Helena Puumala’s SF Romance series features a planet with seven moons. This rather unusual setting gives me the opportunity to talk about some of the remarkable moons in our solar system, as I test different moons for the cover of book 2 of the series. This blog is about I0, one of the four large moons of Jupiter, notable for its intense tectonic activity – i.e. volcanoes and such.
Here are a few facts about Io, courtesy of Wiki:
- It's bigger (about 1800 km radius) than Europa, but smaller than the other two of Jupiter’s four Galilean moons (Ganymede and Callisto). It is just slightly larger than our moon.
- As noted above, it is one of the four original moons discovered by Galileo in 1610 (thus, referred to a Galilean moon).
- It is the closest to Jupiter of the four Galilean moons. It is easy to find in a small telescope.
- It is the most geologically active object in the solar system, with more than 400 volcanoes – even more active than the Earth. Essentially, this is caused by the friction created by the constant gravitational tug of war on Io, between Jupiter and the three other big moons (i.e. tidal heating).
- While Europa is notable for its water content, Io is the driest object in the solar system. Thus, Io is much denser than the other big Jovian moons.
- It is mostly composed of silicate rock, and probably has a liquid iron or iron sulphide core.
- Its distinctive yellowish-brown colour is due to sulphur and sulphur compounds. The huge volcanoes spew sulphur and sulphur dioxide high above (500 km) the surface. They also produce extensive lava flows (500 plus km). Changes in these lava flows have been detected between different space missions (Voyager and Galileo), indicating lava had flowed up to 100 km in less than 20 years.
- The extensive tectonic activity means that the surface is constantly regenerated – thus the surface is young and crater free.
- The material ejected from the volcanoes plays a role in enhancing Jupiter's magnetic field, and thus contributes to the high radiation environment, via capture of the solar wind.
- At 36 Sieverts per day, the radiation dose at the surface would be fatal within hours (5 or so is fatal).
- Honestly, the word “hellish” seems appropriate for Io.
- Io participates in a 1:2:4 orbital resonance with the two Galilean moons that it is nearest to, Europa (second from Jupiter) and Ganymede(third from Jupiter). That means, for every one time Ganymede goes around Jupiter, Europa goes around twice and Io goes around four times.
Here's a picture of Io, taken by a NASA probe.------------------------------------------------------------------------------------------------------
Now, here’s a moon-based pitch for Helena Pummala’s latest SF Romance series, The Witches’ Stones:Helena Puumala's SF Romance series features the planet Kordea, home to a race of beautiful and powerful psychic aliens, known as the Witches of Kordea. The planet has seven moons, an extraordinary arrangement for a terrestrial sized planet in its star's habitable zone, as is noted in Book 1, which you can get from the link below: :).
http://www.amazon.com/The-Witches-Stones-Book-One-ebook/dp/B008PNIRP4In fact, the moons of Kordea become a central element in Book 2, soon to come out. The cover below actually borrows the moon Io, one of the moons of Jupiter. I will by testing out different moons for the cover of the Witches' Stones Book 2, so, as noted above, this gives me the opportunity to do a mini-tour of some of the major moons of our solar system. Moons, including our own, are fascinating. A terrestrial planet with seven moons would be cool (though it would probably be a very unstable arrangement).