars has ever hosted any form of life, and things aren't looking certain on that front, it's not like there's any local flora or fauna to be disturbed by the debris.
Still, though, if only on the principle that littering is to be avoided, you'd have to think that at some point we'll need to do something about it all.
Thankfully, all or most of these debris clusters are tracked and located (since they have almost all come from missions that cost huge amounts to run, and constitute valuable data fields themselves).
Not all of the debris is from failed missions, either - once a rover is on the surface of Mars, after all, there's no easy way to get it back home.
This means that once its machinery fails, it runs out of juice, or it simply stops working due to wear and tear, it effectively becomes a permanent fixture in the barren landscape of Mars.
This applies to famous landers like Beagle 2 and, more recently, Insight, along with the identical rovers Spirit and Opportunity, all sent by space agencies to Mars over the years.
All of this is hard to change until we finally get humans to the planet. While their first priority won't exactly be trash cleanup duty, this will doubtless eventually be on the agenda, even if it comes decades or centuries down the line.
After all, if you don't keep your house in order you'll risk suddenly discovering that you're living in filth, and while a planet of Mars' size might take a long time to fill up, there's no sense in starting off on a bad footing.