Overview

• At 137 kilometers wide, C/2014 UN271 is nearly 14 times wider than the asteroid that wiped out the dinosaurs and more than twice the size of comet Hale-Bopp.
• Observations with ALMA in Chile at 16.6 astronomical units from the Sun revealed high-speed jets of carbon monoxide and the initial formation of a coma.
• Astrochemist Nathan Roth said the explosive outgassing patterns raise new questions about how UN271 will evolve as it travels toward the Sun.
• Scientists combined recent ALMA data with earlier measurements to refine estimates of the comet’s dust mass and thermal properties.
• Researchers expect increasing frozen gas vaporization as the comet nears Saturn’s orbit in January 2031 to offer insights into the Solar System’s primordial makeup.