In one of my universes, Humanity found a so-called "world anchor" on the Moon. They removed the anchor and returned to Earth. A few days later, the Moon exploded and a planet about the size of Mars appeared, just barely further than the Moon's orbit. The other planet, N'valdir, had a sentient species with technology barely better than modern Human technology. [EDIT- The N'valdir have technology equivalent to a K0.9 Civilization N'valdir, viewed from a 2d stellar map, would be pointed slightly towards Earth, at a rough 83 degree angle.]
1.) Would these two species be able to stop their planets from colliding? If so, with what technology?
2.) What effect would this have on the planets, and more so, to the species' on them?