I read this short story about thirty years ago. It takes place on a planetary body other than Earth, possibly the Moon. If memory serves, it's airless, so the (human) characters wear pressure suits outside of their habitat. Parts of the surface are subject to unpredictable space/time anomalies, into which people have been known to irretrievably disappear. At one point while on the surface, the protagonist spots the distant figure of someone whom he knows to have been lost many years before to one of these time-slip incidents. It was the eeriness of this scene that has kept the story in my mind for all these years. Does my description ring any bells with anyone?
Unpredictable space/time anomalies on a planet other than Earth cause people to irretrievably disappear
It could be "Masquerade" aka "Operation Mercury" by Clifford Simak
The power station on Mercury tolerates the "Roman Candle" energy beings that cavort outside - until a crew member goes missing.
...Curt shivered as he thought of the spacemen who had walked into just such warps in the early days. Daring mariners of space who had ventured to land their ships on the Sunward side, had dared to take short excursions in their old-type spacesuit. Most of them had died, blasted by the radiations spewed out by the Sun, literally cooked to death. Others had walked across the plain and disappeared. They had walked into the warps and disappeared as if they had melted into thin air...
...Some subtle warning, a nasty little feeling between his shoulder blades, made Craig spin around to face the warp. Just in front of the warp stood a man, and for a moment Craig stared at him, frozen, speechless, unable to move.
For the man who stood in front of him, not more than 40ft away, was Curt Craig!...
1Please don't post copyright infringing links.– DavidWOct 29, 2020 at 2:03
2@DavidW It may be out of copyright by now; it's available at the Internet Archive. archive.org/details/… Oct 29, 2020 at 3:29
1@user14111 Or at least archive.org has a bit of respectability and isn't likely to be serving malware.– DavidWOct 29, 2020 at 10:32
@DavidW, user14111 got it ) Oct 29, 2020 at 11:02