Comet PanSTARRS (C/2017 S3) glowed blue-green and sported a several-degree-long gas tail in this photo taken on July 20. The comet was ~7th magnitude at the time. Michael Jäger
Yesterday I said that getting up before dawn isn’t easy especially in summer, when the sun rises so early. And while I may not rise with the birds for the space station I will for a comet. Comet PanSTARRS (C/2017 S3) has become active in the past couple weeks after an “outburst” at the end of June when it shot up to magnitude 9.5, putting it within range of a modest-sized telescope. It’s one of many discovered by the Panoramic Survey Telescope and Rapid Response System (PanSTARRS) based atop Mt. Haleakala on Maui, a popular Hawaiian island tourist destination. Although it was discovered on Sept. 23, 2017, it only recently grew bright enough to see in amateur telescopes.
In this animation made from multiple photos on July 20 you can see how dynamic the tail is. Michael Jäger
I didn’t bring this to your attention back then because the comet was too dim to spot in binoculars or a small telescope. Indeed, C/2017 S3 began to fade and become more diffuse ...