Moons of our Solar System: Himalia

Hi,
it has been about 4 months since I last posted about moons. The last post was about Amalthea (pretty cool name huh?). I thought that maybe I should resume some of the series so lets see how it will go. (its mostly astronomy blog so no wonder that these things are here.)

If I count right, Himalia has 29 pixels!

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Last time I was talking about Jupiter’s moons so I will continue with those. Today the topic is Himalia.

As you could guess, this name is connected to Jupiter (Zeus in Greek mythology). Most of the time all the people (moons) are lovers of Zeus and Himalia is no exception, she was the nymph that brought 3 sons to Zeus, those were Spartaios, Kronios and Kytos.

Though I found that she is good for watching I highly doubt this since the apparent magnitude (how bright it is) is only 14.6 which makes it almost as visible as Charon, the moon of Pluto (15.55).

Himalia is the largest irregular satellite of Jupiter. To be irregular satellite means to be formed somewhere else and be captured later on by the planet. Such moon has highly eccentric orbit which is also inclined and even retrograde. She orbits much further from Jupiter than the other moons I talked about. The distance ranges from 11-13 million kilometers! This is one 15th of the distance of Earth to Sun which is quite a lot for a moon!

Since there are many other objects around Jupiter like Galilean moons that are easier to study (also more interesting) not many missions studied this piece of rock. It was discovered on 3rd December of 1904 by Charles Dillon Perrine. We know some things from spectroscopy, it is similar to C-type asteroid which means that it contains minerals with

Not so good either

water though otherwise such an asteroid is pretty dark. While Himalia is small compared to planets, it has masss of 4.19*10^18 [1]. It’s diameter is not very clear because the closest pictures were taken millions of kilometers away. There are basicly two pictures of this moon, one which you can see above is by Cassini-Huygens and second is by New Horizons (on the right).

It was thought that Himalia has something to do with the disappearance of other even smaller moon Dia when it disappeared in 2000. Dia was luckily found in 2010 so Himalia is innocent.

Dragallur

[1] This does not mean that Himalia is heavy in Solar System, Earth has roughly 6*10^24.

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