A team of salvage divers has discovered an unexplained object resting at the bottom of the Baltic Seanear Sweden.

"This thing turned up. My first reaction was to tell the guys that we have a UFO here on the bottom," said Peter Lindberg, the leader of the amateur treasure hunters.

Sonar readings show that the mysterious object is about 60 meters across, or, about the size of a jumbo jet. And it's not alone. Nearby on the sea floor is another, smaller object with a similar shape. Even more fascinating, both objects have "drag marks" behind them on the sea floor, stretching back more than 400 feet.

"Could this be the Star Wars Millenium Falcon, a plug to an inner world or a marine version of Stonehenge?" asks CNN's Brooke Bowman:

Well, it could just be another shipwreck. Or, mud.

But Lindberg says the ship theory doesn't really hold up because of the unusually large size of the objects. "Of course it would be something from another ship but it's quite big," he told CNN. Lindberg notes that some observers have speculated that the objects may be Russian warships built around the end of the 1800's. However, Lindberg points out that not only were those ships much smaller, they were not patrolling the Baltic during that era.

The Baltic Sea is a literal treasure trove for salvage teams and a "shipwreck laboratory" for researchers. The sea's low salinity levels help preserve objects that sink to the bottom. "Right now, we know about 20,000 objects, mostly shipwrecks, in the Baltic Sea. But I think there may be more than 100,000," said sonar expert Ardreas Olsson, "I'm not sure what you will see when you go down. But I'm excited. It's going to be interesting to see what it is."

The Ocean Explorer team first made their find back in August and had no plans to return to the scene. For now, Lindberg is waiting for calmer waters in the Baltic, possibly in May, before taking his salvage team to the bottom for a closer look at the mysterious objects. They originally had no plans to return to the spot, but the spike in interest from the public has led them to begin planning a return trip.