For the past few years the European Space Agency (ESA) has been working on a masterpiece, their "Jupiter Icy Moons Explorer" or its funny nickname JUICE, to try and find life on Jupiter's mysterious moon Ganymede, which has frozen water underneath the surface. The spacecraft costs over 1 billion dollars and is supposed to launch this April and arrive at Jupiter in 2030, but now it could be in trouble. Because of the germs from our own planet.
One thing about detecting life on other worlds using robots is making them clean. Meaning no germs to confuse the spacecraft’s high tech scanners that there's life down on the surface. But unfortunately JUICE might be carrying some and this could cause other problems…
Another thing that could happen is, at that end of its mission JUICE is supposed to crash into Ganymede. But let's say we have unwanted travelers that could have survived the crash (and everything else they have been put through.) And what if there was microscopic life that we hadn’t detected yet and our unwanted germs kill them off. Then we have basically without knowing gotten rid of some life forms from another celestial body.
Lastly, germs could affect the whole mission, if there are germs then engineers at ESA will have to unload the spacecraft from the rocket that it's in. Which could take weeks, and then take it back to a sealed laboratory where engineers would spray it down for days trying to get rid of the germs. This would screw up the whole schedule and possibly delay the mission for years.
But space is a very unwelcoming place to live, and if there are any germs it's very likely that the freezing cold temperatures will kill them.
Hopefully this will not affect the mission and JUICE will be able to get to Jupiter and make discoveries that will benefit humanity.