This tiny, sizzling exoplanet could be made of molten iron

The newfound planet is smaller than Earth, as dense as iron and hot enough to melt

illustration of exoplanet GJ 367b next to a glowing red star

Exoplanet GJ 367b, shown in this artist’s illustration, is as dense as iron and close enough to its star that its surface may be molten.

SPP 1992 (Patricia Klein)

A newly discovered exoplanet is really making astronomers prove their mettle.