NASA Points Space Telescope At A Smoldering Super Earth With Lava Rain And Molten Oceans
As NASA's James Webb Space Telescope (JWST) nears readiness, the space agency is already preparing a list of exhilarating targets. One of those targets is a super-hot super-Earth where lava rain falls into molten oceans.
JWST is just weeks away from full operation, according to a post on NASA's website. The space telescope's mirror segments are aligned and its scientific instruments are performing final calibrations. Once those calibrations are complete, the long awaited observations from JWST will begin commencing.
There is no doubt that scientists and astronomers with NASA have a long wish-list of deep space targets for JWST to peer at. Among those planned within the first year are studies of two exoplanets classified as "super-Earths", due to their size and rocky composition. The two planets that the space telescope will train its high-precision spectrographs on are 55 Cancri-e and LHS 3844 b.
Super-hot super-Earth 55 Cancri e is a lava covered exoplanet that orbits less than 1.5 million miles from its Sun-like star. It completes one trip around the star in less than 18 hours. Temperatures on the planet reach far above the melting point of typical rock-forming minerals, and the day-side of the planet is believed to be immersed in molten oceans of lava.
A planet that orbits as close to its star as 55 Cancri e are thought to be tidally locked, which means one side faces the star at all times. This results in the hottest spot on the planet being the one that faces the star most directly. The temperature on the day-side should not vary much over the course of time.
One of the questions that arise with a planet such as this is if it has a thick atmosphere. "55 Cancri e could have a thick atmosphere dominated by oxygen or nitrogen," explained Renyu Hu of NASA's Jet Propulsion Laboratory in Southern California. "If it has an atmosphere, (Webb) has the sensitivity and wavelength range to detect it and determine what it is made of," Hu remarked.
If 55 Cancri e is not tidally locked, however, it could be like Mercury, in that it rotates three times daily for every two orbits. This would result in a day-night cycle for the planet. If this is true, then there is a possibility that "the vapor would cool and condense to form droplets of lava that would rain back to the surface, turning solid again as night falls," according to NASA.
LHS 3844 b is a super-Earth that orbits extremely close to its star, and completes one revolution every 11 hours. Unlike 55 Cancri e, this exoplanet's star is relatively small and cool. Prior Spitzer observations also indicate that the planet is unlikely to have a substantial atmosphere.
Webb will attempt to study the surface of LHS 3844 b, being aided by the lack of an obscuring atmosphere. A team will use MIRI to capture the thermal emission spectrum of the day side of the planet, and then use it to compare to spectra of known rocks.
"It turns out that different types of rock have different spectra," Laura Kreidberg at the Max Planck Institute for Astronomy explained. "You can see with your eyes that granite is lighter in color than basalt. There are similar differences in the infrared light that rocks give off."
The observations of the two exoplanets will be conducted as part of Webb's Cycle 1 General Observers program. The world awaits on pins and needles for the space telescope to begin capturing images of deep space, and unlocking long held secrets the universe has been kept hidden up until now.
Top Image Credit: NASA