In 2017 and 2018, three comets are passing near the Earth, enabling scientists to study them without launching a spacecraft. Their names are 41P/Tuttle-Giacobini-Kresak, 45P/Honda-Mrkos-Pajdusakova, and 46P/Wirtanen.
Astronomers call them 41P, 45P, and 46P, for short.
At closest approach on April 1, 41P was only 56 times farther from Earth than the moon. 45P was even closer at 31 lunar distances when it flew by on February 11.
But the comet 46P/Wirtanen might be the biggest attraction to stargazers. It’ll approach within 30 lunar distances of Earth on December 16, 2018 and might – at that time – become visible to the unaided eye from dark sky sites.
Telescopes around the world have been trained on these comets as they’ve passed by, studying their structure and chemical compositions.
Learn more in the video above, and see photos below from the EarthSky community!
Bottom line: New NASA ScienceCast about comets passing near Earth in 2017 and 2018.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.