This is my report of my astronomical observations for the night of 29 September, 2009.
The observations began at 8:00 pm (EST) in my back yard at Neptune Beach Florida. The impromptu session began while I was smoking a cigar and enjoying a rare cooler autumnal Florida evening.
All observations were conducted with a Bushnell, NorthStar model three-inch reflector mirror telescope with a 114mm focal length and viewings were performed with a 4mm and 20mm lens.
Primary observations began with the Moon. Our moon. Why do all of the other planets have beautiful names for their moons and ours is named “Moon”? Come to think of it, we named Earth, Earth synonymous with “Dirt”. That is not an original idea by the way. I got it from the novel Illegal Aliens by Phil Foglio.
The Moon on this night was a Waxing Gibbous (Bit of trivia, Gibbous is Latin for bulbous) at 85% of full. Position was 181 degrees by an elevation of approximately 50 degrees.
On the moon I once again identified The Lighthouse, (Palus Somni) and Luna’s Crater (Albategnius Crater), and began making a concentrated study of Mare Tranquillitas, Mare Crisium, and the Copernicus Crater.
At this point I interrupted my observations to test my friend Allison, to let her know I was looking at the Moon. She texted me back asking if that was Jupiter hanging below and to the right of the moon. She had heard about it that day and switched my focus.
Most of my observations of Jupiter were conducted with the 4MM eyepiece. At 8:55 pm (EST) I the planet and 4 Jovian bodies under view.
According to the Jupiter calculator at homepage.ntlworld.com/mjpowell/Astro/Naked-Eye-Planets/Jupiter-Path.htm the mirror reversed line up was Ganymede, Jupiter actual, Io, Europa, and Callisto.
Ganymede began to eclipse. By 9:10 pm (EST) it was in totality. Prior to its eclipse I observed a body rising up over the horizon of Ganymede and after the eclipse that body was left in its place. I have yet to identify it. (Flight of Fantasy; If I discovered a new moon I am naming it Cowford.)
Research and seeking peer advice I wanted to know what I saw. I was directed to this article at SkyandTelescope.com. Jupiter’s Moons Dance For You! It reports that Jupiter’s point in relationship to ours an event called “Mutual Phenomenon” occurs where the Jovian moons will occult and/or eclipse each other due to our two worlds being almost exactly edge-on with each other.
According to their chart this occulting and eclipsing occurred on the 23rd, and the 30th of September. Not on the night of my observations. It’s reporting on the 30th that Io occulted Europa to a percentage of 49% at 5:18 pm Universal Time (UT) and at 7:07 pm (UT) eclipsed it to 81%
I was diligent about documenting everything I saw as it was happening. I verified every sighing two or three times, and texted Allison so I could slow and not get carried away. I have since purchased her a pair of binoculars so we can try to verify each others observations, and share in grand discoveries!