Two Interstellar Visitors

Time-lapse of Comet 2I Borisov

We had a few interstellar visitors at the end of last year. They were not little alien creatures or UFOs. On December 8, 2019, a newly discovered Comet 2I Borisov looped around our Sun after a journey of more than 100 million years. Let's think about that - 100 million years. The Sun heated this chunk of ice and gas enough to throw off the gases that gave it the foggy, bigger, brighter look of a comet.

The comet visited our solar system neighborhood for the holidays and that loop around the Sun slung it back out of our solar system. This the first observed interstellar comet and the second observed interstellar interloper.

The first visitor was ʻOumuamua which presented a unique case for the International Astronomical Union that assigns designations for astronomical objects. This visitor was originally classified as comet C/2017 U1, and later reclassified as asteroid A/2017 U1.

When it was identified as coming from outside our Solar System, a new designation was created. The letter "I" is now used to designate an Interstellar object. ʻOumuamua is "1I."  The name ʻOumuamua comes from Hawaiian and it appropriately means "first scout."

I prefer the originally suggested namefor this visitor - "Rama" That seems to me to be a much better name than 1I. Rama is the name given to an alien spacecraft discovered under similar circumstances in the 1973 science fiction novel Rendezvous with Rama by Arthur C. Clarke. It's a novel I really enjoyed reading. That fictional object was seen as an alien craft that was on a scouting expedition checking out the rest of the universe.

The actual object ʻOumuamua is tumbling through space, rather than smoothly rotating, and is moving so fast relative to the Sun that there is no chance it originated in the Solar System. It also cannot be captured into a solar orbit. It will leave our Solar System and resume traveling through interstellar space after roughly 20,000 years of travel in our Solar System.

I love that there is still mystery out there. ʻOumuamua's planetary system of origin and the actual amount of time it has spent traveling amongst the stars are unknown.

An artist’s impression of `Oumuamua as a dark red highly-elongated metallic or rocky object,
about 400 meters long, and unlike anything normally found in the Solar System.