On: Spaceprob.es catalogues all the probes that still ...

[cygx]

Also [...] the time it takes to arrive back here

For reference:

    Voyager 1, interstellar space    21 lighthours
    Perseverance, Mars surface       12 lightminutes
    Artemis, lunar orbit            1.2 lightseconds

[spzb → cygx]

Aren't those measures of distance?

[gberger → spzb]

Yes, but the data travels at approximately the speed of light, so you can just drop the "light" unit in front of the time units

[spzb → gberger]

But where’s the fun of pedantry in that?

[cygx → spzb]

Sure, but conversion to travel time is trivial given a signal velocity of c. Or just assume a 'natural' system of units where c=1 :p

[argvargc → spzb]

Delete "light" and it's the answer.

[emayljames → argvargc]

Yeah, it takes me 2 trainhours to get to work.