A beautiful clear night in May put me in the mood to take some pictures. I originally went out to take a picture of a comet that is currently in our skies and I am still working on that image. That comet is proving difficult to process. I had a little bit of time left that night so I also snapped a few shots of another target that was in close proximity to the comet. It is called M13 and is a globular cluster of stars located in the constellation Hercules. A globular cluster is a collection of stars in a tight spherical formation. They are quite common with over 150 of them known just in the Milky way.
M13 is a beautiful globular cluster with hundred of thousands of stars. Just to put size into perceptive, the diameter of this ball of stars is 145 light years across and it is 24,100 light years away from Earth.
M13 was cataloged by Charles Messier in 1764, but first discovered by Edmond Halley in 1714. Halley is most notably known for determining the orbit of Halley's Comet.
The most interesting fact for me is that M13 was chosen as the target to beam the Arecibo message. Taken straight from Wikipedia, the Arecibo message that was sent in 1974 contains the following info:
Dr. Frank Drake, then at Cornell University and creator of the Drake equation, wrote the message with help from Carl Sagan, among others.[1] The message consists of seven parts that encode the following (from the top down):[4]
- The numbers one (1) to ten (10) (white)
- The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA) (purple)
- The formulas for the sugars and bases in the nucleotides of DNA (green)
- The number of nucleotides in DNA, and a graphic of the double helix structure of DNA (white & blue)
- A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth (red, blue/white, & white respectively)
- A graphic of the Solar System indicating which of the planets the message is coming from (yellow)
- A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish (purple, white, & blue)
Since it will take nearly 25,000 years for the message to reach its intended destination (and an additional 25,000 years for any reply), the Arecibo message is viewed as a demonstration of human technological achievement, versus a real attempt to enter into a conversation with extraterrestrials. In fact, the core of M13, to which the message was aimed, will no longer be in that location when the message arrives.[1] However, as the proper motion of M13 is small, the message will still arrive near the center of the cluster.[5]
The technical card of the image I took. There are some other small galaxies in the picture, with NGC 6207 being the most noticeable.
