The James Webb Telescope will only be fully operational in a handful of weeks, but its first missions have already been scheduled by NASA. One of them will aim to study the geological diversity of the planets of our galaxy.
For this, two exoplanets have been selected, and the first information about them is already very interesting.
A promising mission
Positioned about 1 million kilometers from Earth, the famous James Webb telescope managed to perfectly align its 18 mirrors last January. And if the space scientific observatory is not yet fully ready to reveal its full potential, several targets have been chosen to be analyzed in depth. The lucky ones are 55 Cancri e and LHS 3844 b, exoplanets of which we already know certain particularities.
Laura Kreidberg, from the Max Planck Institute of Astronomy, explains in particular that observing them will make it possible to obtain ” fantastic new perspectives on Earth-like planets “, while helping us to ” understand what early Earth looked like when it was warm, like on these planets today “. Indeed, the two exoplanets in question seem inhospitable to say the least…
A very warm study
55 Cancri e is probably not very welcoming. Located 40 light-years from Earth, the planet orbits less than 2.5 million kilometers from a star quite similar to our Sun. The temperatures there therefore exceed the melting point, and it is a safe bet that its surface is covered by oceans of lava. Also, given its proximity to its star, the exoplanet is supposed to undergo a gravitational locking phenomenon. This means that 55 Cancri e would always present the same face to the star in question.
Yet NASA’s Spitzer Space Telescope noticed that the hottest region, which should be the one facing the star, is actually offset. This observation could be explained by the fact that a dynamic atmosphere rich in oxygen or nitrogen would displace heat. It will be up to dear James Webb to affirm or invalidate this hypothesis.
A bit of freshness (but not too much anyway)
Finally, LHS 3844 b is intended to be colder (while remaining very warm) than 55 Cancri e. This second exoplanet is also extremely close to its star, since it completes a complete revolution in just 11 hours. However, the surface would not be covered with lava, but with solid rock. This (relative) coolness would originate from the fact that the star is actually quite small and cold. Still according to the data collected by Spitzer, LHS 3844 b would also be devoid of “ substantial atmosphere “.
This parameter could favor the study of the surface that Webb will be able to perform via infrared spectroscopy mechanisms. This technique will detect the hypothetical presence of rocky elements such as granite or basalt, and even volcanic gas, if volcanoes are still active. This is going to be exciting!
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The James Webb Telescope is almost ready and is practicing to track “near” objects
Source : NASA
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