Re: Is Mars, Venus, Mercury etc flat too?
« Reply #20 on: December 20, 2016, 05:19:07 AM »
personally I do think they look like flat disks through a telescope, and until I see them any closer, thats what im gonna stick with

*

Offline rabinoz

  • *
  • Posts: 1441
  • Just look South at the Stars
    • View Profile
Re: Is Mars, Venus, Mercury etc flat too?
« Reply #21 on: December 20, 2016, 09:09:56 AM »
personally I do think they look like flat disks through a telescope, and until I see them any closer, thats what im gonna stick with
Just how do you explain the big changes in the apparent size of Venus and the fact that it displays phases just like the moon. You do need a telescope to see this, but even Galileo saw it with his small telescope. Here is a set of more modern photos.

Phases of Venus. Image credit: ESO
Quote from:  Fraser Cain
Phases of Venus
Even in ancient times, astronomers knew that Venus changed in brightness in the sky. Sometimes it’s like a dim star, and other times it becomes the brightest object in the sky (after the Moon); bright enough to cast shadows. But it wasn’t until Galileo first turned his rudimentary telescope on Venus in 1610 that astronomers first realized that Venus goes through phases, just like the Moon.
            
Think about the orbit of Venus for a moment. As you know, Venus orbits closer in to the Sun than Earth. One half of the planet is always in sunlight, and the other half of the planet is in shadow. It’s our view of Venus that changes. Sometimes we see Venus on one side of the Sun, and other times we see it on the other side. We can never see when Venus is completely illuminated because that’s when it’s on the opposite side of the Sun. We also can’t see when it’s completely in shadow because then it’s in between the Earth and the Sun, and the Sun obscures Venus from our view.
From Astronomy, Guide to Space, Phases of Venus

That looks like what we would expect from a sphere, not a flat disk.