They found the spectrum of GJ1214b to be featureless over a wide range of wavelengths, or colors. The atmospheric model most consistent with the Hubble data is a dense atmosphere of water vapor.So a few important items to note here beyond the facts and figures.
"The Hubble measurements really tip the balance in favor of a steamy atmosphere," Berta said.
Since the planet's mass and size are known, astronomers can calculate the density, of only about 2 grams per cubic centimeter. Water has a density of 1 gram per cubic centimeter, while Earth's average density is 5.5 grams per cubic centimeter. This suggests that GJ1214b has much more water than Earth does, and much less rock.
As a result, the internal structure of GJ1214b would be an extraordinarily different world than our world.
"The high temperatures and high pressures would form exotic materials like 'hot ice' or 'superfluid water,' substances that are completely alien to our everyday experience," Berta said.
Theorists expect that GJ1214b formed farther out from its star, where water ice was plentiful, and migrated inward early in the system's history. In the process, it would have passed through the star's habitable zone, where surface temperatures would be similar to Earth's. How long it lingered there is unknown.
GJ1214b is located in the direction of the constellation Ophiuchus, and just 40 light-years from Earth. Therefore, it's a prime candidate for study by the planned James Webb Space Telescope.
1: At first glance it appears that the intense atmospheric pressure could be hostile to most life on Earth, but if you recall, we've found microbes, worms, and other simple organisms thriving in heat vents on the ocean floor, so anything is possible.
2: Hubble is still a relevent and extraordinary piece of equipment for finding planets--and not just an instrument for deep space only missions. It's a shame that its life expectancy won't be lengthened, but it's nice to know that the exoplanet work carried out by the James Webb Telescope can earmark GJ1214b for future study.
Bonus excersise: If life does exist on this steamy, high-pressure world, what form do you think it takes? Feel free to speculate in the comments....
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