There could be frozen volcanoes behind the four violent eruptions that took place in a few days on the mysterious comet 29P / Schwassmann-Wachmann, increasing its brightness by 250 times enough to make it visible even with small amateur telescopes in the constellation Auriga.
The hypothesis was put forward by astronomer Richard Miles of the British Astronomical Association (BAA), who has been studying this bizarre celestial body for years.
"The current explosion, which began on September 25, appears to be the most energetic of the last 40 years," explains the expert. "In just 56 hours, four eruptions quickly followed one another, creating a super explosion" whose effects are still visible. The phenomenon has left astronomers speechless, although comet 29P has been known for nearly a century.
Discovered in 1927, this 60-kilometer-wide ball of ice was initially classified as a fairly common comet, despite following an almost circular orbit between Jupiter and Saturn. This perception began to change when the first eruptions were observed: more recent studies have counted about twenty a year. In a study published five years ago, Miles reviewed nearly a decade of eruptions, finding that the comet rotates every 57.7 days and that the most active volcanic chimneys are concentrated mostly on one side.
According to the British astronomer, these are frozen volcanoes, not powered by lava but by a mix of liquid hydrocarbons similar to those found in the lakes and rivers of Saturn's moon Titan.
This material (termed 'cryomagma') would contain a splash of dust and gases (carbon monoxide and molecular nitrogen) that would be trapped beneath the surface, ready to explode as soon as a crack opens.
