I see there's now a Wikipedia page for BLC-1, the intriguing SETI detection made by Breakthrough Listen at the Parkes Observatory in Australia. The dataset in which the signal, found at 982 MHz, turned up comes from observations made in April and May of 2019, and it's good to know that Breakthrough is working up two papers on the signal and subsequent analysis, given that the public face of the detection was originally in the form of a story leaked to the British newspaper The Guardian before the backup research was available. Image: CSIRO's Parkes radio telescope in New South Wales, Australia. Credit: Shaun Amy. The first thing to say about BLC-1 is that the acronym stands for Breakthrough Listen Candidate 1, marking the first time a signal has made it through to actual 'candidate' status after five years of observations, which is itself noteworthy given the intensity of the effort. The second thing is that this is a transient, meaning it's short-lived, and it hasn't repeated. That...
JPL Work on a Gravitational Lensing Mission
Seeing oceans, continents and seasonal changes on an exoplanet pushes conventional optical instruments well beyond their limits, which is why NASA is exploring the Sun's gravitational lens as a mission target in what is now the third phase of a study at NIAC (NASA Innovative Advanced Concepts). All of this builds upon the impressive achievements of Claudio Maccone that we've recently discussed. Led by Slava Turyshev, the NIAC effort takes advantage of light amplification of 1011 and angular resolutions that dwarf what the largest instruments in our catalog can deliver, showing what the right kind of space mission can do. We're going to track the Phase III work with great interest, but let's look back at what the earlier studies have accomplished along the way. Specifically, I'm interested in mission architectures, even as the NASA effort at the Jet Propulsion Laboratory continues to consider the issues surrounding untangling an optical image from the Einstein ring around the Sun....
The FOCAL Radio Bridge
Getting a probe to another star is a big enough problem, but woven inextricably through it is the issue of communications. Adding payload steepens the propulsion curve in dramatic fashion, which is why recent thinking has dwelled so firmly on miniaturizing the spacecraft. Thus Breakthrough Starshot, which envisions payloads roughly on the order of a computer chip. No wonder, with spacecraft of that size, getting data back to Earth is such a daunting challenge. Can gravitational lensing help? We've seen that the Sun's mass shapes spacetime around it, bending light from targets on the other side so that electromagnetic waves come to a focal point about 550 AU out. The implications for imaging are under intense study at the Jet Propulsion Laboratory, where Slava Turyshev's team, working with a Phase III NIAC grant, is exploring "Direct Multipixel Imaging and Spectroscopy of an Exoplanet with a Solar Gravitational Lens Mission," taking two prior studies, a Phase I and II at NIAC, forward...
Developing FOCAL Mission Concepts
In the early summer of 2005, I found myself, thanks to the efforts of Greg Matloff and Princeton's Ed Belbruno, in Princeton for a conference called New Trends in Astrodynamics and Applications II, which Dr. Belbruno had organized. I was to give a brief talk at the end of the session summarizing what was going on in the interstellar travel community. Two days of chill rain didn't dampen my enthusiasm at seeing Greg and his wife, the artist C Bangs, as well as Belbruno himself, who had been a great help as I put together my Centauri Dreams book. And on the morning of the first day of the conference, I joined Greg, C and Claudio Maccone for breakfast at the Nassau Inn, Princeton's lovely colonial era hostelry. I've since had the opportunity to talk with Dr. Maccone many times at conferences, and one year enjoyed memorable meals with him in the Italian Alps, but that first encounter really sticks in my mind. I had been thinking about gravitational lensing for several years, but it was...
Claudio Maccone: A Deep Dive into Gravitational Lensing
Sorry for the server problems the last few days, which resulted in some tinkering under the hood by people far more skilled at such things than I am. Meanwhile, those experiencing deja vu at seeing this post should take heart -- there is a simple explanation. Last week I posted an earlier article about Claudio Maccone's upcoming presentation on gravitational lensing and the FOCAL mission to exploit it, but had to withdraw the post when I realized the live session, a 'webinar' organized by Ravi Kumar Kopparapu (NASA GSFC) and Jacob Haqq Misra (Blue Marble Space Institute of Science), might not be available beyond a restricted audience. Once that was straightened out, the meeting had already occurred, but fortunately Dr. Maccone's session was recorded and is now available here. I'm going to go ahead and run the rest of that earlier post now, because most people didn't see it. Even so, and despite the fact that it was only up on the site for a few minutes, that turned out to be long...
Server Problems Resolved
I'm going to keep Alex Tolley's fine essay (below) at the top for another day, in hopes of re-starting the comment thread that was going along so nicely before the site went down. Then tomorrow we'll start talking about gravitational lensing, in the first of a series that may extend until next week.
Distinguishing Between Biological and Machine Civilization Techno-signatures
If we ever make a SETI detection, will it be of biological beings or machine intelligence? As Alex Tolley explains in today's essay, there are reasons for favoring the latter possibility, leading our author to compose what he calls a 'light-hearted speculation' about machines searching for other civilizations of their own kind. Life seems to be easy compared to this. We are developing the tools to delve into planetary atmospheres in search of biosignatures, hoping to cull out ambiguities. But is there an equivalent in the machine world of a biosignature, and how would it be found? Interesting implications arise, some of them seemingly close to home. by Alex Tolley Curiosity Rover. Credit Nasa. Terry Bisson's amusing short sci-fi story "They're made Out of Meat" [4], is a communication between two individuals who express their disbelief that a biological species (detected on Earth by a galactic survey) can possibly be intelligent. The denouement is to erase the record of discovery...
Deep Future: The Next Supercontinent
Science fiction writers range freely through time, making many scientific papers fertile ground for plot ideas and settings. So here's an extraordinary one. We know that Earth's continents used to be packed into a single large land mass called Pangaea, which is thought to have broken apart about 200 million years ago as tectonic plates shifted. Interestingly, we can expect a remote future in which the continents will have once again come together, as Michael Way (NASA GSFC) has pointed out at an online poster session at the ongoing virtual meeting of the American Geophysical Union. And such a supercontinent has ramifications for habitability. Let's talk about those because they have a bearing on astrobiology as we examine exoplanets and consider their suitability for life. We're a decade or so (at minimum) away from being able to determine how land and sea are distributed on a nearby world, but climate modeling is useful as we look toward estimating habitability. That involves, as...
Musings on Fusion and the Interstellar Ramjet
Proton-proton fusion produces 99 percent of the Sun's energy, in a process that begins with two hydrogen nuclei and ends with one helium nucleus, releasing energy along the way. We'd love to exploit the fusion process to create energy for our own directed uses, which is what Robert Bussard was thinking about with his interstellar ramjet when he published the idea in 1960. Such a ship might deploy electromagnetic fields thousands of kilometers in diameter to scoop up atoms from the interstellar medium, using them as reaction mass for the fusion that would drive it. Carl Sagan was a great enthusiast for the concept, and would describe it vividly in the book he wrote with Russian astronomer and astrophysicist Iosif S. Shklovskii. In Intelligent Life in the Universe (1966), the authors discuss a journey that takes advantage of time dilation, allowing a lightspeed-hugging starship powered by these methods to reach galactic center in a mere 21 years of ship-time; i.e., time as perceived by...
A Centaur in Transformation
There was a time when the Solar System seemed relatively well defined, with nine planets including Pluto and an asteroid belt that orbited in a niche between Mars and Jupiter. These days, in addition to the Kuiper Belt and Oort Cloud, we have to factor in all the objects that move on unusual orbits. We have a mission in the works, called Lucy, to the Jupiter Trojans, those asteroids that share the giant planet's orbit around the Sun. And today we're looking at Centaurs, which cross the orbits of giant planets and are in rapid dynamical evolution. The subject comes up because a newly discovered comet -- 2019 LD2 (ATLAS) -- is not only a Centaur, but a Centaur that is rapidly on its way to becoming another class of object, a Jupiter Family Comet (JFC). The latter are short-period comets with an orbital period of less than 20 years, largely under the influence of Jupiter. A paper by Jordan Steckloff (Planetary Science Institute) and team lays out the case: Centaurs are objects in...
Exoplanet Imaging via a Fast New Camera
The world's largest superconducting camera by pixel count has been deployed at the Subaru Telescope at Mauna Kea in Hawaii. This is a technology we'll want to watch, for it assists the effort to image exoplanets directly from the surface of the Earth, a goal that not so long ago would have seemed impossible. But it can be done, and we have a new generation of extremely large telescopes (ELTs) on the way, so the progress in support technology for such installations is heartening. The new device is called the MKID Exoplanet Camera (MEC), with the four-letter acronym standing for Microwave Kinetic Inductance Detector. A superconducting photon detector was first developed as far back as 2003 at Caltech and the Jet Propulsion Laboratory, paving the way for devices that can operate at wavelengths ranging from the far-infrared to X-rays. The MEC comes out of the laboratory of Ben Mazin at the University of California at Santa Barbara as part of an effort that includes contributions from...
Simultaneous Growth of Star and Planet?
The evolving system known as [BHB2007] 1 is a part of the Pipe Nebula (also called Barnard 59), about 600 light years away in the constellation Ophiuchus. It is part of a binary star system in formation that has been studied with the Atacama Large Millimeter Array (ALMA). Both protostars show disks in formation around them, surrounded by filaments of gas and dust drawn from the larger disk that are being referred to as 'feeding filaments.' Paola Caselli (Max Planck Institute for Extraterrestrial Physics, Germany), who made that reference in 2019, is co-author of new work on the stellar object, which gives us an unusual look at early system formation. Image: This false-color image shows the filaments of accretion around the protostar [BHB2007] 1. The large structures are inflows of molecular gas (CO) nurturing the disk surrounding the protostar. The inset shows the dust emission from the disk, which is seen edge-on. The "holes" in the dust map represent an enormous ringed cavity seen...
Arecibo in Petition and Poetry
I'm tracking an online petition conceived by Jorge Santiago Ortiz that challenges the National Science Foundation: Repair the Arecibo Observatory, do not decommission it. Given Friday's news of the planned shutdown due to problems with support cables and the dangers of possible repairs, it's good to see an effort being made to explore the possible. Ortiz points out that the observatory employs more than 120 people, is visited by some 200 scientists every year working on research projects, and draws 100,000 visitors yearly from the general population. I notice the petition is approaching 6,000 signatures this morning as people react to the Arecibo news. It is possible there is a path toward keeping the observatory alive? Also noted by Centauri Dreams reader Jeff Brandt, himself a resident of Puerto Rico, is an attempt to free the facility from National Science Foundation funding and repair the structure. Brandt notes that Jenniffer González-Colón, Puerto Rico's representative...
On Losing Arecibo
I always wanted to get to Arecibo, the magnificent 305-meter telescope that has for so long been a locus for radio astronomy research, but I was never able to make it to Puerto Rico. Now I've run out of time. The National Science Foundation doesn't make these decisions lightly but multiple engineering companies have delivered assessments that point to catastrophic failure of the telescope structure as a real possibility. Too dangerous to repair, and faced with stability issues even if it could be repaired, the Arecibo Observatory will be decommissioned. The breakdown in the vast structure has been ongoing, bits and pieces of news that added further dismay to an already dismal 2020. A support cable detached in August, resulting in an evaluation from the University of Central Florida, which manages the site. Replacement auxiliary cables were then on the way, temporary cables available, but on November 6 another main cable broke. The stresses on the second cable evidently told the...
DESTINY+: Mission to 3200 Phaethon
With successful operations at Ryugu (Hayabusa2) and Bennu (OSIRIS-REx), asteroid exploration seems to be moving full tilt, with the prospect of surface samples on the way. We can also look ahead to 16 Psyche, the object of interest for a NASA mission planned to launch in 2022, and the Lucy mission to Jupiter's trojan asteroids, with launch now scheduled for 2021. The latest asteroid entry comes in the form of an interesting collaboration between the Japan Aerospace Exploration Agency (JAXA) and the German Aerospace Center (DLR) targeting asteroid 3200 Phaethon, a flyby mission designed to launch no earlier than 2024. DESTINY+ is its name, the acronym standing for Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science (try to say all that quickly before you've had your morning coffee). The agreement for the bilateral mission was signed on November 11 as part of a joint strategy dialogue between the two space agencies. The new...
Exoplanet Atmospheres: Keeping Up with ARIEL
How is a planet’s composition related to its host star? The European Space Agency’s ARIEL mission (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is designed to probe the question, examining planetary atmospheres to determine the composition, temperature and chemical processes at work in a large sample of planetary systems. Transmission spectroscopy is the method, examining spectra as known exoplanets pass in front of, then behind their host stars. Researchers will use light filtering through the atmospheres to unlock the chemical processes within each. ARIEL will survey about 1,000 planetary systems in both visible and infrared wavelengths, probing not just chemistry but the thermal conditions that affect their composition. The mission’s focus is on super-Earths to gas giants, all with temperatures greater than 320 Celsius. I suspect that principal investigator Giovanna Tinetti (University College London) has been asked about the choice of targets to the point of...
A New Source for Plumes on Europa
How salty should we expect the ice on Europa’s surface to be? It would be helpful to know, because the salinity of the surface will be a factor in how transparent the ice shell is to radar waves. Europa Clipper will fly with an instrument called REASON -- Radar for Europa Assessment and Sounding: Ocean to Near-surface -- which will be investigating both the surface ice and the ocean beneath. Recent research, in which its principal investigator, Don Blankenship (University of Texas), is involved is offering insights into the salinity of the ice. Here’s a bit of background on REASON from a NASA page on Europa Clipper: Depending on their wavelength, radio waves can either bounce off or penetrate different materials. REASON will use high frequency (HF) and very high frequency (VHF) radio signals to penetrate up to 18 miles (30 kilometers) into Europa’s ice to look for the moon’s suspected ocean, measure ice thickness, and better understand the icy shell's structure. The instrument will...
Radioactive Elements and Planetary Habitability
A planetary dynamo may be a key factor in creating the conditions needed for life. And creating that dynamo seems to depend on the radioactive decay of thorium and uranium, generating internal heating and driving plate tectonics. Let's carry this line of thought further, though, as the authors of a new paper out of UC-Santa Cruz do, and point out that these heavy elements are necessary to create a magnetic field like Earth's, which protects us from damaging radiation. In the rocky planets, magnetic fields are generated by convection in a metallic core, which in turn is driven by heat extracted into the mantle (Nimmo 2015; Labrosse 2015; Boujibar et al. 2020). Since mantle radiogenic heat production controls how much heat is extracted from the core, it will also influence the presence or absence of a dynamo. Similarly, heat production will control the mantle temperature and thus the rate of silicate melting and volcanism. That quote is from the paper, whose lead author is Francis...
An Unusual (and Promising) Brown Dwarf Detection
The naming of names is quite a project when it comes to new astronomical objects, and given the sheer numbers -- 300 million habitable planets around G- and K-class stars, for example -- we might do better to stick with simple identifiers. On the other hand, it's a bit charming that a new brown dwarf known by its identifier as BDR J1750+3809 has been dubbed 'Elegast' by the discovery team. This is the first substellar object found through radio observations. The name is both appropriate and specific to the discovery space. Elegast appears in a poem in Middle Dutch (12th or 13th Century) called 'Karel ende Elegast,' with the character Elegast being a vassal of Charlemagne who seems to be king of the elves (Wikipedia to the rescue, vindicating once again my decision to send them a monthly donation). The Dutch connection is that the radio work comes out of LOFAR (Low-Frequency Array), which is currently the largest radio telescope operating at the lowest frequencies that we can observe...
Europa: Night-time Glow a New Tool for Analysis
When it comes to Europa, it's the surface that counts as we try to learn more about the ocean beneath. Maybe one day we'll be able to get some kind of probe through the ice, but for now we have to think about things like upwellings of water that percolate up through cracks in the frozen landscape, and unusual areas like Europa's 'chaos' terrain. Here, fractures and evident 'rafts' of ice show disruptions where the icy surface of the moon experiences Jupiter's tidal effects. Image: The surface of Jupiter's moon Europa features a widely varied landscape, including ridges, bands, small rounded domes and disrupted spaces that geologists called "chaos terrain." This newly reprocessed image, along with two others along the same longitude, was taken by NASA's Galileo spacecraft on Sept. 26, 1998, and reveals details of diverse surface features on Europa. Credit: NASA/JPL-Caltech/SETI Institute. What kind of materials might we find frozen into the cracks and grooves of such terrain? Europa...