Andrew Siemion (Berkeley SETI Research Center) presented results from the first year of the Breakthrough Listen initiative last Thursday at the Breakthrough Discuss meetings in Palo Alto. The data can be acquired here, with the caveat that file sizes can be gigantic and the data formats demand specialized software. Background information and details are available on this BSRC page. Working with the Parkes instrument in New South Wales as well as the Green Bank telescope in West Virginia and Lick Observatory’s Automated Planet Finder on Mt. Hamilton in California, the project is rapidly amassing petabytes of data.
Image: The largest single-dish fully steerable radio telescope began operation in 2000 August in Green Bank, West Virginia, USA. Dedicated as the Robert C. Byrd Green Bank Telescope, the device weighs over 30 times more than the Statue of Liberty, and yet can point anywhere in the sky more precisely than one thousandth of a degree. The main dish is so large that it could house a football game, allowing it to hear even the faint murmurs of quasars located across the universe. Credit: NRAO / NSF.
A paper analyzing 692 stars from the first year of Green Bank data as examined by the Berkeley SETI Research Center science team has been submitted to The Astrophysical Journal covering frequencies from 1.1 to 1.9 GHz. Here we get 400 total hours of observing time comprising 4798 individual observations, with 8 petabytes of raw data acquired. And while the 11 highest ranking events have been getting their share of publicity (you can see the list here, with additional data), the fact is that we have no SETI detections here.
“With the submission of this paper, the first scientific results from Breakthrough Listen are now available for the world to review,” said Dr. Siemion. “Although the search has not yet detected a convincing signal from extraterrestrial intelligence, these are early days. The work that has been completed so far provides a launch pad for deeper and more comprehensive analysis to come.”
Early days indeed, given the magnitude of the challenge, and of course when it comes to doing good science, data rather than preferences or hunches are what we need. Thus SETI is all about the patient accumulation of such data, even as we continue to work the intellectual riddle of possible intelligence elsewhere. We’re making good progress on such key Drake Equation questions as the percentage of stars with planets and the frequency of planets in the habitable zone, but other issues remain completely opaque, including the frequency of life’s emergence and the longevity of a technological civilization.
My own hunch, for what it’s worth, is that it’s the second of these two issues that is the deal breaker.
I hope Breakthrough Listen will prove me wrong. This is a 10-year initiative that will survey the 1,000,000 closest stars to the Earth, while also scanning the center of the Milky Way and the galactic plane as well as examining the 100 galaxies closest to us. We’ll continue to keep a close eye on its proceedings given that the survey covers ten times more of the sky than previous SETI programs and five times more of the radio spectrum at hitherto unrivaled speeds.
The project is also deeply invested in optical SETI, carrying out spectroscopic searches for optical laser transmissions that, according to the project’s founders, can detect a 100 watt laser at the distance of the Alpha Centauri stars. I notice that both Shelley Wright (UCSD) and David Williams (Arizona State) addressed the optical issue at Breakthrough Discuss, with Wright giving the overview of searches in the optical and near-infrared and Williams talking about using telescopes designed for gamma-ray observations to detect engineered optical flashes.
Because I was forced by schedule conflicts to miss Breakthrough Discuss this time around, let me at least post clips from the Breakthrough Initiatives news releases on the conference for a bit more detail. I hope many of you were able to follow the proceedings online. Centauri Dreams reader John Walker reminds me of this significant fact: “Worth noting that in contrast to last year recordings of the proceedings are on offer. For anyone interested in (re)seeing the presentations visit Breakthrough’s Facebook page here: https://m.facebook.com/BreakthroughPrize/video_grid/?ref=page_internal.”
BREAKTHROUGH DISCUSS OPENS WITH LIVELY SESSIONS DEDICATED TO
THE SEARCH FOR PLANETS AND LIFE IN OUR COSMIC NEIGHBORHOOD:
CONFERENCE TO CONTINUE ON FRIDAY, APRIL 21, WITH DISCUSSIONS ON FACEBOOK LIVE
The first day of Breakthrough Discuss 2017 explored planets around nearby stars and their potential for life. Charles Alcock opened the conference with the statement that, “The far-fetched ideas of today are the discoveries of tomorrow,” and Peter Michelson emphasized that the last century of scientific investigation has transformed questions about origins from the realm of metaphysics to a place where they can be investigated observationally.
Three of the participants — exoplanet hunters extraordinaire Guillem Anglada-Escudé, Natalie Batalha, and Michaël Gillon — were recognized at the start of the program for making the 2017 TIME 100, TIME magazine’s distinguished list of the world’s most influential people. Anglada- Escudé served as the keynote speaker on Thursday, and Gillon will serve as the keynote speaker on Friday.
Speakers in the first session described the state of the art in observations of planets around nearby stars. Getting pictures of planets is difficult, and most are found using indirect methods. These methods have shown that most stars have planets in short-period orbits, and since most stars in the galaxy are red dwarfs, these provide promising targets when searching for habitable worlds. Many planets around these stars have recently been reported, including Proxima Centauri b, and LHS 1140 b and the TRAPPIST-1 system. Although red dwarfs have high X-ray and UV radiation, and planets around them are more likely to be tidally locked (with one side always in fierce daylight, and the other in cold night), they are long-lived stars, potentially allowing plenty of time for life to arise.
Image: This illustration shows the seven TRAPPIST-1 planets as they might look as viewed from Earth using a fictional, incredibly powerful telescope. The sizes and relative positions are correctly to scale: This is such a tiny planetary system that its sun, TRAPPIST-1, is not much bigger than our planet Jupiter, and all the planets are very close to the size of Earth. Their orbits all fall well within what, in our solar system, would be the orbital distance of our innermost planet, Mercury. With such small orbits, the TRAPPIST-1 planets complete a “year” in a matter of a few Earth days: 1.5 for the innermost planet, TRAPPIST-1b, and 20 for the outermost, TRAPPIST-1h. This particular arrangement of planets with a double-transit reflect an actual configuration of the system during the 21 days of observations made by NASA’s Spitzer Space Telescope in late 2016. The system has been revealed through observations from NASA’s Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope. Credit: NASA/JPL-Caltech.
The difficulty of imaging planets even around nearby stars is compounded when trying to measure their colors to find indications of life. But, as Mercedes López-Morales described, telescopes that will come online in the mid-2020s will have the capability to detect “biosignatures” in exoplanet atmospheres. By looking for signatures of oxygen and methane, that are naturally destroyed over time if not replenished by such processes as living organisms, perhaps in the next 10 to 15 years we will have found another world where humans could breathe.
Zachary Berta-Thompson noted that 70 years of observations of Pluto saw it simply as a point of light, until the New Horizons probe gave us in-situ measurements of Pluto as a world in its own right. He encouraged the audience to ponder what in-situ observations of habitable zone planets around nearby M-dwarfs might be possible in 70 years’ time.
The second session focused on the search for extraterrestrial intelligence around nearby stars. Andrew Siemion described analysis of the first year of Breakthrough Listen observations of around 700 nearby stars, placing sensitive limits on the presence of engineered emission from these targets, and Danny Price discussed Listen observations of Alpha and Proxima Centauri. Shelley Wright discussed searches in the optical and near-infrared, and David Williams described a novel use of telescopes designed for gamma-ray observations to detect rapid optical flashes. Although no convincing signs of extraterrestrial intelligence have yet been found, the speakers and audience expressed optimism and enthusiasm for what would be possible with the next generation of searches.
The second and final day of the conference, to be held on Friday, April 21, will assess the significance of the newly discovered exoplanets for the long-term Breakthrough Starshot endeavor, a program spearheaded by Yuri Milner to develop a practical interstellar space probe.
As the closest known exoplanet, Proxima b is the current primary target for Starshot, which aims to develop the technology to send gram-scale spacecraft travelling at 20 percent of the speed of light to Alpha Centauri, some 4.367 light-years away. Starshot mission leaders Avi Loeb, Philip Lubin and Zac Manchester are among the distinguished participants at Breakthrough Discuss.
And here is the Breakthrough Initiatives news release for the second day.
SECOND ANNUAL BREAKTHROUGH DISCUSS CONFERENCE CLOSES WITH
FULL DAY DEDICATED TO NEWLY DISCOVERED EXOPLANETS AND
THE SEARCH FOR INTELLIGENT LIFE
Two-day conference brought together the world’s leading astronomers, engineers, astrobiologists, and astrophysicists for conversations on recent discoveries and future endeavors
PALO ALTO, CALIF. – April 21, 2017 – Day Two of Breakthrough Discuss opened with Michaël Gillon describing the discovery of TRAPPIST-1, which has seven temperate planets, including three in the habitable zone. The planets were discovered using small ground-based telescopes, and Gillon noted that on initial viewing of the data, there were “so many transits we couldn’t make sense of them.”
Gillon described how observations from several telescopes were used to study the TRAPPIST-1 system, including Kepler to confirm the existence of the planets, and Spitzer to figure out their orbits. Similarly, a suite of telescopes, including Hubble and the James Webb Space Telescope, could be used in the future to search for signs of water and atmospheres on planets that may be detected by the next generation of giant ground-based telescopes.
The morning continued with a panel on the search for extraterrestrial intelligence. The wide-ranging discussion, chaired by the SETI Institute’s Jill Tarter, discussed how studies of unexplained phenomena might lead to new discoveries in astrophysics, or possible evidence of activity by civilizations inhabiting other star systems. From the odd variations in brightness of a star studied by Tabetha Boyajian, to searches by Beatriz Villarroel for stars that might suddenly disappear, panelists described a variety of creative ways to search large, time-domain survey datasets for events of interest. Panelist Lucianne Walkowicz described how modern machine learning algorithms could allow us to look for strange behavior in data without making presuppositions about the kinds of signals extraterrestrials might generate. Jason Wright emphasized that a great deal of work is required to rule out natural astrophysical explanations before resorting to claims of intelligent aliens, and described an upcoming revision to the Rio Scale that is used to assess the credibility of ET claims.
The afternoon sessions focused on the ambitious Breakthrough Starshot plan to send spacecraft to nearby stars. Avi Loeb described how a gram-scale camera attached to a sail propelled by a powerful ground-based laser beam might reach Proxima b during our lifetime, traveling at 20 percent of the speed of light. Feasibility studies will be completed during the next five years, potentially leading to the construction of a kilometer-scale ground station, and the launch of many small, relatively inexpensive spacecraft to explore nearby star systems.
Philip Lubin described how this technology could enable craft to travel from Earth to the Moon in an hour, to Mars in under a day, and to nearby stars in a couple of decades. He talked about the materials science and engineering challenges in designing a sensor package to fit on a thin silicon wafer, and returning data to Earth, but was optimistic that ongoing technological developments would make this “watershed moment in human history” possible in the near future.
René Heller described a “photogravitational assist” technique that might enable a spacecraft traveling at 20 percent of the speed of light to use photons from the Alpha Centauri system as a brake to enter orbit rather than flying rapidly by. The session’s other speakers discussed how a suite of observations, both remote, and in-situ, could detect spectral features of vegetation, light glinting from oceans, and signs of water and oxygen in planetary atmospheres. The conference closed with a panel on science goals and instrumentation for Breakthrough Starshot.
In total, the two-day event featured three sessions of 19 presentations and 15 panelists. The first day, Thursday, April 20, featured a session that focused on recent observations of nearby planets, including Proxima b, and new techniques for observing them. A second session on Thursday examined the possibility of intelligent life in Earth’s cosmic neighborhood, and recent attempts to search for it with Breakthrough Listen.
The conference was broadcast on Facebook Live at www.Facebook.com/BreakthroughPrize. Viewers from around the world were able to join in the conversation and submit questions, which were answered by the panelists in real-time.
Breakthrough Discuss was hosted by Stanford University’s Department of Physics and the Harvard-Smithsonian Center for Astrophysics and sponsored by the Breakthrough Initiatives.
Breakthrough Discuss is an annual academic conference focused on life in the Universe and novel ideas for space exploration.
Breakthrough Initiatives are a suite of scientific and technological programs exploring the big questions around life in the Universe, such as, Are we alone? What are the nearest habitable planets? And can we become an interstellar civilization?
For more information see https://breakthroughinitiatives.org