07/19/2021 – Ephemeris – How does your telescope’s image orientation compare to how it looks to the naked-eye?

This is Ephemeris for Monday, July 19th. Today the Sun will be up for 15 hours and 6 minutes, setting at 9:22, and it will rise tomorrow at 6:16. The Moon, 2 days past first quarter, will set at 2:35 tomorrow morning.

When you look through a telescope at the Moon, how does it look compare to how it looks to the naked-eye? Yes, it’s bigger and probably brighter. But how did its orientation change? Astronomical telescopes generally give an upside-own image, that is rotated 180 degrees. Newtonian reflector telescopes, with their eyepiece near the top of the telescope, give such an image, as do refractor telescopes where the diagonal mirror near the eyepiece is not used. When such a mirror is used a right side up, but mirror image is the result. The mirror image results when an odd number of reflections occur in the light path. Binoculars use two or four reflections. Newtonian reflectors have two reflections. It can be confusing sometimes.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

07/28/2015 – Ephemeris – The first close up images of Pluto

Ephemeris for Tuesday, July 28th.  The Sun rises at 6:24.  It’ll be up for 14 hours and 49 minutes, setting at 9:13.   The Moon, 3 days before full, will set at 4:32 tomorrow morning.

Two weeks ago the New Horizons spacecraft zipped through the Pluto system gathering a wealth of information including a whole host of images.  Due to their large size the images will take some time to be sent back, however some highly compressed images have been returned and yield a tantalizing look at the dwarf planet Pluto and its large moon Charon.  Rather than an apparently dead heavily cratered body, the first images presented a young surface with plains and mountains with nary a crater to be found.  Young is relative, perhaps 100 million years old or so and implied heating where there appears no source to be found… yet.  The first of many mysteries.  And we have 16 months more  of data and images to be returned.

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

Addendum

First closeup picture the New Horizon Team showed. Two mile high ice mountains, plains, and interesting terrain, but no craters. A young surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.  Click on image to enlarge.

Sputnik Planum (Plain) next to the ice mountains showing polygons and troughs, some with hills. This is part of Pluto’s “Heath”. Note the rectangular lossy compression artifacts in the image. An uncompressed version will be downlinked later. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.  Click on image to enlarge.