Ancient Egyptians described Algol's eclipses

December 17, 2015
Inside the superimposed rectangle is the hieratic writing for the word 'Horus'. Credit: Lauri Jetsu

The Ancient Egyptian papyrus Cairo 86637 calendar is the oldest preserved historical document of naked eye observations of a variable star, the eclipsing binary Algol - a manifestation of Horus, a god and a king. This calendar contains lucky or unlucky prognoses for each day of one year. Lauri Jetsu and Sebastian Porceddu from the University of Helsinki have performed a statistical analysis of the Cairo Calendar mythological texts.

Their analysis revealed that the periods of Algol (2.85 days) and the Moon (29.6 days) strongly regulate the actions of deities in this .

"Until now, there were only conjectures that many of the mythological texts of the Cairo Calendar describe astronomical phenomena. We can now unambiguously ascertain that throughout the whole year the actions of many deities in the Cairo Calendar are connected to the regular changes of Algol and the Moon," says Master of Science Sebastian Porceddu.

This research confirms that the first , as well as its period, were discovered much earlier than was previously thought. These two "classical" milestones in the history of natural sciences need to be shifted three millennia backwards in time to 1244 - 1163 BC.

This also confirms the two "modern" astrophysical results reported by the Helsinki group in the year 2013: The first direct observation ever of the expected increase of Algol's period and the accurate long—term estimate for the mass transfer in this binary system.

"I would have serious doubts, if someone claimed, for example, that the Bible contains information about water in Mars. We claimed that Ancient Egyptian religious texts contain astrophysical information about Algol. It was no surprise to us that there were, and there still are, sceptics," says docent Lauri Jetsu.

The research also confirms that the brightest phases of Algol and the Moon had particularly positive meanings for the Ancient Egyptians.

Explore further: Astronomers discovered ancient Egyptian observations of a variable star

More information: "Shifting Milestones of Natural Sciences: The Ancient Egyptian Discovery of Algol's Period Confirmed", L. Jetsu and S. Porceddu, December, 17th, 2015 in PLOS ONE,

Related Stories

Egypt puts King Tut mask on exhibit after botched epoxy fix

December 16, 2015

Egypt put the famed golden burial mask of King Tutankhamun back on display at the Egyptian Museum in Cairo on Wednesday evening after the relic was repaired following a botched attempt to reattach the mask's beard with epoxy.

57 ancient tombs with mummies unearthed in Egypt

May 23, 2010

(AP) -- Archeologists have unearthed 57 ancient Egyptian tombs, most of which hold an ornately painted wooden sarcophagus with a mummy inside, Egypt's Supreme Council of Antiquities said Sunday.

Leap years prevent 'calendar climate change'

March 1, 2012

Without leap years, Earth would experience "calendar climate change" and the seasons would completely swap every 750 years, a Queensland University of Technology scientist says.

Egypt archaeologists find pharaoh chapel

April 14, 2015

Archaeologists excavating an ancient temple site in Cairo have discovered part of a chapel used by a pharaoh about 2,300 years ago, Egypt's antiquities ministry said on Tuesday.

Recommended for you

STEREO—10 years of revolutionary solar views

October 26, 2016

Launched 10 years ago, on Oct. 25, 2006, the twin spacecraft of NASA's STEREO mission – short for Solar and Terrestrial Relations Observatory – have given us unprecedented views of the sun, including the first-ever simultaneous ...

Image: Changing colors in Saturn's pole

October 26, 2016

These two natural color images from NASA's Cassini spacecraft show the changing appearance of Saturn's north polar region between 2012 and 2016.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.