A team of astronomers, led by the University of Texas at Arlington’s Manfred Cuntz, took a section from Greek poet Sappho’s Midnight Poem and recreated constellations of the time.

The moon has set
and the Pleiades;
It is midnight,
The time is going by,
And I sleep alone.
(Henry Thornton Wharton, 1887:68)

They used the information provided in the above fragment (ie the star cluster known as the Pleiades had set at midnight) and ran it through a software called Starry Night version 7.3 and Digistar 5. They calculated that the earliest date the poem could have been written was on January 25, 570 BC, when the Pleiades set at midnight.

Their research was published in the Journal of Astronomical History and Heritage.

The Pleiades is a group of bright stars also known as the Seven Sisters that is visible from the northern hemisphere and most of the southern. The cluster featured in many ancient cultures, including those of the Australian Aborigines, Vikings, Mayans and Babylonians.