Friday 22nd June 2018 (Jupiter)

You can still easily see Jupiter now - here it is as a small, sharp dot on the left-hand side of the photo. But when you zoom it in, you can also see a faint, fuzzy, grey dot. Perhaps it's Callisto? Or Ganymede? Or Europa? Or even Io?

Time 22:15.
Distance 242,106 miles.
Waxing gibbous phase.
200 degrees S compass point (azimuth).
Altitude 27.9 degrees.

Friday 22nd June 2018

Today, Copernicus is right on the terminator!

Copernicus is named after the astronomer Nicolaus Copernicus. However, it previously had lots of different names: Carthusia (after the Chartreuse Mountains), Phillipi IV (after Philip IV of Spain), Etna M. (after Mount Etna), and has since been nicknamed "The Monarch of the Moon"!

Time 22:15.
Distance 242,106 miles.
Waxing gibbous phase.
200 degrees S compass point (azimuth).
Altitude 27.9 degrees.

Thursday 21st June 2018

See the Moon on the Summer Solstice!

Does the Moon have a solstice, a longest/shortest day?

It was tricky to work out but I think the answer is "yes", but it's a bit more complicated than an Earth's longest/shortest day!

If you were standing on the Moon and the time it takes for the Sun to go away and come back to the same place is a day (a synodic day), than your day would average 29.5 Earth days, varying from 29.26 to 29.83 Earth days, a difference of just over 13 hours!

This month, the Moon's is on lunation 1181 and its day will last 29d 7h 05m!
The Moon's longest day this year was the first couple of weeks in January (lunation 1175), lasting 29d 19h 47m.

Time 19:45.
Distance 239,197 miles.
Waxing gibbous phase.
170 degrees S compass point (azimuth).
Altitude 34.2 degrees.