Mark Megahan
We still don’t know what our interstellar visitor was but we know one thing it wasn’t. It wasn’t a nitrogen iceberg. That means stumped scientists are back to square one, trying to figure out what sent the massive cosmic turd into overdrive, when it wandered through our solar system back in 2017.
Interstellar overdrive
Sounding like something out of a psychedelic rock flash-back, crossed with hard-core science fiction, we had an interstellar visitor a while back. Looking like a giant turd, “Oumuamua” had astronomers thinking of aliens, especially considering the shape was a lot like Art Clarke’s Rama, and it was behaving in eerily similar fashion.
First spotted in October 2017 the object was whizzing by, already on the way out at an impressive 57,000 mph.
Astronomers and physicists are well aware of the acceleration an object can get by dipping into a gravity well. We use the “slingshot” effect all the time with our own deep space probes.
What’s making them tear their hair out, is that the observations show the mysterious interstellar object “accelerated at a pace that couldn’t be explained by the gravitational pull of the sun.” Grasping desperately at straws for some source of propellant, astrophysicists Alan Jackson and Steven Desch thought they figured it out back in March. It was a good try.
At Arizona State University, the pair reasoned in a series of two papers that “Oumuamua was most likely a chunk of nitrogen ice that popped off a Pluto-like planet somewhere outside our solar system.”
There are more holes in their theory than a Swiss cheese. It would solve the interstellar visitor’s invisible propellant mystery but it turns out to be wishful thinking.
Invisible propellant
Physicists would have been able to call it a day and celebrate with a beer if the theory checked out because “evaporating nitrogen gas would have pushed the object and been invisible to telescopes.”
They know for sure that “nitrogen ice exists in our solar system because they’ve found it on Pluto.” The problem as far as the interstellar traveler is concerned is there isn’t nearly enough nitrogen available to make a big enough “fart” to turbocharge the turd.
At Ivy League Harvard, astrophysicist Amir Siraj saw their papers about the interstellar mystery and wondered what they had been smoking. “The moment I saw those papers, I knew that there was no physical mechanism for it to work.”
Even factoring in the chance for error didn’t make it realistic. There “isn’t enough nitrogen in the universe to make an object like Oumuamua, which is somewhere between 1,300 and 2,600 feet long and between 115 and 548 feet wide.
Nitrogen isn’t something you just find laying around in outer space. According to Siraj, “pure nitrogen is rare and has been found only on Pluto, where it makes up about 0.5% of the total mass. Even if all of the nitrogen ice in the universe was scraped off every Pluto-like planet that’s predicted to exist, there still wouldn’t be enough nitrogen to make Oumuamua.”
Especially considering that they’re “ignoring the effects from cosmic rays, subatomic particles that are constantly flying through space at the speed of light and degrading everything they slam into.” The interstellar voyager has already been blasted by cosmic rays for centuries. “When cosmic rays are taken into consideration, about 1,000 times the entire mass of stars in the galaxy would be necessary to generate all the exo-Plutos to build Oumuamua.”
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