One of the seemingly quixotic goals of exoplanet scientists is to understand the chemical and geo-chemical compositions of the interiors of the distant planets they are finding. Learning whether a planet is largely made up of silicon or magnesium or iron-based compounds is essential to some day determining how and where specific exoplanets were formed in their solar systems, which ones might have the compounds and minerals believed to be necessary for life, and ultimately which might actually be hosting life.
Studying exoplanet interiors is a daunting challenge for sure, maybe even more difficult in principle than understanding the compositions of exoplanet atmospheres. After all, there’s still a lot we don’t know about the make-up of planet interiors in our own solar system.
An intriguing pathway, however, has been proposed based on the recent discovery of exoplanets in the process of being shredded. Generally orbiting very close to their suns, they appear to be disintegrating due to intense radiation and the forces of gravity.
And the result of their coming apart is that their interiors, or at least the dust clouds from their crusts and mantles, may well be on display and potentially measurable.
“We know very little for sure about these disintegrating planets, but they certainly seem to offer a real opportunity,” said Jason Wright, an astrophysicist at Pennsylvania State University with a specialty in stellar astrophysics. No intensive study of the dusty innards of a distant, falling-apart exoplanet has been done so far, he said, but in theory at least it seems to be possible.
And if successful, the approach could prove broadly useful since astronomers have already found at least four of disintegrating planets and predict that there are many more out there. The prediction is based on, among other things, the relative speed with which the planets fall apart. Since the disintegration has been determined to take only tens of thousands to a million years (a very short time in astronomical terms) then scientists conclude that the shreddings must be pretty common –based on the number already caught in the act.… Read more