Friday, 19 August 2016

Jupiter’s moon Io

Jupiter’s moon Io

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.

But, more on that at the end of the blog.  Basically, the book gives me the opportunity to do a mini-tour of some of the major moons of our solar system.

This blog is about Io, one of the four large moons of Jupiter, and an interesting one, as it orbits closest to Jupiter and the interactions with Jupiter cause it to look pretty dramatic.

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 sv per day, the radiation dose at the surface would be fatal within hours.
  • 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.

This is claimed to be a true colour representation of Io.  Quite the moon.


Here's a recent picture of Io and some other moons, taken by NASA's Juno probe, on July 5, 2016.  Granted, the moons are pretty small, but this is the first reasonably close-in picture from the new Juno probe.  Hopefully, we will get some more interesting photos of Jupiter’s moons, though I believe the probe’s science mission is mostly focussed on Jupiter itself, the atmosphere in particular.

The moon Io and Love and Intrigue Under the Seven Moves of Kordea

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.

In fact, the moons of Kordea are a central element in Book 2.  The cover below actually borrows the moon Europa, one of the moons of Jupiter 

The Witches’ Stones Series

The Witches' Stones, Book 1 - Rescue from the Planet of the Amartos

Young Earth woman and spaceship mechanic, Sarah Mackenzie, has unwittingly triggered a vast source of energy, the Witches' Stones,  via her psychic abilities, of which she was unaware.  She becomes the focal point of a desperate contest between the authoritarian galactic power, known as The Organization, and the democratic Earth-based galactic power, known as The Terran Confederation.  The Organization wants to capture her, and utilize her powers to create a super-weapon; the Terra Confederation wants to prevent that at all costs.  The mysterious psychic aliens, the Witches of Kordea also become involved, as they see her as a possible threat, or a possible ally, for the safety of their own world.

A small but fast scout-ship, with its pilot and an agent of the Terra Confederation, Coryn Leigh, are sent to rescue her from a distant planet at the very edge of the galaxy, near space claimed by The Organization.  Battles, physical and mental, whirl around the young woman, as the agent and pilot strive at all costs to keep her from the clutches of the Organization.

The Witches' Stones, Book 2 - Love and Intrigue, Under the Seven Moons of Kordea

Sarah has taken refuge on the planet of Kordea, where she is also learning how to control her psychic abilities, through the tutelage of the Witches of Kordea.  Coryn Leigh has now taken up the position of Confederation diplomat to the Kordeans, but he is also charged with keeping the Mackenzie girl safe at all costs.  During their time on the planet, an attraction between them grows, though they try to deny it, to themselves and each other.
But The Organization has plans of its own, including threatening the destruction of the planet Kordea, via destabilizing the orbit of Lina, one of its many moons.  The Organization proves that its threats are in deadly earnest, so, ultimately Sarah, Coryn and the Witches of Kordea must take the fight to the enemy.  Thus is borne a dangerous mission, to  a planet where their foe has based the weapon that threatens Kordea, and ultimately, the balance of power throughout the galaxy.  Sarah and Coryn agree that the machine must be destroyed, even at the possible cost of their own lives and growing love.

The Witches' Stones, Book 3 - Revenge of the Catspaw

Sarah and Coryn have become married, under the traditions of the Witches of Kordea.  But the marriage is performed by the Eldest of the most important coven, a rare honour, that comes with a blessing and a curse.  The slow working out of this blessing and curse forms the backdrop to the story.

Having come so close to their goal of enhancing their weaponry via Witches' Stone power, The Organization will not give up.  In order to lure Sarah into their trap, and thus have her become their Catspaw (someone who is forced into helping another, against their will) they need bait, and Coryn becomes the bait.  He also comes under the domination of a particularly nasty Elite of The Organization, one "Evil Evilla" Copoz.

Sarah, and a picked group of companions, must re-enter The Organization space, this time to the very heart of the empire, to rescue her husband, as he has done for her in the past.  They do so at great peril, but nothing can stop the terrible Revenge of the Catspaw.

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