Breakthrough Initiatives - Listen Technologies

Breakthrough Initiatives is a program founded in 2015 and funded by Yuri Milner to search for extraterrestrial intelligence over a span of at least 10 years. The program is divided into multiple projects. Breakthrough Listen will comprise an effort to search over 1,000,000 stars for artificial radio or laser signals. A parallel project called Breakthrough Message is an effort to create a message "representative of humanity and planet Earth". The project Breakthrough Starshot aims to send a swarm of probes to the nearest star at about 20% the speed of light.

History

The Breakthrough Initiatives were announced to the public on July 20, 2015 at London's Royal Society. Physicist Stephen Hawking, Russian tycoon Yuri Milner, and others created the Initiatives to search for intelligent extraterrestrial life in the Universe and consider a plan for possibly transmitting messages out into space. The announcement included an open letter co-signed by multiple scientists, including Hawking, expressing support for an intensified search for alien radio communications. During the public launch, Hawking said: "In an infinite Universe, there must be other life. There is no bigger question. It is time to commit to finding the answer."

The US$100 million cash infusion is projected to mark up the pace of SETI research over the early 2000s rate, and will nearly double the rate NASA was spending on SETI research annually in approximately 1973â€"1993.

Projects

Breakthrough Listen

Breakthrough Listen is a ten-year initiative with $100 million funding begun in July 2015 to actively search for intelligent extraterrestrial communications in the Universe, in a substantially expanded way, using resources that had not previously been extensively used for the purpose. It has been described as the most comprehensive search for alien communications to date.

Announced in July 2015, the project will use thousands of hours every year on two major radiotelescopes, the Green Bank Observatory in West Virginia and the Parkes Observatory in Australia. Previously, only about 24 to 36 hours of telescope per year were used in the search for alien life. Furthermore, the Automated Planet Finder of Lick observatory will search for optical signals coming from laser transmissions. For processing of the massive data, the experience of SETI and SETI@home will be used. SETI founder Frank Drake is one of the project's scientists.

Overview

The project aims to discover signs of extraterrestrial civilizations by searching stars and galaxies for radio signals and laser transmissions. The search for radio signals is carried out on the Green Bank Telescope in the Northern Hemisphere and the Parkes Telescope in the Southern Hemisphere. The Green Bank Telescope is the world's largest steerable radio telescope, and the Parkes Telescope is second largest telescope in the Southern Hemisphere.

Together, the radio telescopes will cover ten times more sky than previous searches and scan the entire 1-to-10 GHz range, the so-called "quiet zone" in the spectrum where radio waves are unobscured by cosmic sources or Earth’s atmosphere.

The radio telescopes are sensitive enough to detect "Earth-leakage" levels of radio transmission from stars within 5 parsecs, and can detect a transmitter of the same power as a common aircraft radar from the 1,000 nearest stars. The Green Bank Telescope began operations in January 2016, with the Parkes Telescope due to join it in October 2016. The 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.

The search for optical laser transmissions is carried out by the Automated Planet Finder of Lick Observatory. The telescope has the sensitivity to detect a 100 watt laser from a star 25 trillion miles (4.25 light years) away.

Announcement

Breakthrough Listen was announced to the public on 20 July 2015 (the anniversary of the 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 Drake equation that estimates the number of detectable alien civilizations, and Geoff Marcy, an astronomer who has helped find hundreds of exoplanets. The announcement included an open letter co-signed by multiple scientists, including physicist Stephen Hawking, expressing support for an intensified search for alien life. During the public launch, Hawking said:

"In an infinite Universe, there must be other life. There is no bigger question. It is time to commit to finding the answer."

Significance

The project is the most comprehensive search for alien communications to date. It is estimated that the project will generate as much data in one day as previous SETI projects generated in one year. Compared to previous programs, the radio surveys cover 10 times more of the sky, at least 5 times more of the radio spectrum, and work 100 times faster. The optical laser survey is also the deepest and broadest search in history.

Andrew Siemion, a SETI scientist at the University of California, Berkeley, describes that "We would typically get 24â€"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."

Targets

As of April 2016, the targets for the radio search with the Green Bank Radio Telescope in the Northern Hemisphere include the following:

• All 43 stars within 5 parsecs
• 1000 stars of all spectral-types within 50 parsecs
• One million nearby stars
• Center regions of at least 100 nearby galaxies, including spiral galaxies, elliptical galaxies, dwarf galaxies and irregular galaxies
• Exotic Stars: 20 white dwarfs, 20 neutron stars, 20 black holes

The Parkes Radio Telescope will cover similar targets in the Southern Hemisphere from 1â€"4 GHz, and also the galactic plane and center.

The targets for the 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.

While the telescopes are observing, the current targets of the Green Bank Radio Telescope and the Automated Planet Finder can be viewed live at the Berkeley Seti Research Center.

Data processing

All data generated from Breakthrough Listen project will be open to the public. The data is uploaded on the initiative's 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.

The data is also processed by the SETI@Home volunteer computer network, with the first batch of data being made available to SETI@Home in April 2016.

Funding

The project is funded with $100 million from Yuri Milner. One third of this funding will be used to purchase telescope time. 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. Another third will be used for the development of new equipment to receive and process potential signals, and the final third will be used to hire astronomy staff.

Project leadership

• 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.
• Ann Druyan, Creative Director of the Voyager Interstellar Message, NASA Voyager; Co-Founder and CEO, Cosmos Studios; Emmy Award- and Peabody Award-winning writer and producer.
• Martin Rees, Astronomer Royal, Fellow of Trinity College; Emeritus Professor of Cosmology and Astrophysics, University of Cambridge.
• Andrew Siemion, Director, Berkeley SETI Research Center.
• 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.

Breakthrough Message

The Breakthrough Message program is to study the ethics of sending messages into deep space. It also launched an open competition with a US$1 million prize pool, to design a digital message that could be transmitted from Earth to an extraterrestrial civilization. The message should be "representative of humanity and planet Earth". The program pledges "not to transmit any message until there has been a global debate at high levels of science and politics on the risks and rewards of contacting advanced civilizations".

Breakthrough Starshot

Breakthrough Starshot, announced April 12, 2016, is a US$100 million program to develop a proof-of-concept light sail spacecraft fleet capable of making the journey to Alpha Centauri at 20% the speed of light (60,000 km/s or 215 million km/h) taking about 20 years to get there, and about 4 years to notify Earth of a successful arrival.

The interstellar journey may include a flyby of Proxima Centauri b, an Earth-sized exoplanet that is in the habitable zone of its host star in the Alpha Centauri system. From a distance of 1 Astronomical Unit (150 million kilometers or 93 million miles), the four cameras on each of the spacecraft could potentially capture an image of high enough quality to resolve surface features. The spacecraft fleet would have 1000 craft, and each craft, named StarChip, would be a very small centimeter-sized craft weighing several grams. They would be propelled by several ground-based lasers of up to 100 gigawatts. Each tiny spacecraft would transmit data back to Earth using a compact on-board laser communications system. Pete Worden is the head of this project. The conceptual principles to enable this interstellar travel project were described in "A Roadmap to Interstellar Flight", by Philip Lubin of UC Santa Barbara.

Objectives

Breakthrough Starshot aims to demonstrate proof of concept for ultra-fast light-driven nano-spacecraft, and lay the foundations for a first launch to Alpha Centauri within the next generation. Secondary goals are Solar System exploration and detection of Earth-crossing asteroids. The German physicist Claudius Gros has proposed that the technology of the Breakthrough Starshot initiative may be utilized in a second step to establish a biosphere of unicellular microbes on otherwise only transiently habitable exoplanets.

In 2017, Breakthrough Initiatives and the European Southern Observatory (ESO) entered a collaboration to enable and implement a search for habitable planets in the nearby star system, Alpha Centauri. The agreement involves Breakthrough Initiatives providing funding for an upgrade to the VISIR (VLT Imager and Spectrometer for mid-Infrared) instrument on ESO’s Very Large Telescope (VLT) in Chile. This upgrade will greatly increase the likelihood of planet detection in the system.

In August 2016, the European Southern Observatory announced the detection of a planet orbiting the third star in the Alpha Centauri system, Proxima Centauri. The planet, called Proxima Centauri b, could be a potential target for one of the projects of Breakthrough Initiatives.

Breakthrough Starshot is a proof of concept mission to send a fleet of ultra-fast light-driven nanocraft to explore the Alpha Centauri star system, which could pave the way for a first launch within the next generation. An objective of the mission would be to make a fly-by of and possibly photograph any Earth-like worlds that might exist in the system.

Concept

The Starshot concept envisions launching a "mothership" carrying about a thousand tiny spacecraft (on the scale of centimeters) to a high-altitude orbit and then deploying them. Ground-based lasers would then focus a light beam on the craft's solar sails to accelerate them one by one to the target speed within 10 minutes, with an average acceleration on the order of 100 km/s², and an illumination energy on the order of 1 TJ delivered to each sail, estimated to have a surface area of 4 m × 4 m.

If an Earth-size planet is orbiting within the Alpha Centauri system habitable zones, Breakthrough Starshot will try to aim its spacecraft within 1 astronomical unit (150 million kilometers or 93 million miles) of it. From this distance, a craft's cameras could potentially capture an image of high enough quality to resolve surface features.

The fleet would have about 1000 spacecraft, and each one (dubbed a StarChip), would be a very small centimeter-sized vehicle weighing a few grams. They would be propelled by a square-kilometre array of 10 kW ground-based lasers with a combined output of up to 100 GW. Each spacecraft would transmit data back to Earth using a compact on-board laser communications system using its solar sail as an antenna and the propulsion array as the receiver. A swarm of about 1000 units would compensate for the losses caused by interstellar dust collisions en route to the target. In more recent (albeit preliminary) work, it's suggested that mitigating the collisions with dust, hydrogen and galactic cosmic rays may not be quite as severe an engineering problem as first thought.

Technical challenges

Light propulsion requires enormous power: a laser with a gigawatt of power (approximately the output of a large nuclear plant) would provide only a few newtons of thrust. The spaceship will compensate for the low thrust by having a mass of only a few grams. The camera, computer, communications laser, a plutonium power source, and the solar sail must be miniaturized to fit within a mass limit. All components must be engineered to endure extreme acceleration, cold, vacuum, and protons. The spacecraft will have to survive collisions with space dust; Starshot expects each square centimeter of frontal cross-section to collide at high speed with about a thousand particles of size at least 0.1 μm. Focusing a set of lasers totaling one hundred gigawatts onto the solar sail will be difficult, due to atmospheric turbulence. According to The Economist, at least a dozen off-the-shelf technologies will need to improve by orders of magnitude.

StarChip

StarChip is a very small, centimeter-sized, gram-scale, interstellar spacecraft envisioned for the Breakthrough Starshot program, a proposed mission to propel a fleet of a thousand StarChips on a journey to the Alpha Centauri star system, the nearest extrasolar stars, about 4.37 light-years from Earth. The journey may include a flyby of Proxima Centauri b, an Earth-sized exoplanet that is in the habitable zone of its host star. The ultra-light StarChip robotic nanocraft, fitted with lightsails, are planned to travel at speeds of 20% and 15% of the speed of light, taking between 20 and 30 years to reach the star system, respectively, and about 4 years to notify Earth of a successful arrival. The conceptual principles to enable practical interstellar travel were described in "A Roadmap to Interstellar Flight", by Philip Lubin of UC Santa Barbara, who is an advisor for the Starshot project.

Components

Each StarChip nanocraft is expected to carry miniaturized cameras, navigation gear, communication equipment, photon thrusters and a power supply. In addition, each nanocraft would be fitted with a meter-scale lightsail, made of lightweight materials, with a gram-scale mass.

Cameras

Four sub-gram scale digital cameras, each with a minimum 2-megapixels resolution, are envisioned.

Processors

Four sub-gram scale processors are planned.

Photon thrusters

Four sub-gram scale photon thrusters, each minimally capable of performing at a 1W diode laser level, are planned.

Battery

A 150 mg atomic battery, powered by plutonium-238 or americium-241, is planned.

Protective coating

A coating, possibly made of beryllium copper, is planned to protect the nanocraft from dust collisions and atomic particle erosion.

Lightsail

The lightsail is envisioned to be no larger than 4 by 4 meters (13 by 13 feet), possibly of composite graphene-based material. The material would have to be very thin and, somehow, be able to reflect the laser beam without absorbing any of its thermal energy, or it will vaporize the sail.