
A world called TOI-849b could be the exposed, naked core of a former gas giant planet whose atmosphere was blasted away by its star. Every day is a bad day on planet TOI-849b. . It hugs its star so tightly that a year – one trip around the star – takes less than a day. And it pays a high price for this close embrace: an estimated surface temperature of nearly 2,800 degrees Fahrenheit (1,500 degrees Celsius) It’s a scorcher even compared to Venus, which is 880 degrees Fahrenheit (471 degrees Celsius). About half the mass of our own Saturn, this planet orbits a Sun-like star more than 700 light-years from Earth. (NASA/Exoplanet Exploration Program)
The more we learn about the billions upon billions of planets that orbit beyond our solar system, the more we are surprised by the wild menagerie of objects out there. From the start, many of these untolled planets have been startling, paradigm-breaking, mysterious, hellish, potentially habitable and just plain weird. Despite the confirmed detection of more than 4,000 exoplanets, the job of finding and characterizing these worlds remains in its early phases. You could make the argument that learning a lot more about these distant exoplanets and their solar systems is not just one of the great tasks of future astronomy, but of future science.
And that is why Many Worlds is returning to the subject of “Weird Planets,” which first appeared in this column at the opening of 2019. It has been the most viewed column in our archive, and a day seldom goes by without someone — or some many people — decide to read it.
So here is not a really a sequel, but rather a continuation of writing about this unendingly rich subject. And as I will describe further on, almost all of the planets on display so far have been detected and characterized without ever having been seen. The characteristics and colors presented in these (mostly) artistic renderings are the result of indirect observing and discovery — measuring how much light dims when a faraway planet crosses its host star, or how much the planet’s gravity causes its sun to move.
As a result, these planets are sometimes called “small, black shadows.” Scientists can infer a lot from the indirect measurements they make and from the beginnings of the grand effort to spectroscopically read the chemical makeup of exoplanet atmospheres. … Read more