We know thousands of them, and we are discovering more and more quickly: exoplanets sometimes turn out to have strange properties. We propose to look at some of them in this episode of Swipe Into Space.
In 2019, a 17-year-old high school student, Wolf Cukier, then an intern at NASA for only three days, spotted an anomaly. In data collected by a satellite launched a year ago, a mysterious object eclipses the light emitted by a double star periodically. After several hypotheses, the answer arrives: it’s a new planet he has just discovered!
Just like Tatooine in Star Wars, it is a circumbinary planet, that is to say in orbit around two stars. A rather exceptional feature, because of the more than 4,000 exoplanets listed, less than 20 have two suns! Now known as YOU 1338b, this new planet would take a 1300 year journey at the speed of light to reach!
Many unusual planets
Most of the exoplanets discovered are outside the habitable zone. There are very often extreme conditions, as on Gliese 581C. Located 20 light years from Earth, this gravitationally locked planet with its star always shows it the same face, just like the Moon with Earth. So much so that its sunlit side would char you instantly, while its shaded side would freeze you in place. But on its equator, the temperature would constantly fluctuate between 0°C and 40°C, precisely enough to support life.
Another planet surprised astronomers, who studied its chemical composition. Called 55 Cancri e, it contains a concentration of carbon that is far too high, which researchers have associated with a heart filled with diamonds! This very particular form of carbon is formed hundreds of kilometers under the Earth’s mantle, under very precise temperature and pressure conditions. This is why today it is impossible to create them artificially. But on 55 Cancri e, the abundance of these diamonds would represent a mass greater than that of the Earth!