This Saturday, the Santa Monica Amateur Astronomy Club (SMAAC) welcomes astrophysicist and Harvard professor Dr. Avi Loeb, one of the most prominent proponents of the existence of extraterrestrial intelligence.
Scheduled to take place over Zoom, since Dr. Loeb is based on the East Coast, the talk begins at 1 p.m. Pacific Time and will be available to watch both at home by signing up in advance and at the Wildwood School, 11811 Olympic Blvd, where the Club meets every month. Questions will be answered by Dr. Loeb wherever you watch from, but the real action will be with the group when the discussion will almost certainly continue well into the afternoon.
Dr. Loeb is arguably best known for ruffling feathers in the scientific community for suggesting that ‘Oumuamua — the first cosmological object officially classified as “interstellar” that sailed through our solar system in 2017 — could have been an alien spacecraft. A real life Dr. Hans Zarkov, if you will.
Discovered by Robert Weryk at the Haleakalā Observatory in Hawaii, ‘Oumuamua had no bright coma or dust tail, like most comets. Moreover, it has a peculiar shape, vaguely resembling a flattened cigar, plus its small size more befitted an asteroid than a comet, but the fact that it was accelerating away from the sun is what perplexed scientists.
Credit: NASA
When it was first observed, ‘Oumuamua was about 21 million miles from Earth and already heading away from the Sun. It’s estimated to be between 300 and 3,000 ft long, with its width and thickness both estimated between 115 and 548 ft. Being classified as “interstellar” means that its origins are suspected to be from beyond the Oort Cloud, which marks the boundary to our Solar System.
The Cloud is, in essence, a mind-meltingly massive minefield of ice and rock, loosely kept in place by the Sun’s gravity. If you think of the distance from the Earth to the Sun (approximately 93 million miles) as 1 AU (Astronomical Unit) then the Oort Cloud begins, way, way past Neptune at about 1,000 AUs. Even Voyager 1, the furthest a man-made object has ever traveled and the first to pass the outer planets, still has a very long way to go before it reaches the Cloud.
It gets even more brain-bogging, as the Cloud is wider than the radius of the actual Solar System, at approximately 100,000 AUs wide, where our Solar System is less than 100 AUs wide. It will take another 300 years or so for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it.
“We have very little data about the object [‘Oumuamua] because by the time we discovered it, it was already leaving our solar system. So whatever evidence we have cannot conclusively tell us what it is,” said Milla Ivanovska, President of SMAAC.
According to Ivanovska, four interstellar objects have been discovered, including two meteors and a comet. However, ‘Oumuamua exhibited a highly unusual flat shape and non-gravitational acceleration, although it is possible that escaping gas from evaporating frozen liquid has contributed to the object’s delta-v, or change in velocity.
Credit: NASA
“Some scientists believe it’s actually something relatively new, what’s being called a ‘dark comet’ in the scientific community,” Ivanovska says. In essence, this is an object very similar in make up to a regular comet, but it doesn’t produce a distinctive “tail.”
Or, is this object a hollowed-out spacecraft, a research vessel, or possibly an ark even? We accept the idea that life does exist outside of the solar system simply because of the utterly incomprehensible number of planets that orbit stars in the universe. The issue is distance and consequently the amount of time needed to cross vast intergalactic distances. So why wouldn’t a technologically advanced species use something as useful as an asteroid for long distance travel? It’s perfectly plausible.
Dr Abraham “Avi” Loeb is an Israeli-American theoretical physicist who works on astrophysics and cosmology and he has been Director of the Institute for Theory and Computation at the Center for Astrophysics at Harvard since 2007. In 2015, he was appointed as the science theory director for the Breakthrough Initiatives of the Breakthrough Prize Foundation.
Founded in 1981, the SMAAC is open to absolutely everyone. The club holds monthly talks on a variety of topics usually on the second Friday of every month at the Wildwood School. To attend the meeting via Zoom, or for any other inquiries, send an email to samoastronomy@gmail.com.
scott.snowden@smdp.com
