Crack open the Exoplanet Encyclopedia today and you’ll learn that the number of extra-solar planets now stands at 763. While many are more massive than Jupiter and orbit their suns in less than a day, a few are Earth-sized or smaller and orbit in the “Goldilocks Zone” where liquid water might exist. Of all these alien worlds, surely the strangest is the one scientists have nicknamed “Fluffy”.
Discovered just days ago, CHARR b orbits a fiery yellow giant star in the southern constellation Fornax the Furnace. Based on its orbital period – a mere 6 minutes – and the degree it dims its host star during eclipses, astronomers have determined CHARR b’s density at just .37 grams per milliliter. That makes it the least dense of all the planets discovered to date. Indeed, CHARR b appears to have the consistency of a marshmallow.
More recent observations with the infrared-sensitive eyes of the Spitzer Space Observatory have finally given us a clearer picture of this sticky world. Because CHARR b orbits so close to its host sun, its rotation rate has become fixed over time, so that the same side always faces the star. One hemisphere roasts in perpetual sunlight while the other chills out in eternal darkness.
Careful analyses have revealed that a portion of the sun-facing side is much darker and hotter than the rest of the hemisphere. Using a high-dispersion spectrograph, a device that reveals a star or planet’s composition based on the fingerprint of elements in its light, CHARR b’s dark region turns out to be almost pure carbon. A few rogue scientists argue it’s made of black diamond, but the consensus opinion leans more toward a heavily carmelized, semi-molten crust – no surprise given how closely the planet orbits its star.
Additional observations with the Hubble Space Telescope have also detected “hot spots” on the sun-facing side. No one’s sure what these glowing patches are, since they’re at the very limit of resolution, but theories range from volcanic eruptions to crust spontaneously bursting into flame due to intense radiation from the host star.
Astronomers plan to monitor “Fluffy” with every instrument they can. As I write this, plans are underway to launch a probe to snatch a sample of this unique world and return it to Earth later this decade. Dr. Marsh M’Alleau, head of the Institute Astrophysique de S’Mores, calls it an unprecedented opportunity to literally taste another world. Scientists can’t wait for the goodies to arrive.
On the more or less serious side, the International Space Station is wrapping up its morning show with one more week of passes. Beginning April 9, it returns to the evening sky. The times below are for the Duluth, Minn. region. For times for your town, please logon to Heavens Above or key in your zip code on Spaceweather’s Satellite Flyby site.
- Monday April 2 starting at 4:46 a.m. across the northern sky
- Tuesday April 3 at 5:23 a.m. across the top of the sky. Brilliant!
- Wednesday April 4 at 6:01 p.m. in the south-southwest
- Thursday April 5 at 5:05 a.m. high in the south
- Friday April 6 at 5:43 a.m. in the southwest
- Saturday April 7 at 4:49 a.m. Brief pass in the southeast
And before I forget, happy April Fools Day!