Last month, the initiative released analysis of petabytes of data from the first year of observations from the US-based Green Bank Telescope - the world's largest fully steerable radio telescope - including 11 "events" ranked as of "highest significance", although it was unlikely that any of the signals originated from artificial extraterrestrial sources.
The "Breakthrough Listen" programme, which was also scanning huge amounts of data gathered by the Automated Planet Finder in California and the Parkes Radio Telescope in Australia, also recently turned in publication the analysis of 692 stars.
Read more: Are we alone in the universe?
The work was being boosted by a data-crunching "pipeline" at the University of California SETI research centre, designed to scans through billions of radio channels in a search for unique signals that might indicate the presence of technology developed by civilisations outside the solar system.
Scientists could weed out artificial signals from natural processes through features such as narrow bandwidth; irregular spectral behavior, pulsing, or modulation patterns; and broad-band signals with unusual characteristics.
But, because human technology emitted signals similar to the ones being searched for, algorithms had to be designed to ensure that signals were coming from a fixed point relative to the stars or other targets being observed.
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The pipeline produced millions of hits for the sample as a whole, of which the vast majority were almost certainly radio frequency interference from human technology.
The 11 singled out events rose above the pipeline threshold for significance, but further detailed analysis indicates that it is unlikely that any of these signals originate from artificial extraterrestrial sources.
For each star sample, the team searched through the entire database of events, looking for radio channels where events occurred only at one or a small handful of positions on the sky.
While these stars had unique radio "fingerprints", this was by no means convincing evidence that they host planets inhabited by extraterrestrial civilisations.
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However, the search for signals that are localised on the sky and appeared unusual in some way provided an excellent way to select promising targets for follow-up observations.
At a free public lecture at the University of Auckland on Thursday, June 8, Worden, who became chairman of the Breakthrough Prize Foundation and executive director of the foundation's Breakthrough Initiatives on leaving NASA's Ames Research Centre in 2015, will share the initiatives' latest work.
He will be joined by Breakthrough Initiatives chief of staff Jamie Drew, who formerly worked at Ames on SOAREX, a rapid and inexpensive sub-orbital re-entry system.
"It is exciting to have Dr Worden visit New Zealand and share with us the latest progress on a global initiative seeking to discover other intelligent life in the universe," said Professor Nic Smith, dean of the university's Faculty of Engineering.
"It is a fundamental question not just for scientists but for anyone who ever wondered whether there was life beyond our own world."
New Zealand scientists have been contributing to the hunt through global efforts such as the Japan-New Zealand Microlensing Observations in Astrophysics (MOA) collaboration, and the gigantic Square Kilometre Array radio telescope, which, when built, will have a much higher sensitivity and resolution than anything in the world today.
• The lecture will be held from 5.30-6.30pm at the University of Auckland's Fisher and Paykel Appliances Auditorium, 12 Grafton Rd.
