A team of astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA), using NASA’s Hubble Space Telescope, has discovered a “waterworld” planet beyond the solar system.

This exoplanet (i.e. extrasolar planet), dubbed GJ1214b, is located in the constellation Opphiuchus, 40 light-years away from the Earth. It is 2.7 times the size of the Earth and roughly seven times Earth’s weight. At a distance of 1.3 million miles, the watery exoplanet orbits a red dwarf every 38 hours and has a surface temperature of 450º F (230º C).

GJ1214B was first discovered in 2009 by a team of astronomers, led by David Charbonneau of CfA, with the groudbased project MEarth (pronounced “mirth”). Charbonneau and his team were able to detect GJ2124b through transiting, a widely-used method used to search for exoplanets in which one looks to see if a star’s light slightly drops periodically. If it does, a planetary body has traveled in front of the star.

A year later, in 2010, astrophysicist Jacob Bean and his colleagues (also working at CfA) learned that GJ1214b’s atmosphere was chiefly composed of gaseous water. And in 2012, the current group of astronomers working at CfA has confirmed that GJ1214b is indeed veiled in a watery haze.

“GJ1214b is like no planet we know of,” Zachary Berta – an astronomer who is the head of the team – states in CfA’s press release.

Using the parent star’s light, he and his colleagues learned which gases comprise the larger exoplanet’s atmosphere, through which the light passed. With that knowledge, they concluded the GJ1214b and its atmosphere were not mostly made of water, but also hazy – and quite steamy.

The team of was also able to calculate the density of GJ1214b, knowing its size and mass: 2g/cm3. In comparison, Earth’s density = 5.5 g/cm3, and water on Earth 1 gm/cm3. GJ1214b’s larger density suggests that it has more water and less solid material.

“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 explains. Furthermore, GJ1214b cannot harbor any bodies of liquid water due its temperature and proximity to its parent star.

He and his colleagues utilized Hubble to measure GJ1214b’s light spectrum. The spectrum is apparently not restricted to any particular wavelengths, which indicates and further proves the state of the atmosphere. The team is also currently attempting to study the exoplanet’s sunsets through infrared using the Hubble; they can see through the atmosphere more easily with infrared than if they used visible light, which is shorter in wavelength and, hence, cannot traverse thick mediums readily.

According to CfA, theorists have predicted GJ1214b’s formation:

“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. How long it lingered there is unknown.”

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About the author

Sarah Hansen
Sarah is currently earning her M.F.A. in Creative Nonfiction at Sarah Lawrence College. She has an avid interest in the sciences, particularly astronomy, and hopes to one day publish works of fiction, poetry, and creative nonfiction.