Comet 41P/Tuttle-Giacobini-Kresák (image) NASA/Goddard Space Flight Center Share Print E-Mail Caption On March 14, 2017, two weeks before its closest approach to Earth, comet 41P/Tuttle-Giacobini-Kresák glides beneath the galaxy NGC 3198. The green glow comes from light emitted by diatomic carbon molecules. Credit Copyright 2017 by Chis Schur, used with permission Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.