Are we alone? How Rhodes University is helping search for extraterrestrial intelligence

By Siqhamo Jama

 

“Are we the universe’s first technological species, or simply the only one left?”

Dr Chenoa Tremblay began her public lecture at Rhodes University with a question that, over the years, has shifted from philosophy to experiment.

Dr Tremblay is a Project Scientist at the SETI (Search for Extraterrestrial Intelligence) Institute with affiliated roles at Breakthrough Initiatives and the National Radio Astronomy Observatory. She leads real-time radio data analysis at the Karl G. Jansky Very Large Array in New Mexico, where she serves as Project Scientist for the COSMIC system, and is the Project Scientist for the BLUSE system on MeerKAT, which is operated by Breakthrough Listen.

Her visit was hosted by Professor Oleg Smirnov of Rhodes University’s Centre for Radio Astronomy Techniques and Technologies (RATT). The lecture placed the University within a global network of radio telescopes quietly listening for evidence of extraterrestrial technology.

RATT researchers work extensively with MeerKAT data and contribute to radio astronomy software, calibration techniques and signal processing methods that support the telescope’s scientific output. MeerKAT, operated by the South African Radio Astronomy Observatory (SARAO), is a precursor to the Square Kilometre Array (SKA).

Through the BLUSE system, MeerKAT also forms part of the international technosignature effort.

From sending messages to listening

In 1977, NASA launched Voyager 1 and Voyager 2 carrying the Golden Record, a gold-plated message intended for any civilisation that might one day encounter it. Today, the approach has shifted. Instead of sending messages into space, scientists are listening.

The COSMIC and BLUSE systems operate commensally. They run whenever their host telescopes are switched on, analysing vast streams of radio data in real time while astronomers pursue their primary research targets. The technosignature search unfolds quietly in the background.

When scientists search for life beyond Earth, they often distinguish between biosignatures and technosignatures. Biosignature research looks for indicators such as water or oxygen in distant atmospheres. Technosignature research instead searches for signals that stand out from natural astrophysical processes.

Radio waves travel at the speed of light and are widely used by human technology, from radar systems to mobile communication. If another civilisation developed similar methods of communication, radio emissions would be a logical place to look.

Using specialised software, much of it written in Python, Dr Tremblay’s team searches for extremely narrow band signals that drift slightly in frequency over time. Such drift is consistent with a transmitter moving relative to Earth. Signals that remain fixed are usually interference from our own planet.

Dinosaurs playing PlayStation

“If we were looking at a planet that had dinosaurs on it,” Dr Tremblay explained, “we wouldn’t necessarily be able to detect them because the dinosaurs aren’t doing anything technologically advanced. We have to find dinosaurs that are playing PlayStations and have cell phones before we can start to detect them.”

The scale of the task is enormous. During observations of the exoplanet K2 18b, a world that has drawn scientific interest for evidence of atmospheric water vapour, the system identified more than 21 million potential signals. After filtering out satellites, terrestrial transmitters and instrumental effects, none remained.

In multi antenna telescopes such as the VLA and MeerKAT, genuine signals must appear consistently across all dishes. A signal detected by only one antenna is almost always a glitch. So far, every candidate has had a terrestrial explanation.

Null results are part of the process. Dr Tremblay’s team is working with SARAO to catalogue radio frequency interference detected by MeerKAT, refining their filters and strengthening future searches.

Silence and the Fermi Paradox

If increasingly sensitive telescopes continue to find nothing, what does that mean?

The dilemma echoes what is known as the Fermi Paradox, often summarised as the question, “Where is everybody?” Are we among the earliest technological civilisations in the universe? Has intelligent life arisen and disappeared elsewhere? Or is advanced technology simply rare?

Despite six decades of modern SETI research, scientists have examined only a tiny fraction of the cosmic ocean. The absence of detection does not yet provide an answer.

From Makhanda to the Karoo and New Mexico, Rhodes University is linked to a global effort to answer one of humanity’s oldest questions. If one day a signal survives every test, the headlines will follow. Until then, the work continues, patient and methodical, separating cosmic noise from possibility.