The August 2, 2027 Eclipse: Six Minutes of Darkness and How the Ancients Read It

Most total eclipses are short. The Moon is only just big enough in our sky to hide the Sun, so totality usually lasts two or three minutes. On August 2, 2027 NASA gives the longest totality as 6 minutes 23 seconds. Only one total eclipse this century runs longer: July 22, 2009, at 6 minutes 39 seconds, over Asia and the Pacific.

Three things line up to stretch it.

The Moon is close. At the moment of new moon it is 357,375 km from Earth, only hours after its closest point of the month and near its closest of the year. A closer Moon looks bigger and casts a wider shadow.

The Sun is far. Earth reaches its farthest point from the Sun, called aphelion, every July. On August 2 we are still near it, so the Sun looks slightly smaller than average and is easier to cover. NASA's eclipse magnitude of 1.079 means the Moon's disc is almost 8% wider than the Sun's, seen from the ground under the shadow.

The shadow passes nearly under the Sun. At greatest eclipse, near Luxor, the Sun stands 82 degrees up, almost overhead. That puts the ground as close to the Moon as it can be, and the turning Earth carries observers along in the same direction the shadow moves, so the shadow takes longer to pass.

The Moon's dark shadow touches down in the Atlantic, comes ashore at the Strait of Gibraltar in the morning, runs along the North African coast, crosses Egypt around midday and reaches Arabia in the early afternoon before leaving land over the Indian Ocean. NASA lists the countries in the path as southern Spain, Morocco, Algeria, Tunisia, Libya, Egypt, Saudi Arabia and Yemen, and gives the path a width of about 258 km.

We computed the local circumstances for eight places inside it. Cadiz, on the edge of the path, gets under three minutes. Tangier, closer to the centre line, gets almost five. Benghazi gets just over six, and Luxor 6 minutes 21 seconds with the Sun nearly straight up, two seconds short of the maximum NASA gives for a spot a little further along the path. Outside the path the eclipse is partial: London sees about 42% of the Sun's disc covered, Cairo about 95%.

NASA's safety rule is simple. It is safe to look at the Sun without protection only when the Moon completely blocks its bright face. Before and after totality, and anywhere outside the path, use solar viewers that meet the ISO 12312-2 standard; ordinary sunglasses are not enough.

For the scholars of ancient Mesopotamia an eclipse was a message, and they kept a reference book for reading it. The omen series known by its first words, Enūma Anu Enlil, ran to 68 or 70 clay tablets and an estimated 6,500 to 7,000 omens. It was probably put into its standard form in the Kassite period, between about 1595 and 1157 BCE. Tablets 15 to 22 deal with eclipses of the Moon and tablets 30 to 39 with eclipses of the Sun.

The omens were read for the king and the state, not for private people. For a lunar eclipse the scribes looked at the date, the watch of the night and which quarter of the Moon's face darkened first, and used them to work out which lands and cities the eclipse concerned.

The most dramatic response comes from the Assyrian court of the 600s BCE. When an eclipse was read as a threat to the king, a substitute king could be put on the throne to take the danger on himself while the real king stepped aside. Every recorded performance of this ritual can be traced to an eclipse, and King Esarhaddon had it done seven times. The danger was believed to fall within 100 days of the eclipse; records mention substitute reigns of 47, 20, 7 and even 3 days.

In the second century the astronomer Claudius Ptolemy, working in Roman Alexandria, wrote the Tetrabiblos, a four-book survey of astrology. Its second book is about the astrology of whole peoples and places, and eclipses sit at its centre. To Ptolemy an eclipse was the single strongest signal in the sky for events on that scale.

He read an eclipse by where it fell, when it fell and how long it lasted. For the place he looked at where on Earth the eclipse could be seen and which zodiac sign it fell in. For the duration he gave a rule of thumb: the significance of a solar eclipse ran for as many years as the eclipse lasted in hours, and that of a lunar eclipse for as many months.

Ptolemy was also part of a long tradition of telling eclipse stories. Six centuries before him, Herodotus wrote that a battle between the Lydians and the Medes stopped when "day was on a sudden changed into night", that both sides moved to make peace and that Thales of Miletus had foretold it. The eclipse that fits is May 28, 585 BCE. Modern historians doubt that Thales could have known it was coming, since the Moon's role in eclipses was understood only later.

Western astrologers today read an eclipse personally as well as collectively. The key is its degree: 9 degrees 55 minutes of Leo. Astrologers look for that degree in a birth chart, note the house it falls in and look for planets within a few degrees of it. They read the eclipse as a sharpened new moon for that part of the chart. This one falls about a degree and a half from the Moon's South Node, which astrologers associate with release and letting go.

It is the second and last solar eclipse in Leo of this pass of the nodes, after the solar eclipse of August 2026. The whole year's set, with the annular eclipse of February 6 and the lunar eclipses, is in Eclipses 2027, and the day itself, with local times by zone, is in our August 2, 2027 eclipse guide.

To find where 9°55′ Leo sits in your own chart, cast your free birth chart. The new moon that makes this eclipse is one of the thirteen in Why 2027 Has 13 New Moons.