21-10-2017, 01:32 PM
3270
Re: Leisurely Scribbles (part 5)
Originally Posted by
Robert Jnr.
->
Moon here refers to a period of time Gummmy
Your time is about 9 AM, kindly supplied by H Saaaaaamuel EVer Rite watches, remember? "We are the Ovaltinies"
Horace Bachelor & his infra red draw system, K E YN S H A M..
BRIZZLE
Umm....if I may quickly intercede,chaps?
Before the invention of the telescope in the early 1600’s, man just knew of
the Moon—a round, [it was,at the time,unrealised that the Moon was spherical] mysterious
astronomical object that people would gaze at in the night sky. As time progressed however,astronomers realised that having a moon isn’t a feature unique to planet Earth and that other planets had moons too. So exactly what
is a moon? A moon is defined to be a celestial body that makes an orbit around a planet,including all eight major planets, dwarf planets,some minor planets. A moon may also be referred to as a natural satellite,although to differentiate it from other astronomical bodies orbiting another body, e.g. a planet orbiting a star, the term 'moon' is used exclusively to refer to a planet’s
natural satellite. The first moons to be discovered other than our own moon,were the Galilean moons of Jupiter,named after astronomer and discoverer Galileo Galilei. The moons Io,Europa,Ganymede and Callisto are Jupiter’s largest and were the first four to be discovered-to date,a further 59 moons orbiting Jupiter have been discovered,making 63 so far known. Other than the four Galilean moons,Saturn’s moon Titan and Neptune’s moon Triton,are comparable in size to the Earth’s Moon. In fact, these seven moons are the largest natural satellites in the solar system,measuring more than 2600 miles in diameter. Only the two innermost planets Mercury and Venus have
no moons. Well...that we know of to date,anyway...
An interesting fact about some of the solar system’s largest moons is that several of them are geologically active. Although Earth's Moon has no tendencies to spew lava or display any evidence of tectonic activity,Jupiter’s Io and Europa,Saturn’s Titan and Enceladus,plus Neptune’s Triton,have been observed to be volcanically active. Although the 'moon count' of the Solar System had a grand total of just one in ancient times,that number has ballooned to 336 as of today,with 168 moons orbiting the six major planets. The rest are moons of
dwarf planets,asteroids moons,or natural satellites of Trans-Neptunian objects. As more discoveries are made,astronomers find it more difficult to put a defining line on what can/can’t be classified as a 'moon'. I.e;is it correct to call a 10-inch rock that’s orbiting Jupiter in stable orbit,a moon? If
yes,then there could potentially be
millions of moons as yet undiscovered within our Solar System alone. If
no,then where does one draw the line? Size? Mass? Orbital stability? The size and stability of what can officially be designated as 'a moon' is still undecided scientifically,so other than the simple definition of it being 'a natural satellite of a planet', there really is,as of yet,no clear cut answer to the question, 'What is a moon?'. [and gummy dropping his strides doesn't count....m'kay?]