On October 19th, 2017, astronomers made the first-ever detection of an interstellar object (ISO) in our Solar System. This body, named 1I/2017 U1 (‘Oumuamua), was spotted shortly after it flew by Earth on its way to the outer Solar System. Years later, astronomers are still hypothesizing what this object could have been (an interstellar “dust bunny,” hydrogen iceberg, nitrogen icebergs), with Harvard Prof. Abraham Loeb going as far as to suggest that it might have been an extraterrestrial solar sail.
Roughly three years later, interest in extraterrestrial visitors has not subsided, in part because of the release of the Pentagon report on the existence of “Unidentified Aerial Phenomena.” This prompted Loeb and several of his fellow scientists to form the Galileo Project, a multi-national, multi-institutional research team dedicated to bringing the search for Extraterrestrial Technological Civilizations (ETC) into the mainstream.
In the Fall of 2017, the first known interstellar object passed through the Solar System, triggering a revolution in astronomy. Because of the amonolous nature of the object, astronomers from all over the world were at a loss to explain what it was. Neither comet, nor asteroid, nor any other conventional object appeared to fit the bill, leading to all kinds of “exotic” explanations.
A particularly exotic explanation was offered by Harvard Professor Avi Loeb and his former postdoc (Dr. Shmuel Bialy), who hypothesized that ‘Oumuamua could have been an extraterrestrial lightsail. Whereas most rebuttal papers questioned the evidence presented, a new study by astrophysicist and UCLA emeritus professor Ben Zuckerman questioned something else: why would an extraterrestrial civilization want to send a probe our way?
On October 19th, 2017, astronomers from the Haleakala Observatory in Hawaii announced the first-ever detection of an interstellar object in our Solar System. In honor of the observatory that first spotted it, this object (designated 1I/2017 U1) was officially named ‘Oumuamua by the IAU – a Hawaiian term loosely translated as “Scout” (or, “a messenger from afar arriving first.”)
Having spent the past few years presenting this controversial theory before the scientific and astronomical community, Prof. Loeb has since shared the story of how he came to it in his new book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. The book is a seminal read, addresses the mystery of ‘Oumuamua, and (most importantly) urges readers to take seriously the possibility that an extraterrestrial encounter took place
However, the scientific community has since announced that the signal is unlikely to be anything other than the result of natural phenomena. This was also the conclusion reached by Amir Siraj and Prof. Abraham Loeb of Harvard University after they conducted a probability assessment on BLC1. Like the vast majority of candidate radio signals discovered to date, this one appears to be just the forces of nature saying hello.
Recently at UT, author Matt Williams has been writing a series called “Beyond Fermi’s Paradox”, which takes a look at possible resolutions to one of the most famous questions in science: “Where is everybody?” As Matt discusses, there are multiple hypothetical solutions, but there may eventually come a day when we can definitively answer it.
Consideration of that day opens up a whole host of new questions, not the least of which is what will an intelligent civilization we find be like? Carl Sagan popularized the notion that it is very unlikely that any extraterrestrial civilization would be equivalent to ours in terms of technological progress. What he did not address was the relative age of the civilization and what that might mean in terms of their interest in communicating with us. Now a team of astronomers have come up with an answer to that question using one of the most underappreciated mathematical tools: statistics. Their model provides a simple answer: any intelligent civilization is likely older than us, and potentially much older.
The Vera C. Rubin Observatory, formerly the Large Synoptic Survey Telescope (LSST), will commence operations sometime next year. Not wanting to let a perfectly good acronym go to waste, its first campaign will be known as the Legacy Survey of Space and Time (LSST). This ten-year survey will study everything from dark matter and dark energy to the formation of the Milky Way, and small objects in our Solar System.
According to a new study by Amir Siraj and Prof. Abraham Loeb of Harvard University, another benefit of this survey will be the discovery of interstellar objects that regularly enter the Solar Systems. These results, when combined with physical characterizations of the objects, will teach us a great deal about the origin and nature of planetary systems (and could even help us spot an alien probe or two!)
Using the Atacama Large Millimeter/submillimeter Array (ALMA), a team of scientists has identified a mysterious molecule in Titan’s atmosphere. It’s called cyclopropenylidene (C3H2), a simple carbon-based compound that has never been seen in an atmosphere before. According to the team’s study published in The Astronomical Journal, this molecule could be a precursor to more complex compounds that could indicate possible life on Titan.
In the past few decades, the study of exoplanets has grown by leaps and bounds, with 4296 confirmed discoveries in 3,188 systems and an additional 5,634 candidates awaiting confirmation. Because of this, scientists have been able to get a better idea about the number of potentially-habitable planets that could be out there. A popular target is stars like our own, which are known as G-type yellow dwarfs.
Recently, an international team of scientists (led by researchers from the NASA Ames Research Center) combined data from by the now-defunct Kepler Space Telescope and the European Space Agency’s (ESA) Gaia Observatory. What this revealed is that half of the Sun-like stars in our Universe could have rocky, potentially-habitable planets, the closest of which could be in our cosmic backyard!
Last week, an incredible announcement was made about the search for extraterrestrial life: Phosphine gas detected in the clouds of Venus – a potential indicator of life or “biosignature.” Now some gases might be a false positive for biosignatures because they can be created by other chemical processes on a planet like photochemical processes in the atmosphere or geological processes beneath the surface that create a given gas. For example, methane can also be a biosignature, and we’ve been hunting it down on Mars, but we know that methane can also be created geologically. Finding phosphine in Venusian clouds is truly remarkable because we don’t presently know of any way to create phosphine abiotically or without life being a part of the equation. Question is – how much life??
Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that all the aliens are dead!
In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?“
This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which includes the Berserker Hypothesis. This theory suggests we haven’t heard from any alien civilizations because they’ve been wiped out by killer robots!