Rocky Planet Found With an Alien Chemistry Vastly Different than Earth (Today's Most Popular)

 

           

 

New research this past December,  led by Yale University scientists, suggests that a rocky planet twice Earth's size orbiting a nearby star is a diamond planet. "This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth," said lead researcher Nikku Madhusudhan, a Yale postdoctoral researcher in physics and astronomy. "The surface of this planet is likely covered in graphite and diamond rather than water and granite." The study estimates that at least a third of the planet's mass—the equivalent of about three Earth masses—could be diamond.

"By contrast, Earth's interior is rich in oxygen, but extremely poor in carbon—less than a part in thousand by mass," says co-author and Yale geophysicist Kanani Lee. The identification of a carbon-rich super-Earth means that distant rocky planets can no longer be assumed to have chemical constituents, interiors, atmospheres, or biologies similar to those of Earth.

The paper reporting the findings has been accepted for publication in the journal Astrophysical Journal Letters. The planet—called 55 Cancri e—has a radius twice Earth's, and a mass eight times greater, making it a "super-Earth." It is one of five planets orbiting a sun-like star, 55 Cancri, that is located 40 light years from Earth yet visible to the naked eye in the constellation of Cancer.

The planet orbits at hyper speed—its year lasts just 18 hours, in contrast to Earth's 365 days. It is also blazingly hot, with a temperature of about 3,900 degrees Fahrenheit, researchers said, a far cry from a habitable world. The planet was first observed transiting its star last year, allowing astronomers to measure its radius for the first time. This new information, combined with the most recent estimate of its mass, allowed Madhusudhan and colleagues to infer its chemical composition using models of its interior and computing all possible combinations of elements and compounds that would yield those specific characteristics.

Astronomers had previously reported that the host star has more carbon than oxygen, and Madhusudhan and colleagues confirmed that substantial amounts of carbon and silicon carbide, and a negligible amount of water ice, were available during the planet's formation. Astronomers also thought 55 Cancri e contained a substantial amount of super-heated water, based on the assumption that its chemical makeup was similar to Earth's, Madhusudhan said. But the new research suggests the planet has no water at all, and appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates.

The discovery also opens new avenues for the study of geochemistry and geophysical processes in Earth-sized alien planets. A carbon-rich composition could influence the planet's thermal evolution and plate tectonics, for example, with implications for volcanism, seismic activity, and mountain formation. "Stars are simple—given a star's mass and age, you know its basic structure and history," said David Spergel, professor of astronomy and chair of astrophysical sciences atPrinceton University, who is not a co-author of the study. "Planets are much more complex.

This 'diamond-rich super-Earth' is likely just one example of the rich sets of discoveries that await us as we begin to explore planets around nearby stars." In 2011, Madhusudhan led the first discovery of a carbon-rich atmosphere in a distant gas giant planet, opening the possibility of long-theorized carbon-rich rocky planets (or "diamond planets").

The new research represents the first time that astronomers have identified a likely diamond planet around a sun-like star and specified its chemical make-up. Follow-up observations of the planet's atmosphere and additional estimates of the stellar composition would strengthen the findings about the planet's chemical composition.

For more information: "A Possible Carbon-rich Interior in Super-Earth 55 Cancri e," Astrophysical Journal Letters. Journal reference: Astrophysical Journal Letters

The Daily Galaxy via Yale University

Image credit: NASA

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Comments

[Harry R Ray]

This is old news, BUT: there is potentially VERY exciting NEW news about this planet! It MAY have TWO distinctly DIFFERENT magnetic fields! One is bipolar, and generated by a molten iron( a high C/O ratio does NOT preclude the presence of a large amount of iron) core. The OTHER ( and by FAR the MORE INTERESTING) is generated by, of all things, the PIEZOENECTRIC EFFECT! If the planet Does have a large, RIGID diamond mantle, it would be HIGHLY stressed by tidal friction (planetquakes up to 15 on the richter scale are possible due to the planet's eccentric orbit). The planet's eccentricity is believed to be 0.17 (plus or minus 0.04)
and is greter than IO's. NOW IT GETS VERY INTERESTING! On the sunward side of the planet, BOTH FIELDS will be pushed onto the surface of the planet by extremely high radiation pressure! This may force both fields to interact with each other ON THE SURFACE! This nay cause a phenomenon known as magnetic reconnection to occur frequently! If so, explosion of many megatons may occur FREQUENTLY as a result. These explosion would be detectible by radio telescopes as the result of the electromagnetic pulses they emit!

[Walter Beals]

Its interior and computing all possible combinations of elements and compounds that would yield those specific characteristics.

[Truth About Our Solar System]

This is fascinating! I wonder what implications it will have for our understanding of planetary formation... What kind of star does it orbit?

[Gaugain]

at 3,900 degrees Fahrenheit i wonder why they call them superEarths... Even superVenuses doesn`t tell it all...

[Observing from Tejas]

I'm totally not in a position to give an expert take on this weird orb, but my first thought was, "How could a planet double earth's size manage to create the external pressure necessary to make diamonds or other pressurized carbides?" Following that thought, I deduced that the planet itself came from WITHIN a pressure cooker. That is, could this seemingly pressure-cooked planet in reality be the rigid CORE of a really huge gas giant that was hugging its mother star so closely that all its gas layers either got sucked into, or blown away by, the star.

In trying to keep up with the roller-coaster reports of new and candidate worlds recently, I have noticed many such ostensible gas giant finds reported with very similar mother star-hugging orbital periods.

[Hlly Keith]

I am totally agree with your opinion.this blog post is very encouraging to people who want to know these topics.

[Gaugain]

actually this looks more like the nucleus of a star, these bodys were once a double star system probably, one of the stars managed to suck the other`s hidrogen-helium compo.I have seen many simulations of 2 stars uniting, but the core of the smaller one is harder to "eat" and remains orbiting at a certain distance the bigger star. And a diamond core for a star is not a new concept, it seems that many diamond bodys are wondering the universe as remaining cores of old stars.

[globalmed]

These explosions would be detectible by radio telescopes as the result of the electromagnetic pulses they emit!