Just saw this on the news. During the Apollo missions, they left reflectors on the surface of the moon. Periodically, they shoot lasers from the earth at the reflectors to measure the distance between the two. I believe they are doing it tonight.

Anyone know what time? Is it visible?

Sounds pretty amazing, they can determine the distance to within 1mm. And yes, the moon is losing it's gravitational pull by about 1.5" per year.

https://en.wikipedia.org/wiki/...er-ranging_Operation

I knew about it because I am a space junkie, but I honestly think the episode of the Big Bang theory featuring the guys shooting a laser at the reflectors increased the people that knew about it more than anything else since they were place up there

Kevbo,
As a space nerd, you might enjoy this. Real time updates of the Voyager satellites. I can’t even comprehend those distances. Pretty amazing!!!

The “once in a lifetime alignment” is pretty cool as well. Using gravitational pull to swing the satellite through the orbits of 4 planets. Happens every 176 years.

https://voyager.jpl.nasa.gov/

https://www.youtube.com/watch?v=tL1OATdBoY8

James

I was aware of the reflectors left on the Moon and the actions to measure the distance from Earth. I do not know how or when those measurements are scheduled, though. I also knew that the Moon is slowly retreating from the Earth, and that it won't be too long before it's far enough away that total Solar Eclipses won't be possible.

flashguy

quote:

Originally posted by flashguy:
... I also knew that the Moon is slowly retreating from the Earth, and that it won't be too long before it's far enough away that total Solar Eclipses won't be possible.

flashguy

Don't worry, that date is more than a half billion years in the future. The Earth won't even be habitable much longer than that.