Will we ever travel outside the Solar System?

*This text was written by a TecMundo columnist; finally learn more.

Ever since humanity began to look at the stars at the beginning of time, a number of questions began to fill our minds without ever leaving. How big is space? How did we get here? Are we alone in the universe? There is intelligent life in another place Soil?

As we evolve and gain knowledge, we begin to understand a little more about the Cosmos and deftly narrow the gaps of our ignorance. As we explore nature and the space around us to hunt, gather, and eat, we have also ventured out from the furthest reaches of our past to explore with the pure intent of knowing.

After leaving the planet today and considering interplanetary travel between our neighboring planets, it is inevitable to raise the question: will humanity ever travel between the stars?

While the idea of ​​embarking on a Star Trek has dazzled sci-fi fans for at least a century, when we reason with the rigor of the basic sciences we’ve acquired in our lives, we inevitably come to the conclusion that this mission carries a tremendous and great responsibility. daunting technical difficulties. . However, recent advances in modern science show that not only can humanity overcome such challenges, it may be possible to do so in the next few centuries.

The biggest and most difficult problem for the idea of ​​interstellar travel is scale. Astronomical distances are extremely large and unimaginable compared to our daily distances. Even the closest stars to us—except the Sun, of course—are so far away that the kilometer becomes obsolete: distances are measured in light years, which is the unit of how far light travels from a point in a straight line. year period.

A light-year is about 9 trillion kilometers, and if you haven’t been affected before, that’s about 60,000 times the distance between the Earth and the Sun. This unit is so large that even if we consider the nearest neighboring star to it. solar systemProxima Centauri, 4.24 light-years from here, would take about 80,000 years to cover if we traveled in the fastest ship humanity has ever built.

However, this is a limitation of our current technology based on the use of chemical-based propulsion fuels, and it has a clear drawback: the faster and further you want to go, the more fuel you need to take with you. to produce the required energy.

We can then invest in using a more efficient fuel to increase the range and speed of a probe, such as nuclear fission and fusion technologies or matter-antimatter propulsion: chemical-based fuels convert only about 0.0001% of its mass into useful energy, while all these alternative ideas are It is immensely more efficient, achieving a mass-energy conversion rate of 0.7% for fission and fusion, and even 100% theoretical efficiencies for matter-antimatter propulsion.

Also, a highly efficient alternative would be to explore technologies where the propulsion source is independent of the load to be accelerated. This is using a large energy source that can accelerate a spaceship.

Recent advances in optical physics, particularly laser technologies, have led many scientists and engineers to propose that a large and sufficiently aligned laser array in space could be used to accelerate a spacecraft from low Earth orbit to very high speeds.

This is also the basic idea of ​​so-called solar sails made of extremely light material so that radiation pressure produces acceleration. They would be built with large membrane mirrors that could move for long periods of time and could reach speeds of up to 20% of the speed of light.

While we have no plans yet to slow down such a spacecraft, the idea of ​​reaching the nearest star within a single human lifetime is feasible, as it is desirable not only to arrive at another star system but to explore it as well. Taking people, there is another story I dare not tell you now…

Regardless, we may still be a long way from reaching another star, but it’s amazing how far our technology has taken us. In addition, we walked a path that is still magnificent and will surely bring countless other great discoveries in the coming decades!

Nicolas Oliveira, columnist TecMundoHe holds a diploma in Physics and a master’s degree in Astrophysics. Professor and currently doing his PhD working with galaxy clusters at the National Observatory. He has experience in Teaching Physics and Astronomy and researching Extragalactic Astrophysics and Cosmology. He works as a scientific dissector and communicator for the dissemination and democratization of science. Nicolas is found on social networks as: @nicooliveira_.