Star Gazing – June 11: Comparing Size and Naming Origins of Our Solar System

Another Star Gazing Night was held earlier in June, and though it started a little milky, the conditions improved so that we had good views of the moon, several planets, and a few other objects.

We started when it was still twilight – which is pretty late in the day this time of year.  By the way, I recently found an excellent discussion about hours of daylight and what, technically, is the longest day of the year (it might surprise you) on David Epstein’s blog at

We had about a dozen telescope observers and another dozen people wanting to see through them. As the twilight gave way to the night, there were fireflies in the field, twinkling away – creating the illusion that the stars were coming down for a visit.


firefly, by

Our moon, which has the Latin name, “Luna,” (you may have heard of lunar tides, and lunar phases), was near first quarter phase and was the first target.  Nearby was bright Jupiter, which also was an early target.


Moon and Jupiter by C. Austin

The four ‘Gallilean’ moons of Jupiter, three of them slightly larger than our moon, and one slightly smaller, were easy to spot, though it takes looking at a chart to identify which is which.  This Wikipedia article compares the size between solar system objects, which is very interesting, albeit a bit to wade through and think about.

In the south was Mars, bright orange-red.  Mars just passed its closest approach to us in about three decades.  But despite being relatively close, I could only see general dark and light spots and maybe a polar cap.

Saturn was further east from mars.  Here, Saturn is at its most magnificent!  The rings are tilted about as much as possible, so it was easy to see them  against the round yellow globe.  One or two moons could be seen as well.


Saturn, taken by NASA’s Voyager 2

I was involved in several interesting discussions about Pluto:

One discussion was about how Pluto got its name. Was it a girl who named it? Was it named after Mickey Mouse’s dog? The truth involved both. All orbiting bodies of size are named after Greek/Roman dieties. The Romans adapted their dieties from Greek ones, so that, for example, Zeus, the great god of Greek mythology, is the same as Jupiter in Roman mythology. The name, Pluto, initially suggested by a little girl who was interested in Greek mythology, is the Roman equivalent to the Greek God, Hades – the god of the underworld. Pluto, the dog in Disney cartoons, appeared around the time Pluto, the (dwarf) planet was discovered and the dog was likely named after the planet. You can read more about this little girl naming Pluto in the Washington Post or the Smithsonian Magazine.


Pluto, image by New Horizons, an interplanetary space probe

Another discussion was about an object’s ‘status.’  Though I’m not going to try to put that whole discussion into words here, the Wikipedia article above on the size of objects provides one perspective of that discussion.  If we were to replace our moon with Pluto, Pluto would appear in the night sky about two thirds the diameter of our moon.  Just sayin.

The next Star Gazing Night is Friday, July 29- hope to see you there!

Thank you to Craig Austin for this Star Gazing post and these pictures. Craig is often present during Moose Hill’s Star Gazing Nights, along with a few members of the Astronomical Society of Southern New England, and other local amateur astronomers. We are grateful for those who share their scopes and knowledge with anyone who is interested in learning more and seeing the night sky from our open field.

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