When the news was announced that a comet from another solar system — called 2I/Borisov — was passing through our own solar system, one of my first thoughts was, I wonder how long it'll be before Hubble takes a look at it?
It turns out the answer is about six weeks. The comet was discovered on August 30, 2019, and it didn't take long before astronomers realized its orbit was really weird: It's clearly coming from interstellar space, an actual alien comet from another star! A flurry of observations were made, including some with some big 'scopes, and I knew folks would be working overtime to get Hubble observations of it as well.
The image takes a wee bit of explaining, but first, hey, here it is:
Hubble Space Telescope image of the comet 2I/Borisov (formerly C/2019 Q4 (Borisov)). The blue color was added to a grayscale image. The scale shows the size at the comet’s distance, and the direction to the Sun is indicated (note the tail of the comet pointing in the opposite direction). Credit: NASA, ESA, and D. Jewitt (University of California, Los Angeles)
Coooool. There are a few things to note here, but right away I ...