"Guys, I found something off-the-chart weird," Zuri Amari radioed.
While they were laboriously coming to her in the 1/100th gravity, she continued. "It's a deep shaft in middle of the asteroid's orange spot. It's in solid rock, painted orange inside, about 1.25 meters wide and it looks straight as an arrow.
This thing is just the kind of hole that a space ship might drill when seeking ores. Except, it's orange. I can't see the bottom."
Andrew Mitchell and Frank Hodges all puzzling at the phenomenon. Calling down the well , of course, not possible. There was no air to transmit sound.
"I guess someone needs to jump in and look around, Frank, follow me in," Andrew instructed.
Andrew and Frank drifted down. It was a relatively smooth hole in solid rock, with dusty orange powder on the walls. They found elemental carbon.

That made sense because carbon was one of the commonest elements in stars. Other bands were hard, even glossy. This seemed to be a highly mineralized asteroid. On occasion, they had to slow their downward acceleration countering the meager gravity. They merely reached out their gloved hands to the walls, much like they maneuvered in the zero-gravity parts of their spaceship. This asteroid was only a dozen kilometers or so long.
"Back home, they'd call this wall walking," Frank quipped. Andrew didn't respond.
Some twenty-minutes later, Andrew had reached the flat-bottomed end of the shaft and Frank paused several meters up. He could hang there easily. In this micro gravity, up and down barely mattered. They could see Zuri's dim light at the top. The well was that straight. No natural phenomenon could be so accurate, with smooth, circular walls.
"It's just a flat floor, and there's a layer of orange dust. We found orange stains all the way down. This is definitely a drill shaft."
At that, the bottom slid open on its own! There stood the missing astronauts in space suits!
But I, the author, digress. I'll backtrack and explain how all of the intrepid astronauts got out there.