It’s official: Humans have found 6,000 planets beyond our solar system
The age of exoplanets began in 1992, when astronomers detected a pair of orbit planets around a pulsar. Then, in 1995, astronomers discovered the first orbit exoplanet around a main sequence star. While the NASA Kepler and Tess missions took place, the number of confirmed exoplanets continued to increase.
In 2015, NASA announced that Kepler had discovered its 1000th exoplanet. 2016 was a record year for exoplanet detections with almost 1500 this year only. The total number reached 5,000 in March 2022. Nas NASA announced that there were 6,000 confirmed exoplanets.
Exoplanet Science is obviously more than numbers. The variety of planets we have discovered teaches us vital things about nature, our own solar system and on precious earth. Curiously, many of the planets that we have discovered are like nothing in our own solar system.
There are hot jupiters, massive gas giants that orbit their stars in a few days. There are planets at an ultra-short period which shame the short orbital period of Mercury by filling the orbits in a few hours. A strange type of planet is so close to their stars that they are locked at the tide in their star as the moon is on earth. These planets have a hot hot side and an icy side. Some of them can be hot enough to stay melted.
Others have temperatures, pressures and chemical constituents as extreme as they can rain in iron, or can be denser than polystyrene foam. Some may be covered in the oceans. Others have wrapped in toxic gases.
In one way or another, they are all part of nature. Determine how they have become a lasting fascination.
But at the base of all this research and wondering is the only big question: are we alone?
“Each of the different types of planets that we discover gives us information on the conditions in which the planets can form and, in the end, how common planets could be common and where we should look for them,” said Dawn Gelino, head of the NASA exoplanet Exoplanets Exploration Program (EXEP) at the South Jet of the Agency. “If we want to know if we are alone in the universe, all this knowledge is essential.”
The vast majority of exoplanet detections are indirect. The transit method detects the planets by measuring the amount of light from an exoplanet when it passes in front of its star. The radial speed method detects the light prints that exoplanets give to their stars and measure how the star light changes by vacation. Astrometry detects tiny movements and in the gravitational lens, the presence of a planet introduces anomalies in the observed light. Kepler and Tess used the transit method, and this method is responsible for most exoplanet detections with nearly 4,500. The radial speed is then with around 1140 detections.
Although effective, they are indirect. Only direct imagery can measure the chemistry of exoplanet atmospheres and does not require particular alignments or orbital orientations. But it is difficult, and less than 100 exoplanets have been directly imagined.
6,000 confirmed exoplanets are a defined and concrete scientific step. But there are thousands of other candidates, and it takes a lot of work to confirm a candidate. Something else could create the signal, such as a stellar torchage or artifacts with the transit method. The follow -up observations, sometimes with a different telescope, confirm them, and it takes a lot of time and observing resources. In July 2025, Tess had a list of 7,655 exoplanet candidates, a little more than 600, were confirmed.
“We really need the whole community by working together if we want to maximize our investments in these missions that produce exoplanet candidates,” said Aurora Kesseli, the head of assistant science for the NASA exoplanet archives at IPAC. “A large part of what we do in Nexsci is to build tools that help the community get out and transform candidate planets into confirmed planets.”
We could face an overabundance of exoplanet discoveries which was unimaginable a few decades ago.
The candidate exoplanets are still in the Gaia data, even if this mission ended. The nancy nancy grace spatial telescope of NASA, which should be launched in 2027, unless the threats of the current administration to cancel it that has become reality, should discover thousands of others by microlensage.
The age of exoplanets begins to change. Our research becomes more targeted. Rather than launching a large net and seeing what they catch, astronomers seek to find more specific types of exoplanets. Plato de l’ESA is about to detect many other rocky exoplanets around the sun -shaped stars after its launch in 2026. The observatory of habitable worlds is only a proposal at this stage, but it will seek habitable exoplanets in habitable areas and will also contribute to the list of exoplanets in balloon. Other missions, such as Cheops and Ariel, will study the exoplanets known in more detail.
The Holy Grail in exoplanet science is habitability. Many fall into the determination of habitability, with only a few exoplanets displaying any possibility of being habitable. The key is to find biosignatures, special chemicals that tell us that life is active on a planet. The JWST with its infrared atmospheric spectrometry, is just starting to solve this problem and has already produced attractive resultsAlthough nothing concrete yet.
Like all scientific efforts, the search for exoplanets has been stimulated by technological advances, and this will continue in the future. One of the great obstacles of exoplanet science concerns that the stars that orbit the planets. The stars are extraordinarily shiny and the presence of a relatively low exoplanet can be completely obscured by Starlight. This is particularly true in targeted researchers of earth -shaped worlds around stars similar to a sun like the observatory of habitable worlds (HWO) is designed to detect.
The Hwo will need a powerful corongaph or starshade to do its job. If a distant astronomer was looking for the earth around the sun, he would find it difficult to detect it in all this star light. This is indeed what astronomers will do with the Hwo.
China is starting to take advantage of its technological prowess in the exoplanet sphere. Its Earth 2.0 space telescope (and) is expected to be launched in 2028 and will spend four years looking for exoplanet transits. This is the first dedicated exoplanets hunting mission of China and focuses on exoplanets on the size of the earth.
Finally, we will have a list of confirmed exoplanets in the shape of an earth around the sun -shaped stars. Then, we are faced with an even more difficult task: to determine if one of these worlds really organizes life.
THE original version of this article was published on Universe today.
