The Sea of Tranquility

map credit Ask Dr Vector

image credit Nasa


I have been interested in astronomy since I was a boy.

My parents bought me a small refracting telescope for my birthday.

When I started secondary school (aged 11) we were asked to do a class talk on our hobby. I talked about astronomy for 40 minutes! Now that's a challenge with my lectures today!

Galileo'sdrawings were published in 1610. They appeared in a book called Sidereus Nuncius.

Galileo was not the first person to make illustrations of the moon from telescopic observations.

Albert van Helden made some in 1608 and English astronomer Thomas Harriot made some in 1609.

The study of the surface of the moon is called Selenography

The subject of Galileo's drawings is a topic of scholarly debate. Tom Pope and Jim Mosher say in their on-line article Galileo's Moon Drawings that:

"As to the identification of features we have been unable to find a single instance in which Whitaker and Righini [moon scholars] claimed that an object on one of Galileo's engravings represented the same feature on the real Moon"

It seems there is no specific visual reference to The Sea of Tranquility, although the its near neighbour the Sea of Serenity appears to be drawn.

Riccioli's moon book was called Alamgestum Novum. It was published in 1651.

He was a Jesuit who tried to undermine objective scientific knowledge. That's why he used names to show how the moon infuenced the Earth by calling the large dark areas on the moon the Sea of Tranquility, The Sea of Storms, The Sea of Crisis, The Sea of Serenity etc.

He believed that only God could know the true nature of the universe, so it was pointless trying to accurately describe what he saw.

His names caught on with readership of the time and have stayed with us ever since.

Johannes Hevelius is known as the "founder of lunar topography"

He published his moon book Selenographica in 1647 four years before Riciolli's book. His drawings were much more detailed than Riciolli's.

He attempted to record the moon 'as it is' unlike Riciolli who combined several impressions into one idealistic image.





In order to make the moon seem familiar he named everything after places on Earth. That's why what we know as the Sea of Tranquility nearly became known as the Sea of Sicily. If you look closely you can see it in the middle of the map above.

Although he published before Riciolli it was Riciolli's way of naming that won the day.

British astronomer and TV presenter Patrick Moore, predicts likely moon landing site in this video archive footage.

Sky At Night