The sky cleared out on April 4, 2017 around 22:30 and the Moon shone brightly a day after first quarter. I had in my calendar to watch out for the large crater known as Ptolemaeus. The terminator had just recently passed the crater and it was prime for viewing and imaging. Unfortunately the seeing was not too great and I was too
tired to polar align the scope properly. I still got a couple good images
to go along with this post.
 |
| Ptolemaeus |
In the image above Ptolemaeus is centered in the frame. Inside the large crater is a smaller one known as Ammonius which is approximately 9km wide. Ptolemaeus itself is a sizable 153km in diameter. On the right side of the image is a crater known as Herschel named after the famed astronomer William Herschel. The left side has the larger crater called Alphonsus which contains a central peak.
Ptolemaeus was named after the extremely famous Greek astronomer named Claudius Ptolemaeus 100-170AD), colloquially referred to as Ptolemy. He wrote a landmark scientific treatise known as Almagest. His geocentric model of the Universe was accepted until Copernicus discussed heliocentrism during the early Renaissance. His work allowed for accurate predictions of the Moon, planets, Sun, eclipses and stars. Ptolemy had a list of 48 constellations and most are still in use today.
A wider field of the region is shown below.
 |
| Ptolemaeus Wide Field |
I am finding the Moon a more difficult target to view. Certain regions have great visibility in the evening sky about once a month. This gives a potential 12 opportunities each year to properly view certain lunar features. With inclement weather this can drop to perhaps only 5 or 6. Stellar objects are typically available for several months at a time so you're bound to have many good chances to see them.
Typically the day after Ptolemaeus you will be able to see the great craters of
Tycho and
Plato! These are great in any set of binoculars or a telescope!
0 comments:
Post a Comment