A Hole in the Universe by J. H. Wear

Humans are finally leaving the safe confines of Earth. Terraforming has allowed Mars to become a second home for people. The red planet is turning green, allowing greater exploration of Mars to take place. And one discovery leads to speculation humans weren’t the first to arrive on Mars.

Jaret McLeod was used to danger and thinking under pressure, either as a miner in the asteroids, or later as a captain of a spaceship. He was aware of Unidentified Space Objects (USOs) that appeared to break the speed of light, the new discoveries on Mars, and of a recent discovery Meili, a new planet orbiting beyond Pluto.

None of these events appeared to be related, but it turns out anything is possible, as McLeod was about to find out.