inappropriate
Explanation
This comic plays on the dual meaning of "inappropriate" in an astronomical context. A bearded man is explaining something scientific, noting that "it just makes me really uncomfortable when the particles of the solar wind interact with the magnetosphere" and referring to "images of capture of space station" and matters related to "the plane of the ecliptic."
The woman asks "What do you mean?" and the man responds "It's just weird. Why don't you see that it's weird?"
The punchline comes in the final panel, where someone is shown texting on a phone: "Send nudes" followed by "dock pix plz" — revealing that the man was anthropomorphizing celestial phenomena as sexual or inappropriate, and the final panel shows someone sending the astronomical equivalent of a "sext" — requesting pictures of spacecraft docking.
The humor operates by taking astronomical terminology that can sound vaguely suggestive — particles "interacting" with the magnetosphere, "capture," docking — and having a character treat these normal scientific processes as genuinely inappropriate or indecent. The punchline extends this by imagining space enthusiasts requesting "dock pix" (docking pictures) in the style of someone requesting inappropriate photos. It is a classic SMBC move of finding innuendo lurking in technical language.