Oumuamua: The Ballistic Baguette
Oumuamua (Hawaiian for ‘a messenger from afar arriving first’) was our first ever detected visitor from interstellar space and was first found using PanSTARRS. It left a trail of mystery in its wake when it zipped past in late 2017 but all but a few seem to have missed its uncanny resemblance to a chaotically tumbling baguette. With Comet 2I/Borisov - discovered by Dmitri Borisov in August 2019 came closest to earth in December 2019 - we may have not a cosmic croissant but a bowl of Borisov Borscht. Perhaps there is more galactic gastronomy for astronomy to discover! (see the link below for NASA’s idea to intercept future visitors).
A Borisov image captured by Yale astronomers Pieter van Dokkum, Cheng-Han Hsieh, Shany Danieli, and Gregory Laughlin is shown here together with an image that shows how the comet would look alongside planet Earth.
On a more serious note it seems that there will be more of these interstellar objects discovered as we continue to scan the skies with increasing sensitive tools (eg the Vera C Rubin Observatory).
With better telescopes we can now find these objects (that might provide information about the building blocks of other planetary systems besides our own) - reducing the unknown unknowns in detecting potentially hazardous objects (PHOs). This doesn’t actually increase in the probability of them hitting us or perturbing the orbits of other PHOs towards Earth but we can now at least begin to factor this probability into our models. The increasing number of satellites may make it harder to discriminate and detect actual hazardous objects (AHO) particularly when low on the horizon around dusk so we need to listen to the counsel of our experts, Planetary Defence Officer (yes this is an actual job title) in NASA and equivalents elsewhere to ensure there is enough public support to fund detection and preventative actions. Let’s keep a watching brief at least once a year on every Asteroid Day (30 Jun 2019).
Some related podcasts:
A tumbling, tumbling asteroid? Space Nuts - this episode had the shows host the cheerfully chatty Andrew Dunckley coining the term “ballistic baguette” with some earlier episodes here and here
First Interstellar Visitor To our Solar System Confirmed SpaceTime with Stuart Gary
What was Oumuamua? Daniel & Jorge Explain The Universe
More on Comet 2I/Borisov from SpaceTime with Stuart Gary
Intercepting Future Interstellar visitors from NASA
Professor Dan Hooper gives some context on astrophysicist Avi Loeb’s comments on the Big Brains podcast about the biggest miseries mysteries of our universe. Professor Loeb has proposed that Oumuamua may be an alien spacecraft: whether it was or not it is crucial to keep open minds. Professor Loeb 2021 book posits: “Extraterrestrial: The first sign of intelligent life beyond Earth”.
In contrast The State of The Universe Brendan Drachler interviews Dr Ethan Siegel cogently arguing against sensationalist speculation with respect to Oumuamua and more generally proclaiming a First Commandment of Alien Life Discovery as “Thou shalt not conclude aliens with inadequate data”