Our Nearest Planet

[fiction-factory]

There was an interesting piece on Radio 4's excellent More or Less programme last week about which planet is our nearest neighbour. If you didn't hear the programme I'd be interested to know what people think the 'answer' was. Actually it does depend how you frame the question but it did make me think about how we visualise the solar system

[jim360]

I thought it was Venus, followed by Mars, Mercury, Jupiter etc.

[fiction-factory]

On one definition- yes, jim- if all the planets were all lined up in a row, but of course that doesn't happen.

[Old_Geezer]

The nearest planet to me is Earth. Line 'em up how you will.

[jno]

doesn't it vary?

[jim360]

Well, OK, true, but even then, I would have thought that most of the time we'd be nearer to Venus than Mars, and rarely closer to Jupiter than any other planet. Presumably they'd switch around, for sure, but I wasn't sure how pedantic the question wanted to be.

[fiction-factory]

Good point, OG- okay I meant nearest planet to earth.
Yes it varies depending on where they lie - Venus gets closest but sometimes it's Mars and sometimes Mercury- in fact it's Mercury that is closest on average. If you take a snapshot at points in time it is Mercury that is closest most often in terms of distance from Earth

[jno]

"Mercury is on average the closest planet to the Earth: it is closest to Earth 46% of the time; Venus is closest 36% of the time, while Mars is closest just 18% of the time."

https://en.wikipedia.org/wiki/Mercury_(planet)

[jim360]

Well, to be fair, I didn't know that bit :)

[fiction-factory]

Thanks jno. I'd have said Venus or sometimes Mars but once you hear the answer and/or explanation for Mercury it makes sense. It comes from seeing all those diagrams with the planets all lined up ina straight line from Mercury to Neptune (or Pluto for us oldies).
https://www.bbc.co.uk/programmes/p06xvkjc

[douglas9401]

It varies then, like Easter thus proving the existence of God and Jesus, the resurrection and Noye's Fludde and that intelligent design roolz.

The clues have been there for millenia.

[nailit]

Can any one here (cough, cough, JIM) explain to me the following?
When we see visual representations of the planets orbiting the sun, (on a poster for instance) they all appear on the same line. Like they are all orbiting the suns equator. Wouldn't they (in reality) be orbiting in all different directions. Some horizontal, some vertical, some diagonally , some north to south, others east to west etc?


Always been curious about this. Thanks.

[EDDIE51]

Mercury is classed as a 'Dwarf' planet . It is actually thought to be an asteroid captured by The Sun's gravity.

[Theland]

Yes they all appear in the same plane.

[Old_Geezer]

Ignoring captured ones, the cloud of gas from which they formed will have been rotating in a single plane, in the same direction. Collisions after formation may make some orbits more off centre than others though.

[jim360]

All planets are more or less orbiting in the same plane, and all of them go anticlockwise round the Sun, so there is in fact some regularity. The smaller objects aren't quite so reliable.

The reason for this is that the planets will have been formed from material that collected into a disc (rather than just some blob).

[Old_Geezer]

Anticlockwise. Are you looking from above the sun ? Or from below it ?

[New Judge]

Yes, the planets do orbit the sun in near enough the same plane. Here's an explanation why:

https://www.physlink.com/education/askexperts/ae588.cfm

[nailit]

Thanks for that O-G and jim.
Always wondered if these visual representations were just a simple way of describing orbits but apparently they were accurate descriptions.
Thanks again.

[nailit]

Thanks for link NJ.

[jim360]

Haha, good point. From above, OG.