NASA’s Transiting Exoplanet Survey Satellite, or TESS, has recently discovered an Earth-sized rocky planet, which is the second closest known exoplanet to our Solar System. This planet, named HD 21749b, is about three times bigger than Earth and is located about 53 light-years away in the constellation of Reticulum.
HD 21749b is located within the habitable zone of its star, meaning that it could potentially be habitable. This means that it could possibly have liquid water, which is an essential ingredient for life as we know it. However, the planet is too close to its star to be in the habitable zone, so it is likely too hot to be hospitable.
The exoplanet was discovered when TESS observed the star, HD 21749, and found a slight dip in its brightness every 36.6 days. This dip indicated that an object was passing in front of the star, blocking some of its light. After studying the data, scientists concluded that this object was an exoplanet.
HD 21749b is one of the smallest and closest exoplanets to our Solar System, and the first Earth-sized planet to be discovered by TESS. It is roughly one-third the size of Earth and takes 36.6 days to orbit its star. Its temperature is estimated to be around 230 degrees Celsius, which is much too hot for liquid water to exist.
Because HD 21749b is so close to its star, it is tidally locked, meaning that one side of the planet is always facing the star, while the other side is in perpetual darkness. This means that the star-facing side of the planet is much hotter than the dark side.
The discovery of HD 21749b is an exciting development in the search for alien life beyond our Solar System. This exoplanet is a promising candidate for further study, and could provide valuable insight into the conditions necessary for life on other planets.
In addition to HD 21749b, TESS has discovered several other exoplanets in its two-year mission. These discoveries provide further evidence that the universe is filled with planets that may be capable of hosting life. As the mission continues, TESS is certain to discover even more exciting exoplanets, and hopefully some of them will be in the habitable zone.