Earth is our only example of a habitable planet, so it makes sense to search for Earth-size worlds when we’re hunting for potentially-habitable exoplanets. When astronomers found seven of them orbiting a red dwarf star in the TRAPPIST-1 system, people wondered if Earth-size planets are more common around red dwarfs than Sun-like stars.
Prediction is one of the hallmarks of scientific endeavors. Scientists pride themselves on being able to predict physical realities based on inputs. So it should come as no surprise that a team of scientists at Notre Dame has developed a theory that can be used to predict the existence of giant planets on the fringes of an exoplanetary system.
A recent study published in the Proceedings of the National Academy of Sciences, a pair of researchers from the University of Florida (UF) examine orbital eccentricities for exoplanets orbiting red dwarf (M dwarf) stars and determined that one-third of them—which encompass hundreds of millions throughout the Milky Way—could exist within their star’s habitable zone (HZ), which is that approximate distance from their star where liquid water can exist on the surface. The researchers determined the remaining two-thirds of exoplanets orbiting red dwarfs are too hot for liquid water to exist on their surfaces due to tidal extremes, resulting in a sterilization of the planetary surface.
Exoplanets have become quite the sensation over the last decade-plus, with scientists confirming new exoplanets on a regular basis thanks to NASA’s Kepler and TESS missions, along with the James Webb Space Telescope recently examining exoplanet atmospheres, as well. It’s because of these discoveries that exoplanet science has turned into an exciting field of intrigue and wonder, but do the very same scientists who study these wonderful and mysterious worlds have their own favorite exoplanets? As it turns out, four such exoplanet scientists, sometimes referred to as “exoplaneteers”, were kind enough to share their favorites with Universe Today!
NASA’s Kepler planet-hunting spacecraft was deactivated in November 2018, about ten years after it launched. The mission detected over 5,000 candidate exoplanets and 2,662 confirmed exoplanets using the transit method. But scientists are still working with all of Kepler’s data, hoping to uncover more planets in the observations.
A team of researchers have announced the discovery of one more planet in the Kepler data, and this one is nearly a twin of Jupiter.
Looking to the future, astronomers are excited to see how machine learning – aka. deep learning and artificial intelligence (AI) – will enhance surveys. One field that is already benefitting in the search for extrasolar planets, where researchers rely on machine-learning algorithms to distinguish between faint signals and background noise. As this field continues to transition from discovery to characterization, the role of machine intelligence is likely to become even more critical.
Take the KeplerSpace Telescope, which accounted for 2879 confirmed discoveries (out of the 4,575 exoplanets discovered made to date) during its nearly ten years of service. After examining the data collected by Kepler using a new deep-learning neural network called ExoMiner, a research team at NASA’s Ames Research Center was able to detect 301 more planetary signals and add them to the growing census of exoplanets.
When it comes to finding exoplanets, size matters, but so does weight. The larger and heavier the planet, the more likely they will be discovered by the current crop of telescopes. Both the techniques to find exoplanets and the telescopes using those techniques are biased toward larger, heavier planets. So when even the current crop of telescopes manages to find one that is about half the mass of Venus, it is cause for celebration. That is precisely the size of the planet a team from the European Southern Observatory’s Very Large Telescope has found orbiting a star called L98-59.
200 light years away, “super earth” exoplanet K2-141b orbits a star so closely that its “year” is only 7 hours long. Not its day…its YEAR! K2-141b orbits a mere million kilometers from the fiery surface of its star. Earth is 150 million km from our Sun. Even Mercury, the planet closest to our Sun, is never less than 47 million km. Standing on the surface of K2-141b you’d look up at an orange star that filled fifty degrees of the sky appearing a hundred times wider than our Sun appears in Earth’s sky. It would be a giant blazing orb so bright that its light shines two thirds of the way around the entire planet unlike Earth’s two day/night halves. Of course, the surface you’re standing on wouldn’t be much of a surface at all – it would be an ocean of liquid hot magma.
REMINDER: – Universe Today will be hosting an interview with Dr. Dirk Schulze-Makuch, co-author of the research featured in this article, on Thursday October 15th, 2020 at 8:30am PT. Click the video below to watch live or to see the recorded stream afterward
Out Earthing Earth
What planet is this?
If you said Hoth, that’s a good guess. But, it’s actually Earth depicted in one of two known “snowball” states. The entire planet’s surface was locked beneath glacial ice during the Cryogenian Period 650 million years ago and during the Huronian Glaciation 2 – 2.4 billion years ago.