Flat or Spherical Earth? Evaluating Astronomical Observations [Part II]

[Editor’s Note: A.P. scientist Dr. Branyon May holds a Ph.D. degree in Astrophysics from the University of Alabama. Alana May, his wife and co-author, holds an M.S. in Astrophysics from the University of Alabama. Part I of this two-part series appeared in the August issue. Part II follows below, and continues, without introductory comments, where the first article ended.]

Evaluating First-Hand and Photographic Evidence

First-Hand Evidence

In 1961, the Soviet Union shocked the world by sending the first man into space, Yuri Gagarin. This was not only the first manned flight into space, but the first to orbit Earth. Since that time, more than 500 professional astronauts representing 40 countries have traveled into space as pilots, commanders, or crew members of manned spaceflight programs.1 The three countries from which these astronauts have been launched include the United States, Russia (previously the Soviet Union), and China. It is important to note for those who might consider conspiracy theories that over the years of space travel, the three countries providing the launch abilities have had tentative and even hostile relations. Yet, even though the over 40 countries who have sent astronauts into space disagree on politics, religion, and economics, their recognition of a spherical Earth that is able to be orbited and studied is consistent.

Each of these countries has been fortunate enough to send select men and women to space as first-hand observers and scientists to gather data from above the Earth’s atmosphere. With more than 50 years of time and over 500 first-hand observers from over 40 countries, the view of Earth as a majestic globe has not been refuted or even brought into question by these individuals. While some may claim a Flat-Earth view, their arguments do not include spaceflight testimony from first-hand observers.

Photographic Evidence: Full-Disk Imagery

While there are many amazing and beautiful images of our Earth provided by the National Aeronautics and Space Administration (NASA), we want to first focus on the photographic evidence available from numerous international sources. The following collection of photographic evidence only includes imagery from full-planet views of Earth. As you will see, the sources of these images come from a range of satellites, operated by different countries with sometimes different scientific objectives.

Let’s begin with photographic evidence from Japan. The Himawari-8 satellite overseen by the Japan Meteorological Agency (JMA) is currently taking full-disk images of the Earth every 10 minutes, focusing on the region of Japan and its neighbors to the South.2 Here is a satellite imagery synopsis from the JMA Web site:

The Himawari series of geostationary meteorological satellites provides constant and uniform coverage of the earth from around 35,800 km above the equator with an orbit corresponding to the period of the earth’s rotation. This allows them to perform uninterrupted observation of meteorological phenomena such as typhoons, depressions, and fronts.3

Credit: Japan Meteorological Agency Credit: © JAXA

Also the Japanese Aerospace Exploration Agency (JAXA) captured a full-disk view from the Hayabusa satellite.4 This satellite’s main mission was to study the comet Itokawa, but was able to image the full-disk of Earth from a distance of over 180,000 miles away.

Photographic evidence also comes from the currently operating ELEKTRO-L series of satellites launched by the Russian space agency, Roscosmos.5 These geostationary satellites are designed to take meteorological images and monitor weather conditions. The ELEKTRO-L2 satellite is positioned over the Indian Ocean and transmits regular images every 30 minutes.6

From India, we have photographic evidence from the INSAT-3D geostationary satellite, managed by the India Meteorological Department.7 Launched in 2013, this satellite is “designed for enhanced meteorological observations and monitoring of land and ocean surfaces for weather forecasting and disaster warning.”8 New full-disk images are regularly relayed to Earth approximately every half-hour.

Credit: © Research Center for Earth Operative Monitoring (NTS OMZ) Credit: © India Meteorological Department

From a cooperation of numerous European countries, the Meteosat Second Generation (MSG) satellites take full-disk observations. Operated by the EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), the Meteosat satellites are in geostationary orbits 22,300 miles above Europe, Africa, and the Indian Ocean. New images are taken every 15 minutes in visible and infrared wavelengths.9

 Launched in 2010, South Korea successfully placed into orbit its first geostationary satellite, COMS (Communication, Ocean and Meteorological Satellite). Managed by the National Meteorological Satellite Center, the COMS satellite takes regular full-disk images with the stated meteorological missions of “continuous monitoring of imagery and extracting of meteorological products, early detection of severe weather phenomena, and monitoring of climate change and atmospheric environment.”10

Credit: ©2017 EUMETSAT Credit: © NMSC Credit: © CNSA

From China, we have photographic evidence from the unmanned Chinese lunar explorer Chang’e 5. Thetest module took this photograph on November 9, 2014 at a distance of 336,000 miles above the Earth’s surface.11 Notice the darker Moon (upper left) is clearly shown in contrast to the bright Earth.

Lastly, we add the photographic evidence taken by the United States. Decades of space travel and many diverse projects have generated a host of full-disk images of our planet. Going back to the early Apollo missions (1961-1972) aimed at traveling to the Moon, NASA astronauts were able to take first-hand photographs on film. While there are many photos, here are four from Apollo 8,10,13, and 17.12

Credit: Apollo credit: NASA’s Galileo spacecraft

Later, in 1990, as it began its mission to Jupiter, NASA’s Galileo spacecraft took an image back toward Earth from a distance of about 1.5 million miles.13

In 2015, the joint effort of the National Oceanic and Atmospheric Administration (NOAA), NASA, and the United States Air Force launched the Deep Space Climate Observatory (DSCOVR). Located one million miles away, this satellite “will maintain the nation’s real-time solar wind monitoring capabilities” in order to facilitate alerts and forecasts for geomagnetic storms caused by solar flares and coronal mass ejections.14 Different from geostationary satellites that continually maintain the same view of Earth, the DSCOVR satellite will be able to image all of Earth. Being located between the Sun and Earth, it will be able to watch the fully illuminated Earth rotate, imaging all sides of the spherical Earth.

Credit: National Oceanic and Atmospheric Administration (NOAA), NASA, and the United States Air Force launched the Deep Space Climate Observatory (DSCOVR). Credit: NOAA GOES-R satellite

Some of the most recent satellites to take full-disk images are the updated GOES-R series of satellites. These geostationary satellites are managed by NOAA and located to take real-time images of both Eastern and Western Hemispheres of Earth. “The new satellite can deliver vivid images of severe weather as often as every 30 seconds, scanning the Earth five times faster, with four times greater image resolution.”15

Historically Recognized As Spherical

Many of us might remember feeling a bit shocked in grade school when our teacher announced, “Many scholars and aristocracy in the 15th century believed that the world was flat and that if you sailed far enough, you’d go right over the edge. And Christopher Columbus set out to prove them wrong.” The problem with this statement is that Christopher Columbus (and most people in the 15th century) did not believe in a flat Earth, but rather understood the world to be spherical. Even as we look back to the B.C. era, the accredited scientists of the day believed and were able to prove that the Earth was spherical.  As far back as 500 B.C., most Greek scholars accepted the idea that Earth was spherical. Pythagoras (500 B.C.) believed Earth was round for aesthetic reasons, because the sphere was thought to be the perfect shape. Aristotle (384-322 B.C.) was one of the first to make application of scientific observations to expected results, given a round Earth: (1) the hull of a ship disappearing over the horizon before the rest of the ship, and (2) Earth’s shadow being round during a lunar eclipse. Through time, ancient scientists would gain a deeper understanding of the physics of our world and begin to be able to explain what they were seeing in nature with mathematical formulas.

Credit: (Cmglee) 2016 license CC-by- sa-4.0

Eratosthenes of Cyrene (276-194 B.C.) was known as one of the greatest scientists of his time and in the year 240 B.C., King Ptolemy III of Alexandria appointed him chief librarian of what was then considered the hub of learning and the world’s greatest library: the Great Library of Alexandria. Probably one of Eratosthenes’ most well-known contributions to science was his calculations of Earth’s circumference. He was also a leading cartographer of his day and was able to map large regions. But to make a complete map he wanted to know the actual size of Earth. One year, on the Summer Solstice, while he was in Syene (today known as Aswan, Egypt) he noted that the Sun shone directly into the bottom of a well at noon, indicating that it was directly overhead. He realized that since the distance between Syene and Alexandria was known (approximately 5,000 stadia), he could extrapolate that data and determine Earth’s circumference. Back in Alexandria, on the following year’s Summer Solstice, Eratosthenes set up a tent pole of known height and measured the shadow cast by the pole at noon.  Using trigonometric calculations, he found the angle of the shadow to be about 7°, which correlates to about 1/50 of a complete circle.  With this data, he calculated Earth’s circumference to be about 250,000 stadia.16 There has been some disagreement on what a stadia represented, but it is estimated to be somewhere between 500 and 600 feet. Using these numbers, we see that Eratosthenes’ calculation gives the circumference to between 23,000 miles and 29,000 miles. Modern science gives an equatorial circumference of 24,900 miles.17

While Eratosthenes’ method and calculations were somewhat crude, one can see the simplicity and significance that his calculations have provided to the scientific community. It is notable that the belief, investigation, and calculation of Earth’s shape and size predate modern efforts, such as those of NASA, by thousands of years.


In this day and age of readily available information, sometimes just enough “truth” can be given to allow an idea to be plausible and believable in one’s mind. Sometimes an idea is given more credence because a celebrity endorses it. Other times, it might take hold because of a rebellion against the norm and someone wanting to be considered a “free-thinker.”  Whatever the reason a person has for believing something, its source needs to have credibility and must be backed by provable, validated data—evidence.

While the origin of the recent interest in Flat-Earth ideas may not be fully known or pinpointed, we can see that a spherical Earth is the one that has the scientific backing. While we did not consider many other evidences of the Earth’s spherical nature, such as Earth’s magnetic poles, GPS triangulation and satellites, the Coriolis effect, time zones, distant horizon curvature, Arctic and Antarctic exploration, and circumnavigation, we were able to evaluate numerous easily accessible observations. From our assessment of the shapes of other celestial bodies, observations of the Sun and Moon, consideration of historical perspectives, and examination of modern, first-hand and photographic evidences, we can see for ourselves that the scientific data supports a spherical Earth.


1 “List of Astronauts by Name,”; “Timeline of Space Travel by Nationality,”

2 “Satellite Imagery” (2017), Japan Meteorological Agency, Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan; Image shown:

3 “Meteorological Satellites,” Japan Meteorological Agency,

4 “The Earth Pictured by Hayabusa” (2004), Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency,

5 Anatoly Zak (2016), “Russia to Introduce A New Generation of Spacecraft,”

6 “ELEKTRO Geostationary Hydrometeorological Spacecraft (In Operation)” (2011), Research Center for Earth Operative Monitoring,; Image shown:

7; Image archive:


9; Image shown:


11 “Earth and the Moon from Chang’e 5 T1” (2017), The Planetary Society,

12 “Western Hemisphere” (2009), NASA,; “May 18, 1969 – Apollo 10 View of the Earth” (2017), NASA,; “View of Earth from Apollo 13,” Smithsonian National Air and Space Museum,; “Blue Marble – Image of the Earth from Apollo 17” (2007), NASA,

13 “PIA00076: Earth – Full Disk View of Africa” (1996), NASA/JPL,

14 “DSCOVR: Deep Space Climate Observatory,” National Oceanic and Atmospheric Administration,; Image shown:

15 John Leslie and Connie Barclay (2016), “NOAA’s GOES-R Weather Satellite Readies for Historic Launch,”

16 Alan Chodos, ed. (2006), “June, ca. 240 B.C. Eratosthenes Measures the Earth,” APS News, 15[6]:2, June, wiki/File:Eratosthenes_measure_of_Earth_circumference.svg.

17 “Geodesy for the Layman” (1984), Defense Mapping Agency,


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