Breakthrough Listen releases ‘Exotica’ list of potential alien hotspots

23 Jun 2020

Image: © ktsdesign/

The Breakthrough Listen group has released a list of all known objects in the universe that could be of interest to astronomers looking for aliens.

The Breakthrough Listen group funded by billionaire Yuri Milner, which is attempting to find evidence of extraterrestrial life in the universe, has released a new list that should pique the interest of astronomers.

The Exotica list is a collection of more than 700 distinct areas of interest for astronomers looking for technosignatures – indicators of technology developed by extraterrestrial intelligence. These targets include “one of everything in the known universe”, ranging from comets to galaxies, and from mundane objects to the most rare and violent celestial phenomena.

While no confirmed technosignature has ever been detected, Breakthrough Listen said that the new Exotica catalogue will be crucial to the concept of ‘survey breadth’. This means it can help diversify the types of objects observed by astronomers and help them constrain the range of potential habitats for extraterrestrial intelligence, as well as rule out the possibility that any phenomena widely considered natural are, in fact, artificial.

A ‘shakedown cruise around the universe’

The Exotica catalogue contains four categories of object including prototypes (every known kind of celestial object, such as planets, moons and stars), superlatives (objects with extreme properties), anomalies (enigmatic targets with no confirmed behaviour, such as ‘Oumuamua), and a control sample of sources not expected to produce positive results.

Accompanying the catalogue is a discussion of classification of objects and a new classification system for anomalies, as well as plans for upcoming and potential observations based on this work.

“Many discoveries in astronomy were not planned,” said Dr Brian Lacki, lead author of a new pre-print paper discussing Exotica.

“Sometimes a major new discovery was missed when nobody was looking in the right place, because they believed nothing could be found there. This happened with exoplanets, which might have been detected before the 1990s if astronomers looked for solar systems very different than ours. Are we looking in the wrong places for technosignatures? The Exotica catalogue will help us answer that question.”

Lacki added that the scope of the catalogue will not just be limited to the search for alien life, but could be used as a “shakedown cruise around the universe”.

Colm Gorey was a senior journalist with Silicon Republic