Participants in the Breakthrough Listen project completed a full analysis of observations of Oumuamua, the first interstellar asteroid, and completely excluded the possibility of having any radio transmitters 10 times smaller than a cellular phone on its surface.
“In addition to monitoring the radio signals, we checked whether Oumuamua is indeed an asteroid or comet, trying to find radio waves generated by fragments of water molecules, which we have not found anything like, which confirms that this object is an asteroid, as our colleagues have already written,” note Andrew Siemion (Andrew Siemion) from the Center SETI at the University of Berkeley (USA) and his colleagues.
In mid-October last year, the automated telescope Pan-STARRS1 discovered the first “interstellar” heavenly body. This object was conditionally called a “comet”, received the temporary name C / 2017 U1, and dozens of terrestrial and orbiting telescopes began to follow it.
Before she left the near-Earth space, scientists managed to get a lot of pictures and data on its physical properties, which indicated that this object is more asteroid than comet. It was renamed to 1I / 2017 U1, and subsequently received the name Oumuamua, which means “scout” in the language of the indigenous inhabitants of the Hawaiian Islands.
The visit of this “scout” to the solar system attracted the attention of the participants of the program Breakthrough Listen – the project of Yuri Milner, the Russian IT-billionaire, and the British cosmologist Stephen Hawking, whose main goal is to search for radio signals and other signs of activity of extraterrestrial civilizations.
The first observations of Oumuamua using the GBT radio telescope in Green Banks (USA) did not yield any results – Simion and his team could not find any traces of radio transmitters with the capacity of a regular cell phone. Nevertheless, astronomers continued to analyze the data in an attempt to find even weaker sources of radio waves.
The final analysis of the data that scientists released today indicates that traces of extraterrestrial civilizations on Oumuamua are most likely completely absent – there are no sources of radio waves on its surface, whose strength is about ten times less than that of a smartphone.
Despite this setback, the Breakthrough Listen team was able to test those techniques for observing distant stars that they developed to search for signals from extraterrestrial civilizations, which allows them to be used in practice to search for the most inconspicuous traces of their existence at far farther distances.