The Quest for Alien Intelligence in Distant Galaxies

The search for intelligent life beyond Earth, also known as SETI, has made significant progress. Advancements in technology have provided new opportunities for exploring the cosmos and seeking potential signs of extraterrestrial civilizations. For example, commensal observing allows scientists to monitor for signals from distant galaxies while telescopes are engaged in other activities, significantly improving the sensitivity of searches.

The expansion of observing programs has also led to new approaches in the search for alien intelligence. Searching for laser signals among the stars, looking for signs of very advanced civilizations, and exploring the possibility of deliberate signals being sent to coincide with major astronomical events are all under consideration.

Furthermore, the search has extended to the possibility of alien spacecraft lurking in our Solar System, with the next generation of telescopes having the capability to reveal such crafts.

Beyond our own galaxy, a recent study led by Carmen Choza from the Breakthrough Listen team has been searching for signals from beyond the Milky Way using data from the giant Green Bank telescope in West Virginia. This traditional form of SETI, which involves looking for narrowband signals with a radio telescope, has become the most sensitive search ever attempted for intelligence beyond our galaxy.

However, the challenge of detecting a signal from intergalactic distances is significant. For a signal to be detectable at such distances, it would have to be exceptionally powerful – with estimates putting it at over 10^26 watts if broadcast blindly into the cosmos.

Despite the monumental challenges, the search continues. The team combed through over 100 terabytes of data collected by the telescope between 2018 and 2022, resulting in 1,319 possible detections. While no definitive signals meeting the criteria for potential technosignatures were found, the study conducted by Carmen Choza and her team provides valuable insights into the ongoing pursuit of alien intelligence. The dedication and innovation driving this field of scientific inquiry are truly commendable.

Reference:
Choza, C., et al. (2023). The Breakthrough Listen Search for Intelligent Life: Technosignature Search of 97 Nearby Galaxies. arXiv preprint arXiv:2312.03943.