Why Venus looks so much brighter than Jupiter.

Why Venus looks so much brighter than Jupiter. (This is something I don’t usually think about, but over the past month, with the two planets in the same area of the sky, I’ve really noticed it.)

Originally shared by Philip Plait (The Bad Astronomer):

Venus still blazes Jupiter, but 10 times as bright

Venus and Jupiter are still near each other in the sky, and will be for the next few days. Just go outside after sunset and face west; you can hardly miss them!

Venus is the brighter of the two by a long shot. That might seem weird; after all, Venus is about the same size as Earth, but Jupiter is over 11 times wider (and 140 times the area)! So why is Venus brighter?

Math! At least, math + geometry + science. Let me show you…

Jupiter and Venus still blaze in the west

[Image credit: Robert Blasius at fotografie.robert-blasius.de as part of Astronomers Without Borders]