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”
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”
Iridium is a satellite constellation consisting of 66 satellites. It provides satellite phone services over the entire Earth surface. The first generation satellites have three door-sized reflective antennas. Because of their reflectivity, Iridium satellites will occasionally reflect sunlight to Earth’s surface. The Iridium flare will look like a bright flash over a few seconds.
Most flat-Earthers deny the existence of satellites. Iridium flares provide an easy opportunity to confirm the existence of satellites, at least until the end of 2018, when they are replaced by newer non-reflecting satellites.
Continue reading “Iridium Flare”
“If satellites really exist, then why would mobile phone operators bother to install transceivers everywhere?” Flat-Earthers ask this question a lot.
Their logic is that if using a satellite can get you a huge coverage area, then spending a lot of money and effort to install towers everywhere does not make any sense. Usually, they would follow-up and conclude that “satellites don’t exist”.
They are wrong. Satellites do exist, and there are good reasons why mobile phone communication utilizes cellular architecture.
Continue reading “Celullar Network vs. Satellite Communications”
The GPS system is one-way. The satellites broadcast signals. GPS devices receive and process the signals to determine their location.
Flat-Earthers often point out the fact we were unable to locate the ill-fated MH370 as ‘evidence’ GPS doesn’t work and therefore doesn’t exist. They are wrong. GPS satellites never receive any signal from GPS devices, and it is not possible for them to locate MH370.
Continue reading “The MH370 Disaster and the Inability of the GPS System to Locate It”
How much of Earth we can see at once depends on our distance from the Earth. The closer we are to the surface of the Earth, then the smaller part of the Earth we can see at once. Conversely, the farther we are from the Earth, more of the Earth are visible to us.
The difference in the size of North America in these pictures relative to the size of the Earth is often presented as “evidence” that we have been lied to. In reality, it is simply a perspective effect. The pictures are taken from a different distance from the Earth and with a different camera field of view.
Continue reading “The Size of North America in Pictures of the Earth Taken From Space”
“Why don’t we see satellites in photos taken from the ISS?” (or from space in general). That’s a recurring question within the flat-Earth community, usually asked without expecting an answer, assuming that an answer is impossible, and that it is a glaring oversight when the powers that be purposefully made the picture using CGI.
But no, the pictures are real. And satellites are not visible because they are too far spaced apart from each other.
Continue reading “Why Don’t We See Satellites in Photos Taken From The ISS?”
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”
Thermosphere is a layer of the Earth’s atmosphere from about 95 km to 600 km. It is named ‘thermosphere’ because its temperature increases with altitude. Temperature in the thermosphere can reach 2500°C.
Flat-earthers question this fact a lot:
“If temperature in the thermosphere can reach 2500°C, then how is it possible for human to travel to space? Not to mention that many satellites —including the ISS— are in the thermosphere.”
Short answer: air density in the thermosphere is much, much lower than at the surface of the Earth.
Continue reading “Space Flight and Temperature In The Thermosphere”