## Predicting Satellites’ Visibility

The orbital parameters of most satellites (the TLE data) are freely available, and we can use them to predict the visibility of the satellites. The following is a very simple Python script to predict the visibility of the ISS for the next few weeks.

Flat-Earthers invented many “explanations” about the visibility of satellites. By studying the satellites’ orbital parameters and how they can be used to predict the visibility of the satellites, we know that flat-Earthers’ claims are just nonsense.

## Galilean Moons: First Objects Observed to Orbit Another Object

Jupiter has four moons (Io, Europa, Ganymede, & Callisto) that we can easily observe using a binocular or telescope. They are the first objects found to orbit another, proving it is possible for a satellite to orbit planets other than Earth.

Flat-Earthers like to demand evidence of an object orbiting another. All they have to do is use a telescope to observe Jupiter. Its moons have short orbital periods (1.8 to 16.7 days), & thus, it is not hard to observe the orbiting motion.

## Satellites in Earth’s Photos

A satellite’s size is as small as a mobile phone to as large as a football field. The largest is 109 m, still far too small compared to Earth at 2742 km in diameter.

Satellites are not visible in Earth images. Flat-Earthers use the fact as “evidence” of deception. In reality, satellites are tiny compared to Earth. They are invisible in Earth images the same way ants are not visible in images of a football field.

## Satellite Tracking Apps and the Two-Line Element Set Data (TLE)

The orbit of an Earth-orbiting satellite is often described using two-line element set (TLE) data. From the TLE data of a specific satellite, we can determine its position at a certain time.

Flat-Earthers discovered that changing their device’s time will cause satellites’ positions to change in some satellite tracking apps, and they use it as “evidence” of wrongdoing. In reality, these apps work by getting the TLE data from the Internet periodically and then using the data to calculate the satellites’ positions in the app itself. Therefore, these apps depend on the accuracy of the devices’ time.

Unlike what these flat-Earthers imagine, these apps do not work by receiving telemetry data from the satellites in real-time.

## How Satellites Can Orbit and Stay Up There

Earth’s gravity pulls things toward Earth. Satellites can stay up there because they are orbiting. They are moving at the right speed and right direction to counter the pull of gravity.

Flat-Earthers claim that satellites should fall down if gravity pulls toward Earth. In reality, we do not just launch satellites to space. We also give them the correct speed & direction, so they neither fall toward Earth nor keep going farther away.

Flat-Earthers noticed “mysterious” wandering vehicles with a Google branding and strange equipment mounted on them. They use the fact as “evidence” that Google Maps does not use satellites to obtain the images. In reality, these vehicles record images for Google Street View. It is impossible for street-level
vehicles to obtain the aerial images used by Google Maps.

## Cellular Network Backhaul

In cellular telecommunications, backhaul is the connection between a base transceiver station and the core network. The means of the connection can be anything, including cable, fiber optic, microwave links, and satellite links.

Flat-Earthers use the fact that cell phones communicate with base stations as “evidence” satellites do not exist. In reality, some cellular companies do utilize a satellite for backhaul purposes, especially for stations in remote, isolated areas.

## Satellite Watching

We can observe satellites with the naked eye, and they will appear like fast-moving stars across the sky. The required conditions: the satellite is large enough and/or close enough, the sky is dark enough, and the satellite is lit by the sun. As a result, the best time to observe satellites is a few hours before sunrise and a few hours after sunset.

Flat-Earthers claim it is impossible to see satellites and use the fact as “proof” the satellites do not exist. In reality, we can observe the satellites even with the naked eye. Apps and websites like heavens-above.com provide us with information on satellite watching opportunities.

## Why It is Difficult for Satellites to Locate the Missing MH370 Flight

If many satellites provide navigation and surface imagery, why is it challenging to locate the missing MH370 flight?

Satellite navigation, including GPS, is passive. Satellites emit signals, which are processed by receivers —including those on board the MH370— to determine their own locations. The satellites never receive anything from MH370 and cannot determine its location.

Airliners do broadcast their positions using ADS-B. However, at the time of MH370, only ground-based ADS-B stations existed. There were no satellite-based ADS-B receivers yet, and no coverage in the middle of oceans.

## Cellular Network vs Satellite Communications

A cellular network consists of several cells. Each of the cells is serviced by a base station operating with a specific frequency. Adjacent cells are each assigned a different frequency. A non-adjacent cell will be able to use the same frequency without interfering.

Flat-Earthers like to tell us that a single satellite can cover an entire country, yet phone operators choose to install base stations everywhere instead. Then they use the fact to “prove” that satellites do not exist. In reality, a cellular network has several advantages compared to one single base station, like a satellite.

## Where’s the Curvature?

A human eye can only visually perceive the curvature of the Earth if we are at a considerable altitude from the surface, which is still beyond the reach of most humans today. A commercial jet airliner is the highest position realistically attainable by most humans today. We can only perceive very slight curvature at such altitude and, even then, only in an ideal condition.

The basis of flat-Earthers’ belief is that the horizon appears flat. They would say if we cannot see the curvature, then there’s no curvature, and therefore, the Earth is flat. In reality, only a few people can travel high enough to see the curve.  The highest we can realistically go is by getting on a commercial jet airliner, which can only go about 11-15 km up, only a fraction of Earth’s radius.

## Sun Outage

A Sun outage is a disruption of geostationary satellite signal caused by interference of the sun when it falls directly behind a satellite with which a receiver is communicating. Sun outages occur around the March equinox and September equinox.

Flat-Earthers fail to understand how the schedule of a Sun outage depends on the satellite and the receiver’s location. And they use it to discredit the fact. In reality, it is not difficult to visualize how a Sun outage occurs, and it will be consistent with the expectation.

## Perspective of Earth Due to Different Observer Distance

Because of a perspective effect, an observer in space can see more of Earth’s surface if they are farther from Earth.

Flat-Earthers noticed the different visible Earth’s surface in different Earth images and used it to “prove” they are fake. In reality, it is just a perspective effect caused by the fact that the Earth was seen from a different observer distance.

## Balloon Satellites

In the context of spaceflight, a satellite is an object that has been placed into orbit. A few of these satellites are balloon satellites. These are satellites that are inflated with gas after they have been put into orbit. Other human-made objects are also called satellites, only placed at a much lower altitude and with a very different operating method. These are, in fact, regular high-altitude balloons but providing services traditionally provided by orbiting satellites.

Flat-Earthers deny satellites’ existence, and after they discovered the existence of balloon satellites, they started to use the fact as “proof” that orbiting satellites do not exist. It is a fallacy of proof by example. By the same “logic”, we can use the existence of trucks to “prove” buses do not exist.

## Curved Appearance of a Rocket Trajectory

Rocket launches have a curved trajectory because their objective is not only to reach space but also to enter Earth orbit. To achieve it, a spacecraft needs to gain a sufficient horizontal speed, parallel to Earth’s surface.

Flat-Earthers claim the curved appearance of a rocket launch trajectory “proves” rockets never reach space. In reality, it is caused by the motion of the rocket parallel to Earth’s surface, perspective effect, and the curvature of the Earth.

## Fiber-Optic vs Satellite Communication

Fiber-optic communication is a method of transmitting data by sending pulses of light through an optical fiber. These days, the majority of data communication involves a fiber-optic connection. However, other methods of transmitting data exist, including satellites.

Flat-Earthers use the prominence of fiber-optic communication as “proof” of the nonexistence of satellites. Such reasoning is a fallacy of hasty generalization. By the same “logic,” we can “prove” trains do not exist just by showing the existence of cars.

## Geostationary Satellites

If a satellite is placed in an orbit 35786 km above the equator, it will be in motion at the same speed as the Earth’s rotation. As a result, the satellite will appear practically motionless from an observer on Earth’s surface. Many communication satellites are in this orbit so that a satellite receiver does not need to track the satellite continuously.

Flat-Earthers often take the fact that satellites are in motion, and most satellite dishes have a fixed direction as ‘proof’ the receivers cannot be pointing to satellites. In reality, it is possible to place a satellite in a geostationary orbit to make it appear in a fixed position in the sky relative to an observer on Earth.

## Satellite Phones and Cellular Phones

Cellular phones communicate with cell base stations, and cannot work without cell base stations nearby. On the other hand, satellite phones communicate with satellites and will work in remote locations as long as there is a line of sight to the satellites.

Cellular phones do not function in a remote location, and flat-Earthers use the fact as “proof” that satellites do not exist. In reality, nobody claimed that cellular phones communicate with satellites. The phones that communicate with satellites are called satellite phones, and they still function in a remote location.

## Google Maps Live Traffic and Simon Weckert’s Virtual Traffic Jam

Google Maps live traffic works by crowdsourcing. It determines the current traffic by aggregating information sent by many phones carried by many different traveling users.

In February 2020, artist Simon Weckert successfully gamed the system and faked a traffic jam in Google Maps. He did that by pulling a cart full of active phones and walking in the middle of roads. Google Maps system thought there were many slow-moving cars on the road and regarded that as a traffic jam. As a result, during Simon’s operation, an empty road appeared as dark red in Google Maps, as if a traffic jam was ongoing.

Flat-Earthers claimed that it proves that satellites do not exist; possibly because they did not know how the system works. It might be that they previously thought the traffic data was obtained directly from satellite imagery. In reality, satellite navigation systems, like the GPS, is very much involved in the system.