 |
| Alien Technology Needs To Reach Earth |
An exoplanet entered our solar system in 2017; This object was the asteroid Oumuamua, a body that did not come from any region outside the solar system. It was an interstellar object from outside the solar system that was completely new to humans.
Oumuamua
 |
| Oumuamua |
Some scientists, such as renowned particle physicist Stephen Hawking, believed that this asteroid was nothing more and nothing less than an extraterrestrial spacecraft visiting our solar system. However, as soon as telescopes and radio telescopes were pointed at the exoplanet to study it better, we realized that it was just an inert rock, lifeless and not emitting any strange signals.
In other words, it resembled an ordinary asteroid. A few days after entering our solar system, Oumuamua left the Sun's gravitational influence following its solitary path through the universe. Although, in this case, it was only an asteroid, many scientists do not rule out that it could be an extraterrestrial spacecraft at some point in the future.
Technology for interstellar travel
 |
| Alien Technology |
Humanity cannot travel to other stars because our technology does not allow us to do so.
Chemical Fuel
The rockets we use to get off Earth run on solid or liquid fuel made from chemicals in the ground. Generally, a rocket needs a large amount of fuel to leave the Earth which weighs a lot. 80% of the total weight of a spacecraft is the fuel used to leave the planet. With such a ship we could go to the moon and the nearest planets. However, we could not use it to travel to the stars because it is consumed very quickly and once used it is impossible to recover. That's why we can say that aliens won't use chemical fuels like our spaceships, but then... what kind of technology do aliens need to reach Earth?
Gravitational Assistance
The fastest spacecraft ever built by mankind is the Parker Probe studying the Sun, which reached a speed of 150 kilometers per second.
Speed
To give you an idea of how fast that speed is, you can orbit the Earth in just 4.5 minutes, or go from the Earth to the Moon in less than an hour. Parker Probe did not reach this high speed with any fuel but with the help of Sol's gravity. As the name suggests, gravity assist takes advantage of the gravitational field of a celestial body to propel us. Note that gravity can be used to both accelerate and decelerate spacecraft.
Gravitational assistance is the only mechanism that allows us to reach such high speeds; Unfortunately, the distance of the universe is considerable, and even with the speed of this ship, it would take thousands of years to reach the nearest star. This method is only useful within the solar system; Once outside, you must fend for yourself; Since there would be no celestial body to propel itself with, extraterrestrials would not choose this method to reach Earth, so it is ruled out.
Nuclear Propulsion Pulse
 |
| Nuclear Propulsion Pulse |
In 1946, particle physicist Stanisław Marcin Ulam, who participated in the Manhattan Project, proposed a novel project called Project Orion, which aimed to build a spacecraft capable of reaching very high speeds with nuclear power.
Nuclear Propulsion Repulse
Project Orion envisioned a revolutionary ship that would have cabins near the void where a series of small atomic bombs would be detonated for short periods of time. That is why it is called Nuclear Propulsion Repulse. As the bombs explode, the ship produces a series of short pulses of thrust until it reaches relative speed. (Note: Relativistic velocity is understood to represent a percentage close to the speed of light.)
The energy released by the atomic bomb would give the ship such a significant boost that, driven by a turbine, it would be capable of reaching one-tenth the speed of light, i.e., per second. About 30,000 km. Thus, it would be possible to reach the nearest star to Earth (Proxima Centauri) in just 40 years, a much more reasonable time than thousands of years with conventional ships. According to the Institute for Advanced Study in Princeton, the technology currently exists to create something like this.
Unfortunately, the Partial Nuclear-Test-Ban Treaty of 1963 (TPPEN) and societal fear of nuclear weapons put an end to this project in the middle of the last century. If aliens didn't have the same social problems as us and laws preventing them from conducting nuclear tests, pulse nuclear propulsion would surely be among their first options for interstellar travel. However, this technology will allow them to go to stars close to the solar system because the number of nuclear explosions of the spacecraft will be very limited and will not be able to go more than 100 light years, if we consider that our galaxy (Milky Way) is more than 100,000 light years in diameter. To travel beyond the stars near their solar system, the aliens must employ a type of technology that far surpasses that developed by humans.
Antimatter
 |
| Antimatter |
The first of these technologies will be an antimatter engine. Antimatter, as the name suggests, is matter with the opposite charge of ordinary matter. That is, if you have a negatively charged electron, an antielectron would be an electron, but with a positive charge, we know the opposite of an electron. Antimatter exists, and it can be created in particle accelerators like the famous Large Hadron Collider (LHC), a huge machine operated by CERN (European Center for Nuclear Research), which is responsible for creating antimatter particles by colliding with elementary particles.
The exciting thing with antimatter is that they self-annihilate each other when they come into contact with ordinary matter, releasing a lot of energy in the process. To date, the LHC, in its more than ten years of operation, has failed to produce a single gram of antimatter. However, suppose it will be followed one day. In that case, one gram of well-stabilized, controlled, and controlled antimatter could produce enough energy to power a city like New York for several years.
According to Dr. Gerald Smith of Pennsylvania State University, with an engine that can harness the energy produced when matter and antimatter combine, it only takes one microgram of antimatter to reach the outermost region of the solar system is known as the Oort Cloud, a region of great importance to the Universe.
Best fuel for Interstellar Travel (Antimatter)
Only a few kilos would be needed to reach the nearest star, and several tons to a star 100 light-years away. Certainly, antimatter is the best fuel for interstellar travel within the galaxy, unfortunately to date, the human race has not yet been able to mass-produce this material, but if the aliens take advantage of our at least 1000 years for them, then it is already a reality, it is their spacecraft. It may also be their favorite method to manipulate.
The only downside for them would be that they would find themselves in another galaxy. So far, we've explored technologies that an extraterrestrial race could use to reach Earth from any star in the galaxy, but what about aliens that can't be found in the Milky Way? In this case, suppose a civilization at least 10,000 years more advanced than ours, which would be found in another galaxy, for example, in the spiral galaxy M31, better known as Andromeda.
If this race of extraterrestrials wanted to travel to Earth, they would have the difficulty that the distance between their galaxy and ours is considerable, more than 2.5 million light years. That means it would take more than 2.5 million years to reach our planet even with a ship that can reach the speed of light, that's too long, maybe this is where they have access to technology that currently only exists in our imaginations.
Warp Speed
The first of these technologies is WarpSpeed, so you'll understand quickly. This concept was first introduced in the famous Star Trek television series. The Enterprise ship used a curvature displacement motor to travel faster than light. The first person to explain how this theoretical design of the WARP system could work was the Mexican physicist Miguel Alcubierre, who proposed a theoretical model that did not violate Albert Einstein's laws of special relativity.
In this model, the spacecraft would be covered with a distorted space bubble. Behind the ship, space-time will expand in the opposite direction, leaving the starting point behind. In front of the ship, space-time contracts will be made by placing the destination point closer and closer. Thus, the ship will move freely within the space-time bubble; It is not the ship that will move but the space enclosed within the ship that will deform. Matter cannot travel faster than light in space. However, space can go faster than light, so spacecraft can reach superliminal speeds, faster than light, even up to 80 million kilometers per second.
At this speed we could travel the distance between the Sun and the star Proxima Centauri in just three days. Unfortunately, for now, this technology is completely beyond human capabilities, there is still a lot about space-time that we don't understand, and even physicist Miguel Alcubierre himself has said that building a WARP engine requires a large amount of extraneous matter. , which is a type of elemental matter that does not exist in abundance in the universe. Can the aliens solve this problem and build their own Star Trek-style ships? If so, it wouldn't be strange for them to meet us in the coming years, but if it's a million years ahead of us, it might involve a lower warp speed for them.
Wormholes
 |
| Warmhole |
A wormhole is a rift in space-time that connects two points in the universe. These act as portals that serve to travel from one place to another instantly from anywhere in the universe. No engine, no fuel, just going one place and instantly exiting another far away. Too good to be true?
Well, you're right; Although wormholes are very famous for science fiction movies like Interstellar, the reality is that they do not exist outside of mathematical theory. To date, there is no evidence that these objects exist, but this does not mean that they will never exist; Many scientists in the field of particle physics think that quantum foam may contain matter at the subatomic level, that there may be micro wormholes, cracks in space-time that open and close in fractions of a second, perhaps an alien race far away.
Something more advanced than ours could keep one of these cracks open long enough to make it large enough for a large spacecraft to pass through. However, for now, that remains in the imagination. Indeed, we do not know what the aliens are like or what technology they will use to reach our planet; Let's hope they come in peace with whatever technology they use.