Archive
10/02/2014 – Ephemeris – The gibbous Moon tonight
Ephemeris for Thursday, October 2nd. The sun will rise at 7:41. It’ll be up for 11 hours and 39 minutes, setting at 7:21. The moon, 1 day past first quarter, will set at 1:50 tomorrow morning.
Tonight the moon will be featuring some of my favorite lunar landmarks, and if you spend any time looking at the moon with a small telescope, they become yours. The place to look is at the terminator, the sunrise line on the moon. In the north not far from the terminator is the walled plain called Plato. A bit farther away is a gash in the lunar Alps mountains caller the Alpine Valley. Near the center of the terminator and split by it is the fabulous crater Copernicus with a triple central peak which should poke into sunlight. Near the south pole is the large crater Clavius with an arc of decreasingly smaller craterlets on its floor. A bit north of that is the crater Tycho, which is more prominent when the moon is full than it is now.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The gibbous Moon one day after first quarter at 9 p.m. October 2, 2014. Created using Virtual Moon Atlas.
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.
03/11/2014 – Ephemeris – Observing the moon tonight: Bay of Rainbows and more
Ephemeris for Tuesday, March 11th. The sun will rise at 8:02. It’ll be up for 11 hours and 41 minutes, setting at 7:43. The moon, 4 days past first quarter, will set at 5:39 tomorrow morning.
The moon tonight is a pretty fat gibbous shape, with the sunrise line or terminator revealing the Bay of Rainbows, Sinus Iridium, that large half crater at the moon’s upper left edge, and the edge of the Sea of Showers, Mare Imbrium. In the figure of the man in the moon Imbrium is his big eye, kind of like the cartoon “Bill the Cat”. To the right of it, looking like a hole in a mountain chain, is Plato, whose dark floor is unmistakable even at full moon, when shadows are absent. The crater Copernicus is now beginning to be washed out as the morning shadows shrink. To the left of Copernicus, just catching the sun’s rays on the terminator, is the smaller crater Kepler. When the moon is full Kepler will show a fine ray system.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon at 10 p.m. on March 11, 2014. Created using Virtual Moon Atlas.
Note for those not in the Eastern Daylight time zone. 10 p.m. is 2 hours March 12, 2014. If viewing before that time the terminator will be shifted to the right. After the terminator will be shifted to the left.
11/03/11 – Ephemeris – The moon tonight
Thursday, November 3rd. The sun will rise at 8:22. It’ll be up for 10 hours and 6 minutes, setting at 6:28. The moon, 1 day past first quarter, will set at 2:21 tomorrow morning.
In a telescope the moon will present some interesting features and craters. They will be seen near the terminator, the sunrise edge of the moon, where the shadows are longest. The moon is gray on gray, so the best way to see detail is by shadow. At the top or north end of the moon is a mountainous arc called the Alps. Mountain ranges on the moon are names after earthly mountain ranges. Cutting through the range is a fault called the Alpine Valley. Along the Alps at the terminator a crater will be coming into view this evening. It is the crater Plato. It is sometimes called a walled plain, since its floor is flat, or rather is slightly convex conforming to the shape of the lunar sphere. It’s cool watching the shadows of the walls recede as the sun rises.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Moon 1 day after first quarter. Created using Virtual Moon Atlas
Bob Moler's Ephemeris Blog 