There is new light on the “lava planets”

Through unprecedented numerical simulations, a new study provides for two extreme evolutionary states.

A new study in the journal Nature Astronomy introduces a simple theoretical structure to describe the evolution of the interior-atmosphere coupled system of hot rock exoplanets known as “Lava Planets”.

“Lava planets are in such extreme orbital configurations that our knowledge of rocky planets in the solar system does not apply directly, leaving uncertain scientists what to expect when watching Lava planets,” the first author Charles-Isouard Boukaré, assistant professor at the Faculty of Science and Astronomy at the York University Faculty of York, Canada.

“Our simulations propose a conceptual picture to interpret their evolution and provide scenarios to investigate their internal dynamics and chemical changes over time. These processes, although expanded on the lava planets, are fundamentally the same as shaping the rocky planets of our own solar system.”

Exotic worlds can reveal processes that drive planetary evolution

The lava planets are worlds with sizes ranging between the earth’s and a super terra, orbiting extremely close to their host stars and completing an orbit in less than a terrestrial day.

Very Side to the Moon of the EarthIt is expected to be coupled with tide, always showing the same face to their star.

Its daytime surfaces reach temperatures so extreme that silicated rocks are melted – and even vaporized – creating different conditions of everything in our solar system. These easily observable exotic worlds due to their ultra -cuid orbital period, provide unique information on the fundamental processes that shape planetary evolution.

Investigating planetary interiors through the properties of the atmosphere and the surface

The study combines knowledge in geophysical fluid mechanics, exoplanetary atmospheres and mineralogy to explore how the lava planet compositions evolve through a distillation -like process.

When rocks melt or vaporize, elements such as magnesium, iron, silicon, oxygen, sodium and potassium are differently between vapor, liquid and solid phases.

The unique orbital configuration of the Lava planets maintains the liquid and solid-liquid vapor balances over millions of millions of years, boosting long-term chemical evolution.

Using unprecedented numerical simulations, the team foresees two extreme evolutionary states:

• Interior totally melted (probably young planets): The atmosphere reflects the general planetary composition, and heat transport within the melted interior keeps the surface on the hot and dynamic night side;
• Predominantly solid interior (probably older planets): Just a shallow lava ocean on the daytime side, and the atmosphere is impoverished in elements such as sodium, potassium and iron.

Testing hypotheses with James Webb

Boukaré explains that this research on Lava exoplanets began as a highly exploratory effort, with little initial expectations. It is based on a new modeling approach he has developed to study melted rocky planets, in collaboration with colleagues from PHGP (Institut of Physique Du Globo de Paris), University of Paris, published in the journal Nature earlier this year.

What began as an exploratory study opened a promising new line of investigation. The forecasts described in this paper helped to guarantee 100 hours of observation time in the James Webb (JWST) space telescope – the most advanced infrared observatory ever built, with a 6.5 meter segmented mirror and ultrasound instruments to probe the older galaxies and the atmospheres of distant exoplanets with one unprecedented accuracy. These next observations of JWST, led by co -author Lisa Dang, from the University of Waterloo, will directly test the theoretical framework proposed in this study.

“We really hope to be able to observe and distinguish old lava lava lava planets. If we can do this, it will be an important step in going beyond the traditional instant view of exoplanets,” says Boukaré.