Why do Saturn and Jupiter look so similar in size right now, despite Saturn being so much further away?


I consider myself a fairly intelligent, college-educated individual, but lately, I’m seeing all these telescopic photos of the Jupiter/Saturn conjunction, and I’m confused as to how the two planets have close apparent sizes. How is this so, despite Saturn being millions of miles further away?

In: Physics

Can you link one of these pictures where they’re about the same size? Because all the pictures I see doing a search shows Saturn considerably smaller than Jupiter, as you’d expect.

They aren’t the same size if you only count the planet itself, Saturn is noticeably smaller than Jupiter in the sky. However Saturn also has it’s rings which are very large, if you include them in your measurement then it is nearly the same size as Jupiter in the sky.

|Planet|Minimum Size/ arcseconds|Maximum Size/ arcseconds|
|Saturn + Rings|33 ish|44 ish|

Maybe “close apparent sizes” is not what I meant to say. I think what is confusing to me is that, in the same photo (that is, at the same magnification), both planets are quite clearly visible. This surprises me, because with Saturn being almost twice as far away, and smaller than Jupiter, I wouldn’t expect it to be as visible as Jupiter at the same magnification.

Here is the image that prompted this post:


(Also, yes, I realize that this is a composite shot, as they are not currently, this close, but they were supposedly taken at the same magnification and just moved closer together in post)

The distance from Earth to Saturn is currently about twice the distance from Earth to Jupiter, and Saturn is roughly the same size as Jupiter. Taking these two factors into account, I’d expect Saturn to currently appear to be roughly half the size of Jupiter in the night sky. This is consistent with what’s in the image.