Sep 152017

This morning the Cassini spacecraft entered the atmosphere of Saturn and ultimately became part of the planet it was sent to study.

Artist rendering of Cassini’s atmospheric entry.
Credit: NASA/JPL

The spacecraft entered orbit around Saturn on the 1st of July 2004 after a six year trip to the planet. It has been studying Saturn and its rings and moons since that time. One of the first things the spacecraft did was to deploy the Huygens probe toward Saturn’s largest moon, Titan. The probe became the first lander on a solar system moon other than our own.

Artist rendering of Huygens’ landing on Titan. Credit: NASA/JPL

Image from the surface of Titan. Credit: ESA/NASA/JPL/ University of Arizona

There are too many discoveries over the 13 years Cassini spent in the Saturnian system to list. Probably the most surprising was the discovery of geysers erupting from the southern pole of the ice covered moon Enceladus.

Geyser plumes from the southern pole of Enceladus. Credit: NASA/JPL

Subsequent study has revealed the material being ejected from the moon to be salty water carrying organic molecules. This implies the conditions necessary for life exists in the outer solar system in a place scientists never expected.

In addition to the scientific discoveries is the vast archive of images that Cassini took. The beauty of the planet and rings was worth the investment.

Saturn as seen by Cassini.
Credit: NASA/JPL

To the entire Cassini/Huygens team, thank you. Well done.
 Posted by at 10:24
Jun 142017

Yesterday’s rain eased off and the clouds cleared around 2300. That gave me an opportunity to open up the dome and get a short series of Saturn images before the clouds closed back in. The atmosphere was fairly steady and the images showed it. Jupiter had already set below my western tree line so I was unable to get any additional images of Jupiter for NASA’s JunoCam project.

I was not the only one taking advantage of the clear sky. The other party posed for a selfie on the PTO’s all sky camera.

 Posted by at 20:06
May 152017

The Jupiter session on May 13 went long enough that I decided to stick around a little longer and see how Saturn was looking. Saturn is 17° lower on the southern horizon than Jupiter. That puts it right in the light dome from Eglin AFB and, on the 13th, only 34° high. The atmosphere wasn’t too bad and the resulting images were acceptable.

 Posted by at 21:55
May 032016

Although there was no forecast for clear skies last night, it did clear up late and I got a short chance to try Saturn with the x2 Barlow.
It was obvious that the focus was not close, but I was able to check the full capture process again. I think I had the gain adjusted too high during capture so that will be the focus of the next test. Clouds closed in fairly quickly so I was not able to do any testing other than capture.

 Posted by at 21:50
Apr 302016

The last two nights were the first planetary tests of my ‘new’ Point Grey solar system camera. Up till now I have only used it to image the Sun through the H-Alpha telescope. Thursday night was a shakedown run to make sure all the correct camera drivers and software were installed and to see if I could find a planet sized target with the camera’s small field of view. I did not have any problems and the end-to-end ‘process’ worked fine but the images produced by the camera were very small. It also became very obvious that I really missed focus.

p_Jup_215141_g3_ap14 p_Sat_015834_g3_ap10

So last night I added a x2 Barlow to the mix. It made finding the planet a little more difficult but the image size is now large enough to work with. This image of Jupiter is the best 5,000 frames of a 10,000 frame video capture through the x2 Barlow. The dark spot visible near the right edge of the planet is the shadow cast by the Galilean moon Io. The moon has not left the disk of the planet and as such is in the image but I cannot reliably pick it out. The planet is displayed in the traditional orientation with south at the top. Unfortunately, clouds moved in before Saturn rose above the tree line so I was not able to include it in last night’s test.


This is also the first time I have used Firecapture to record the video stream. Firecapture is free software that supports many machine vision cameras and is a very popular package for solar system imagers.

I consider last night’s test a success and will, for now, use that configuration as my standard for planetary imaging. The next step is to integrate a filter wheel and RGB filters to add color to the images.

 Posted by at 16:05