>Now that Zhurong has got down successfully, scientists will try to get at least 90 Martian days of service out of it, studying the local geology. 90 days, doesn't that seem short?
All things considered, 90 days is pretty good for how harsh of an environment Mars can be. Also, there are dozens of ways to make the mission last longer but no ways of accomplishing that without adding more weight.
What’s actually so harsh about Mars?
Let’s imagine some alien civilization tries to send a probe to Earth, they’d be saying things like:
“Dude, that atmosphere is gonna burn our shit up before it even touches ground, if we’re not careful.”
“Holy shit, what are these huge animals with long noses and big ears? They’re gonna destroy our probe if they walk over it.”
“Let’s avoid landing in that area where those bipedals are still waging war.”
“The rain is acidic! WT bloody F?”
“Ugh, those black-and-white swimming things seem like assholes who like to play with their food, let’s steer clear of them.”