View source for Astronomy:Breakthrough Listen

{{short description|Initiative to search for intelligent extraterrestrial life}}
[[File:GBT.png|thumb|The Green Bank Telescope is one of the radio telescopes used by the project<!-- to search for alien communications-->.]]
'''Breakthrough Listen''' is a project to [[Astronomy:Search for extraterrestrial intelligence|search for intelligent extraterrestrial communications]] in the Universe.<ref name="Merali0720">{{cite journal|title=Search for extraterrestrial intelligence gets a $100-million boost. Russian billionaire Yuri Milner announces most comprehensive hunt for alien life.|journal=Nature|volume=523|issue=7561|pages=392–3|last=Merali|first=Zeeya |date=20 July 2015|publisher=Nature News|doi=10.1038/nature.2015.18016|pmid=26201576|bibcode=2015Natur.523..392M |doi-access=free}}</ref><ref name=":2"/> With $100 million in funding and thousands of hours of dedicated telescope time on state-of-the-art facilities,<ref>{{cite web |url=http://timesofindia.indiatimes.com/home/science/breakthrough-detects-15-radio-bursts-from-dwarf-galaxy-might-be-from-alien-spacecraft/articleshow/60296645.cms |author=Chethan Kumar |title=Breakthrough detects 15 radio bursts from dwarf galaxy; might be from 'alien' spacecraft |date=August 31, 2017 |work=Times of India}}</ref> it is the most comprehensive search for alien communications to date.<ref name="Merali0720" /><ref name=":2">{{cite magazine |url=https://www.wired.co.uk/news/archive/2015-07/20/breakthrough-listen-project|title=$100m Breakthrough Listen is 'largest ever' search for alien civilisations |last=Rundle |first=Michael |date=20 July 2015 |magazine=Wired|access-date=20 July 2015}}</ref> The project began in January 2016, and is expected to continue for 10 years.<ref name=":0"/> It is a component of [[Biography:Yuri Milner|Yuri Milner's]] [[Astronomy:Breakthrough Initiatives|Breakthrough Initiatives]] program. The science program for Breakthrough Listen is based at Berkeley SETI Research Center,<ref>{{Cite web |url=https://seti.berkeley.edu/listen/ |title=Berkeley SETI |website=seti.berkeley.edu |language=en |access-date=2017-09-21}}</ref><ref name=":1"/> located in the Astronomy Department<ref>{{Cite web |url=http://astro.berkeley.edu/p/breakthrough-listen |title=Breakthrough Listen Initiative – News from Department of Astronomy |website=astro.berkeley.edu |access-date=2017-09-21}}</ref> at the [[Organization:University of California, Berkeley|University of California, Berkeley]].

The project uses radio wave observations from the [[Astronomy:Green Bank Observatory|Green Bank Observatory]] and the [[Astronomy:Parkes Observatory|Parkes Observatory]], and visible light observations from the [[Astronomy:Automated Planet Finder|Automated Planet Finder]].<ref name="Sample0720">{{cite web |url=https://www.theguardian.com/science/2015/jul/20/breakthrough-listen-massive-radio-wave-project-scan-far-regions-for-alien-life |title=Anybody out there? $100m radio wave project to scan far regions for alien life |last=Sample |first=Ian |date=20 July 2015 |work=The Guardian |access-date=20 July 2015}}</ref> Targets for the project include one million nearby stars and the centers of 100 galaxies. All data generated from the project are available to the public, and [[Astronomy:SETI@home|SETI@Home]] (BOINC) is used for some of the data analysis. The first results were published in April 2017, with further updates expected every 6 months.<ref name=":1" />

== Overview ==
The project aims to discover signs of [[Astronomy:Extraterrestrial life|extraterrestrial civilizations]] by searching stars and galaxies for [[Radio wave|radio signals]] and [[Physics:Laser|laser]] transmissions. The search for radio signals is carried out on the Green Bank Telescope in the [[Earth:Northern Hemisphere|Northern Hemisphere]] and the Parkes Telescope in the [[Earth:Southern Hemisphere|Southern Hemisphere]]. The Green Bank Telescope is the world's largest steerable [[Astronomy:Radio telescope|radio telescope]], and the Parkes Telescope is the second-largest steerable radio telescope in the Southern Hemisphere.<ref name="public.nrao.edu">{{Cite web |url=https://public.nrao.edu/news/pressreleases/gbt-breakthrough-listen |title=Green Bank Telescope Joins 'Breakthrough Listen' – NRAO: Revealing the Hidden Universe |website=public.nrao.edu |access-date=2016-04-14}}</ref><ref>{{Cite web |url=http://breakthroughinitiatives.org/Telescopes/1 |title=Telescopes |website=Breakthrough Listen |access-date=2016-04-14}}</ref>

Together, the radio telescopes will cover ten times more sky than previous searches and scan the entire 1-to-10&nbsp;GHz range, the so-called "quiet zone" in the spectrum where [[Radio wave|radio wave]]s are unobscured by cosmic sources or Earth's atmosphere.<ref>{{Cite magazine|url=https://www.wired.com/2015/07/russian-tycoon-spending-100-million-hunt-aliens/|title=A Russian Tycoon Is Spending $100 Million to Hunt for Aliens|magazine=WIRED|language=en-US|access-date=2016-04-14|date=2015-07-20|last1=Zhang|first1=Sarah}}</ref>

The radio telescopes are sensitive enough to detect "Earth-leakage" levels of radio transmission from stars within 5 [[Astronomy:Parsec|parsec]]s,<ref name=":0"/> and can detect a transmitter of the same power as a common aircraft [[Engineering:Radar|radar]] from the 1,000 nearest stars.<ref name="arstechnica.com">{{cite web|last=Brodkin|first=Jon|title = $100 million search for aliens will listen for messages from 100 galaxies|url = https://arstechnica.com/science/2015/07/100-million-search-for-aliens-will-listen-for-messages-from-100-galaxies/|publisher=[[Ars Technica]]|access-date = 24 July 2015|date=2015-07-20}}</ref> The Green Bank Telescope began operations in January 2016, and the Parkes Telescope from October 2016.<ref name=":0"/> The [[Astronomy:Five hundred meter Aperture Spherical Telescope|FAST]] radiotelescope in China also joined forces in October 2016 with the Breakthrough Initiatives to launch a coordinated search, including the rapid sharing of promising new signals for additional observation and analysis.<ref>{{cite press release |url=http://astrobiology.com/2016/10/national-astronomical-observatories-of-china-breakthrough-initiatives-launch-global-collaboration-in.html |title=National Astronomical Observatories of China, Breakthrough Initiatives Launch Global Collaboration in Search for Intelligent life in the Universe |publisher=Breakthrough Initiatives |via=Astrobiology Web |date=12 October 2016 |access-date=2016-10-14 }}</ref>

The search for optical [[Physics:Laser|laser]] transmissions is carried out by the [[Astronomy:Automated Planet Finder|Automated Planet Finder]] of [[Organization:Lick Observatory|Lick Observatory]].<ref name=":5"/> The telescope has the sensitivity to detect a 100 watt laser from a star 25 [[Orders of magnitude (numbers)#1012|trillion]] miles (4.25 [[Light year|light year]]s) away.<ref name="arstechnica.com" />

== Announcement ==
[[File:Stephen Hawking in Cambridge.jpg|thumb|right|Physicist Stephen Hawking was among the scientists who co-signed an open letter of support for Breakthrough Listen.]]
Breakthrough Listen was announced to the public on July 20, 2015 (the anniversary of the [[Engineering:Apollo 11|Apollo 11]] Moon landing) by Milner at London's Royal Society. The event was flanked by scientists such as Frank Drake, who is known for the [[Astronomy:Drake equation|Drake equation]] that estimates the number of detectable alien civilizations<!--as well as for being the founder of SETI/-->, and [[Biography:Geoffrey Marcy|Geoff Marcy]], an astronomer who has helped find hundreds of [[Astronomy:Exoplanet|exoplanet]]s.<ref>{{cite magazine|url = https://www.wired.com/2015/07/russian-tycoon-spending-100-million-hunt-aliens/|title = A Russian Tycoon Is Spending $100 Million to Hunt for Aliens|access-date = 11 August 2015|magazine =Wired |last = Zhang|first = Sarah|date = 2015-07-20}}</ref> The announcement included an open letter co-signed by multiple scientists, including physicist [[Biography:Stephen Hawking|Stephen Hawking]], expressing support for an intensified search for alien life.<ref name=Merali0720 /><ref name=Questions>{{cite magazine|last1=Vella|first1=Matt|title=Read the Inspiring 'Questions of Existence' Letter from the World's Greatest Thinkers|url=http://time.com/3964301/breakthrough-listen-letter/|magazine={{wipe|Time (magazine)}}|access-date=21 July 2015|date=21 July 2015}}</ref> During the public launch, Hawking said:
{{cquote|In an infinite Universe, there must be other life. There is no bigger question. It is time to commit to finding the answer.<ref name="Merali0720" />}}

== Significance ==
The project is the most comprehensive [[Astronomy:Search for extraterrestrial intelligence|search for alien communications]] to date.<ref name="Merali0720" /> It is estimated that the project will generate as much data in one day as previous [[Astronomy:Search for extraterrestrial intelligence|SETI]] projects generated in one year.<ref name="Merali0720" /> Compared to previous programs, the radio surveys cover 10 times more of the sky, at least 5 times more of the radio [[Spectrum|spectrum]], and work 100 times faster.<ref name=":5">{{Cite web |url=http://breakthroughinitiatives.org/Initiative/1|title=Listen |website=Breakthrough Listen |access-date=2016-04-14}}</ref> The optical laser survey is also the deepest and broadest search in history.<ref name=":5" />

Andrew Siemion, director of the [[Organization:Berkeley SETI Research Center|Berkeley SETI Research Center]] at the [[Organization:University of California, Berkeley|University of California, Berkeley]], describes that "We would typically get 24–36 hours on a telescope per year, but now we'll have thousands of hours per year on the best instruments...It's difficult to overstate how big this is. It's a revolution."<ref>{{Cite journal|title=Search for extraterrestrial intelligence gets a $100-million boost|journal=Nature|volume=523|issue=7561|pages=392–393|doi=10.1038/nature.2015.18016|pmid=26201576|year=2015|last1=Merali|first1=Zeeya|bibcode=2015Natur.523..392M|doi-access=free}}</ref>

== Targets ==
As of April 2016, the targets for the radio search with the Green Bank Radio Telescope in the Northern Hemisphere include the following:<ref name=":0"/>
* All 43 stars within 5 [[Astronomy:Parsec|parsec]], or 16.3 light-years, or 1.03 million astronomical units, or {{val|1.545|e=14|u=kilometres}}
* 1000 stars of all [[Astronomy:Stellar classification|spectral-types]] within 50 pc, or 163 ly, or 10.3 million au, or {{val|1.545|e=15|u=km}}
* One million nearby stars
* Center regions of at least 100 nearby galaxies, including [[Spiral galaxy|spiral galaxies]], elliptical galaxies, [[Astronomy:Dwarf galaxy|dwarf galaxies]] and [[Astronomy:Irregular galaxy|irregular galaxies]]
* Exotic stars: 20 [[Astronomy:White dwarf|white dwarf]]s, 20 [[Astronomy:Neutron star|neutron star]]s, 20 [[Astronomy:Black hole|black hole]]s
The Parkes Radio Telescope will cover similar targets in the Southern Hemisphere from 1–4&nbsp;GHz, and also the galactic plane and center.<ref name=":0"/>

The targets for the [[Astronomy:Automated Planet Finder|Automated Planet Finder]] will closely match those of the Green Bank radio search, with small adjustments due to the telescope's much smaller field of view.<ref name=":0" />

While the telescopes are observing, the current targets of the Green Bank Radio Telescope and the [[Astronomy:Automated Planet Finder|Automated Planet Finder]] can be viewed live at the Berkeley Seti Research Center.{{citation needed|date=October 2019}}

In January 2017, the project published its initial targets, which are the 60 nearest stars and a further 1649 stars which are the closest representatives of each spectral type.<ref name=":6">{{Cite journal |arxiv=1701.06227 |display-authors=5 |author1=Howard Isaacson |author2=Andrew P. V. Siemion |author3=Geoffrey W. Marcy |author4=Matt Lebofsky |author5=Danny C. Price |author6=David MacMahon |author7=Steve Croft |author8=David DeBoer |author9=Jack Hickish |author10=Dan Werthimer |author11=Sofia Sheikh |author12=Greg Hellbourg |author13=J. Emilio Enriquez |title=The Breakthrough Listen Search for Intelligent Life: Target Selection of Nearby Stars and Galaxies |journal=Publications of the Astronomical Society of the Pacific |volume=129 |issue=975 |pages=054501 |doi=10.1088/1538-3873/aa5800 |year=2017 |bibcode=2017PASP..129e4501I |s2cid=119077156 }}</ref> The initial targets also include 123 galaxies which cover all morphological types of galaxies.<ref name=":6" />

In October 2019 it was announced that Breakthrough Listen will collaborate with scientist from NASA's [[Astronomy:Transiting Exoplanet Survey Satellite|Transiting Exoplanet Survey Satellite]] (TESS) team. Over a thousand new planets found by TESS will be scanned for technosignatures. The search will use Listen's primary facilities (Green Bank and Parkes Telescopes, [[Astronomy:MeerKAT|MeerKAT]], and the [[Astronomy:Automated Planet Finder|Automated Planet Finder]]) as well as partner facilities (including [[Astronomy:VERITAS|VERITAS]], NenuFAR, [[Astronomy:Five-hundred-meter Aperture Spherical Telescope|FAST]], the [[Astronomy:Murchison Widefield Array|Murchison Widefield Array]], [[Astronomy:Low-Frequency Array (LOFAR)|LOFAR]] stations in Ireland and Sweden, [[Astronomy:Jodrell Bank Observatory|Jodrell Bank Observatory]], [[Astronomy:MERLIN|e-MERLIN]], [[Astronomy:W. M. Keck Observatory|Keck Observatory]], [[Astronomy:Sardinia Radio Telescope|Sardinia Radio Telescope]], along with the [[Astronomy:Allen Telescope Array|Allen Telescope Array]]). In addition to targeting of TESS planets with Listen facilities, the TESS lightcurves themselves will be searched for anomalies, for example caused by [[Astronomy:Dyson sphere|megastructures]].<ref>{{Cite web|url=https://greenbankobservatory.org/breakthrough-listen-announces-new-collaboration/|title=Breakthrough Listen Announces New Collaboration|last=Observatory|first=Green Bank|date=2019-10-23|website=Green Bank Observatory|language=en-US|access-date=2020-01-10}}</ref><ref>{{cite web |title=Breakthrough Listen Releases its one-of-Everything "Exotica" Catalog |url=https://www.universetoday.com/146741/breakthrough-listen-releases-its-one-of-everything-exotica-catalog/ |website=Universe Today |access-date=13 May 2022 |date=5 July 2020}}</ref>

== Breakthrough Listen Exotica Catalog ==
Breakthrough Listen Exotica Catalog is a list of 700 targets that were chosen "to include "one of everything" in the observed Universe – ranging from comets to galaxies, from mundane objects to the most rare and violent celestial phenomena".<ref name="exotica">{{cite web |title=BREAKTHROUGH LISTEN RELEASES LIST OF "EXOTICA" – ONE OF ALMOST EVERY KIND OF OBSERVABLE OBJECT OR PHENOMENON IN THE UNIVERSE |url=https://breakthroughinitiatives.org/news/29 |website=breakthroughinitiatives.org |access-date=13 May 2022 |language=en}}</ref><ref>{{cite journal |last1=Lacki |first1=Brian C. |last2=Brzycki |first2=Bryan |last3=Croft |first3=Steve |last4=Czech |first4=Daniel |last5=DeBoer |first5=David |last6=DeMarines |first6=Julia |last7=Gajjar |first7=Vishal |last8=Isaacson |first8=Howard |last9=Lebofsky |first9=Matt |last10=MacMahon |first10=David H. E. |last11=Price |first11=Danny C. |last12=Sheikh |first12=Sofia Z. |last13=Siemion |first13=Andrew P. V. |last14=Drew |first14=Jamie |last15=Worden |first15=S. Pete |title=One of Everything: The Breakthrough Listen Exotica Catalog |journal=The Astrophysical Journal Supplement Series |date=1 December 2021 |volume=257 |issue=2 |pages=42 |doi=10.3847/1538-4365/ac168a |arxiv=2006.11304 |bibcode=2021ApJS..257...42L |s2cid=219966544 |doi-access=free }}</ref><ref>{{cite web |title=One Of Everything: The Breakthrough Listen Exotica Catalog - Astrobiology |url=http://astrobiology.com/2020/06/one-of-everything-the-breakthrough-listen-exotica-catalog.html |website=astrobiology.com |date=23 June 2020 |access-date=13 May 2022}}</ref>

There are four types of targets in the catalog:<ref name="exotica"/>
# "Prototypes: a list containing at least one example of every known kind of celestial object (apart from those too transient to present realistic observation targets). Planets and moons, stars at every point of their life cycle, galaxies big and small, serene star clusters and blazing quasars, and more are all included in the list."
# "Superlatives: objects with the most extreme properties. These include examples like the hottest planet, stars with unusually high or low metal content, the most distant quasar and fastest-spinning pulsar, and the densest galaxy."
# "Anomalies: enigmatic targets whose behavior is currently not satisfactorily explained. For instance, the famous "[[Astronomy:Tabby's Star|Tabby's Star]]" with its bizarre dimming behavior; ’Oumuamua – the interstellar object that passed near Earth in 2017; unexplained optical pulses that last mere nanoseconds; and stars with excess infrared radiation that could conceivably be explained as waste heat from alien megastructures."
# A control sample of sources not expected to produce positive results.

== Data processing ==
Analyzing radio observations for possible signals requires intensive data analysis to cover all of the possible signal types. To carry out an in-depth search, the data recorder at the Green Bank telescope has been significantly upgraded.<ref name=":8">{{Cite journal |arxiv=1707.06024 |display-authors=5 |author1=David H.E. MacMahon |author2=Danny C. Price |author3=Matthew Lebofsky |author4=Andrew P. V. Siemion |author5=Steve Croft |author6=David DeBoer |author7=J. Emilio Enriquez |author8=Vishal Gajjar |author9=Gregory Hellbourg |author10=Howard Isaacson |author11=Dan Werthimer |author12=Zuhra Abdurashidova |author13=Marty Bloss |author14=Ramon Creager |author15=John Ford |author16=Ryan S. Lynch |author17=Ronald J. Maddalena |author18=Randy McCullough |author19=Jason Ray |author20=Mark Whitehead |author21=Dave Woody |title=The Breakthrough Listen Search for Intelligent Life: A Wideband Data Recorder System for the Robert C. Byrd Green Bank Telescope |journal=Publications of the Astronomical Society of the Pacific |volume=130 |issue=986 |pages=044502 |doi=10.1088/1538-3873/aa80d2 |year=2018 |bibcode=2018PASP..130d4502M |s2cid=59378232 }}</ref> The system records 6&nbsp;GHz of bandwidth at 24GB of data per second, making it among the highest data rate recording systems in radio astronomy, and there is a plan to double its capabilities in the near future.<ref name=":8" /> Once this data has been recorded, it is analysed for signals using a computing cluster with 64 [[GeForce 10 series|GTX 1080]] [[Graphics processing unit|GPUs]].<ref name=":8" /> The raw data is reduced to a lower resolution to allow long-term storage, but even this reduced data totals approximately 1 [[Petabyte|petabyte]] per year.<ref>{{cite arXiv |eprint=1901.04636 |title=Self-Supervised Anomaly Detection for Narrowband SETI |author1=Yunfan Gerry Zhang |author2=Ki Hyun Won |author3=Seung Woo Son |author4=Andrew Siemion |author5=Steve Croft |class=astro-ph.IM |year=2019 }}</ref>

All data generated from Breakthrough Listen project will be open to the public.<ref name="Breakthrough Initiatives">{{Cite web |url=http://breakthroughinitiatives.org/OpenData/1 |website=Breakthrough Initiatives |title=Open Data |access-date=2016-04-14 |archive-date=2016-04-16 |archive-url=https://web.archive.org/web/20160416013015/http://breakthroughinitiatives.org/OpenData/1 |url-status=dead }}</ref> The data is uploaded on the initiative's [http://www.breakthroughinitiatives.org/OpenDataSearch Open Data Archive], where any user can download it for software analysis. Breakthrough Initiatives are developing open source software to assist users in understanding and analyzing the data, which are available on [[GitHub]] under UCBerkeleySETI.<ref name="Breakthrough Initiatives" />

The data is also processed by the [[Astronomy:SETI@home|SETI@home]] (BOINC) volunteer computer network, with the first batch of data being made available to SETI@home in April 2016.<ref name=":0">{{Cite web |url=http://breakthroughinitiatives.org/News/3 |website=Breakthrough Initiatives |title=Breakthrough Listen Initiative Publicly Sharing Data from Unprecedented Search for Intelligent Life in the Universe |date=April 12, 2016 |access-date=2016-04-14}}</ref>

== Funding ==
The project is funded with $100 million from [[Biography:Yuri Milner|Yuri Milner]].<ref name=":3">{{cite web|last=Toor|first=Amar|title = Yuri Milner will spend $100 million to look for aliens|url = https://www.theverge.com/2015/7/20/9002339/yuri-milner-alien-search-breakthrough-listen|website = [[The Verge]]|access-date = 24 July 2015|date=2015-07-20}}</ref> One third of this funding will be used to purchase telescope time.<ref name=":4">{{Cite web|url=http://www.skyandtelescope.com/astronomy-news/breakthrough-listen-a-giant-leap-for-seti/|title="Breakthrough Listen": Giant Leap for SETI|website=Sky & Telescope|language=en-US|access-date=2016-04-14|date=2015-07-22}}</ref> So far, the project has signed contracts for around 20 percent of the time on the Green Bank Telescope for the next five years, and 25 percent of the time on the Parkes Telescope.<ref name="public.nrao.edu"/><ref>{{Cite web|url=http://csiro.au/en/News/News-releases/2015/CSIRO-and-Internet-investor-Yuri-Milner-strike-deal-for-ET-search|title=CSIRO and Internet investor Yuri Milner strike deal for ET search|last=CSIRO|website=csiro.au|language=en-AU|access-date=2016-04-14}}</ref>  Another third will be used for the development of new equipment to receive and process potential signals,<ref name=":4" /> and the final third will be used to hire astronomy staff.<ref>{{Cite news|url=https://www.nytimes.com/2015/07/21/science/yuri-milner-russian-entrepreneur-promises-100-million-for-alien-search.html|title=Stephen Hawking Joins Russian Entrepreneur's Search for Alien Life|last=Overbye|first=Dennis|date=2015-07-20|newspaper=The New York Times|issn=0362-4331|access-date=2016-04-14}}</ref>

== Project leadership ==
Among the projects leaders are:{{citation needed|date=October 2019}}
* Frank Drake, chairman emeritus, SETI Institute; professor emeritus of astronomy and astrophysics, University of California, Santa Cruz; founding director, National Astronomy and Ionosphere Center; former Goldwin Smith Professor of Astronomy, Cornell University.
* [[Biography:Ann Druyan|Ann Druyan]], creative director of the [[Astronomy:Voyager Golden Record|Voyager Interstellar Message]], NASA Voyager; co-founder and CEO, Cosmos Studios; Emmy Award- and Peabody Award-winning writer and producer.
* [[Biography:Martin Rees|Martin Rees]], Astronomer Royal, Fellow of Trinity College; emeritus professor of cosmology and astrophysics, University of Cambridge.
* Andrew Siemion, director, [[Organization:Berkeley SETI Research Center|Berkeley SETI Research Center]].<ref>{{cite web |url=http://www.breakthroughinitiatives.org/News/1 |title=Yuri Milner and Stephen Hawking Announce $100 Million Breakthrough Initiative to Dramatically Accelerate Search for Intelligent Life in the Universe |website=Breakthrough Initiatives |date=July 20, 2015 |access-date=2015-07-24}}</ref>
* Dan Werthimer, co-founder and chief scientist of the SETI@home project; director of SERENDIP; principal investigator for CASPER.
* Pete Worden, chairman, Breakthrough Prize Foundation.

== Results ==
* In April 2017, the project released its first set of results, covering the observations of 692 nearby stars at frequencies from 1.1–1.9&nbsp;GHz (the [[Astronomy:L band|L-band]]).<ref name=":1">{{Cite web |url=https://breakthroughinitiatives.org/News/10 |title=Breakthrough Listen Initiative Publishes Initial Results |date=April 20, 2017 |website=Breakthrough Initiatives |access-date=2017-09-21}}</ref><ref name=":7" /> These observations included 11 events which passed the threshold for significance, but it was concluded that they were all consistent with radio frequency interference.<ref name=":7">{{Cite web |display-authors=5 |author1=J. Emilio Enriquez |author2=Andrew Siemion |author3=Danny C. Price |author4=David Macmahon |author5=Matt Lebofsky |author6=Howard Isaacson |author7=Greg Hellbourg |author8=Vishal Gajjar |author9=Steve Croft |date=April 21, 2017 |title=The Breakthrough Listen Search for Advanced Life: 1.1–1.9Ghz Observations of 692 Nearby Stars |type=Draft |url=http://blpd0.ssl.berkeley.edu/lband2017/Lband_BL_SETI_Submitted_Draft.pdf |via=berkeley.edu}}</ref> A summary of the observations and the raw data relating to them has been published online.<ref>{{Cite web|title=Breakthrough Listen: L-band 2017|url=http://seti.berkeley.edu/lband2017/statistics.html|access-date=2021-03-09|website=seti.berkeley.edu}}</ref> The project plans to continue publishing updated results approximately every 6 months.<ref name=":1" />

The project has begun at lower frequencies as these have a lower frequency range<!-- Repetition? Needs rewording if not. --> which is easier to record and process, and plans eventually to observe in a wide range of frequencies from 1.15&nbsp;GHz to 93&nbsp;GHz.<ref name=":8" />
* On August 30, 2017, Breakthrough Listen said it picked a series of 15 radio bursts coming from a dwarf galaxy about 3 billion light years away.<ref>{{Cite news|url=https://www.geekwire.com/2017/alien-hunting-breakthrough-listen-project-tracks-strange-series-15-radio-bursts/|title=Alien-hunting Breakthrough Listen project tracks strange series of 15 radio bursts|date=2017-08-30|work=GeekWire|access-date=2017-09-01|language=en-US}}</ref> Breakthrough Listen researchers said the possibility of the source being extraterrestrial life cannot yet be ruled out.{{Update inline|date=March 2021|reason=Does this statement still apply?}} The radio emissions were detected by the Green Bank Telescope in West Virginia. The source is [[Astronomy:Fast radio burst|FRB]] [[Astronomy:Fast radio burst#FRB 121102|121102]] which was already known but the activity was vastly different in the latest findings.{{citation needed|date=October 2019}}
* In December 2017, Breakthrough Listen observed [[Astronomy:ʻOumuamua|ʻOumuamua]], an [[Astronomy:Interstellar object|interstellar]] [[Astronomy:Asteroid|asteroid]] with an unusually elongated shape, for any signs of radio emissions.<ref name=Guarddian2017-12-11>{{cite web |url=https://www.theguardian.com/science/2017/dec/11/astronomers-to-check-interstellar-body-for-signs-of-alien-technology |title=Astronomers to check interstellar body for signs of alien technology |first=Ian |last=Sample |work=The Guardian |date=December 11, 2017 |access-date=2017-12-12 |quote=Green Bank telescope in West Virginia will listen for radio signals from ‘Oumuamua, an object from another solar system ... "Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions," said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. "If we do detect a signal that appears artificial in origin, we'll know immediately." ... While many astronomers believe the object is an interstellar asteroid, its elongated shape is unlike anything seen in the asteroid belt in our own solar system. Early observations of ‘Oumuamua show that it is about 400m long but only one tenth as wide. "It's curious that the first object we see from outside the solar system looks like that," said Loeb.}}</ref> Over eight hours of observing over a range of frequencies from 1.1–11.6&nbsp;GHz, no emissions were detected.<ref>{{Cite journal |arxiv=1801.02814 |display-authors=5 |author1=J. E. Enriquez |author2=A. Siemion |author3=T. J. W. Lazio |author4=M. Lebofsky |author5=D. H. E. MacMahon |author6=R. S. Park |author7=S. Croft |author8=D. DeBoer |author9=N. Gizani |author10=V. Gajjar |author11=G. Hellbourg |author12=H. Isaacson |author13=D. C. Price |title=Breakthrough Listen Observations of 1I/′Oumuamua with the GBT |journal=Research Notes of the American Astronomical Society |volume=2 |issue=1 |pages=9 |year=2018|bibcode=2018RNAAS...2....9E |doi=10.3847/2515-5172/aaa6c9 |s2cid=119435272 |doi-access=free }}</ref>
* In December 2018, a search for laser light emissions from [[Astronomy:KIC 8462852|Boyajian's Star]] was carried out using the Automated Planet Finder, which is sensitive enough to detect a 24 MW laser at this distance. Although a number of candidates were identified, further analysis showed that they are coming from the Earth and not from the star.<ref>{{cite journal |arxiv=1812.10161 |display-authors=5 |author1=David Lipman |author2=Howard Isaacson |author3=Andrew P. V. Siemion |author4=Matt Lebofsky |author5=Danny C. Price |author6=David MacMahon |author7=Steve Croft |author8=David DeBoer |author9=Jack Hickish |author10=Dan Werthimer |author11=Greg Hellbourg |author12=J. Emilio Enriquez |author13=Nectaria Gizani |title=The Breakthrough Listen Search for Intelligent Life: Searching Boyajian's Star for Laser Line Emission |journal=Publications of the Astronomical Society of the Pacific |volume=131 |issue=997 |pages=034202 |year=2018 |doi=10.1088/1538-3873/aafe86 |s2cid=119476899 }}</ref>
* In January 2020, a preliminary results for the nearby (<150 parsecs away) stars were announced, with no positive detections of artificial transmitters comparable to the terrestrial [[Astronomy:Arecibo Observatory|Arecibo Observatory]] in the 3.95-8.00 GHz band. Also, it was concluded that at least 8% of 252 nearby stars in a zone allowing [[Astronomy:Variable star#Planetary transits|detection of Earth by occultation method]] do not have the [[Engineering:Duty cycle|100%-duty]] (artificial) transmitters of the sort sought by the survey.<ref>{{cite journal|arxiv=2002.06162|last1=Sheikh|first1=Sofia Z.|last2=Siemion|first2=Andrew|last3=Emilio Enriquez|first3=J.|last4=Price|first4=Danny C.|last5=Isaacson|first5=Howard|last6=Lebofsky|first6=Matt|last7=Gajjar|first7=Vishal|last8=Kalas|first8=Paul|title=The Breakthrough Listen Search for Intelligent Life: A 3.95-8.00 GHZ Search for Radio Technosignatures in the Restricted Earth Transit Zone|journal=The Astronomical Journal|year=2020|volume=160|issue=1|page=29|doi=10.3847/1538-3881/ab9361|bibcode=2020AJ....160...29S|s2cid=211126496 |doi-access=free }}</ref>{{Clarify|reason=What is meant by 'artificial transmitters'?|date=March 2021}}
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* In December 2020, it was reported that in April and May 2019, a narrowband signal at 982.002 MHz was intercepted that showed shifts in its frequency consistent with the movement of a planet. No modulation was detected.<ref name="NYT-20201231">{{cite news |last=Overbye |first=Dennis |title=Was That a Dropped Call From ET? - A spooky radio signal showed up after a radio telescope was aimed at the next star over from our sun. |url=https://www.nytimes.com/2020/12/31/science/radio-signal-extraterrestrial.html |date=31 December 2020 |work={{wipe|The New York Times}} |access-date=31 December 2020 }}</ref> The signal appears to  have originated from the direction of [[Astronomy:Proxima Centauri|Proxima Centauri]]. It has been given the name Breakthrough Listen Candidate 1 ([[Astronomy:BLC1|BLC1]]). {{As of|2020|December}}, the researchers were still working to rule out terrestrial interference, which they considered the most likely cause. One researcher called it "on par" with the [[Astronomy:Wow! signal|Wow! signal]].<ref>{{cite news |last1=O'Callaghan |first1=Jonathan |last2=Billings |first2=Lee |title=Alien Hunters Discover Mysterious Signal from Proxima Centauri |url=https://www.scientificamerican.com/article/alien-hunters-discover-mysterious-signal-from-proxima-centauri/ |access-date=19 December 2020 |work=Scientific American |language=en}}</ref><ref>{{Cite web|date=2020-12-18|title=Scientists looking for aliens investigate radio beam 'from nearby star'|url=http://www.theguardian.com/science/2020/dec/18/scientists-looking-for-aliens-investigate-radio-beam-from-nearby-star|access-date=2020-12-18|website=The Guardian|language=en}}</ref>{{Needs update|date=July 2023}}
* In May 2022, Breakthrough Listen conducted the first targeted search for the Wow! Signal.<ref>{{Cite web |title=1st Coordinated Green Bank Telescope/Allen Telescope Array Observes Possible Source of the WOW! Signal |url=https://www.seti.org/1st-coordinated-green-bank-telescopeallen-telescope-array-observes-possible-source-wow-signal}}</ref> It was its first collaboration between the [[Astronomy:Green Bank Telescope|Green Bank Telescope]] and the SETI Institute's [[Astronomy:Allen Telescope Array|Allen Telescope Array]].<ref>{{Cite web |author1=Elizabeth Howell |date=2022-11-07 |title=No signs of alien life found near source of famous 'Wow!' signal |url=https://www.space.com/seti-wow-signal-search-no-life-signs |access-date=2022-11-13 |website=Space.com |language=en}}</ref> The observations lasted 1 hour from Greenbank, 35 minutes from ATA, and 10 minutes simultaneously.<ref>{{Cite journal |last=Perez |first=Karen I. |title=Breakthrough Listen Search for the WOW! Signal |journal=AAS|year=2022 |volume=6 |issue=9 |page=197 |doi=10.3847/2515-5172/ac9408 |bibcode=2022RNAAS...6..197P |s2cid=252540293 |doi-access=free }}</ref> No technosignature candidates were found.<ref>{{Cite web |title=Breakthrough Listen Search for the WOW! Signal |url=https://seti.berkeley.edu/wow/ |access-date=2022-11-13 |website=seti.berkeley.edu}}</ref>

== See also ==
* [[Astronomy:Communication with extraterrestrial intelligence|Communication with extraterrestrial intelligence]]
* [[Astronomy:List of nearest stars and brown dwarfs|List of nearest stars and brown dwarfs]] within 20 light years
* [[Organization:Nexus for Exoplanet System Science|Nexus for Exoplanet System Science]]
* [[Organization:Ohio State University Radio Observatory|Ohio State University Radio Observatory]]
* [[Open data]], [[Open-source software]]
* [[Astronomy:Search for extraterrestrial intelligence|Search for extraterrestrial intelligence]]
* [[Organization:SETI Institute|SETI Institute]]

== References ==
{{reflist}}

== External links ==
* [https://breakthroughinitiatives.org/initiative/1 Breakthrough Listen], Breakthrough Initiatives website
* [https://seti.berkeley.edu Berkeley SETI Research Center], Berkeley SETI Research Center website
{{Astrobiology}}
{{Extraterrestrial life}}
{{Interstellar messages}}

[[Category:Search for extraterrestrial intelligence]]
[[Category:Interstellar messages]]

{{Sourceattribution|Breakthrough Listen}}