Humanity has been trying to find signals from extraterrestrial civilizations for more than a century. Prior to focusing our eyes and ears on the galaxy and universe beyond, early efforts in the Search for Extraterrestrial Intelligence (SETI) concentrated on listening for messages from within the Solar System.

There have been no alien signals found thus far in these searches. While one signal remains enigmatic, it most likely stems from a human or natural source. But given that we (aside from our stray signals) don’t broadcast ourselves on a regular basis, is it unreasonable to assume that alien civilizations would do the same?

Messaging for Extraterrestrial Intelligence, or METI, is introduced. While it wouldn’t be accurate to state that humanity hasn’t communicated with the cosmos, there have undoubtedly been a few. The Golden Records are audio and visual files that NASA’s Voyager I and Voyager II spacecraft “selected to portray the diversity of life and culture on Earth.” Aliens will probably never find these. However, we have also sent other signals, like the Arecibo Message, which was directed about 21,000 light-years from Earth toward the globular star cluster M13. With only 210 bytes of data, the message was small but contained information about the 4 billion people that lived on Earth at the time, a stick figure of a person, a double helix, and a drawing of the Arecibo radio telescope that sent the message.

The organization METI International was founded in 2015 with the intention of communicating with extraterrestrial civilizations. They delivered a similar message to the super-Earth exoplanet GJ273b in October 2017, which is only 19 light-years away from Earth and may be habitable.

This is where METI becomes a little contentious. A map of the solar system was also included in the Arecibo message, and there are (very speculative) reasons why we might not want to communicate with aliens in our cosmic backyard or even send a return address.

The explanation of the Fermi paradox offered by what is now widely referred to as the “Dark Forest Hypothesis” is one of the reasons METI is controversial.

In short, it looks like the universe is full of planets that might be habitable, but we have never picked up a signal from an alien civilization.

The very dark Dark Forest Hypothesis, which is explained in Liu Cixin’s Remembrance of Earth’s Past trilogy, says that alien civilizations hide their existence because you can’t be sure what other civilizations want. There’s no way for you to know if they are hostile or friendly, or what their intentions are.

It’s possible that you, as a friendly civilization, find an alien civilization that is also friendly and about the same level of development as yours. You know you’re nice, but you don’t know if they’re also calm. Even worse, because of how far away these civilizations are and how long it takes to receive light and signals from them, you have no idea how their society has changed since the signal from them reached yours. In the meantime, they may have made huge technological leaps. This means that even if the planet you are looking at seems peaceful and not too far ahead of yours, everything could have changed by the time the light gets to you.

On top of that, there is the pressure of resources. According to the books, you also know from your own planet that life uses and spreads all the resources it can find. But there are only so many resources in the universe.

You still have to deal with the fact that you don’t know if they know that you are peaceful if you decide that they are peaceful. Since they think or even just suspect that you are bad, it makes sense that they would try to kill you before you could kill them. You could talk to them, just like you can here on Earth, to reassure them even more of your plans. In space, though, it could take hundreds or even thousands of years for your new message to get there. During that time, they could have began an attack to destroy you. With this many red flags, Liu comes to the conclusion that the only smart thing for a civilization that wants to stay alive is to hide in the forest and kill any civilizations that make noise, before they kill you.

Scientists are serious about the idea of hostile aliens, even though the idea became popular in fiction. In 2015, Stephen Hawking started a project to look for alien civilizations. He talked about why it might not be a good idea to say hello back.

According to Space.com, Hawking told the crowd, “We don’t know much about aliens, but we know a lot about humans.” “If you look at history, interactions between humans and less intelligent creatures have often been terrible for them, and interactions between civilizations with advanced and primitive technologies have also been bad for the less advanced.” If someone reads one of our messages, they might be billions of years ahead of us. They will be much stronger if that’s the case, and they might not value us more than we value bacteria.

However, the Dark Forest theory is still a long way from being proven. It is important to think about hostile aliens when deciding whether to contact other species and who should make that decision. David Brin, an American author and scientist, asked “whether small groups of zealots should bypass all institutions, peer critique, risk appraisal, or public opinion, to shout ‘yoohoo’ into a potentially dangerous cosmos.”

In a way, the fact that METI exists could be used to show that the Dark Forest Hypothesis is wrong. Let’s say there are very advanced societies out there. Assuming that some people in these advanced civilizations have access to advanced broadcast technology is a reasonable thing to do. Another reasonable guess is that if they were that advanced, they would have built this civilization with science instead of magic.

The civilizations would probably gather information about other star systems in the same way that we do, unless they have a good reason for not wanting to know about life beyond their own planet. Assuming that this information and broadcast technology aren’t somehow limited across all civilizations, there must be some people who would be crazy enough to try to get in touch with other civilizations. While obviously speculating wildly, it’s possible that an alien METI species that likes to take risks might try to warn other, younger civilizations about how the universe is like a dark forest. Also, we haven’t heard from these actors, which could mean that the long silence has a different cause than the Dark Forest Hypothesis.

That, or the METI problem, might only happen in new civilizations that send out messages every so often before we learn about the universe’s dark side and do everything we can to stay quiet.

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.