A strange ice giant that can’t be explained by previous theory has been discovered by NASA Scientists using the exoplanet-sleuth Transiting Exoplanet Survey Satellite (TESS, which had “first light” on Aug. 7, 2018). The planet, TOI-849 b, is the most massive Neptune-sized planet detected to date, and the first to have a density that is comparable to Earth. The odd proportions of planet orbits a star about 750 light years from Earth every 18 hours, and is 40 times more massive.
There’s been increasing speculation that many of the Milky Way’s more than 4,100 known exoplanets might resemble the ocean worlds of Jupiter’s storied moon Europa and Saturn’s Enceladus. “So if we’re thinking about these places as being possibly habitable, maybe bigger versions of them in other planetary systems are habitable too,” says NASA’s Lynnae Quick about planets with oceans that may be orbiting many of our galaxy’s one trillion stars.
“Plumes of water erupt from Europa and Enceladus, so we can tell that these bodies have subsurface oceans beneath their ice shells, and they have energy that drives the plumes, which are two requirements for life as we know it,” says Lynnae Quick, a NASA planetary scientist who specializes in volcanism and ocean worlds, about speculation that many of the more than 4,000 known exoplanets might resemble some of the watery moons around Jupiter and Saturn. “So if we’re thinking about these places as being possibly habitable, maybe bigger versions of them in other planetary systems are habitable too.”
Andrew Siemion, director of the University of California Berkeley SETI Research Center, recently wrote in an email to The Daily Galaxy that “I suspect there are other intelligent civilizations in the Milky Way Galaxy– we just need to look!” Now, new calculations place an upper limit of 0.18 Earth-like planets per G-type star in our Galaxy, according to University of British Columbia researcher Michelle Kunimoto about six billion rocky, Earth-sized planets orbiting in the habitable zones of Sun-like (G) stars in the Milky Way.
The most abundant types of star in our Milky Way galaxy are red dwarfs, hosting the bulk of our galaxy’s planet population reports NASA’s Hubble Site, which could number tens of billions of alien worlds. Among the more than 4,000 known exoplanets, is planet KOI-456.04 –less than twice the size of Earth, it orbits, Kepler-160, much liker our life-giving G-type main-sequence Sun (image above), sometimes referred to as a yellow dwarf, that formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. And it does so with a star-planet distance that could permit planetary surface temperatures conducive to life.
“Thousands of exoplanets have been identified so far, but little is known about how they form,” says Anthony Boccaletti at the Observatoire de Paris, about observations made with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) that have revealed the first direct evidence of a star system, AB Aurigae, being born. Astronomers know planets are born in dense dusty discs surrounding young stars, like AB Aurigae, as cold gas and dust clump together.
