If earth is geoid and every moon and planet are not a perfect sphere, why do NASA images show an exact circle?

 Okay, so let's take a look at the most famous picture of Earth that NASA ever took.

This photo has been compressed by Quora for display purposes, but my original image says it's 3000 x 3002 pixels. Let's say there are roughly 20–25 pixels of blackness on each side, that gives us an image size of roughly 2950 x 2960 for the Earth. Let's divide 7,901 miles by 2950. That gives us a visual scale of roughly 2.7 miles per pixel. That would make Mount Everest about 2 pixels tall, should be right there at the upper right. That scale would make the equatorial bulge about 5 pixels on either side!

Do you see the problem now? This photo from NASA shows the Earth as a nearly perfect sphere because it is! The variations from perfectly spherical are far too tiny to see at this scale. You're trying to see lumps and bumps less than a couple of pixels in size. You're looking for ten pixels of total bulge at the equator.

You can't see such tiny variations! You could easily measure them in Photoshop, but you can't see them on this screen.

This photo was taken from 18,300 miles away. From that distance, the Earth appears to be a nearly perfect sphere.

8 Days To 9 Months

 

• 286 days in space, 4577 orbits around the planet and flying over a distance spanning 195.2 million kilometres, Nasa astronaut Sunita William has safely returned home.

• The astronaut, who went on an eight-day mission to space with fellow astronaut Butch Wilmore, was forced the stay in zero gravity for nine months after the Starliner spacecraft she piloted to space developed multiple technical faults.
• They splashed down off the coast of Florida aboard a SpaceX Crew Dragon capsule Tuesday around 5:57 p.m. ET.
• Bone and muscle deterioration, radiation exposure, and vision impairment are some of the challenges space travelers have to face upon their return to Earth after a prolonged stay.
• One of the most dangerous impacts of spending time in space is radiation exposure.
• "We discussed how proud we are of you and your work. Following this interaction, I could not stop myself from writing to you," —-PM Modi said.