Two intriguing hot rocky planets somewhat larger than Earth are among the targets planned for the James Webb Space Telescope's first year of investigation.These are lava-covered 55 Cancri e and airless LHS 3844 b.Researchers will train Webb's high-precision spectrographs on these planets with a view to understanding the geological diversity of planets throughout the galaxy and the evolution of rocky planets like Earth.55 Cancri e orbits less than 2.2 million kilometers from its Sun-like star (twenty-five times less than the distance between Mercury and the Sun), completing a circuit in less than 18 hours.With surface temperatures well above the melting point of typical rock-forming minerals, the day side of the planet is thought to be covered in oceans of lava.Planets orbiting so close to their star are assumed to be tidally locked, with one side facing the star at all times.As a result, the hottest spot on the planet should be the one most directly in front of the star, and the amount of heat coming from the day side should not change much over time.But this does not seem to be the case.Observations of 55 Cancri e from NASA's Spitzer Space Telescope suggest that the hottest region is offset from the side that most directly faces the star, while the total amount of heat detected on the dayside varies, NASA reports.One explanation for these observations is that the planet has a dynamic atmosphere that moves heat."55 Cancri e could have a dense atmosphere dominated by oxygen or nitrogen," explained Renyu Hu of NASA's Jet Propulsion Laboratory, who is leading a team that will use Webb's near-infrared camera (NIRCam) and infrared instrument. (MIRI), to capture the thermal emission spectrum of the planet's day side."If it has an atmosphere, Webb has the sensitivity and wavelength range to detect it and determine what it's made of," Hu added.Yet another intriguing possibility is that 55 Cancri e is not tidal locked.Instead, it can be like Mercury, turning three times for every two orbits (known as a 3:2 resonance).As a result, the planet would have a day-night cycle."That could explain why the hottest part of the planet is moving," said Alexis Brandeker, a researcher at Stockholm University who leads another team studying the planet."Just like on Earth, it would take a while for the surface to warm up. The hottest time of day would be in the afternoon, not right at noon."Brandeker's team plans to test this hypothesis by using NIRCam to measure the heat given off by the sunlit side of 55 Cancri e during four different orbits.If the planet has a 3:2 resonance, they will look at each hemisphere twice and should be able to detect any differences between the hemispheres.In this scenario, the surface would heat up, melt, and even vaporize during the day, forming a very thin atmosphere that Webb could detect.At night, the steam would cool and condense to form lava droplets that would rain back to the surface, turning solid again by nightfall.While 55 Cancri e will provide insights into the exotic geology of a lava-covered world, LHS 3844 b provides a unique opportunity to analyze the solid rock on the surface of an exoplanet.Like 55 Cancri e, LHS 3844 b orbits extremely close to its star, completing one revolution in 11 hours.However, because its star is relatively small and cool, the planet is not hot enough for the surface to melt.Furthermore, Spitzer's observations indicate that the planet is highly unlikely to have a substantial atmosphere.While we won't be able to image the surface of LHS 3844 b directly with Webb, the lack of an obscuring atmosphere makes it possible to study the surface with spectroscopy."It turns out that different types of rock have different spectra," explained Laura Kreidberg of the Max Planck Institute for Astronomy."You can see with your eyes that granite is lighter in color than basalt. There are similar differences in the infrared light that rocks emit."Kreidberg's team will use MIRI to capture the dayside thermal emission spectrum of LHS 3844b and then compare it to spectra of known rocks, such as basalt and granite, to determine their composition.If the planet is volcanically active, the spectrum could also reveal the presence of trace amounts of volcanic gases.What time does Stranger Things season 4 premiere on Netflix?Queen Letizia, radiant and with new espadrilles at her appointment with the Book FairThe actor Luis Lorenzo and his wife, accused of poisoning their aunt to deathNews and current affairs portal of the Europa Press Agency.© 2022 Europe Press.The redistribution and redistribution of all or part of the contents of this website without your prior and express consent is expressly prohibited.