Those Old Scientists

In the 24th century, an away team from the Starfleet starship USS Cerritos arrives at the planet Krulmuth to perform routine scans on an old portal. While Ensign Brad Boimler excitedly says that it was discovered by the crew of the USS Enterprise, led by Captain Christopher Pike, D'Vana Tendi insists it was found by an Orion science vessel that her ancestor was stationed on. When Boimler has his picture taken at the portal, it unexpectedly activates and he is sucked through to the 23rd century where he meets the Enterprise crew.

Summary from Wikipedia, CC BY-SA 4.0.