Analysis of silicate spherules in Estonian bogs show that the possible age of the impact craters could be approximately 7,600 years.

[5] A study based on elevated iridium signal in a nearby bog suggested the much younger age of 4th century BC.

[6] The craters were formed by a meteor with an estimated impact velocity of between 10 and 20 km/s (6.2 and 12.4 mi/s) with a total mass of between 20 and 80 metric tonnes.

One of them is in runes 47, 48 and 49 of the Kalevala epic: Louhi, the evil wizard, steals the Sun and fire from people, causing total darkness.

The virgin of the air starts to make a new Sun, but the spark drops from the sky and hits the ground.

Finnish heroes see the ball of fire falling somewhere "behind the Neva River" (the direction of Estonia from Karelia).

According to a theory proposed by Lennart Meri, it is possible that Saaremaa was the legendary Thule island, first mentioned by ancient Greek geographer Pytheas, whereas the name "Thule" could have been connected to the Finnic word tule ("(of) fire") and the folklore of Estonia, which depicts the birth of the crater lake in Kaali.