Not long ago, we existed in a galaxy with only a few known planetary systems, all of which orbited our Sun. However, a recent slew of findings marks a watershed moment in science: more than 5,000 planets are now verified to dwell within our solar system. The collection catalogs exoplanet sightings that have been published in community scientific journals and validated using various investigative techniques or methodological approaches. So far, 5,000 planets have been discovered, including tiny, rocky worlds like Earth, gaseous goliaths many times the size of Jupiter, and “hot Jupiters” in dangerously tight orbits around their stars.
There are probably hundreds of billions of such planets in our galaxy. The constant bombardment of revelation commenced in 1992, with the discovery of bizarre new worlds around an even more exotic star. It was a pulsar, which is a fast-spinning celestial body that flashes with millisecond outbursts of scorching energy. Scientists discovered satellites in orbit around the pulsar by measuring minor variations in the frequency of the pulses. Ground-based telescopes handled the majority of the work in the formative days, and it took many additional investigations to find the first planet orbiting a sun-like star in 1995. That world was not warm and friendly to live in the way we know it; it was a blazing hot ball of gas that whirled around its host star in only four Earth days. Astronomers discovered these planets by observing star bumps caused by planets tugging on them. Larger worlds were simpler to detect because they caused larger wobbles. Astronomers indicated at the time that they would need to use something called the “transit” approach to identify other Earth-sized planets. This would analyze a star’s light and check for minor changes when a planet passes through it.
Wolszczan, who continues to hunt for exoplanets as a professor at Penn State, believes we are entering a period of discovery that will go above and beyond merely adding additional planets to the list. The Transiting Exoplanet Survey Satellite (TESS), which was deployed in 2018, is still discovering new exoplanets. But, beginning with the newly launched James Webb Space Telescope, enormous next-generation observatories, and their incredibly sensitive equipment could soon collect light from the environments of exoplanets, detecting which gases are there to possibly find tell-tale indicators of liveable circumstances.
In NASA’s release, Jessie Christiansen, scientific director for the exoplanet archive and a research scientist at the NASA Exoplanet Science Institute at Caltech in Pasadena, stated that 5,000 is “not simply a number.” “Each one is a brand-new universe, a brand-new galaxy. “Everyone excites me since we don’t know anything at all about them.” Christiansen, on the other hand, believes that there is still more to learn and uncover. “Now that we have a sufficient number of planets, we can truly slice and dice and question how various types of planets are formed,” or how the lifetimes of stars impact their circling planets. “The more universes we have, the more answers we have,” she continued.