What's Up the Observatory of Eilat and the Arava

25/01/2025

I go out almost every night by appointment. The lineup was even better for the last few months. We now begin a little after 18:00 to see Saturn as high as can be. Saturn is interesting now because it rings are still visible but are disappearing for a while.
I can be reached at 054 481 9973
Get a group of people together for a great cold night in the desert. At my site at Mt Yehoram you can also make a campfire.

09/01/2025

Planet Mercury, yesterday - those shadowed craters are likely full of ice. Amazing place to discover water!

https://www.esa.int/Science_Exploration/Space_Science/BepiColombo/Top_three_images_from_BepiColombo_s_sixth_Mercury_flyby

09/01/2025

A good demonstration that we live on a sphere.

Our photo and one posted by an overseas follower in response shortly after.

09/01/2025

Saturn's rings are enormous but extremely thin, with the following dimensions: [1, 2, 3, 4, 5]

Width

The main rings are about 175,000 miles (282,000 kilometers) across. The D ring is 66,900–74,510 kilometers from Saturn's center and 7,500 kilometers wide, the C ring is 74,658–92,000 kilometers from Saturn's center and 17,500 kilometers wide, and the B ring is 92,000–117,580 kilometers from Saturn's center and 25,500 kilometers wide. [1, 3, 4, 5]

Thickness

The main rings are only about 30 feet (10 meters) thick. If you had a model of Saturn that was a meter stick wide, its rings would be about 10,000 times thinner than a razor blade. [3, 4, 5]

Mass

The total mass of Saturn's rings is only about 1.5 × 1019 kg, about 0.41 times the mass of Saturn's moon Mimas. [2]

Spokes

Spokes can be longer than 10,000 miles (16,000 kilometers), greater than the diameter of Earth. [6]

Gaps

The Cassini Division separates Rings A and B, with a gap measuring 2,920 miles (4,700 kilometers) in width. [4]

The rings are mostly made of particles of water ice ranging in size from smaller than a grain of sand up to the size of a mountain. [7]

Generative AI is experimental.

[1] https://en.wikipedia.org/wiki/Rings_of_Saturn[2] https://www.britannica.com/place/Saturn-planet/The-ring-system[3] https://coolcosmos.ipac.caltech.edu/ask/108-How-large-are-Saturn-s-rings-[4] https://science.nasa.gov/saturn/facts/[5] https://www.smorescience.com/how-old-are-the-rings-of-saturn/[6] https://science.nasa.gov/mission/cassini/science/rings/[7] https://www.youtube.com/watch?v=vbr8y_Y433Y

Saturn's ring formation has been a mystery since Galileo first discovered them in 1610. Now, scientists at the Massachusetts Institute of Technology and the ...

08/01/2025

https://en.wikipedia.org/wiki/Bortle_scale #:~:text=The%20Bortle%20dark%2Dsky%20scale,interference%20caused%20by%20light%20pollution.

29/12/2023