The planets in our solar system have been the focus of most studies for a long time. After all, scientists had reason to believe that these were the only planets in the universe. But this soon changed when they discovered the first exoplanet. We look at what this planet entails and how the first sighting set the wheels in motion for more advancements in this field.
Reviewing the Exoplanet
Exoplanets are planets that are not in our solar system. Some of these are rogue such that they do not orbit any star, while most orbit a star. Since their discovery was recent, much of the information on them is still in the developmental phases, creating a gap that researchers are working hard to fill. So far, research points to the following attributes.
Size and structure
These planets vary in their composition and masses. The first category is gas giants – these are big (similar to Jupiter) and comprise gases in their atmosphere. They do not have solid surfaces but can instead have liquid if their pressures increase. Rocky planets make up the second category. Like our planet, they have solid surfaces and comprise a mix of rock and metal, making them habitable and increasing the possibility of liquid water. In the third category, we have ice giants. They also comprise rock and metal in their cores but often have water, methane, ice, and ammonia in their atmospheres.
Orbiting
Some planets do not follow orbits and float freely in space. Those that orbit do so at varying speeds based on their nearness to their stars. Those that are close to their stars have short orbital periods and are often within the habitable zone due to this proximity. But those that are far away often have long periods and fall outside the habitable zones.
Atmospheric conditions
Atmospheres depend on the size and composition of the planet. Those comprised of gas often have gases. But those with solid surfaces can have thin atmospheres or no atmospheres at all. Some also have pressurized atmospheres due to thick layers that can make it hard for life forms to survive.
Temperatures
Planets that are very near their stars experience a lot of heat, with ranges in the thousands of degrees Celsius. Conversely, those far from their stars are often very cold, and preliminary studies indicate that they could have ice surfaces. At the same time, many of these planets are tidally locked such that one side will face the star and experience high temperatures while the other will remain cold and in darkness.
The combination of these factors helps scientists understand whether a planet can prove habitable in the long term.
A Journey Through Discoveries
Before 1992, the concept of an exoplanet was just that – a concept. But the numbers now stand at just over 5,500. How did we get here?
- 1917. While the first confirmation was in 1992, an astronomer first discovered the possibility of other planets in this year. However, the evidence was inconclusive.
- 1988. An astronomer discovered what they thought was a planet around Gamma Cephei. But like with other past cases, there wasn’t enough evidence to warrant its confirmation – this changed in 2003 when the same planet was sighted and confirmed.
- 1992. Astronomers confirmed the first exoplanets this year. Interestingly, these planets were orbiting a neutron star.
- 1995. 51 Pegasi b made its way to historical books this year. Not only could scientists confirm its existence, but they were also able to prove that it orbited a star similar to our Sun.
- The Early 2000s. The findings in the 1990s prompted researchers to push for more advanced methods that would enable them to sight and confirm more planets. As such, they came up with new detection methods, including the transit method, which allowed astronomers to quickly find and confirm planets.
- The Late 2000s. 2009 was a milestone year in the field of astronomy as NASA launched the Kepler Space Telescope, which relied on the transit method. Its ability to map out planets while filtering for distractions was instrumental in the discovery of thousands of other planets.
- 2010 to 2020. In 2015, astronomers marked the discovery of the 1,000th planet – this was thanks to the Kepler Space Telescope. The year after, they laid eyes on Proxima b, a planet that has sparked a lot of interest in the possible habitability of exoplanets.
- 2020 to date. Astronomers now have more than 5,500 planets to study. The number keeps growing as advances in technology allow researchers to discover even more planets, adding to the diversity of the current list.
Predictions show that some of the discoveries could have the habitability answers researchers have been looking for all along.
The Impact of These Discoveries
Astronomers are over the moon with these new findings. After all, they pave the way for the following advances:
They help us understand our planets more
One key perspective that these studies have introduced is diversity. Researchers now have thousands of planets to compare when modeling planet formations, which allows them to offer more accurate perspectives.
They might be habitable
Many of the discoveries are within the habitable zones. As such, it is likely that their atmospheric conditions and temperatures could be suitable for life forms. Moreover, with the recent technological advances, scientists will have the means to scan the planets for signs of life.
They have fostered innovation
As they say, necessity is the mother of invention. Such is the case in this field. As researchers pushed for more data, they created a gap which was met with new technologies and detection methods, allowing scientists to uncover more about the planets and other beings in the universe.
They have provided insights into stars
The quest for information about planets has also shone a light on the stars they orbit. We now have more information on their compositions, stellar flares, and other characteristics that help us understand how these changes could affect our planet.
What’s more, these discoveries have led to renewed interest in the world of astronomy, not just for people in the field but also for students who wish to take up related careers.
Conclusion
The sighting of the first exoplanet opened the world up to countless possibilities. As scientists gain more understanding of these planets, we will get more answers to pertinent questions regarding how planets came to be and whether there could truly be life outside our solar system.