There are a lot of telescopes in space (optical, radio, X-ray and Gamma-ray), but how about microscopes?
Does the ISS have a general-purpose microscope? It could come in handy for failure analysis or even some medical tests.
Any robotic-mission microscopes for looking at rocks or particles or micrometeorites, impacts, or space-dust?
There are a couple, at least, on the ISS.
The main one seems to be the Light Microscopy Module (PDF).
Light Microscopy Module (LMM) is housed within and used in conjunction with the glovebox in the Fluids Integrated Rack (FIR).
Images provided by the LMM can provide data to scientists and engineers to help understand the forces that control the organization and dynamics of matter at microscopic scales.
The LMM microscope is capable of using most standard Leica objectives. The present on-orbit compliment includes: 2.5x,10x, 20x, 40x, 50x, 63x, 63x oil, and 100x oil, objectives. New or different objectives may also be flown as needed.
The LMM contains a digital black and white low noise scientific camera. PI specific specialty cells (sample holders) are under development for temperature control and electric field experiments. Three dimensional (3D) confocal (point illumination) upgrades are scheduled for 2015-2016.
The Light Microscope Module (LMM) flight unit features a modified commercial off-the-shelf (COTS) Leica RXA microscope, which is configured to operate in an automated mode with some interaction from the ground support staff or the astronaut crew. The microscope is modified and enhanced to provide additional capabilities including, video microscopy to record sample features including basic structures and crystal growth dynamics and basic biological system observations. Currently, demonstrated imaging techniques use a high resolution black and white microscopy, bright field, epifluorescencent (EPI), and fluorescent techniques.
An investigator can choose from standard Leica objective lenses of different magnifications. This suite of measurements enabled by the LMM allow for a detailed characterization of fluids, colloids, and two-phase media, including biological samples. A backlighting LED sample holder was also developed to enhance biological imaging, and is available onboard the ISS.
The LMM was recently (May 2017) upgraded with "a laser light package, scanner and two high-resolution digital scientific cameras. In addition to 3D imaging, this update will significantly improve the microscope’s resolution and contrast by eliminating unnecessary light." (source)
New to me was the NanoRacks Microscope.
Send us your slides and have ISS crew members take pictures during your 30 day mission.
I hope that's not as "name a star after yourself" as it sounds.
Curiosity has a "Hand Lens", the Mars Hand Lens Imager.
The self-focusing, roughly 1.5-inch-wide (4-centimeter-wide) camera takes color images of features as small as 12.5 micrometers, smaller than the diameter of a human hair.
To me this conjures up images of a robotic Sherlock Holmes peeking through his magnifying glass, so perhaps this is not considered a microscope.
In addition to all other mentioned microscopes, there has been a Voxa Mochii miniature scanning electron microscope on the ISS since mid-February 2020.
See this answer for more details.
There are some high-resolution cameras on the Perseverance rover on Mars.
The SHERLOC instrument has a context camera with a resolution of 10.1 micrometres, and the WATSON tool has a colour camera with a resolution of 15 micrometres. Previous missions also had high-resolution cameras with resolutions up to about 15 micrometres. These resolutions qualify these cameras as "microscopes".
The Chinese Tiangong Station has one as well:
(Translation: microscopic observation and recording equipment for medical samples)
