If your child is interested in the search for extraterrestrial intelligence – and you are OK with that – then you might want to encourage them to apply to Penn State (formally known as The Pennsylvania State University) in State College, Pennsylvania. The school is home to the Penn State Extraterrestrial Intelligence Center and recently hosted the First Penn State SETI Symposium, where a paper was presented describing an interesting technique for eavesdropping on extraterrestrial communications sent by aliens who may be using our Sun as a gravitational lens to relay and power messages. Can it work? And where were programs like this when you were trying to decide between majoring in English or accounting?
“It has also been considered as a way that humans might communicate with our own probes if we ever sent them to another star. If an extraterrestrial technological species were to use our sun as a lens for interstellar communication efforts, we should be able to detect those communications if we look in the right place.”
Jason Wright is a professor of astronomy and astrophysics at Penn State and the director of the Penn State Extraterrestrial Intelligence Center. He taught the course that resulted in the study, accepted for publication in the Astronomical Journal and available on the preprint server arXiv, but his name is familiar in SETI circles. Back in 2017, he proposed that the interstellar asteroid Oumuamua was potentially a Von Neumann probe – one of thousands of self-replicating robotic spacecraft sent by an extraterrestrial species to explore the galaxy. In 2016, he theorized that KIC8462852, nicknamed “Tabby’s Star” for Yale University astronomer Tabetha “Tabby” Boyajian, was mysteriously dimming because it was surrounded by a Dyson sphere built by aliens to harvest its energy. He also puts his (OK, Penn State’s) money where his mouth is – his frustration with government funding for NASA’s missions to find extraterrestrial life has inspired his involvement in the university’s Consortium for Planetary and Exoplanetary Sciences and Technology (CPEST), he developed Penn State's first graduate-level course in SETI, worked on the Breakthrough Listen Initiative at the University of California, Berkeley, and helped host the Penn State SETI Symposium. This sounds like the ‘Wright’ person to lead young people in the quest to communicate with extraterrestrials.
“There have been a few previous searches using optical wavelengths, but we chose to use radio wavelengths, because radio is a great way to communicate information across space.”
In a Penn State press release, Macy Huston, a graduate student who helped lead the project, helps to explain in layperson terms why this technique makes sense. We humans use cell phones on networks of cellular towers which pass electromagnetic waves between each other. Television, radio, and internet signals travel on point-to-point network communication systems. Thus, it makes sense that, if ETs think like we do and follow their own Einstein’s Theory of General Relativity, they can create a galactic interstellar network using stars as gravitational lenses to relay and power signals. If we can find the network, Nick Tusay, another graduate student on the project, concluded, “We can infer where probes would need to be located in order to use them.” In other words … eavesdrop on ETs.
“We included what is known as the ‘waterhole’ wavelengths, which are often a focus of SETI searches because they would be an ideal part of the radio spectrum to communicate in and could act like a waterhole on Earth, where many species convene. These wavelengths are generally free from other radio waves coming from cosmic objects, so it’s a clean part of the spectrum to communicate in.”
Huston again puts the project in terms we can understand – animals signal to let each other know where the nearest watering holes are, thus making them convenient gathering places for animal-to-animal communications. Anyone (or any similar species) eavesdropping on those ‘conversations’ would no doubt pick up the location of the next nearest watering holes. the students chose Alpha Centauri — the closest stars in our galaxy – as our next ‘watering hole’ or node for a gravitational lensing node. They then plotted out an area more than 550 times the Earth-sun distance around Alpha Centauri to narrow down where a signal might be coming from that would use our Sun as a node for sending radio transmissions that might be signals to Earth, signals to probes exploring the solar system, signals passing through to another node, or even signals being bounced back to Alpha Centauri. To make this truly a real-life, limited budget scenario, the student researchers had to collect their data over a single night at the Green Bank Telescope in West Virginia. Showing that it pays to have friends with connections, the data collection and analysis were conducted in collaboration with Breakthrough Listen.
So, what did the students hear when they conducted “A Search for Radio Technosignatures at the Solar Gravitational Lens Targeting Alpha Centauri” – the title of the study?
“Our search was limited to one night, so anything that wasn’t broadcasting while we were observing was not going to get picked up. Although our limited search could miss existing probes if they weren’t constantly broadcasting at these frequencies, this was a good test to see if this kind of search is possible.”
Don’t worry -- Nick Tusay, Macy Huston and the other students still passed the course, even if they didn’t catch any juicy ET gossip on their intergalactic wiretap. However, they proved the viability of the technique, and showed how students from a variety of disciplines -- including astrobiology, astronomy, chemistry, and geophysics – can work together to search for extraterrestrial communications. As they pointed out in their presentation at the SETI Symposium, other students can now expand their observations to different stars and hopefully get more time on the telescope. Proving once again that astronomers should never throw out any data, they are also digging through archival data from Breakthrough Listen for clues to other areas that might make great ‘watering holes’ for ET networks and probes.
Kudos are in order for Professor Jason Wright, his students on the study and Penn State University for bringing the search for extraterrestrial intelligence to legitimacy as a discipline worthy of college courses and, perhaps one day, college degrees. Go Nittany Lions!