Although we have all complained at some point about the clouds when they have ruined us a sunny daywithout them the Earth would be much more inhospitable. Therefore, the discovery that the James Webb Space Telescope has just made on an exoplanet located 12 light years from us is really interesting.
It’s not ammonia, it’s water. Epsilon Indi Ab is a gas giant even larger than Jupiter, located in a star system made up of two brown dwarfs and a K-type star. This planet is known to have clouds in its atmosphere, just like Jupiter. Given their similarity, one could expect that the clouds of both would have the same composition.
Jupiter’s clouds are basically made up of ammonia. However, when some scientists have analyzed the composition of the clouds of Epsilon Indi Ab with the help of James Webb, they have discovered that there is hardly any ammonia in them. In reality they are composed mostly of frozen water, like what we have here on Earth.
Hotter than expected. The exoplanet Epsilon Indi Ab is located at a distance from its star similar to that which separates Uranus from our Sun. Uranus is a very very cold planet for obvious reasons. However, Epsilon Indi Ab is much larger and younger, so it still retains much of the heat that came with its formation. Although there is no clear figure, it is believed that it may have an average temperature of 0ºC. That may seem cold to us if it catches us on Earth without shelter, but for a planet so far from its planet it is quite hot. That heat is emitted in the form of infrared radiation and this is where the good stuff begins.
James Webb comes into play. The James Webb Space Telescope It has a great ability to detect and measure infrared light. Therefore, it has been with it that these clouds have been analyzed. To do this, the first step was to block the star’s light. If this were not done, it would interfere with the infrared radiation emitted by the planet and could not be analyzed properly. Once this was done, filters that capture 10.6 and 11.3 μm of light were used. Thus, the observation would focus on the planet’s radiation, right in the ranges of interest.
Ammonia crystals are known to block 10.6 μm light when it passes through them. If the clouds of our exoplanet were like those of Jupiter, a large blockage would have been observed in this range. But it wasn’t like that. There must have been another substance in them. By studying the 11.3 μm filters and also observing a slight emission of light at 3 and 5 μm, it was concluded that this other substance must be water. The cloud crystals of Epsilon Indi Ab are frozen water, like on Earth.
A companion in the rear. Since water clouds are very important for the habitability of a planet, this finding demonstrates James Webb’s ability to analyze one more factor when searching for terrestrial analogues beyond our solar system. The best thing is that, as NASA announced this weekthe Roman Space Telescope, which will be launched in September if all goes well, can join forces with those of the James Webb, providing even more precise results. Perhaps we are facing the perfect team to find that planet we have been searching for for so long.
Image | EC Matthews, MPIA / T. Müller, HdA
GIPHY App Key not set. Please check settings