How Fast Is the Moon Moving Away from Earth?

[elistein]

Hi all

It's a well known fact that the moon is drawing away from Earth by 3.82 ± 0.07 cm/year.

I was googling a lot to find the exact distance between Earth - moon

that this data was measured.

A plain number or a link will be much appreciated.

Thanks in advance

Elistein

 

[Dr. Courtney]

https://en.wikipedia.org/wiki/Lunar_distance_(astronomy)

 

[elistein]

Hi Dr. Courtney

Thanks for your reply.

Yes, I know about the min, max and average distance.

What I'm interested: what was the exact distance at the time this data was determined:

"The Moon is spiraling away from the Earth at an average rate of 3.8 cm (1.5 in) per year"

 

[russ_watters]

There can't be an exact/single value for something that is an average. The value was almost certainly derived from decades of lunar ranging experiments.

 

[Janus]

If you want the distance from Earth to Moon at any given time, go here:

http://ssd.jpl.nasa.gov/horizons.cgi#top

And set the Moon as the target body.

The time span setting will allow you to set the date, time, time duration and time steps for the generated list. Under table settings, you can choose which properties you want to see in the list.

 

[elistein]

russ_watters and Janus

Thanks for your replies. I'll look into it right away

 

[tfr000]

There can't be an exact/single value for something that is an average. The value was almost certainly derived from decades of lunar ranging experiments.

Yup.
See http://physics.ucsd.edu/~tmurphy/apollo/doc/Dickey.pdf