Acquisition of NASA’s James Webb target: a super-Earth covered in oceans of lava

Showtime draws closer to NASA’s cutting-edge mission to unveil an unfiltered universe and redefine “stargazing” fantasy. After a successful journey so far – having achieved milestones such as traversing a million miles from Earth and aligning its 18 gold-plated hexagonal mirrors – the James Webb Space Telescope is just “weeks” away from its fully functioning, according to the agency.

In preparation for Webb’s earliest cosmic discoveries, NASA is accumulating a list of exciting interstellar targets. On Thursday, he announced two that certainly don’t disappoint: a pair of scorching super-Earths that roughly resemble Star Trek worlds.

One is covered in oceans of lava and the other exists without an atmosphere.

“They will give us fantastic new insights into Earth-like planets in general, helping us understand what early Earth was like when it was warm like these planets are today,” said Laura Kreidberg of the Institute. Max Planck astronomy. statement.

Exoplanet muse n°1

First, we have exoplanet 55 Cancri e, or as NASA puts it, a super hot super-Earth.

This rocky orb is about 40 light years away from us – a light year is the distance light travels in a year – and is 8.63 times the mass of our planet.

55 Cancri e orbits a sun-like star, similar to the unbreakable bond between Earth and the sun, but since it is less than 1.5 million kilometers from this star, it is extremely hot. Extremely. Hot. For context, the Earth orbits the sun at a distance close to 95 million miles. This is why scientists believe that the rocks of 55 Cancri e are literally melting into oceans of lava. And that’s not even the weirdest part.

This ultra-hot planet’s proximity to its “sun” also leads to a major mystery, and it’s one Webb is well equipped to solve.

“Planets orbiting this close to their star are assumed to be tidally locked,” NASA said, meaning one side of the planet must face the star at all times. Intuitively, scientists think that such a tidal lock would make the side of the planet facing the stars much hotter than the other, and that this level of heat shouldn’t really fluctuate. But… 55 Cancri e does not seem to have these characteristics.

One possible explanation, however, is that “55 Cancri e could have a thick atmosphere dominated by oxygen or nitrogen,” Renyu Hu of NASA’s Jet Propulsion Laboratory in Southern California said in a statement. Or, alternatively, Alexis Brandeker, a Stockholm University researcher who leads another team studying 55 Cancri e, suggests we might be wrong about 55 Cancri e’s tidal lock in the first place.

“That could explain why the hottest part of the planet is shifting,” Brandeker said. “Just like on Earth, it would take time for the surface to warm up. The hottest time of day would be in the afternoon, not just at noon.” If Brandeker is right, it’s also quite likely that 55 Cancri e is not just home to oceans of lava, but also to lava rain.

This is where Webb comes in.

On the one hand, Hu and his fellow researchers are determined to get to the bottom of things by taking Webb’s revolutionary Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) to the dayside of the planet. Both technologies harness the power of infrared imaging to see what the human eye can’t see.

Light emanating from the infrared region of the electromagnetic spectrum is essentially invisible to us, but these instruments can pick up these photons, even when they come from deep space, and translate them into signals readable by us mere mortals. “If there is an atmosphere, [Webb] has the sensitivity and wavelength range to detect it and figure out what it’s made of,” Hu said of 55 Cancri e.

And on the other hand, Brandeker and his fellow researchers also plan to use NIRCam to measure the heat emitted from the illuminated side of 55 Cancri e during four different orbits.

Exoplanet muse n°2

A little further from us than 55 Cancri e – 48 light years to be exact – is another very hot, though technically cooler, extrasolar planet called LHS 3844 b. This one is something like 2.25 times the mass of Earth and orbits a red dwarf star called LHS 3844. The planet’s main attraction is that it doesn’t seem to have… air ?

Or rather, it has no “substantial atmosphere,” NASA said.

Webb can decode the secrets of this planet using his powerful infrared spectroscopy mechanisms. NIRCam may not work in this case due to lack of atmosphere, but MIRI might. MIRI cannot exactly “image” LHS 3844 b, but it can detect the presence of different rock compositions, such as granite or basalt, and possibly even volcanic gas – if the planet is volcanically active, that is- to say.

“It turns out that different rock types have different spectra,” Kreidberg said. “You can see with your eyes that granite is lighter in color than basalt. There are similar differences in the infrared light emitted by rocks.”

And while both of these exoplanets are truly impressive Webb science targets, they only scratch the surface of what this telescope could do for astronomy in the next few years. Researchers around the world have already added informally to Webb’s arsenal, such as a team identifying alien biosignatures and another team focusing on a supermassive black hole ancestor.

This multi-billion dollar high-tech bezel could solve the riddle of why Neptune is getting weirdly cool and maybe even give us a glorious, twinkling view of Earendel, the most distant star ever seen by scientists. humans.

Only time will tell. The ball is in your court, Webb.