So far, this decade has been pretty good for seeing cosmic events. In addition to the total solar eclipse and the sun getting close to its busiest time, which will create beautiful auroras on Earth, T. Coronae Borealis will soon go nova, which was first written about in a medieval manuscript.

There are still a few more treats in store for us in this decade, like a visit from the asteroid 99942 Apophis. According to observations, Apophis was at level 2 on the Torino impact hazard scale when it was first found in 2004. A score of 0 means there is almost no chance of impact, and a score of 10 means “a collision is certain, capable of causing a global climatic catastrophe that may threaten the future of civilization as we know it, whether impacting land or ocean.”

Even though Level 2 is low, it’s for things that are “making a somewhat close but not highly unusual pass near the Earth” and need more astronomers’ attention. It was raised to level 4 in December of that year, though, because there was a 1.6% chance that the asteroid would hit Earth in 2029.

NASA says that level 4 is “a close encounter that deserves astronomers’ attention.” “Right now, calculations show that there is a 1% or higher chance of a collision that could destroy a region.” It’s likely that new telescopic observations will lead to a move to Level 0. If the meeting is less than ten years away, the public and public officials should pay attention.

Over the years that scientists have been looking for and keeping an eye on near-earth objects (NEOs), none of them have gotten above level 4. Because they could be dangerous to Earth, they named one of them Apophis, after the Egyptian god of darkness and destruction. More observations showed that there would not be a collision in 2029, 2036, or 2068. However, they will still come very close.

“We no longer think that the asteroid will hit Earth in 2068,” Davide Farnocchia of NASA’s Center for Near-Earth Object Studies said. “Our calculations don’t show any impact risk for at least the next 100 years.”

This asteroid will come very close to Earth in 2029, coming within 32,000 kilometers (20,000 miles) of the surface. That’s closer than some of our satellites. The European Space Agency called the asteroid’s passing “one of the rarest space events of our lives,” and people in the Eastern Hemisphere should be able to see it without a telescope or binoculars.

1. Apophis will miss Earth

Apophis will miss Earth when it flies past our planet on 13 April 2029. If you only remember one of these facts, make sure it’s this one. pic.twitter.com/coOtFY5r2i

— ESA Operations (@esaoperations) June 19, 2024

The event is very rare because the object is so big—its average diameter is 375 meters (1230 feet)—and so close to Earth.

An X post from ESA said, “The 2029 flyby is a very rare event.” Scientists think that an asteroid as big as Apophis only comes this close to Earth once every 5,000 to 10,000 years. They found this by looking at the sizes and orbits of all known asteroids and impact craters around the solar system.

NASA wants to visit the asteroid during its approach with its OSIRIS APEX mission. This mission repurposed the asteroid sampler that used to be called OSIRIS-REx and sent it to meet the asteroid soon after it flew by.

“Our planet’s gravitational pull is expected to alter the asteroid’s orbit, change how and how fast it spins on its axis, and possibly cause quakes or landslides that will alter its surface,” NASA says about their planned mission. Researchers on Earth will be able to see these changes thanks to OSIRIS-APEX. Apophis is a “stony” asteroid made of silicate (or rocky) material and a mix of metallic nickel and iron. The OSIRIS-APEX spacecraft will also dip toward the surface of Apophis and fire its engines to kick up loose rocks and dust. By doing this, scientists will be able to determine the composition of the material just below the asteroid’s surface.

The ESA also wants to visit the asteroid because a flyby will teach us more about how to protect the Earth from these kinds of objects.

“Earth’s gravity will’stretch’ and’squeeze’ Apophis, triggering landslides and revealing lots about the asteroid’s material, structure, density, and cohesion,” ESA said. “This knowledge will help us protect Earth in the future.”

ESA said again that the asteroid is not a threat in 2029; it is just a beautiful sight and a chance to do some cool science in space.

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.