Last spring the Sardinia Radio Telescope inaugurated the observations dedicated to the Seti project. Today, July 30, 2021, some small antennas installed next to the large dish have picked up, together with an INAF antenna in Bologna, a simulated “alien” signal, launched by a satellite of the Italian company D-Orbit. The search for extraterrestrial life also passes through these experiments
We would have liked to surprise you with an Orson Welles-style message but, especially these days, we would have risked a complaint for alarm. Yet we are really working on receiving signals from alien intelligence, improving the technologies in the field from time to time.
For example, the Sardinia Radio Telescope ( Srt ) of San Basilio, one of the largest and most advanced radio telescopes in Europe, has finally entered full operation in the Seti (Search for Extra Terrestrial Intelligence) project. In fact, the first observations began last March, as scheduled, thanks to the tireless work of Andrea Melis, engineer technologist of INAF of Cagliari and member of the Seti committee within the International Academy of Astronautics (Iaa).
«In 2021», says Melis, «the Sardinia Radio Telescope became part of the telescope network of the Breakthrough Listen program . The main targets are the most promising exoplanets and the center of the Milky Way. The data analysis is already underway, about one hundred hours of dedicated observations, by colleagues from the University of Berkeley. After the Srt upgrade is completed, we will be able to expand the frequency range from the current 26 GHz to over 100 GHz, a unique feature for which Srt has been chosen to complement the Green Bank Telescope for the high frequency Seti. “.
But it is not only the Sardinia Radio Telescope that is involved in Seti observations. Alongside the 64-meter main dish, a series of small low-frequency omnidirectional antennas, called “ Vivaldi antennas ” , have been installed since 2016 , placed on the ground within a circle also 64 meters in diameter.
This is the Saad (Sardinia Aperture Array Demonstrator) project, curated by the INAF of Cagliari in order to test the potential of the large networks of low-frequency telescopes of the future, such as the Ska project , still to be built, or the Dutch Lofar network , inaugurated in 2012.
And it is precisely some of these small antennas that recorded, on Friday 30 July 2021 at 15:55, a very particular signal launched by a satellite built and sent into orbit by the Italian aerospace company D-Orbit . This is the famous message of Arecibo , designed by astrophysicist Frank Drake and sent to deep space in 1974 by the Puerto Rican radio telescope unfortunately recently collapsed and consequently decommissioned. The intent, then, was to reach some form of intelligent life in the globular cluster of Hercules , an area rich in stars about 23,000 light years away from us.
Today, however, after almost half a century, the Arecibo message has been sent by the Italian satellite – called Ion ( In orbit now ) Scv Dauntless David – towards the Earth, and in particular towards the radio telescopes of the National Institute of Astrophysics. However, from a citizen science perspective , even amateur radio groups could be involved in this type of observations in the future.
The antennas of Bologna and Cagliari turned on to pick up the signal from D-Orbit which, in fact, simulated an alien source. The satellite began to be visible in radio waves at 15:55 and passed through for a few minutes until it disappeared a few seconds after 16:00.
The scenario, which in the next experiments will evolve towards increasingly complex tests, does not only contemplate the technical capacity of receiving a coded signal, but also the capacity for coordination and communication in case of reception of a real alien signal and all the implications of cultural and social character that this would entail.
Indeed, the interface between Seti, D-Orbit and Inaf was not a pool of astrophysicists or experts in satellite telecommunications, but an Italian artist who currently lives in the Netherlands: Daniela De Paulis , who has been working alongside and integrates her artistic activity with that of radio equipment and radio telescopes operator. De Paulis is also a member of the Seti committee of the Iaa, together with Andrea Melis, Stelio Montebugnoli of the INAF of Bologna and many other Italians, as can be read on the page dedicated to members from about fifteen countries. And it is precisely through Seti that the artist came into contact with the radio astronomers of INAF.
«The project», says De Paulis, «will last about two years: we will involve other scientific institutes and international radio telescopes, using messages made specifically with a group of specialists: philosophers, anthropologists, radio astronomers. The aim is to involve both the scientific community involved in SETI and the general public in receiving and interpreting a possible extraterrestrial signal, simulating in an experiential way a hypothetical scenario in which, as a human species, we are faced with the actual existence of a extraterrestrial intelligence. On an artistic level, it is a global performance, in which scientists and the public will interact via a digital platform, ideally crossing the terrestrial cultural barriers ».
The title of the project, A Sign in Space (a sign in space), is inspired, as in many of the artist’s works, by the title of the homonymous story in Italo Calvino’s Cosmicomics collection .
The reception of this signal by the two INAF radio telescopes is an important experimental verification of this project, which combines art and science in an unusual way and which does not stop there, rather it is only at the beginning.
“We have also decided to participate as a Medicine group”, adds Stelio Montebugnoli of the INAF of Bologna, “because in our country the Seti has historically started at the Medicine radio astronomy station in the early nineties – and interest is still very much alive for this very important program, for the scientific and even more philosophical aspect, for man. As Seti advisor to the scientific direction of INAF, I am very satisfied with this experiment, as it allows us to simulate the reception of a signal whose structure is not known (theoretically) – in practice, the modulation – and the real exercise will be that to extract some information from the received signal ».
Featured image: In the foreground on the right, the “Vivaldi” antenna which successfully picked up the signal sent by the Italian satellite of the D-Orbit. In the background the Sardinia Radio Telescope of San Basilio, near Cagliari. Credits: Paolo Soletta / Inaf Cagliari
Provided by INAF