Julia DeMarines

Julia DeMarines
University of California, Berkeley | UCB · Department of Astronomy

MSc

About

53
Publications
19,284
Reads
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3,560
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Introduction
Julia DeMarines is an Astrobiologist and science communicator working at the UC Berkeley SETI Research Center and with Blue Marble Space. She is a 2019 National Geographic Explorer and 2018 Grosvenor Teacher Fellow, and a 2019 AGU Voices for Science advocate. Her research involves detecting life in the Universe through biosignatures and technosignatures and the ethics of sending powerful, intentional messages into space. She is passionate about inspiring the next generation of scientists.
Additional affiliations
November 2011 - January 2014
Denver Museum of Nature and Science
Position
  • Astrobiology Research Associate

Publications

Publications (53)
Article
The search for extraterrestrial intelligence at radio frequencies has largely been focused on continuous-wave narrowband signals. We demonstrate that broadband pulsed beacons are energetically efficient compared to narrowband beacons over longer operational timescales. Here, we report the first extensive survey searching for such broadband pulsed b...
Preprint
The search for extraterrestrial intelligence at radio frequencies has largely been focused on continuous-wave narrowband signals. We demonstrate that broadband pulsed beacons are energetically efficient compared to narrowband beacons over longer operational timescales. Here, we report the first extensive survey searching for such broadband pulsed b...
Article
The Breakthrough Listen (BL) Initiative, as part of its larger mission, is performing the most thorough technosignature search of nearby stars. Additionally, BL is collaborating with scientists working on NASA’s Transiting Exoplanet Survey Satellite (TESS) to examine TESS Targets of Interest (TOIs) for technosignatures. Here, we present a 1–11 GHz...
Article
We present Breakthrough Listen’s Exotica Catalog as the centerpiece of our efforts to expand the diversity of targets surveyed in the Search for Extraterrestrial Intelligence (SETI). As motivation, we introduce the concept of survey breadth, the diversity of objects observed during a program. Several reasons for pursuing a broad program are given,...
Chapter
Ethically responsible searches for extraterrestrial intelligence require careful reflection. Different projects and goals raise different ethical concerns. At the same time, there are overarching ethical considerations that apply to any search for intelligent life in the cosmos. In this chapter, we explain both specific and general concerns and add...
Preprint
A line-of-sight towards the Galactic Center (GC) offers the largest number of potentially habitable systems of any direction in the sky. The Breakthrough Listen program is undertaking the most sensitive and deepest targeted SETI surveys towards the GC. Here, we outline our observing strategies with Robert C. Byrd Green Bank Telescope (GBT) and Park...
Preprint
New radio telescope arrays offer unique opportunities for large-scale commensal SETI surveys. Ethernet-based architectures are allowing multiple users to access telescope data simultaneously by means of multicast Ethernet subscriptions. Breakthrough Listen will take advantage of this by conducting a commensal SETI survey on the MeerKAT radio telesc...
Preprint
We report polarization properties for eight narrowband bursts from FRB 121102 that have been re-detected in a high-frequency (4-8 GHz) Breakthrough Listen observation with the Green Bank Telescope, originally taken on 2017 August 26. The bursts were found to exhibit nearly 100% linear polarization, Faraday rotation measures (RM) bordering 9.3$\time...
Article
We report polarization properties for eight narrowband bursts from FRB 121102 that have been re-detected in a high-frequency (4–8 GHz) Breakthrough Listen observation with the Green Bank Telescope, originally taken on 2017 August 26. The bursts were found to exhibit nearly 100% linear polarization, Faraday rotation measures bordering 9.3 × 10 ⁴ rad...
Preprint
We present Breakthrough Listen's "Exotica" Catalog as the centerpiece of our efforts to expand the diversity of targets surveyed in the Search for Extraterrestrial Intelligence (SETI). As motivation, we introduce the concept of survey breadth, the diversity of objects observed during a program. Several reasons for pursuing a broad program are given...
Preprint
As it stands today, the search for extraterrestrial intelligence (SETI) is highly dependent on our ability to detect interesting candidate signals, or technosignatures, in radio telescope observations and distinguish these from human radio frequency interference (RFI). Current signal search pipelines look for signals in spectrograms of intensity as...
Article
The discovery of ubiquitous habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, has ushered in a renaissance in the search for extraterrestrial intelligence (SETI). Large scale SETI activities are now underway at numerous international facilities. The Five-hundred-meter Aperture Sphe...
Preprint
Full-text available
The discovery of ubiquitous habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, has ushered in a renaissance in the search for extra-terrestrial intelligence (SETI). Large scale SETI activities are now underway at numerous international facilities. The Five-hundred-meter Aperture Sph...
Preprint
The star EPIC 249706694 (HD 139139) was found to exhibit 28 transit-like events over an 87 day period during the Kepler mission's K2 Campaign 15 (Rappaport et al. 2019). These events did not fall into an identifiable pattern and could not be explained by a multitude of transit scenarios explored by the authors. We conduct follow-up observations at...
Preprint
Full-text available
The discovery of the ubiquity of habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, have ushered in a renaissance in the millenia-old quest to answer our most profound question about the Universe and our place within it - Are we alone? The Breakthrough Listen Initiative, announced i...
Preprint
Full-text available
Breakthrough Listen is the most comprehensive and sensitive search for extraterrestrial intelligence (SETI) to date, employing a collection of international observational facilities including both radio and optical telescopes. During the first three years of the Listen program, thousands of targets have been observed with the Green Bank Telescope (...
Preprint
Full-text available
Breakthrough Listen (BL) is a ten-year initiative to search for signatures of technologically capable life beyond Earth via radio and optical observations of the local Universe. A core part of the BL program is a comprehensive survey of 1702 nearby stars at radio wavelengths (1-10 GHz). Here, we report on observations with the 64-m CSIRO Parkes rad...
Article
Full-text available
There is currently a divide among astrobiologists on the question of whether to transmit intentional, directed messages into space. This debate raises several questions pertaining to space ethics, and it demands rigorous ethical analysis before active transmission occurs. Here we address ethical issues of responsibility, consensus, shared values, m...
Article
Full-text available
The search for life in the universe is a major theme of astronomy and astrophysics for the next decade. Searches for technosignatures are complementary to searches for biosignatures, in that they offer an alternative path to discovery, and address the question of whether complex (i.e. technological) life exists elsewhere in the Galaxy. This approac...
Article
Full-text available
1.1. What is astrobiology? Astrobiology is the science that seeks to understand the story of life in our universe. Astrobiology includes investigation of the conditions that are necessary for life to emerge and flourish, the origin of life, the ways that life has evolved and adapted to the wide range of environmental conditions here on Earth, the s...
Article
Full-text available
The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both i...
Article
Full-text available
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absen...
Article
Full-text available
Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, iron sulfides, amorphous material, and trioctahedral smectites. The John Klein smectite has basal spacing of ~10 angstroms...
Article
H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbona...
Article
Full-text available
The ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in compositi...
Article
Full-text available
“Jake_M,” the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the Curiosity rover, differs substantially in chemical composition from other known martian igneous rocks: It is alkaline (textgreater15% normative nepheline) and relatively fractionated. Jake_M is compositionally similar to terrestrial mugearites, a rock type...
Article
Full-text available
The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor a...
Article
Full-text available
Stable isotope ratios of H, C, and O are powerful indicators of a wide variety of planetary geophysical processes, and for Mars they reveal the record of loss of its atmosphere and subsequent interactions with its surface such as carbonate formation. We report in situ measurements of the isotopic ratios of D/H and O-18/O-16 in water and C-13/C-12,...
Article
Full-text available
Volume mixing and isotope ratios secured with repeated atmospheric measurements taken with the Sample Analysis at Mars instrument suite on the Curiosity rover are: carbon dioxide (CO2), 0.960(±0.007); argon-40 (⁴⁰Ar), 0.0193(±0.0001); nitrogen (N2), 0.0189(±0.0003); oxygen, 1.45(±0.09) × 10⁻³; carbon monoxide, < 1.0 × 10⁻³; and ⁴⁰Ar/³⁶Ar, 1.9(±0.3)...
Article
Full-text available
Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcro...
Article
Full-text available
Abstract Astrobiology is a transdisciplinary field with extraordinary potential for the scientific community. As such, it is important to educate the community at large about the growing importance of this field to increase awareness and scientific content learning and expose potential future scientists. To this end, we propose the creation of a tr...
Article
Assessing the challenges associated with the detectability of primitive biosignatures present on early Earth (methane and ethane) and addressing the observational difficulties when we begin to observe extrasolar atmospheres with a TPF-O mission.
Conference Paper
In the summer of 2011, researchers from NASA Ames Research Center joined a multi-institute team on a playa in Railroad Valley, Nevada to acquire ground-based and airborne observations supporting measurements from the Greenhouse Gases Observing Satellite (GOSAT). In-situ measurements of carbon dioxide (CO2) and methane (CH4) with 10 Hz temporal reso...
Conference Paper
Carbon dynamics of desert and semi arid ecosystems, which occupy 30% to 45% of the Earth's terrestrial surface, is poorly understood and understudied. However, these regions are of particular interest due to increasing desertification, as a result of climate and land-use change, and due to recent reports which indicate net CO2 uptake by deserts sug...
Conference Paper
During the 2010 Greenhouse gas Observing SATellite (GOSAT) calibration and validation campaign at Railroad Valley (RRV) playa, NV, unexpected methane and carbon dioxide fluctuations were observed at the dry lakebed. Possible sources included the presence of natural gas (thermogenic methane) from oil deposits in the surrounding playa, and/or methane...
Article
Messaging to extraterrestrial intelligence (METI) is a branch of study concerned with constructing and broadcasting a message toward habitable planets. Since the Arecibo message of 1974, the handful of METI broadcasts have increased in content and complexity, but the lack of an established protocol has produced unorganized or cryptic messages that...
Article
Extrasolar planetary detection is at an exciting stage, one in which we are detecting and imaging extrasolar planets as well as measuring their atmospheric constituents. New World Observer (NOW) is a new idea in imaging extrasolar planets currently being proposed to NASA's decadal review.
Conference Paper
We present the results of the Astrophysics Strategic Mission Concept Study for the New Worlds Observer (NWO). We show that the use of starshades is the most effective and affordable path to mapping and understanding our neighboring planetary systems, to opening the search for life outside our solar system, while serving the needs of the greater ast...
Article
Over 300 extrasolar planets have been discovered in the last decade. Detection methods include indirect means such as transits and dopplar shift and only one has been directly imaged. New Worlds Observer is a mission that will revolutionize the direct detection of extrasolar planets by not only having the capability to image terrestrial-sized plane...
Article
Full-text available
SUMMARY We present the results of the Astrophysics Strategic Mission Concept Study (ASMCS) for the New Worlds Observer (NWO). We show that the use of starshades is the most effective and af- fordable path to mapping and understanding our neighboring planetary systems, to opening the search for life outside our solar system, while serving the needs...

Projects

Project (1)