Astrophotography – solar system

Venus and the Schroter effect

Dichotomy, or half-phase for Venus was predicted to be 6th January but due to the Schroter effect may appear late. This is a phenomenon in which the observed phase of Venus appears less than the predicted phase. As a result, dichotomy (half phase) occurs early at evening elongations, and late at morning elongations. The time difference between calculated and observed dichotomy is about a week. The effect was discovered by the German astronomer Johann Hieronymus Schröter (1745–1816). The cause may be that the region near the terminator is darker than the rest of the illuminated disk.

Here is a rather poor image of Venus from the window-sill this morning.


Here is the general view from this morning (9/1/2019). I didn’t manage this yesterday. Early risers can look forward to the Venus-Jupiter conjunction on 22nd January.

Christmas present and Ultima Thule

One of my Christmas presents was a book by David Eicher and Brian May – “Mission Moon 3D”. This is a superb book that amongst other things contains lots of 3D photos (and a viewer) from the Moon missions.

Turns out that Mr May is a stereoscopic photo enthusiast, and has produced some stereo images of Ultima Thule – see

It works too! (at least with the viewer from the book)


Ultima Thule and Image Processing

While we are waiting agog for images of Ultima Thule from the New Horizons probe, I thought you all might be interested in a bit of “professional” image processing by NASA. See

I wonder if New Horizons has a window-sill?!

Just out of curiosity, I wondered what GIMP might do with the “RAW” image on the left:

Shows what you can do simply for free!