[Dead Corpse]

Cool down in a couple of ways. One, ice. It melts. That takes heat. Two, gets rid of the SO by the impact blowing it right off the planet. Three, it'll also set up a water cycle on a planet that currently doesn't have a lot with as much water as we have here on Earth. Water vapor clouds will block a bunch of the IR coming in from reaching the ground. That alone will reduce surface temps.

Just off the top of my head....

[furball4paws]

"Cool down in a couple of ways. One, ice. It melts. That takes heat."

First I don't know how much ice Ceres has, but the heat produced by friction as it enters the atmosphere will create a lot of heat. You may not get much here.

"Two, gets rid of the SO by the impact blowing it right off the planet."

You'll have to do a lot better here. Got some calculations?

"Three, it'll also set up a water cycle on a planet that currently doesn't have a lot with as much water as we have here on Earth. Water vapor clouds will block a bunch of the IR coming in from reaching the ground. That alone will reduce surface temps."

Now, I like this possibility. Is there enough water with Ceres? But even if the IR cannot penetrate water, it certainly doesn't penetrate Venus' current atmosphere. Boiled in aqueous acid is not good for life, even the extremophiles we find on Earth.