Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Mariana on 04/02/2019 12:20:17

Title: What made the Earth tip on its axis?
Post by: Mariana on 04/02/2019 12:20:17
Elenore wants to know:

What made the Earth tip on its axis? Are other planets also tilted?

Can you help figure this out?
Title: Re: What made the Earth tip on its axis?
Post by: yor_on on 04/02/2019 13:52:46
Deopends on what we look at. Seems as if Earth really have tilted completely some eight hundred million years ago according to https://www.princeton.edu/news/2006/08/25/planet-earth-may-have-tilted-keep-its-balance-say-scientists?section=newsreleases. A real surprise if it is correct, but then you have the ice loss at both the Arctic and the Antarctic that we see now, it also 'tilts' our Earth. https://cosmosmagazine.com/geoscience/why-is-earth-s-axis-shifting, If we now add that that IPPC (The Intergovernmental Panel on Climate Change) never get the acceleration right, from publication to publication, then we're moving towards really interesting times.  https://www.sciencenewsforstudents.org/article/antarcticas-melting-speeds

Then you just need to take a look each year of how much fossil energy we 'burn' to see if the trend turns.  And the last link should be the one that's closest to the truth when it comes to the ice loss. Let's add this one for the Arctic and Greenland so we get a better look at the ice loss rate we're looking at now. https://www.nytimes.com/2019/01/21/climate/greenland-ice.html
Title: Re: What made the Earth tip on its axis?
Post by: Halc on 04/02/2019 14:58:18
The tilt of most planets probably has to do with the original angular momentum of the material from which the planet formed.  Earth may well be an exception to this since it appears to have taken an almighty hit some 4.5 billion years back, and no evidence remains as to what our tilt might have been before that hit.

Mercury has no effective tilt, but all the other planets do.  Jupiter is most 'upright' with a 3 degree tilt.
Our tilt is similar to that of Mars, Saturn, and Neptune.  Saturn incidentally also has the most similar gravity.  Your weight there is closer to Earth weight (only ~8% higher) than it is on any other planet.

Uranus is tilted at 98%, meaning it is close to sideways, and for decades at a time, the sun shines only on one side of the planet when one of the poles faces that way.
Venus tilt is just shy of 180% so it is upside down.  It rotates so slowly that if it was right side up, its day would be longer than its year.
Title: Re: What made the Earth tip on its axis?
Post by: acsinuk on 04/02/2019 23:22:35
Could be to do with the position of the moons rotations which are locked magnetically to their host planets by our star. The sun sees the planet/moon combination as a single unit, a single target for its solar wind particles and electromagnetic energy.
Title: Re: What made the Earth tip on its axis?
Post by: chiralSPO on 05/02/2019 00:37:12
Could be to do with the position of the moons rotations which are locked magnetically to their host planets by our star. The sun sees the planet/moon combination as a single unit, a single target for its solar wind particles and electromagnetic energy.
no
Title: Re: What made the Earth tip on its axis?
Post by: yor_on on 05/02/2019 09:57:42
Seems as if they have made some progress testing 'polar wander' in Australia. Although?

Shouldn't it be more said about it for 2019? http://geoweb.princeton.edu/people/maloof/tpw.html from 2006 as well as https://www.princeton.edu/geosciences/people/maloof/papers_pub/36Maloof.pdf from 2012.