Global Navigation Challenge

Quick access to the challenge details:

Central time or GMT -5

Arcturus 45.7°
Polaris 45.6°
Procyon 25.2°

90° is straight up

Send submissions to

Update: The challenge was solved in 4 minutes. “Bacon” on discord’s answer was within 6km of my position. Here are partially unredacted screenshots:


Timbo Turtle:

On February 19 I released a $10,000 Flat Earth Sextant challenge, followed by an update that allows flat earthers to use the celestial sphere for star positions as published in nautical almanacs. After several weeks, there have been no submissions.

See the other challenges for details on the background.

This challenge is to use any celestial navigation methods to determine the observer’s position from star angle measurements.

The prize is $100 paid via a Bitcoin transfer to the winner. The money is in escrow described here:

The official challenge is in this downloadable file:

The uncompressed TXT file’s SHA 256 Checksum is 7f512b7dffd147e9aab97be34b1af70411b8dbce5626bd65dd3203ea78808786

The SHA256 sum was generated on command line:

> shasum -a 256 Global Navigation Challenge.txt

…and verified by copy-pasting on this web site:

The contents of the file are reproduced below. Note that the reproduction here is not the official challenge, the downloadable text file linked above with the matching checksum is the official challenge.

There are two zip files.

“Star” has the screenshots from the Theodolite app with the latitude and longitude redacted. SHA256 Checksum: 0c04b91711c6f3e2f671af7be89cdc3f03c47bef40a31ab21a368bb0ea5969fd

“Unredacted star” has 4 screenshots for each star and includes the latitude/longitude to 3 significant figures. This also includes screenshots from the app I used to confirm the identity of the star I was measuring. SHA256 Checksum: 5c5f19ebb335381ea0bc3fb037137397f811462b7abca3d49b4f28937da72ec4

Set of elevation angles to three separate stars:

To be published 2022-04-06 at 6:00 pm Central time. I’m in Minnesota.

This file includes 4 screenshots from the Theodolite app on my iPhone in a single zip file. There is an additional screenshot from one of the stars for clarity.

Legit Challenge Framework v0.9b

Celestial navigation has long been used to obtain one’s position on the earth. Navigators have used celestial navigation for centuries. The foundations of celestial navigation are based on knowing specific information about the earth, a rotating globe, and the stars in the celestial sphere around the globe. Celestial navigation uses measuring devices to obtain the angular differences between features on the earth, stars, planets, the sun, or the moon. A common measuring instrument is a Sextant. Using a sextant for celestial navigation is so common that the term “using a sextant” is somewhat synonymous with celestial navigation.

Devices other than sextants are used to measure the angular elevations of stars. Theodolites, and astrolabes, for example. Today smartphones have the necessary sensors to measure vertical angles to 0.1° or better. This challenge uses the star angle measurements from a smartphone to obtain the angles and determine the viewer’s location.

Flat earth: the idea that the earth as a whole, excluding topography, is generally a flat plane. This includes these ideas: the earth is an infinite plane, all horizontals are parallel, the surface of undisturbed water is flat, and other ideas that have similar implications.

Flat plane: see definition for “flat earth”.

Flat earther: a person that posits Flat Earth idea as defined above.

Use the elevation angles to three separate stars to determine the observer’s position on the earth. Any method relying on the star’s angular measurements may be used. Calculations presuming the earth is a globe, flat, or velociraptor shaped may be used.

Acceptance parameters:
The position of the observer must be determined to be within 25 statute miles. The location can be in latitude/longitude or identify the closest town with a population of at least 300.

The method shall use the known and documented behavior of light propagation. Unexplained or arbitrary treatment in the path of light taken from the star to the observer will disqualify a submission.

Submission method:
Email the latitude/longitude or the name of the city to It is very likely that multiple entries will be submitted in a short time. Only the first email according to the timestamps of the receiving email server that meets the acceptance criteria wins.

A confirmation of receipt via email will be sent back to the winning submitter. The submission is not complete until a confirmation of receipt has been received via email to the submitter.

$100 US Dollars. Payment will be via Bitcoin using the most favorable to the submitter conversion rate from on the day the first submission is first sent in UTC time zone. If the escrowed funds are less than $100 in value, the full balance of the escrowed funds shall be awarded. If a previous prize has been awarded for a different competition and the escrowed value is less than $100, the remaining balance will be awarded.

Timing and Number of solutions:
The challenge opens on April 6, 2022, at 6:00 pm Central Time for all entries. At most one single winner shall be awarded.

0.4BTC is held in escrow by Brainy Beaver. Brainy Beaver will transfer funds to the winner in the event of a successful solution. See escrow documentation on

MCToon is the primary judge.

Should an entry be submitted but rejected by the judge, and this rejection not accepted by the submitter, a panel of three experts shall be named in accordance with the Legit Challenge Framework specification version 0.9b section 5.1. See

Each judge must be qualified in one of the following ways:

-Professional ship navigator with at least 5 years of navigation experience and currently employed as a ship navigator.
-Professional celestial navigation educator with at least 5 years of educational experience and currently teaching celestial navigation at least once a year.

Judges must be able to provide verification of their qualifications.

The challenge automatically expires 10 years from issuing on April 6, 2032, at 6:00 pm Central time. At MCToon’s discretion, the challenge can be withdrawn. This will be announced on MCToon’s YouTube channel with at least 30 days prior notice.

If a winner is ever declared and prizes are awarded, the challenge expires.

The set of elevation angles to three separate stars will be published separately from this document. This will be on the website on the same page as this challenge is published. The set will be noted on the website as “Set of elevation angles to three separate stars”.

The set of elevation angles are screenshots from the Theodolite App on an iPhone. The screenshot contains the date/time to the nearest second, the elevation of the observer, the zenith angle of the star, and the true (non-magnetic) bearing of the camera.

The original screenshots include the latitude and longitude, which have been redacted since that is the point of the challenge. The same screenshots, revealing three significant figures of both latitude and longitude, will be published with the accepted solution.

The star can be seen on all the screenshots unless the star is exactly in the crosshair intersection. When the star is obstructed by the crosshair the filename indicates this is the case.

The set of elevation angles to three separate stars has been verified to work using globe-presuming celestial navigation techniques.