Which exoplanet is nicknamed Methuselah because of its great age?

PSR B1620-26 b is the exoplanet nicknamed Methuselah because of its extraordinary age. Its estimated age is about 12.7 billion years, making it nearly as old as the universe and far older than Earth.

Methuselah orbits a remarkable binary system in the globular cluster Messier 4, about 12,400 light-years away in Scorpius. Its two stellar companions are a rapidly spinning pulsar and a white dwarf. The planet’s orbit carries it around both stars, making it a circumbinary planet; it takes roughly a century to complete one orbit.

The planet was first identified through changes in the pulsar’s precisely timed radio pulses. The planetary interpretation was proposed in 1993, while observations confirming the expected white-dwarf companion were announced in 2003 using the Hubble Space Telescope. The nickname refers to Methuselah, the exceptionally long-lived biblical figure.

Its age is an estimate based on the age of the stellar system, not a direct measurement of the planet. “Genesis planet” is another informal nickname, while PSR B1620-26 b remains the standard astronomical designation.