Which way are we tilted?

[RobF (Rob)]

I hate to confess it but for ages I've realised I need to read up which way the earth spins, direction of our orbit around sun, which direction earth is tilted at various points of earth's orbit.
Have rectified that sorry state of affairs today courtesy of a few websites. This one was particularly helpful.

It's bugged me long enough I can't visualise it all properly when I'm gazing up at night through the ecliptic and out into space. Imagine how hard it was for most of man's existence on Earth.


Anyway, on the 3rd of January we'll be at Perihelion (closest distance to Sun) with the Southern hemisphere baking with the sun high overhead. From "above" the solar system, the earth will be tilting directly away from the sun. Hope link above is of value to someone else too.

[Robh (Rob)]

The actual orbit of the Earth around the Sun (ecliptic) is tilted at about 60 degrees to the galactic plane.
The Earth's axis remains essentially tilted in the same direction relative to the galaxy (ignoring precession of course). Thus, the Earth's axis stays pointed to the north and south celestial poles and that is why objects generally can be given fixed celestial co-ordinates. The cycle of axial precession for the Earth takes about 26000 years, the orbit of the Sun around the galaxy takes some 225 million years. Precession will require noticeable change of celestial coordinates (one degree about every 72 years), while the coordinates of extra galactic objects will change minutely over time relative to galactic objects (one arcsecond about every 174 years).

Regards Rob

[RobF (Rob)]

Thanks Rob for the extra info on galactic orientation. Now I think back, it was in winter as I was gazing at the galaxy overhead at Qld Astrofest and then started to try and visualise the ecliptic and our orientation to the sun that this train of thought originally started.

How different our existence would be if any one of these things was a bit different (assuming we were stil around of course )

[bartman (Bart)]

Thanks RobF and RobH,
That has always been a question of interest for me too. Especially our orientation tho the Galactic plane....
Cheers
Bartman

[Barrykgerdes]

Whether the Earth is tilted or upside down is all a matter of relativity. We on Earth experence orientation based on gravity and relate everything to this eg if you are at the north pole the Earth spins CCW but on the south pole it spins CW (I think that is the way).

For scientific purposes we have based everything on an imaginary plane that we call the ecliptic (I think) that is the plane of the path the Earth follows around the Sun.

Barry