The Discovery of Exoplanets: A New Era in Astronomy

Thirty years ago, two Swiss astronomers announced the discovery of the first known planet orbiting a sun-like star. This milestone marked the beginning of a remarkable era of discoveries in the field of astronomy, with thousands of exoplanets discovered since then.

The Beginning: Discovering the First Planet

The discovery of the first planet orbiting the star 51 Pegasi was a significant leap in the field of astronomy. This planet was described as a “hot Jupiter” due to its very close orbit to its star. This discovery opened the door for scientists to search for more worlds beyond our solar system, leading to the discovery of thousands of new planets.

Discoveries continued thanks to space missions like NASA’s Kepler and TESS, which significantly contributed to identifying exoplanets. Other telescopes also played a role in this field, enhancing our understanding of the universe.

Diversity of Exoplanets

The “planetary zoo” shows an astonishing diversity of planets, ranging from giant gas planets close to their stars to “super-Earths” and “mini-Neptunes.” Some of these planets feature multi-planet systems that move in musical harmony, while others roam freely in the galaxy.

Systems with planets orbiting binary stars, like the planet “Tatooine” from the Star Wars series, have become a reality. These systems offer unique opportunities to study planet formation and evolution.

Nearby Planets: Proxima Centauri and TRAPPIST-1

Proxima Centauri is the closest star to the Sun, with several small planets orbiting it. One of these planets is believed to be Earth-like and located in the habitable zone. The relative proximity of Proxima Centauri makes these planets ideal candidates for future visits by interstellar spacecraft.

The TRAPPIST-1 planetary system contains seven Earth-sized planets, some of which are in the habitable zone. This system serves as an ideal laboratory for studying the evolution of Earth-sized planets at different distances from their stars.

Musical Planetary Systems: K2-138 and TOI-178

The K2-138 planetary system is notable for its six planets moving in musical harmony, with some planets orbiting three times in the same period others orbit twice. This phenomenon allows astronomers to understand the processes leading to planet formation.

The TOI-178 system contains a group of tightly packed planets around their star. Theoretical predictions suggest that such systems can form when planets move significantly in their early years.

Conclusion

Planetary discoveries in recent decades have revolutionized our understanding of the universe. Advanced observation techniques and global telescope collaborations have led to the discovery of thousands of new planets, greatly enhancing our knowledge of how planets form and evolve. These discoveries not only expand our astronomical horizons but also open new possibilities for searching for life beyond Earth.