"Ask a Spaceman" and "Space Radio" are hosted by Paul M. Sutter, who is also the author of "How to Die in Space." Space.com's expert voices: op-ed and insights was written by Sutter.
Robert Weryk, an astronomer at the University of Hawaii at Manoa, spotted a new object with the Panoramic Survey Telescope and Rapid Response System in Hawaii. It was a weird object from the moment it was discovered.
The first known object to visit the solar system was dubbed 'Ouamuamua'. Astronomers were able to observe the odd visitor for only 11 days before they realized it was too small and dim to be seen. The true nature of 'Ouamuamua remains a mystery even today, considering the scant information obtained from such a short observation window.
The solar system's first interstellar visitor was explained in photos.
The object is an emissary, a representative of some distant (and unknowable) star system, and the name Oumuamua is an apt one. For hundreds of millions of years, it had been wandering through the emptiness of the universe before it came face to face with the sun.
The biggest side is between 100 and 330 feet wide and it could fit inside a football field.
Astronomers were told that the object was tumbling end over end every few hours by the reflected sunlight from 'Oumuamua. Astronomers determined that 'Oumuamua is shaped like a cigar or a pancake because of the variation in the light.
It was already out of the solar system when 'Oumuamua was detected. The object was not bound to the sun because of its speed and steep angle.
Astronomers monitored 'Oumuamua with a variety of ground and space-based telescopes. 11 days is all. Oumuamua is too distant and dim to be seen with even our most powerful instruments, and no rocket could ever hope to catch up with it.
It's gone.
They are known unknowns.
Oumuamua is the strangest object we have ever seen in the solar system. Our catalog of objects 100 meters or larger isn't exactly complete, but no other asteroid or comet has a shape like that. The dusty red color of Oumuamua is similar to other deep-solar system objects. It was not a comet, the most common small object at those distances.
The local standard of rest is the average speed of stars in our neighborhood. Most of the stars have individual velocities that are much higher than that. Why should 'Oumuamua have something close to the average number? It is a mystery.
Astronomers were puzzled by the fact that 'Oumuamua was moving away from the sun at a slightly faster pace. Outgassing of materials can cause comets to have abnormal acceleration profiles. Observations of 'Oumuamua did not show any activity.
It's the ultimate origins.
Since the original discovery, only one other visitor has been seen. The object, called 2I/Borisov, looked and acted like a comet. It has never been seen before or since.
What is 'Oumuamua'? Speculation is ripe in a poor data environment. The lack of data was used to propose that 'Oumuamua is an alien spaceship. Considering intelligent aliens may be capable of doing whatever they want, this could be an explanation for most observations.
There are also non-alien explanations offered by the astronomer. One idea is that 'Oumuamua is a nitrogen ice cube that has been there for a long time. It's not possible because pure nitrogen is very rare on the dwarf planet and in the universe as a whole. The mass of exo-Plutos required to create a pure nitrogen 'Oumuamua was calculated to be mind-bogglingly high.
Some researchers think that a block of solid hydrogen formed in the outskirts of a giant cloud as a result of solar system creation. Others think that 'Oumuamua is a comet that got kicked out of the native solar system by some kind of interaction, or that it was formed in our own solar system and then migrated far away before circling in for one last dance.
We will never know. We should just move on, like that strange visitor.
You can listen to the "Ask a Spaceman" show on the internet. You can ask your own question using the #AskASpaceman or following Paul on Facebook.
Follow us on social media.
All Rights Reserved © 2024
