Convert moon's altitude to kilometers

Question

I'm getting information about the moon's altitude from yr.no's API and they print the altitude as 50.0496753501172.

How can I convert that to kilometers; even if it is already in kilometers?

This is probably the moon's apparent altitude above the horizon, not the distance from the moon to the earth. — Jeremy Kemball, May 17 '13 at 15:14
@shadyyx: Are you sure? The height above the sea (altitude) is not normally in minutes :) — Airikr, May 17 '13 at 15:15
maybe you mean angular elevation? the moon's "altitude" is ~350,000-400,000km — Marc B, May 17 '13 at 15:16
@MarcB: I might be true that it's angular elevation yr.no's API mean. — Airikr, May 17 '13 at 15:18
@Jerryf: Not live because Windows 8 and WAMP Server doesn't corporate as fine as Windows 7 and WAMP :( — Airikr, May 17 '13 at 15:19
Looks like it is degrees from the horizon http://www.timeanddate.com/worldclock/astronomy.html?obj=moon&n=25 — Jerryf, May 17 '13 at 15:26
@MarcB you'd also need to define if you mean "distance from the Earth surface" (which is roughly constant) or "distance above the plane tangential to the Earth's gravitational isosurface at the observer's point (that is, above the idealized horizon)" (which is roughly proportional to the sine of the elevation. — John Dvorak, May 17 '13 at 15:32

score 2 · Accepted Answer · answered May 17 '13 at 15:26

The only altitude I see in the API response (below) is nested under the <sun> element, not <moon>. The API documentation you linked to refers to it as:

The angle to the sun at solar noon is also given.

So what this <noon altitude="50.0496753501172" /> really means is that, at noon, the sun will be about 50 degrees above the horizon. That's it. Nothing to do with the moon, nothing to do with distance.

Convert moon's altitude to kilometers

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