Planets question - probably missing something obvious

Planets question - probably missing something obvious

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WhisperingWasp

Original Poster:

1,574 posts

144 months

Friday 21st February 2020
quotequote all
Hi all.

Have a question about the planets which probably has a logical answer but for the life of me I can't figure it out. Tbh I'm probably just being a bit thick and missing an obvious explanation.

I'm looking out of my window at Venus and loaded my app up to confirm that it was what I thought. I then notice that every planet is on exactly the same axis. From top to bottom it is Uranus, Venus, Neptune, Mercury (very slightly off line), (the sun), Saturn, Pluto, Jupiter, Mars.

This strikes me as being unusual/a coincidence but given ALL the planets are along the same line I'm now thinking there must be a logical explanation...

So why is this so? Why aren't the planets "dotted about"? Why aren't some behind me?

Please enlighten me and make me kick myself!

Cheers.

Edited by WhisperingWasp on Friday 21st February 20:15

Eric Mc

122,856 posts

272 months

Friday 21st February 2020
quotequote all
Some may very well be "behind you".

But you have noticed something quite fundamental to the Solar System, all of the planets and most of the moons and asteroids all orbit the sun along the same plane. This plane is actually called The Ecliptic.

When the solar system formed 4.5 billion years ago, it evolved out of a flat disc of dust and gas. As a result, most of the objects in the solar system lie along the plane of that old disc. There are some exceptions.

Here is a diagram which shows how the planets lie along this plane. There is some deviation but on the whole, the planets are more or less aligned with the sun's equator.




cherie171

367 posts

124 months

Friday 21st February 2020
quotequote all
It's called a conjunction. As I'm sure you're aware all the planets in our system rotate around the sun on a mostly flat plane, and due the different lengths of their orbits, it's rare that they're all on the same side of the sun at the same time.

RSTurboPaul

11,270 posts

265 months

Friday 21st February 2020
quotequote all
Eric Mc said:
Some may very well be "behind you".

But you have noticed something quite fundamental to the Solar System, all of the planets and most of the moons and asteroids all orbit the sun along the same plane. This plane is actually called The Ecliptic.

When the solar system formed 4.5 billion years ago, it evolved out of a flat disc of dust and gas. As a result, most of the objects in the solar system lie along the plane of that old disc. There are some exceptions.

Here is a diagram which shows how the planets lie along this plane. There is some deviation but on the whole, the planets are more or less aligned with the sun's equator.

I had to look up what 'Bennu' is - fascinating!

Amazing that we've been able to get a probe to track it, photograph it, and try and land on it.
https://en.wikipedia.org/wiki/101955_Bennu

RSTurboPaul

11,270 posts

265 months

Saturday 22nd February 2020
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If only Pluto hadn't been downgraded from a Planet!

https://en.wikipedia.org/wiki/Pluto


Einion Yrth

19,575 posts

251 months

Saturday 22nd February 2020
quotequote all
RSTurboPaul said:
If only Pluto hadn't been downgraded from a Planet!

https://en.wikipedia.org/wiki/Pluto

It's still a planet, it's just been granted the adjective "dwarf" as a badge of honour.

Eric Mc

122,856 posts

272 months

Saturday 22nd February 2020
quotequote all
One of the reasons why its status was changed was partly because of its tilted orbit.

WhisperingWasp

Original Poster:

1,574 posts

144 months

Saturday 22nd February 2020
quotequote all
Thanks for the replies all.

Fully understand the same plane thing - thank you.

Think what surprised me was how close they all were. If I held my phone at arm’s length I had to move the screen 3-4 feet to capture all the planets.

Let’s just say I was covering 10 degrees. There was another 350 degrees of the plane that none of the planets were in?!

Eric’s picture above shows that they could look close together from our perspective but be very far apart (understatement I know!) but as I say why were they all in “that direction”? How comes none were orbiting behind us? Particularly given most planets are farther out than us.

WhisperingWasp

Original Poster:

1,574 posts

144 months

Saturday 22nd February 2020
quotequote all
Sorry just re-read my OP and it wasn’t very clear.

Further to my last reply let’s just say I was standing up and the plane of the planets was perpendicular to me (so a horizontal disc as such). Using a clock face to make the point how comes all the planets were between 12 and 1 (say) and none 2 o’clock, 3 o’clock up to 11 o’clock?

Eric Mc

122,856 posts

272 months

Saturday 22nd February 2020
quotequote all
There will be occasions where all the planets are lined up in such a way that they are visible in the night sky, although only Mercury, Venus, Mars, Jupiter and Saturn are actually visible to the naked eye. Uranus and Neptune were discovered by telescopic observations (1781 and 1841 respectively).

There will be occasions when the planets further from the sun than earth (Mars, Jupiter, Saturn, Uranus and Neptune) are "behind us". Don't forget that the earth rotates on its axis so even though a planet may be behind you, within any 24 hour period, the earth will rotate so you may get to see that planet that was "behind" you later on if you are willing to hang around long enough. What will perhaps prevent you seeing a planet is the fact that it may be above your local horizon during daylight hours. So, technically you could see it if only it wasn't for the sky being so bright.

V8LM

5,265 posts

216 months

Sunday 23rd February 2020
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Ratios of planetary orbital periods fall close to the Fibonacci series so are approximately Golden in ratio, hence synodic conjunctions happen (almost) as infrequently as possible - http://www.pattern-recogn-phys.net/1/185/2013/prp-...

Lynchie999

3,469 posts

160 months

Sunday 23rd February 2020
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Ive just finished reading "The Secret Life of Planets" book ... pretty much explains everything in this thread!

AshVX220

5,933 posts

197 months

Monday 24th February 2020
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RSTurboPaul said:
Eric Mc said:
Some may very well be "behind you".

But you have noticed something quite fundamental to the Solar System, all of the planets and most of the moons and asteroids all orbit the sun along the same plane. This plane is actually called The Ecliptic.

When the solar system formed 4.5 billion years ago, it evolved out of a flat disc of dust and gas. As a result, most of the objects in the solar system lie along the plane of that old disc. There are some exceptions.

Here is a diagram which shows how the planets lie along this plane. There is some deviation but on the whole, the planets are more or less aligned with the sun's equator.

I had to look up what 'Bennu' is - fascinating!

Amazing that we've been able to get a probe to track it, photograph it, and try and land on it.
https://en.wikipedia.org/wiki/101955_Bennu
I've just read the wiki on that as well, as I hadn't heard of it before and it is fascinating. Not only have they predicted it's closest approach and given it odds of an impact, but for the closest approach they've put it closer to earth than the moon, so I guess that not only is there risk of impact with earth (though un-likely) there's also risk of impact with the moon.....and if that happens would that have almost as bad ramifications for earth?

Eric Mc

122,856 posts

272 months

Monday 24th February 2020
quotequote all
No.