A mysterious volcanic comet has just reawoken, unleashing four major eruptions in less than 48 hours and spraying out enough of its icy guts to make the city-size object appear almost 300 times brighter than normal, researchers say. The latest outbursts, which are the largest in more than three years, add to the growing confusion about when and why this explosive oddball blows its top.
The comet, known as 29P/Schwassmann-Wachmann (29P), is a large icy object spanning around 37 miles (60 kilometers) across — around three times the length of Manhattan. It is one of around 500 comets known as "centaurs" that spend their entire lives confined to the inner solar system. However, 29P is also part of an even rarer group, known as cryovolcanic, or cold volcano, comets.
