When you saw the title of this piece, did you think, “What? Have they located a hitherto unknown moon?” I know I did when my chum Jay Dowling pointed me to this video with the same name.
In reality, as we soon discover, one portion of this excellent Numberphile video focuses on an asteroid called Cruithne. In turn, from the Wikipedia we learn that:
3753 Cruithne is a Q-type, Aten asteroid in orbit around the Sun in 1:1 orbital resonance with Earth, making it a co-orbital object. It is an asteroid that, relative to Earth, orbits the Sun in a bean-shaped orbit that effectively describes a horseshoe, and that can change into a quasi-satellite orbit. Cruithne does not orbit Earth and at times it is on the other side of the Sun, placing Cruithne well outside of Earth’s Hill sphere. Its orbit takes it near the orbit of Mercury and outside the orbit of Mars. Cruithne orbits the Sun in about one year, but it takes 770 years for the series to complete a horseshoe-shaped movement around Earth. The name Cruithne is from Irish and refers to the early Picts (Old Irish: Cruthin) in the Annals of Ulster and their eponymous king (“Cruidne, son of Cinge”) in the Pictish Chronicle.
As Matt Henderson, who is the creator of this video, says about Cruithne: “[…] that has been referred to Earth’s ‘second moon,’ but that’s just sensationalist kind of thing.” Of course, this makes it all the more ironic that he should title his video, “The Strange Orbit of Earth’s Second Moon”; and only slightly less ironic that I should follow his lead in naming this blog. It really is a funny old world when you come to think about it, and no mistake.
But we digress… In this video, Matt shows graphical representations of computer simulations of the ways in which the patterns of the paths of other planets might be perceived from the perspective of persons propagating on the Earth. The results are amazing concatenations of curves formed from combinations of circular and elliptical elements, all coming together in Spirograph-esque structures. In fact, one of the commenters to the video noted, “A minute in and I’m getting all nostalgic for Spirograph.”
I don’t know about you, but I find the fact that these sorts of patterns are hidden in plain sight — also, that they (and other mathematical constructs) appear to underlie everything we see — to be strangely comforting. It’s almost as though someone, somewhere has a plan. What say you about all of this?