The Pond Tranquillitatis or Mer of Peace is a lunar Mare located on the face of the the Moon turned towards the Ground. It acts in fact of a vast plain of Basalte (volcanic rock) correspondent with an old basin of impact formed shortly after the birth of our Solar system, there is 4,5 billion years.

In 1965, the space probe Ranger 8 was crushed in the Sea of Peace after having transmitted 7.137 Photographie S of the Moon.

The Sea of Peace is undoubtedly the lunar sea most famous; it is indeed on the Base of Peace that the July 21st 1969 was posed the Aigle , the lunar module of the American mission Apollo 11.

It has as coordinates 8° 30 ' NR 31° 24 ' E and an average diameter of 873 km.