Going to extremes

WASP-76b isn’t the only exoplanet that is completely different from the eight planets in our Solar System. Here are five more impressively bizarre extrasolar objects:

TrES-2B

If WASP-76b is the most metal planet, then TrES-2b must surely be the most goth. Identified in 2011 by the Transatlantic Exoplanet Survey, it’s the darkest exoplanet ever discovered, reflecting less than 1 per cent of all light, less than coal.

55 CANCRI E

The top prize for most bling goes to 55 Canceri e. It’s about twice the size of Earth, 40 light-years away in the constellation Cancer. Roughly one-third of the planet’s mass is estimated to be made up of carbon. And with current temperature and pressure estimations, scientists think it’s likely much of the carbon is in diamond form. Fancy.

GLIESE 436 B

And now for something truly weird: this exoplanet, just 30 light-years away in the constellation Leo, is thought to be covered in ‘burning ice’. Even though its surface temperature is a blistering 440°C, powerful gravitational forces squeeze the surface so tightly that it remains solid.

PSR B1620-26B

Nicknamed Methuselah, at 12.7 billion years old, PSR B1620-26b is one of the oldest known exoplanets, 12,400 light-years away in the constellation Scorpius. For context, the Universe is around 13.7 billion years old, and the Solar System 4.6 billion years old.

TrES-4B

At more than 250,000km across, or 1.8 times the diameter of Jupiter, TrES-4b is one of the largest exoplanets discovered so far. It was spotted 1,400 light-years away in the constellation Hercules by the Transatlantic Exoplanet Survey in 2006.