If Apollo Happened Today

Marianne Dyson, December 2018

Considering that we are celebrating the 50th anniversary of Apollo, and that NASA has contracted with Firefly Aerospace and Intuitive Machines to provide new lander vehicles, I thought you all might enjoy this article I wrote that was originally published in Ad Astra in 2013.

Every year at space conference parties, enthusiasts have pondered the question: If we flew an Apollo mission to the Moon with today

Triangles to Mars

Marianne Dyson, July 2018

At the end of July, Mars will be its brightest in 15 years because it will be only 35.8 million miles (57.6 million kilometers) away. Since no one has ever been to Mars, how do we know this distance so precisely?

Triangles! If the length of one side and two angles of a triangle are known, the length of the other sides can be calculated. Way back in 1673, Giovanni Cassini (1625-1712) used this knowledge of triangles to estimate the distance to Mars. This method is called parallax. [Ref: A Teacher