Researchers have also promised that the search for these distant worlds will accelerate as new generation telescopes are launched.
What do you need to know?
So, the science of exoplanets has reached a new milestone. NASA has announced that there are now 6,000 confirmed exoplanets. They vary widely in type and size, as well as the types of stars they orbit.
The era of exoplanet discovery began not too long ago—in 1992. At that time, found a pair of such objects orbiting a pulsar. Then, in 1995, scientists discovered the first exoplanet orbiting a main-sequence star (the type of star that is young enough to be visible in the optical range, unlike protostars). With the launch of NASA’s Kepler and TESS missions, the number of confirmed exoplanets continued to grow.
By 2015, the agency announced that the Kepler telescope had discovered its thousandth exoplanet. The year 2016 was significant for the number of discovered distant worlds, as scientists identified nearly 1,500 such objects that year alone. By March 2022, the total number of discovered exoplanets reached 5,000.
And now NASA has confirmed that there are already a thousand more. Is that a lot? Compared to the hundreds of billions of exoplanets that may exist in the , it’s quite small. However, for a young space-faring civilization like ours, it’s a reason to celebrate.
The fact is impressive considering how difficult it is to detect these distant worlds, primarily due to the vast distances that separate us from them. Many exoplanets are hidden in the bright light of their stars or are located incredibly far from them.
The science of exoplanets is not just about numbers. These discovered planets shed light on the mysteries of our Solar System and Earth, as noted by Live Science.
Many of the discovered exoplanets are unlike any others. Among them are hot Jupiters—massive gas giants that complete an orbit around their star in just a few days. There are also planets with ultra-short orbital periods lasting mere hours. Some are so close to their stars that they are tidally locked, like our Moon is to Earth.
There are planets with extremely extreme temperatures, pressures, and chemical compositions. It may rain iron on some of them. Some are covered by oceans, while others are shrouded in toxic gases.
Why search for them?
All these searches boil down to one big question: are we alone in the universe?
“Each type of planet we discover gives us information about the conditions of their formation and, ultimately, about how common Earth-like planets are and where we should look for them,” said Don Helin, head of NASA’s Exoplanet Exploration Program at the Jet Propulsion Laboratory. According to her, if humanity wants to find out whether we are alone in the universe, all this knowledge is essential.
The vast majority of exoplanet discoveries are made indirectly. The transit method allows scientists to find a planet by measuring the amount of light it blocks as it passes in front of its star. Meanwhile, the radial velocity method can detect small wobbles that exoplanets induce on their stars and assess how the star’s brightness changes due to these fluctuations.
Kepler and TESS, for example, used the transit method, which helped them discover the largest number of exoplanets—around 4,500. Meanwhile, the radial velocity method is the next most effective, having led astronomers to discover about 1,140 exoplanets.
However, only direct imaging allows scientists to determine the chemical composition of exoplanet atmospheres. Currently, this process is technologically challenging, so the number of direct images of these planets is only around 100.
6,000 confirmed planets beyond our Solar System is a significant scientific milestone. But there are still many potential exoplanets—so to speak, candidates waiting to be identified. As of July 2025, the TESS list contained 7,655 exoplanet candidates, of which just over 600 have been confirmed.
However, the era of exoplanets is beginning to change. Researchers are becoming more targeted in their searches. They are focusing on identifying specific types of planets. After the launch of the European Space Agency’s (ESA) PLATO spacecraft in 2026, it will seek as many rocky exoplanets as possible around sun-like stars. NASA’s Habitable Worlds Observatory, which is still in development, will concentrate on finding distant planets suitable for life. Meanwhile, missions like ESA’s CHEOPS and ARIEL will be dedicated to the in-depth study of already known exoplanets.
Photo: NASA