Comet Lemmon Enters Peak Visibility After Close Pass to Earth

Overview

• The comet reached its closest approach to Earth on October 21 at about 90 million kilometers and is now brightening as it moves toward the Sun.
• Observers in both hemispheres, including much of Brazil, can look for it near sunset from locations with low light pollution, with binoculars revealing more detail.
• Peak viewing is expected in early November, with forecasts ranging from October 31 to November 8, though the full Moon on November 5 could reduce visibility.
• The comet’s green glow comes from gases such as cyanogen and diatomic carbon released as solar heating triggers outgassing.
• Identified early this year by the Mount Lemmon Survey, the visitor is not expected to return for roughly 1,300 to 1,350 years.