A RARE astronomical event that only takes place every 18 years is happening once again.
It’s called a major lunar standstill – and some believe it may even be linked to Stonehenge.
WHAT IS A LUNAR STANDSTILL?
A major lunar standstill is an event that happens every 18.6 years.
It takes place across several months, and sees the Moon taking a more dramatic path across the sky.
The reasons why are very complicated, but ultimately it’s linked to the angle between the Moon and the celestial equator (its declination).
Normally the Moon rises and sets in roughly the same place.
But during a major lunar standstill, its tilt does a bigger swing and the Moon rises further north and south.
In practice, it means that the Moon will appear to move differently to normal.
The points on the horizon where the Moon rises and sets are at their most northern and southern during a major lunar standstill.
It means that we see steeper angles, with the Moon appearing to rise much higher on some nights – and also peak lower on others.
Effectively the highest and lowest points of the Moon’s position in the sky are more extreme than they normally would be.
WHEN TO SEE THE LUNAR STANDSTILL
The major lunar standstill isn’t something that happens on a single day, but happens over a period of time.
We last saw a major standstill in 2006.
The next one begins in 2024 with the Moon’s declination becoming more extreme.
The Moon – our closest neighbour explained
Here’s what you need to know…
- The Moon is a natural satellite – a space-faring body that orbits a planet
- It’s Earth’s only natural satellite, and is the fifth biggest in the Solar System
- The Moon measures 2,158 miles across, roughly 0.27 times the diameter of Earth
- Temperatures on the Moon vary wildly. Nasa explains: “Temperatures near the Moon’s equator can spike to 250°F (121°C) in daylight, then plummet after nightfall to -208°F (-133°C). In deep craters near the Moon’s poles, permanent shadows keep the surface even colder — NASA’s Lunar Reconnaissance Orbiter has measured temperatures lower than -410°F (-246°C).”
- Experts assumed the Moon was another planet, until Nicolaus Copernicus outlined his theory about our Solar System in 1543
- It was eventually assigned to a “class” after Galileo discovered four moons orbiting Jupiter in 1610
- The Moon is believed to have formed around 4.51billion years ago
- The strength of its gravitational field is about a sixth of Earth’s gravity
- Earth and the Moon have “synchronous rotation”, which means we always see the same side of the Moon – hence the phrase “dark side of the Moon”
- The Moon’s surface is actually dark, but appears bright in the sky due to its reflective ground
- During a solar eclipse, the Moon covers the Sun almost completely. Both objects appear a similar size in the sky because the Sun is both 400 times larger and farther
- The first spacecraft to reach the Moon was in 1959, as part of the Soviet Union’s Lunar program
- The first manned orbital mission was Nasa’s Apollo 8 in 1968
- And the first manned lunar landing was in 1969, as part of the Apollo 11 mission
For keen skywatchers, the standstill is expected to be most extreme in late 2024 through to early 2025.
The best chances to see the effects are during full Moons.
Here’s a list of full Moons coming up:
- June 21, 2024
- July 21, 2024
- August 19, 2024
- September 17, 2024
- October 17, 2024
- November 15, 2024
- December 15, 2024
- January 13, 2025
- February 12, 2025
- March 14, 2025
- April 12, 2025
- May 12, 2025
- June 11, 2025
- July 10, 2025
- August 9, 2025
- September 7, 2025
- October 6, 2025
- November 4, 2025
- December 4, 2025
It’s believed that at least one major standstill was marked during the early phase of Stonehenge, potentially influencing the monument’s design and purpose.
English Heritage
The best time to see the effects of the standstill will be around the equinoxes in September 2024 and March 2025.
The equinoxes are when the lengths of days and nights are roughly equal.
If you regularly watch the Moon from the same location, you should see significant changes in how it appears to move across the sky over the weeks and months.
The upcoming equinoxes are expected to be on September 22, 2024 and March 20, 2025.
HOW DOES IT LINK TO STONEHENGE?
Some experts believe that the mysterious Stonehenge monument in England is linked to major lunar standstills.
“It’s believed that at least one major standstill was marked during the early phase of Stonehenge, potentially influencing the monument’s design and purpose,” English Heritage explains.
The organization continues: “On a major lunar standstill, the moon rises and sets in a place on the horizon that the sun never reaches.
“For people who track the movement of the sun across the year – such as farming communities who use horizon calendars for planting and harvesting – the appearance of the moon further north and south than the extremes of the sun may have been highly significant.
“Perhaps this would have been a moment when the lunar deity was stronger than the solar one.
“Happening only every 19 years or so, the major lunar standstill would have been a generational event – spoken about in the stories that passed orally from one generation to the next.”
English Heritage will also be livestreaming the southernmost moonrise from Stonehenge on June 21 at its YouTube channel.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
