09/02/2014 – Ephemeris – Viewing the first quarter Moon

Ephemeris for Tuesday, September 2nd.  The sun will rise at 7:06.  It’ll be up for 13 hours and 11 minutes, setting at 8:17.   The moon, at first quarter today, will set at 12:52 tomorrow morning.

Tonight on the moon there are some very prominent craters on the terminator or sunrise line that’s cutting the moon in half.  From the top or north of the moon there’s Plato, which is also called a ringed plain because it has a flat floor.  South of there is Eratosthenes, at the end of the arc of the Apennines mountain chain.  At the south or bottom end of the moon are two other of my favorite craters.    First is the crater Tycho, that doesn’t look spectacular now, but will when the Moon is full with its rays of ejecta crossing a long way across the face of the moon.  A little bit farther south, partially entering sunlight is the large crater Clavius.  On my blog, bobmoler.wordpress.com, I’ll illustrate what the Moon’s image looks like in different types of telescopes.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addenda

The Moon tonight at 9 p.m. (September, 2, 2014). Created using Virtual Moon Atlas.

Image orientation in telescopes

The orientation of what one sees in an astronomical telescope depends on the type of telescope and the placement of the eyepiece.  The orientations shown are for observers in the northern hemisphere.  For the images below the moon shown is due south.

The orientation of the Moon as seen with the naked eye, binoculars, spotting scopes and telescopes with an erecting eyepiece.

The orientation of the Moon as seen in a refractor or a Schmidt-Cassigrain or similar type reflector with a diagonal at the eyepiece end, and the eyepiece pointing up. This is a mirror image due to an odd number of mirror reflections in the telescope.

The orientation of the Moon as seen with a refractor or Schmidt-Cassigrain and diagonal with the eyepiece oriented horizontally. It is a n inverted mirror image.

The orientation of the moon through a Newtonian reflector or a refractor without an eyepiece diagonal. It is an inverted image, an image rotated 180 degrees.

For southern hemisphere observers for these images to work the moon would be due north and all the images would have to be upside down.

Correction 09/02/2014 11:07 p.m.

All images created using Virtual Moon Atlas.