November 22, 2024

The Solar Corona from Apollo 11

I have been skimming through the Apollo 11 in Real Time Website and it has been fascinating following all of the chatter between the various mission controllers as well as all of the radio transmissions with the crew. Most of what we usually see and hear are just tiny bits and pieces from the key segments of the mission and it doesn’t capture what it was like to fly the mission. One neat episode that I have not heard before occurs at about Mission Elapsed Time of 71h30m. At this point Apollo 11 is about 11,000 miles from the moon and they enter the moon’s shadow for the first time. The temperature of the spacecraft plummets, though the temperature inside the spacecraft remains stable. Through the windows the crew can see the limb of the moon silhouetted solar corona and the face of the moon is lit by Earthshine. They turn the lights off inside the spacecraft to get a good look at the solar corona and light from the Earthlit moon pours in through the windows. Armstrong also describes being able to clearly see the stars for the first time in the mission.

Very cool.