Carl Sagan once said, “Somewhere, something incredible is waiting to be discovered.” It is this desire to know what is not yet known that drives humanity beyond the stars. We go beyond our own world into the cosmos to see what is out there. And what we have discovered is literally beyond comprehension. Telescope James Webb sent back images of the universe stretching back more than 13 billion years, almost to its very creation.
We have seen thousands of galaxies containing billions of stars and potentially hundreds of billions of worlds. All in space, just like us. And the question remains, are there others like us? Are there other people out there? Or things that breathe and live and grow? The search continues, and it involves more methods than you might think.
10. Monitoring starlight
The vast space between here and literally anywhere makes the search for alien life a little more difficult than finding a lost pair of socks. In many cases, it’s easier to look not for aliens per se, but for signs that they exist. That’s why we started monitoring starlight.
Light from distant stars is often one of the few things we can see from a distant galaxy. Even with the James Webb Telescope, we're not going to be looking into the windows of alien homes. But a star can tell us a lot about a solar system just by analyzing the light that reaches us.
Starlight also looks for signs of alien technology, not just their worlds. For example, if you had a massive space station, it would cast a shadow, and we would also be able to see the starlight that was blocking it. The idea is that a sufficiently advanced race would create amazing technological feats , such as star-sized power plants or computers that occupy entire solar systems.
Stars like the distant one Boyajian's star, are prone to periodic dimming, leading scientists to wonder if there are alien megastructures that could interfere with the transmission of light from there to here.
9. Tracking biosignatures in alien atmospheres
The planets pass in front of the stars. Using a technique called spectroscopy , we can analyze the spectrum of light coming from a star when a planet passes in front of it. There will be a color change that will allow us to see the spectrum of the planet itself and the gases that must be present in the planet's atmosphere to filter out certain frequencies of light.
Methane is a gas produced by living things in our experience that supports life. If a planet has methane in its atmosphere, it is a possible carrier of life. So we can analyze the light spectrum, filter out the light from the star that will not change, and determine what gases are present in the planet's atmosphere and possibly whether there is life.
With thousands of exoplanets already discovered, and now tens of thousands more on the horizon thanks to the Webb telescope, there will be plenty of opportunities to search for life. Narrowing the search means looking for specific things, like biosignatures , signs that there is, or at least could be, life on the planet.
We look in the atmosphere for gases like oxygen and methane, things we know support life because they are in our own atmosphere and living things need them or produce them. While oxygen is an obvious choice, it is not an all-or-nothing proposition, especially since we know that oxygen has only existed on Earth for part of its life. Instead, scientists have identified thousands of potential compounds that may indicate life , which we can look for. Things like carbon dioxide, but not carbon monoxide, are also potential indicators of life, or at least habitability.
8. Technosignatures in alien atmospheres
So, we've seen how biosignatures and technologies are targets for searching for alien life. But with a little modification to these search methods, we can also hone in on technosignatures.
What we have described so far is a search for markers of life or the possibility of life. Hunting for technosignatures is a search for signs of industry. More precisely, pollution. A species that can build is capable of polluting. This means that we can search in the atmosphere , For example, nitrogen dioxide . While it comes from natural sources, it also comes from burning fuels.
Solar panels are another potential technosignature we might detect. Since every planet must orbit a star for life to exist, it is reasonable to assume that intelligent species would harness the energy of their sun in the same way we do. Solar panels reflect a lot of light, and that light would have a specific spectral characteristic If we find this, it may indicate life.
7. Radio signals
One of the oldest and still most popular ways to search for alien life is to look for radio signals. Researchers at MIT have discovered in July 2023 repeating signal, a heartbeat-like sound that emanates from Earth billions of light years away. Its exact location has not been determined, but it is one of many signals, some mysterious and others natural, that we have detected over the years .
Shortly before this signal, Chinese scientists announced that they too had detected an alien signal, possibly from an extraterrestrial intelligence, using their massive Sky Eye telescope .
SETI, the Search for Extraterrestrial Intelligence, began looking for radio signals back in 1960 with its Ozma project . One of the big problems with this method is the narrowing of the search area across the vastness of space and the fact that there are many natural sources of radio waves. Stars and many other celestial bodies emit radio frequencies, and these must be examined and excluded in the search. The hope is to one day find a signal that is more than just background noise and offers a clear sign of intelligent intent.
6. Telescopes
Perhaps the most obvious way to find planets is still at the forefront of efforts. Using a telescope isn’t as easy as it sounds, but it’s how we get those amazing images that come back to us from things like Hubble and then the Webb telescope. The hard part is knowing where to look.
There are many telltale signs you can rely on to determine where to point your telescope. One method is oscillation method You find a distant star and observe the light. If the star looks like it is wobbling, it means that something may be orbiting it, so you point the telescope at that area.
We have already filled the skynumerous satellites and probes that will help us in our search. Webb and Hubble are two, but there are also Spitzer, Kepler, Tess and Cheops, with many more on the way. The European Space Agency plans launch PLATO in 2025 with the ability to observe 1 million stars and search for planets around them
5. Quantum communications
The average person isn't very familiar with the idea of quantum communication, but it's of interest to those searching for alien life. Signals can be sent across galaxies using photons without losing any of the information in the signal. Instead of standard bits like our computers now have, with their 1s and 0s, quantum communications use something called qubits. People are still thinking about this idea to develop secure communication networks that we believe will provide unprecedented security for potential quantum internet .
While we're just getting the hang of it, the idea is that more complex types would have mastered it and could use it by now. This could also explain why our search for signals is coming up empty. Looking for radio signals in the quantum universe would be like trying to track down dinosaurs in a zoo. You're just late to the party, and what you want to find no longer exists. But if we change what we're looking for, we might start finding better results.
4. Search robots-probes
Closer to home, the moons of Saturn and Mars are still full of possibilities. Although we have not yet detected signs of life, that does not mean that nothing has been found. And more effective detection tools will increase our chances.
NASA has considered the idea of sending probes to moons like Europa and Enceladus, which could be sent beneath the ice as we know it, to look for signs of life. The team robots can be placed in liquid water under the ice and allowed to swim far and wide to see what they can see.
This would be just one type of future intelligent probe, capable of searching and then determining for itself whether it has found anything useful. Since signals from space take a long time to reach Earth, they could use AI to assist in searching and analyzing, reporting only when they think they have found something noteworthy.
3. Gravitational lensing
If you remember "Star Trek IV" (the one with the whales), then you probably know that there is precedent for things orbiting the sun. And as fantastically fictional as that movie is, there is science behind the idea of using the sun's gravity to move things. It's called gravitational lensing, and it could help us intercept alien signals.
If something is big enough, its gravitational pull can even bend light. As a result, it also focuses and magnifies that light. The researchers say that communication signals could be curved and focused in the same way. This means that stars like our Sun can be used as terrestrial satellite networks, transmitting and repeating signals throughout the galaxy. If another race of beings used stars in this way, and we set up a satellite relay, we could eavesdrop.
However, communication is not everything. Also being studied influence sun to light . If we positioned a spacecraft or satellite so that its light was refracted and then focused by our Sun, we could get a much clearer view of alien worlds. The Sun would effectively become a natural telescope, magnifying our view. At least one researcher believes the effect would be staggering — perhaps achieving a resolution of 20 kilometers per pixel. Clear enough to see continents and even weather patterns on other worlds.
2. Wet chemistry
As repulsive as it may sound, wet chemistry offers the potential to find life on other worlds. This one works on planets closer to home, like Mars, not in distant galaxies.
Using something called Sample Analysis at Mars , or SAM, the Curiosity rover examined the Martian soil in search of the building blocks of life. This includes any organic compounds that may contain substances such as oxygen and nitrogen. Soil samples are analyzed in three different chambers where they can be exposed to various solvents , as well as in other chambers where they can be dried. As a result, various organic molecules were discovered that would not have been missed in a normal sample analysis. We certainly did not discover life, but it gave us a much clearer picture of what was there and can certainly help in the future.
This technique could be applied again elsewhere, such as on Saturn's moons like Titan.
1. Auroral radio waves
Have you ever heard of the radio waves of the northern lights? It's not something that often comes up in casual conversation, but it is of particular interest in the search for alien life.
Here on Earth, the Northern Lights occur when charged particles from the sun collide with gases in our atmosphere. They occur at both poles, not just the North. They are most often green, but different gases produce different colors. And Earth is not the only planet where this happens.
The aurora borealis produces radio waves, and these radio signals can give us information about the planet they are coming from, including what kind of magnetic field it has. This is important because magnetic field is essential for life on the planet as we know it. Our magnetic field is the reason why our atmosphere remains stationary and harmful particles from space cannot reach us and destroy all life on the surface.
If an exoplanet is discovered and has aurora borealis, we can analyze these radio waves. If they indicate a strong magnetic field, this could be a strong sign that the planet is a suitable place for life. Likewise, the signals themselves may lead us back to planets we might otherwise miss.
Оставить Комментарий