People are very interested in Stonehenge, which is one of those famous landmarks. It is very clear that it lines up with the sun at the solstices, but no one is sure what the monument is for. But over the next few months, scientists will look at a different kind of alignment: some stones may be lined up with the lunar standstill.

In the sky, things move around. The sun moves around during the year because the planet is tilted with respect to its orbit. This means that the times when it rises and sets are often different. Stonehenge is set up so that the first rays of dawn on the summer solstice and the last rays of sunset on the winter solstice both pass through the middle.

But outside the stone circle are the so-called station stones, whose purpose is unknown. They don’t seem to be linked to the sun, but to the moon. The position of the moonrise and moonset changes because the moon’s orbit is tilted relative to the earth. This is similar to how the sun moves. But it doesn’t happen every year. The cycle goes around and around for 18.6 years.

When the Moon is at the fullest point of its cycle, it moves from 28.725 degrees north to 28.725 degrees south in just one month. The next one won’t happen until January 2025. This time is called the major lunar standstill (lunistice). So, scientists will be going to Stonehenge several times over the next few months, even during the major standstill, to figure out how the monument might line up with our natural satellite.

Talked to Heather Sebire, senior property curator at Stonehenge. “I think the moon in general would have been very important to them.” “And you know, maybe they could do things they couldn’t do other times when there was a full moon because there was more light.”

“They think the lunar standstill might have something to do with this because there are four rocks out in the middle of the ocean that are called “station stones.” Only two of them have been found so far. Together, they form a rectangle, which some people think may have something to do with the setting outside the circle.

When the Moon is in a minor standstill, its distance from the Earth is between 18.134° north and south. It will happen again in 2034.

As archaeologists continue to look into this interesting alignment, Stonehenge wants everyone to join in the fun. As usual, people will be able to enter the circle for the solstice, which this year is the earliest since 1796. However, the next day will be all about the lunistice.

 

 

 

 

 

 

 

 

 

 

 

 

As the moon rises, the lunar standstill event can only be seen online. You can watch the livestream from the comfort of your own home and wonder with the researchers if this great monument was also lined up with the Moon.

 

Some of the diagrams and animations that show how the planets move around the sun are not quite accurate. To be more precise, they are making the planets’ orbits easier to understand so that teachers don’t have to explain barycenters to kids who are still getting used to the idea that Earth isn’t the only planet in the universe.

Most of the time, the way you learn about how planets move around the sun looks like the video below.

But this version is easier to understand. The Sun has about 1,048 times the mass of Jupiter, making it the largest object in the Solar System. However, gravity works both ways. For the same reason that the Earth pulls on itself, you pull on the Earth as well, though it is much smaller.

“Kepler’s third law describes the relationship between the masses of two objects mutually revolving around each other and the determination of orbital parameters,” NASA says.

“Think about a small star that circles a bigger star. The two stars actually move around the same mass center, which is called the barycenter. That’s always the case, no matter how big or heavy the things are. Using a massive planet to measure how fast a star moves around its barycenter is one way that planetary systems linked to faraway stars have been found.

To keep things simple, we say that the planets go around the Sun. But because the Sun has the most mass, the barycenter of the Solar System’s objects is usually close to it. However, because of Jupiter and Saturn’s orbits and effects, it is almost never inside the Sun. The paths look a bit more like the video below, which was made by planetary astronomer and science communicator James O’Donoghue.

Because of this, the Earth is not orbiting a point inside the Sun right now because the barycenter is not there. We are not going around the sun, but that point in space.

“Planets orbit the Sun in general terms,” O’Donoghue says on Twitter, “but technically, they don’t orbit the Sun alone because the gravitational influence of (mainly) Jupiter means planets must orbit a new point in space.”

“The planets do orbit the Sun, of course; we are just being pedantic about the situation,” he said. “The natural thinking is that we orbit the Sun’s center, but that very rarely happens, i.e., it’s very rare for the solar system’s center of mass to align with the Sun’s center.”

Things that are smaller, like planets and their moons, are the same way. The Earth and Moon go around a point about 3,100 miles (5,100 kilometers) from the Earth’s center. This path changes as the moon moves farther away from the earth.

In 1846, Urbain Le Verrier, an astronomer and mathematician, set out to find a planet that no one had ever seen before. The Newtonian theory of gravity said that Uranus would move in strange ways as it grew up.

The way Uranus’s orbit was seen to be different from how Newtonian physics said it should be, even though the differences were small,. Le Verrier suggested in July that a planet other than Uranus might be to blame for the difference. He also made guesses about the path of this unknown body in space.

Since he was a mathematician first and an astronomer second, he didn’t want to use a telescope to look for it after he found it in math. That job was given to the German astronomer Johann Gottfried Galle. Galle looked at the spot where Le Verrier said the planet would be on September 23, 1846, and found that it was pretty close—by just one degree. It was Neptune.

Don’t worry; we will get to Spock soon.

By looking at the orbit of another planet, Le Verrier found a new planet. Now he was asked to look at Mercury, a planet whose name doesn’t also mean “butt hole.” For now, Mercury is the hardest planet to observe because it is so close to the sun (if there isn’t already a Planet Nine). Le Verrier was told to use Newtonian physics to figure out Mercury’s orbit.

He tried, but he failed. He tried very hard, but Mercury’s strange orbit just didn’t make sense. Newton’s theory says that the planets move in elliptical paths around the Sun. However, observations have shown that Mercury’s path wobbles more than the gravitational pull of the other known planets could explain.

He thought that, like with Uranus, this was because of another planet that was changing the path of the planet. Because he was a big fan of Star Trek, he named the planet Vulcan after the Roman god of fire.

Soon, astronomers started writing about what they saw on this planet. Edmond Modeste was the first to do so on March 26, 1859. After nine months, he told Le Verrier about his work when he saw an article about it. At that point, he was only an amateur astronomer. Le Verrier predicted the planet’s path based on Modeste’s observations. He thought it would pass through the sun twice to four times a year.

Others said they had seen Vulcan, but this could have been due to sunspots, known planets, or seeing nearby stars. Le Verrier made his calculations better by looking at other things, but it was never really seen as concrete.

The planet, on the other hand, wasn’t just a passing trend; it lasted for about 70 years. Based on calculations by the famous astronomer Theodor von Oppolzer, newspapers in 1879 said that Vulcan would pass in front of the Sun. It didn’t show. During this time, it was looked for during almost every eclipse but never found.

Since you already know about eight planets, why didn’t you learn about Vulcan? Because there wasn’t much of it. Einstein’s theory of general relativity invalidated a prediction about the planet that came from Le Verrier’s mathematics.

Einstein’s theory could tell us where Mercury would go even if there were other planets in the way of its wobble. Massive objects are believed to stretch spacetime, which has a greater impact on objects that are closer to the massive objects. So the theory could explain why Mercury’s orbit changes or wobbles. The outer planets, on the other hand, are farther from the Sun and are less affected by the curvature, so the new calculations don’t have much of an effect on them.

So, Einstein’s theory could explain both Mercury’s orbit and the orbits of Earth, Mars, and Jupiter without the need for other planets.