A satellite in a high enough orbit can remain operational for a very long time because in space there is practically no air resistance. This is a situation that never occurs in our everyday life. A car requires a constant consumption of fuel to keep running, but a satellite can remain in motion without consuming any fuel because there’s practically no force stopping it.
Flat-Earthers claim that satellites cannot stay up there for such a very long time because ‘we never refuel any satellites.’ They are wrong. In space, there is practically no drag, and satellites only need to consume fuel to adjust their speed periodically.
Continue reading “Orbital Station-Keeping”
The orbit of the Earth and that of the Moon are not perfectly aligned in the same plane. The orbital plane of the Moon is inclined 5.145° from the Earth’s orbital plane. This is the reason an eclipse does not happen every month.
Sometimes we see flat-Earthers claim that an eclipse should happen every month. But it does not, and they take that as ‘evidence’ of the failure of modern science to explain the occurrence of an eclipse. Their mistake is that they don’t account for the orbital inclination.
Continue reading “Orbital Inclination: The Reason an Eclipse Does Not Occur Every Month”
Jupiter possesses four large moons: Io, Europa, Ganymede, and Callisto. These are called the Galilean Moons. They are easy to observe and the first objects found to orbit a planet other than the Earth.
Flat-Earthers are often seen demanding proof that an object can orbit another object. All they have to do is to use a telescope to observe Jupiter and its Galilean moons.
Continue reading “Galilean Moons: The First Objects Observed to Orbit Another Object”
The directions of up and down are determined from the direction of the Earth’s gravitational acceleration. Up is in the opposite direction, and down is in the same direction as the Earth’s gravitational acceleration.
Flat-Earthers are often seen making fun of this fact. They show us ‘upside down’ pictures taken in the southern hemisphere. They are wrong. To anyone in the southern hemisphere, down is in the same direction as the Earth ‘s gravitational acceleration, the same as anyone in the northern hemisphere.
Continue reading “The Directions of Up and Down”
If Earth’s gravity pulls everything towards the Earth, then how can satellites stay up there and are not falling towards the Earth?
The answer is that satellites orbit the Earth. They have the correct velocity with respect to Earth’s position and gravitational pull.
Continue reading “How Satellites Can Orbit and Stay Up There”
A satellite can be placed in an orbit 35786 km above Earth’s surface, and the satellite will be in motion at the same speed as the rotation of the Earth. As a result, the satellite will appear practically motionless when observed from the surface. Many communication satellites are placed in this orbit, and a satellite dish receiving signals from the satellite doesn’t have to track the satellite.
Flat-Earthers often take the fact that satellites are in motion and most satellite dishes have a fixed direction as ‘proof’ there’s something suspicious about satellites. They are wrong.
Continue reading “Geostationary Satellites”
Every time we see a rocket launch, its trajectory is always curved, never straight up. Why would they do that? Aren’t they supposed to go up to space?
No, it is not because they have malicious intentions, as implied by a lot of flat-Earthers.
The curved trajectory is what we call the ‘gravity turn’.
Continue reading “Curved Rocket Trajectory”
“So, where’s the curvature? If we can’t see it using our own eyes then there’s no curvature, and hence, the Earth is flat!”
That’s a very common position held by most flat-Earthers. So, let’s do some simulation to show that the condition they are demanding is completely unrealistic. We’ll be using the excellent curvature simulation tool by Walter Bislin.
Continue reading “So, Where’s the Curvature?”