I caught a sweet shot of The Moon and the red planet, Mars last night just before the clouds rolled in. The pair were separated by around 1* or so. This pairing is often referred to as a conjunction or alignment.

This was a more interesting image to process as the two are so far apart in brightness. The image I chose was a bright one (so that Mars would be visible). As such, the moon was a way washed out. To better deal with this, I created a duplicate layer in GIMP. This allowed me to process the two separately and then re-combine them later. For the moon, I used a number of Curves to dramatically reduce the overall brightness.  This revealed details on the lunar surface. For Mars, I used the Curves function to dramatically brighten the image. Not sure if this is cheating, but I took a copy of a black section and covered over the moon on this one. Otherwise, it was going to get brighter still. Finally, I selected just Mars and did an additional Curves and Levels function on just this object. This made Mars stand out significantly. Finally, I merged the two layers to create one nicely integrated image.

Astro Photo Details:

* Designation: The Moon
* Magnitude: roughly mag -12
* Size: roughly 1/2*

* Designation: Planet Mars
* Magnitude: mag -1.22
* Size: 15″

Astro Photo Processing Details

* Canon Digital Rebel XTi
* 1 x 1/2s exposure at ISO400
* Gimp Curves

1. Brooks, November 27, 2007:

   I was hanging outside with a few friends last night and saw the same sweet thing. Very cool. I’m going to check it out tonight with the telescope if the clouds break.

2. jaron, November 27, 2007:

   So thats what i saw next to the moon last night, i will try capture it next chance i get.

3. anthony, November 27, 2007:

   I was actually caught slightly by surprise… not expecting the two to be as close together as they were.

4. GBrooks, December 2, 2007:

   Hi Anthony,

   I just got my XTi and I’m on the chase for great pics as well. The hardware for scope attachment is on its way and I’m making another barn door mount to hold the mak and camera.

   Focusing the stars has been my biggest challenge so far…do you have a favorite lens and method for this?

   Thanks in advance,

   Gerald

5. anthony, December 2, 2007:

   Hey Gerald
   I don’t have a fancy technique. I basically make use of the fact that I have a good goto mount in the Losmandy G-11. I basically make sure that I’m tracking properly via a multi-star alignment. Next, I bounce back to a bright star and then swap the eyepiece and the camera. Since I’m pointed at a very bright star, I can usually see it quite well in the view finder of the camera. I then just play with the focus until it looks sharp. You could snap a quick shot at this point to verify that it is well focused. After this, I have the scope slew back to the object that I’m looking to image. Since I previously verified that I could goto this, I’m confident that the object will be in the field of view. At this point, I’ll snap a short exposure to see where the object sits in the field of view. I’ll make any corrections required to center the object and snap short exposures to verify that my corrections were appropriate.
   There are undoubtedly better, more high-tech ways to focus your camera, but this has worked well for me. Once I get an astronomical ccd camera, there are automated focusers and software to ensure that you are precisely focused. I look forward to the challenges and benefits of these astro-cams.
   Anthony

6. GBrooks, December 2, 2007:

   Thanks for the reply….I just found a website that does mods on XTi for Astrophotography…removing the IR filter and replacing it with a UV or broadband filter or others. Hutech is the name to search on, though you probably already know it.

   Thanks again,

   Gerald

7. Catie, December 3, 2007:

   This is a really cool pic. What was the latitude and time of day?

8. anthony, December 3, 2007:

   This was taken from my home in Park City, Utah
   This puts me just about 40* and 45′ North latitude.
   It was taken about 9:20pm on 2007-11-26
   Anthony

9. Catie, December 4, 2007:

   Thanks for the info!

10. Tom, January 21, 2008:

    Nice photos!

    When will future Mars-Moon conjunctions occur?

11. anthony, January 23, 2008:

    There is a book with all the planetary conjuctions (and other events)
    http://www.willbell.com/math/mc4.htm
    Also, many astronomy programs have the ability to show this information.
    An old one I used to use RedShift had this where you could specify the minimum or maximum distance between the objects you were interested in.
    I’m sure Starry Night Pro has this feature… but I’m not sure where it is
    Thanks for checking in…

    Anthony