This is our second guest post by Tim Cullen, and it is a superb piece of work presented in a professionally produced document, which builds on his first post. There are 32 stunning images in this piece, and I cannot do them all justice with wordpress’ limited formatting capabilities. Please download the full article and feast your eyes and feed your mind with Tim’s intriguing and thought provoking work. Here’s the intro and the first few images as a tempter-taster:
The Mystery of the Missing Magnetosphere
Tim Cullen. Malaga April 2012
Like many a whoduniti drama this investigation is presented in three acts, contains a sting in the tailii and is conducted by an eccentric amateur who leaves the audience to decide whether the story should be filed under fact or fiction.
The mystery began when it was noted that settled scienceiii believes that the Mooniv only has a mini-magnetospherev lurking on the far side of the Moon that is 360 kilometres across and is surrounded by a 300 kilometre thick region of enhanced plasmavi fluxvii caused by the solar windviii.
The diminutive size of the Moon’s magnetosphereix is apparently associated with the Moon’s very weakx external magnetic field which is described as being less than one-hundredthxi that of the Earthxii.
The plot thickens when comparisons are made with other terrestrial planets.
Mercury is described as having a strong magnetospherexiii and a significantxiv magnetic field which is also [contradictorily] weakxv because it is only about 1.1% as strong as the Earth’sxvi i.e. very close to the Moon’s less than one-hundredthxvii that of the Earth.
Mercury’s magnetotailxviii is estimated to vary from 10s Mercury radii to 100s Mercury radiixix and even up to 1.5 million milesxx. Using values from Wikipedia the magnetosphere of Mercury may extend up to a maximum of 100 RM (Mercury radii)xxi i.e. 243,970 kilometres.
Venus lacks an intrinsic magnetic field but a weak external magnetic field is induced by an interaction between the ionosphere and the solar wind that supports an induced magnetosphereii that stretches for some 45,000,000 kilometres into spaceiii.
Therefore, the core of the mystery is:
Why doesn’t the Moon have a large magnetosphere like Mercury and Venus?
Act I – Lumps of Rocks in Space
Perhaps the best way to start the investigation is to remove ourselves from the whole concept of magnetospheres. Let’s begin by simply focusing upon how lumps of rock in space interact with the solar windiv as they travel through the Solar Systemv.
Lumps of rock in space are also known as Cometsvi and Wikipedia informs us (without any sign of blushing and without reference to American astronomer Fred Whipplevii) they are also popularly described as “dirty snowballs”.
Comet Hale-Bopp Image Credit: Wikipedia
Comet McNaught Credit: Akira Fujii
Download the full document to feast your eyes and feed your mind.