By the time we got their attention they'd be over the horizon.
And then they were gone over the horizon behind him.
Before they got his range, he would be over the horizon.
To his right, the sun was low over the horizon.
The morning sun was only beginning to show over the horizon.
By then the sun was well up over the horizon.
You're going to be seeing a lot of them over the horizon.
He tried to figure how many minutes it would be until they raised Earth over the horizon, ahead.
They could, then, be just over the horizon at this moment.
In the world above, the Sun had just appeared over the horizon.