NASA has announced the discovery of dozens of new exoplanets, pushing the total number to more than 5,000. Exoplanets are planets that lie outside this solar system. The first confirmation of an exoplanet happened only in 1992, but thousands more have been detected in the last thirty years. NASA discovered its 4,000th exoplanet in June 2019, and it has taken the agency less than three years to find 1,000 more.

Most exoplanets roam around a star, just like the Earth and other planets in this solar system orbit around the sun. However, many of the exoplanets are also ‘rogue planets,’ which are rare cosmic bodies comparable in mass to regular planets but do not have a star to orbit around. Researchers have also found rogue exoplanets reasonably frequently and discovered “at least 70” of them just last December.

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NASA’s Jet Propulsion Laboratory (NASA JPL) has confirmed the discovery of more than 5,000 exoplanets in a cosmic milestone that it claims marks a new scientific high point. On Monday, NASA reached the milestone after finding a new batch of 65 planets outside this solar system. The new discoveries are part of the NASA Exoplanet Archive, which records confirmed discoveries of exoplanets. Many more such findings are expected to be made in the coming years, especially with the Nancy Grace Roman Space Telescope expected to be deployed in 2027.

Exoplanets Vastly Differ From One Another

Image Courtesy: NASA/JPL-Caltech

According to NASA, the discovered exoplanets include a wide variety of cosmic bodies, including some that are similar to planets in this solar system, while others are vastly different. For example, some of the exoplanets are rocky worlds like Earth, while others are gas giants many times larger than Jupiter. Then there are ‘hot Jupiters,’ which revolve around their stars in extremely close and tight orbits, making them scorching hot.

Some of the exoplanets are also described as Super-Earths, which range in size between that of the Earth and Neptune, and are primarily rocky worlds like Earth. Two other types of exoplanets are Mini Neptunes and Neptune-like. While the former are smaller versions of Neptune, the latter are similar in size to Neptune and Uranus but can be ice giants or much warmer. Some exoplanets orbit not one but two stars at the same time. Yet others orbit around the collapsed remnants of dead stars.

Researchers believe that the 5,000-odd exoplanets discovered thus far represent just a tiny fraction of the total number of such celestial bodies. According to NASA estimates, there are likely “hundreds of billions” of exoplanets in the Milky Way galaxy. With the discovery of new planets in full swing, NASA believes that someday it might stumble upon potentially habitable planets “or even habitable worlds,” which will undoubtedly be a game-changer in more ways than one.