The universe’s most valuable exoplanet
Another planet that orbits close to its host star – taking under 18 hours to complete an orbit – 55 Cancri e is also inhospitably hot, reaching temperatures as high as 2,300 degrees Celsius (4,172 degrees Fahrenheit). But what really sets this world apart is its composition, which makes the exoplanet formally known as Janssen perhaps the most conventionally valuable object in the universe.
The fact that 55 Cancri e is twice the size of Earth but has around eight times the mass led astronomers to propose that this super-Earth could be composed of highly pressurised carbon in the form of graphite and diamond, mixed with some iron and other elements.
The estimated value of 55 Cancri e is £19.6x1030 ($26.9x1030). That’s 384 quadrillion times more than Earth’s entire Gross Domestic Product (GDP), which was valued at £51 trillion ($70 trillion) in 2011. Some astrophysicists suggest that such diamond worlds could form fairly regularly when protoplanetary dust clouds that contain high ratios of carbon collapse to form planets.
The idea that 55 Cancri e is made of diamond has been challenged since the exoplanet was first discovered in 2004, moving in and out of favour and proving diamonds may not be forever. Yet despite all these extreme worlds, the most extraordinary exoplanets may still be out there for us to discover, and they may exist in systems we have never encountered before.
“Some astrophysicists suggest that such diamond worlds could form fairly regularly”