Scientists at NASA's Transiting Exoplanet Survey Satellite, an MIT-led mission, discovered an "ultrahot Jupiter" that's about five times Jupiter's mass and revolves around its star in 16 hours. The planet, TOI-2109b, has shortest orbit of any known gas giant to date. Its day side is estimated to be around 6,000 degrees Fahrenheit, making it the second hottest detected so far.