Planet WASP-121b
Image Credit: NASA

Metal, Rubies & Sapphires Blow Across This Planet

A team of international researchers have discovered a fast-moving exoplanet, nearly 13 times larger than Earth, with vast clouds of liquid metal and corundum – the mineral which forms rubies and sapphires – blowing across the planet.

Super Leap Year

This gas-giant, called WASP-121b, orbits its star every 1.27 days, which is among the fastest planetary “years” ever discovered. It’s also tidally locked, with no net change in its rotation rate over the course of a complete orbit. Simply put, that means one side of the planet always faces its star while the other faces the darkness of space. That condition is responsible for the gemstones and liquid metal which rain down on the planet.

See WASP-121b on NASA’s Interactive Website

Clouds of Gemstones & Metal

The temperature on the seared side of the planet approaches 4,500 degrees F (2,500 C), which is hot enough to vaporize the metals present. Among those metals are magnesium, chromium, vanadium, and aluminium, which condenses into the mineral corundum.

According to a team from the Massachusetts Institute of Technology, observing WASP-121b through a spectroscopic camera aboard the Hubble Space Telescope,:

It is possible that some of these clouds may be red or blue in color, as a result of their potential gemstone composition, and that liquid gems could be raining on the nightside of the planet.

That gemstone rain might better be characterized as hail, considering that those winds attack the nighttime hemisphere in excess of 11,000 miles per hour.


Condensation curves for relevant refractory species are shown in Fig. 3a, namely corundum, perovskite, VO, Fe, forsterite and enstatite. The corundum, perovskite and Fe condensation curves are crossed during the WASP-121b diurnal cycle, and it is also likely that those of forsterite, VO and enstatite are crossed in the coolest regions of the nightside hemisphere.

Read the full paper: Diurnal variations in the stratosphere of the ultrahot giant exoplanet WASP-121b

John Pollard

John Pollard is Senior Director of Education for IGI, overseeing and expanding the institute’s traditional educational offerings and diploma programs, instructed at 14 schools of gemology around the world, along with customized eLearning courses, tutorials, seminars, and webinars for IGI clients across all sectors, including leading luxury brands.

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