Perihelion today

[von Tom (Tom)]

The Earth was at perihelion today. I managed just 2 cloud free images. Here is one side by side with a shot at Aphelion 6 months ago at the same focal length (1500mm).

Tom

[Dennis]

Nice work Tom – I love these very visual representations that so vividly reveal the often hidden dynamics of our solar system. 10 out of 10 for finding the cloud free holes!

Cheers

Dennis

[Derek Klepp]

Thanks Tom

[astronobob (Bob)]

Nice work Tom, can note the size difference re 5 mill odd Ks closer with the 2nd ?

[deanm (Dean)]

Very nice!

I pasted your image into a graphics application and measured the apparent diameters North-South and East-West.

The size difference (in both orientations) between Aphelion and Perihelion images is almost exactly 1 percent.

This corresponds very well with the actual difference in earth-Sun distance - 1 percent!

Dean

[multiweb (Marc)]

Excellent montage - very cool post.

[John Hothersall]

Thats a great project for a forgotten fact about Earth's orbit, difference is obvious.

John.

[Clayton]

Nice one Tom

[von Tom (Tom)]

Thanks for the comments everyone. Dennis I was determined to get the perihelion Sun that day those clouds weren't going to stop me!

Dean I tried the measurement myself (about) 576 pixels/596 pixels = 96.6%
147.1 million km/ 152.1 Million km = 96.7%

I didn't really know how the comparison would look when I took the second pic and I'm glad it seems to be consistent! I had fun trying to work out how best to display it too.

Cheers,

Tom

[RobF (Rob)]

I really enjoyed seeing this Tom - this sort of work really broadens our minds to the realities of our orbit. Amazing just how small the apparent change is. Thanks for sharing.

[Paul Haese]

An excellent representation. I did something similar with the moon years ago; all on slide film. You might like to try that one next.

[von Tom (Tom)]

Thanks Paul - I got full Moon images at apogee and perigee from last year and I'm working on it

Tom

[mswhin63 (Malcolm)]

Well done. Nice to see basic science and arithmetic evolving from these images

[deanm (Dean)]

Tom: our percentage figures appear to differ, but actually don't (mathematically): it just depends on whether the larger number is divided by the smaller, or vice versa...!

Dean

[von Tom (Tom)]

Hi Dean, I understand. There's many ways to measure and calculate. I'm just glad my images are consistent with what's expected