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Time Out

No Centauri Dreams posts this week — I’ll be back next Monday. I’ve been running hard and it’s time for a break. I’ll keep up with comment moderation as best I can, though I’m going to be trying to catch up with many long overdue commitments outside the interstellar field in coming days. As always, thanks to all for the continuing support. See you soon!


Comments on this entry are closed.

  • Jim Franklin September 26, 2016, 10:39

    Paul, take a rest and have a holiday – turn off the mobile, laptop, tablet or anything else people can use to contact you…sit somewhere lush but quiet…and chill man…we all need a scene change from time to time to reset things…

  • Michael September 26, 2016, 10:57

    Enjoy your well deserved break Paul,

  • Mark Zambelli September 26, 2016, 11:35

    Make use of the break Paul and see you back soon… take care.

  • andy September 26, 2016, 13:36

    Enjoy the well-earned break! It’s always important to take some time out to recharge now and again.

    Meanwhile I’m wondering what the NASA Europa announcement today is about. My guess is that it may have something to do with the alleged plumes, but for now I have to wait and see.

  • ljk September 26, 2016, 15:12

    Enjoy your well-deserved break, Paul.

    This is probably a good place to post the latest relevant news and other items for the week to keep everyone up to date. I will start.

    Europan water plume detected (thank you, HST):


    Mercury is tectonically active (thank you, MESSENGER):


    A new SETI book, Waiting for Contact, by Lawrence Squeri:



    A subsurface ocean of liquid water on Pluto 60 miles deep?!


    The late Robert Bradbury had this idea over a decade ago: Globular star clusters might be great places to find advanced ETI:


    A must-read review of three new books on “greening” the Sol system and beyond by Freeman Dyson, with goes well beyond mere reviewing with some very important commentary about exploring and settling space:


    The U.S. Senate gives NASA money with a mandate to send humans to Mars:


    All this is just from the last few days! But what will the media focus on instead tonight? Take a guess.

  • ljk September 26, 2016, 16:07

    Cornell University wants to send the first CubeSat to orbit Luna. A step in the direction towards Breakthrough Starshot?


    Humanity’s largest single dish radio telescope, China’s FAST observatory, begins tests. China has also made it no secret that they want to be the first nation to discover ETI with this instrument. Will they also do radio METI with it?


    Tomorrow, September 27, we should also find out what supposedly sent a signal from HD164595, by the science team at RATAN-600:


  • Matt September 26, 2016, 16:50

    It will be a struggle to survive a whole week without Centauri Dreams.

    I do want to say again that I appreciate you work here.

    — Matt

  • RobFlores September 26, 2016, 18:23

    Earned Break Mr P. G.

    I did come across a click bait article on time’s arrow. A new “study” indicating that Time is an observer dependent emergent property.


    Maybe this means that the moment a single species in one universe rises to be an “observer Species” it is Ejected from the multiverse to become essentially closed to inter change of information to-and-from other universes?. Does this mean only intelligence can arise in each universe?
    beats me, but maybe another explanation for the Fermi Paradox.

  • Paul Gilster September 26, 2016, 19:49

    Hey, I just checked in and really appreciate the good thoughts. Thanks to all!

  • Asteroidenbergbauer September 27, 2016, 3:26

    thank u 4 all yr effort! hang loose

  • Garry September 27, 2016, 6:23

    Have a good rest Paul, looking forward to more news when you come back.

  • ljk September 27, 2016, 9:01
  • Michael T September 27, 2016, 13:55

    Have a great break!

    This is a wonderful site, and doing web stuff myself I know how much work it can entail.


  • JonW September 27, 2016, 14:12

    ljk, great list, thanks. In the Freeman Dyson article you posted from NYRB, he mentioned the notion of flying a spacecraft through the geysers on Enceladus (and obviously now Europa would be another target), and bringing back the samples here for analysis. And it made me think: as far as I know, no spacecraft has ever returned from Jupiter’s orbit or beyond, right? Given the deep gravity wells invoved it’s not obvious how to do that. What possibilities have been proposed? Could you conceivably get back via gravity assist? (my uneducated guess is that even if this is possible, you’d need to have a carefully calibrated trajectory to do the moon flyby with enough precision to hit the geysers, and this would be extremely difficult at the speed necessary to leave you unbound to Jupiter)

    Paul, please enjoy your break. I really appreciate your work here.

    • ljk September 27, 2016, 17:39

      You may find this article to be of high interest and use:


      This site is also invaluable when it comes to planetary missions. Just enter the word Europa in the search engine box at the upper left of the home page and have fun:


      • JonW September 28, 2016, 14:54

        Fantastic information, ljk. I find it amazing that you can spend a couple of years getting gravity assists from Jovian moons while in orbit around Jupiter, to boost your speed and make it easier to eventually escape the giant’s clutches. Returning material from the outer solar system does seem within reach today based on this information and I can’t wait to see it happen.

  • Sean Meaney September 27, 2016, 20:10

    Elon Musk disclosed his Mars colonization plan. ;-)

  • Andrew Palfreyman September 28, 2016, 8:01

    This is a fantastic site and much appreciated.

    Today, Musk pushed out the visionary boat and made people sit up.

  • ljk September 28, 2016, 9:22

    Why is it taking a few individual billionaires to get us into space permanently and conducting SETI and METI to do what governments used to do or are at least supposed to do?

    Elon Musk has plans for Mars and beyond:



    Musk plans on sending an unmanned test version of his Red Dragon vessel to land on Mars with a launch in 2018. An actual manned mission is planned for 2024. NASA won’t be able to conduct a similar mission until sometime in the 2030s, despite presumably having far more money and resources. What is wrong – or maybe right – with this picture?

    • Robert September 29, 2016, 12:41

      When his people land on Mars, they can claim it. Then folks on earth will complain so Musk will put out a flag on Mars that says ‘Come and Take it’…
      Then the government will offer to buy out the program for really big bucks. :)

  • ljk September 28, 2016, 9:28

    From Futurism:

    It’s Official: We’re Going to Mars

    It looks like Republican and Democratic senators alike are keen on safeguarding America’s space programs. With the potential chaos of a new president on the horizon, the Senate Committee on Commerce, Science, and Transportation passed a bipartisan bill giving NASA $19.5 billion to continue working on a mission to Mars. It also includes support for the continuation of the program to send astronauts on private rockets to the International Space Station (ISS) from American soil no later than 2018.

    “We have seen in the past the importance of stability and predictability in NASA and space exploration – that whenever one has a change in administration, we have seen the chaos that can be caused by the cancellation of major programs,” Republican Senator Ted Cruz, lead sponsor of the bill, commented. “The impact in terms of jobs lost, the impact in terms of money wasted has been significant.”

    Full article here:


    To quote:

    A bipartisan bill was passed by the U.S. Senate committee that oversees NASA space projects. The bill would allocate $19.5 billion in funds to NASA in 2017, but it has a critical mission for the space agency: send men to Mars.

  • ljk September 28, 2016, 9:30
  • ljk September 28, 2016, 9:32

    Physicists Have Figured Out How to Create Matter and Antimatter Using Light

    A team of researchers from the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS) has just announced that they managed to calculate how to create matter and antimatter using lasers. This means that, by focusing high-powered laser pulses, we may soon be able to create matter and antimatter using light.

    To break this down a bit, light is made of high-energy photons. When high-energy photons go through strong electric fields, they lose enough radiation that they become gamma rays and create electron-positron pairs, thus creating a new state of matter.

    “A strong electric field can, generally speaking, ‘boil the vacuum,’ which is full of ‘virtual particles,’ such as electron-positron pairs. The field can convert these types of particles from a virtual state, in which the particles aren’t directly observable, to a real one,” says Igor Kostyukov of IAP RAS who references their calculations on the concept of quantum electrodynamics (QED).

    Full article here:


    To quote:

    Just milligrams of antimatter could get us to Mars, but it costs a quadrillion dollars to make one gram. Now, a new calculation could allow us to make antimatter from light.

    This could significantly bring down the cost and give us a viable way to make antimatter.

  • ljk September 28, 2016, 10:23

    Rosetta is set to land on Comet 67P/Churyumov–Gerasimenko on September 30. To quote:

    “The end is near for Rosetta. As I explained earlier this month, ESA plans to set Rosetta down on the surface of the comet on September 30, with its final signals reaching Earth at 04:20 PDT / 07:20 EDT / 11:20 UTC / 13:20 CEST, give or take 20 minutes. Upon impact, the spacecraft will automatically “passivate,” cutting the radio connection to Earth and ending the mission forever. (Why does the mission have to end? Read ESA’s FAQ.)”

    Details here (check out the ESA FAQ especially):


    The Planetary Society’s take on SpaceX’s big announcement:


    To quote:

    Musk’s plans are so ambitious, they nearly defy analysis. Of all the modern private space firms claiming they will ferry tourists to orbit, mine asteroids and set up commercial space stations, SpaceX may stand alone in its ability to present such a staggeringly audacious plan and still be taken seriously. Even NASA might raise more objections if it were to drop an equally zealous version of its current Journey to Mars plans.

    Put simply, Musk wants to colonize Mars. Humanity, he believes, must become an interplanetary species before some future calamity wipes our presence from the Earth.

    Whereas NASA’s humans-to-Mars plans envision an Antarctica-like research station with a rotating crew of astronauts, Musk wants to have a million people there in 40 to 100 years. He stopped short of saying he wanted to terraform the planet, but frequently alludes to the possibility; SpaceX’s new video on its Mars transportation system ends by showing the Red Planet spinning into an Earth-like orb.


    Despite all the details revealed in today’s presentation, many questions remain: What kind of life support systems will be used? Where will SpaceX build all this? How will the colonists stay healthy on their trip? And on Mars? What kind of infrastructure will support them there? Will SpaceX build a NASA-esque Deep Space Network for Mars communications? The list goes on and on.

    There are also ethical considerations. NASA builds its spacecraft with the mentality that “failure is not an option,” always keeping in mind tragedies like Columbia, Challenger and Apollo 1. Musk, on the other hand, openly admits people are likely to die.

    And what about planetary protection? Will SpaceX’s vision of the future clash with detractors that wish to keep the planet pristine?

  • ljk September 28, 2016, 11:05

    Seth Shostak takes on aliens and Stephen Hawking’s rather standard view of them (basically the plot to Independence Day) in the links below:



    To quote:

    These simple arguments lead to a simple conclusion. Any society with the capability to threaten Earth is overwhelmingly likely to already have the kit required to pick up the leakage we’ve been wafting skyward for seven decades. The requisite radio technology is far easier than the necessary rocket technology.

    And since we’ve been busy for a lifetime filling the seas of space with bottled messages marking our existence and position, it’s a bit silly to fret about new bottles.

    So should we worry about a future, deliberate transmission to the stars? Nasa doesn’t seem concerned: in 2008, it broadcast a Beatles song in the direction of the north star. It will take four centuries to get there.

  • ljk September 28, 2016, 11:10

    Another discovery of water in space – how boring. We must search for alien life

    The latest find on Jupiter’s moon Europa offers the potential to really look for life. It’s not time to shy away – and Nasa needs to rise to the challenge

    Stuart Clark

    Wednesday 28 September 2016 07.20 EDT

    For a decade now, the Nasa mantra for looking for life in outer space is to “follow the water”. In the beginning, this was a valid way to identify the places where we should then start searching. Each new discovery of “water” is automatically paired with a statement that this increases the chance of finding alien life. But in recent years – the latest example being the discovery of water this week on Jupiter’s moon Europa – we have been hearing it so often that it is starting to become boring.

    The evidence for water on celestial bodies such as Mars, Europa and Saturn’s moon Enceladus is now overwhelming. It is time to take the next step and actually look for life itself.

    Full article here:


    To quote:

    When I say life, I don’t mean little green men who say: “Take me to your leader.” Microbes will do because the discovery of single alien microbe would be the greatest advance that science could ever make. We still do not know how life began on Earth. If we could find some elsewhere, we could look to see how similar or different it was from Earth life. Does it rely on DNA, for example? Do its similarities and differences hold clues about how it, and therefore we, were formed?

    However, this is where the risk and the fear of failure lies. Despite what you might think from the news stories, water is no guarantee of life. Water is certainly a prerequisite on Earth and there are good scientific reasons for believing water may be essential for life of any description, but there is no guarantee that a watery celestial body will automatically play host to microbes.

    Perhaps this is the reason that Nasa has seemed strangely reluctant to take the next step of actually looking for life. Earlier this century, they shied away from the Terrestrial Planet Finder, a telescope designed to look for Earth-like worlds and analyse their atmospheres for traces of life. With their Mars Curiosity rover in 2012, they specifically did not put any life-detecting equipment on board.


    Nasa was not always this timid. In the 1970s it sent two landers to the surface of Mars. These Viking missions carried experiments to look for life. The results were deemed inconclusive and then simply not followed up. This could have been a mistake. A recent re-analysis of the data suggested that, while the results fell short of a clear detection of Martian life, there were enough positive indicators to warrant a follow-up.

    Perhaps in response, Nasa has now quietly stated that its next Mars rover in 2020 will also look for life. But at least the European Space Agency is proving bolder. In 2020 it plans to launch the ExoMars rover to Mars that will carry a suite of instruments capable of looking for the evidence of life, either past or present. That search should now be extended to Europa.

    There is admirable scientific caution, and there is ducking the challenge. To go to Europa now without the ability to look for life is the latter. It is time for vision and commitment: discovering life on another planet would send shockwaves through science and fundamentally transform our understanding of our place in the universe: we must step up the search.

  • ljk September 28, 2016, 14:11

    As I was searching the Internet in hopes of finding this paper finally being online:

    “SETI observations on the RATAN-600 telescope in 2015 and detection of a strong signal in the direction of HD 164595,” BURSOV N., FILIPPOVA L., FILIPPOV V., GINDILIS L., MACCONE C. et al.

    It was supposed to be presented yesterday by the IAA SETI Permanent Committee during the 67th International Astronautical Congress (IAC) in Guadalajara, Mexico.

    I came across these two fairly recent papers on SETI which are online here:

    ET Probes: Looking Here as Well as There


    SETI at X-ray Energies – Parasitic Searches from Astrophysical Observations


    • ljk September 29, 2016, 14:23

      From the tweet:

      #B_Listen science team @UCBerkeley publish raw data from obs of star HD 164595, in direction of signal heard in May, 2015:


      To quote:

      Breakthrough Listen is the most powerful search yet for signatures of extraterrestrial technology, and uses the world’s most powerful telescopes to scan the skies for signs of life. A commitment from Breakthrough Initiatives (https://breakthroughinitiatives.org), the project’s sponsors, is to make as much data as possible available to the public, and the team at Berkeley agrees that openness and transparency are extremely important. Although data volumes are large, and formats are technical, we are today releasing the raw data from our observations of HD 164595 into the Breakthrough Listen archive for independent analysis by anyone with appropriate technical experience.

      Most of the GBT data in the archive are in filterbank format (see our github page about data formats at https://github.com/UCBerkeleySETI/breakthrough/blob/master/GBT/waterfall.md), and an iPython notebook demonstrating how to import these files into Python (https://github.com/UCBerkeleySETI/breakthrough/blob/master/GBT/voyager/voyager.ipynb). Since the HD 164595 observations were undertaken in a raster scanning mode (to match the way that the original RATAN-600 data were taken) rather than our usual “on-off” mode where the telescope alternates between target positions, filterbank files cannot be generated for this particular set of observations. We are therefore releasing the raw “baseband” data for HD 164595 into the archive.

  • ljk September 29, 2016, 9:54

    Next Big Future posted an article on Robert Zubrin’s Nuclear Salt Water Rocket Design on September 27, 2016:


    To quote:

    Consider for example, an NSWR utilizing a 2% uranium bromide solution with 90% enriched U233, and obtaining a 90% fission yield. Assuming a nozzle efficiency of 0.9, the exhaust velocity of this system will be 4725 km/s, or about 1.575% of the speed of light (a specific impulse of 482,140 seconds). If the 300 tonne Titan mission spacecraft is endowed with 2700 tonnes of propellant (for a mass ratio of 10) a maximum velocity of 3.63% of speed of light could be obtained, allowing the ship to reach Alpha Centauri in about 120 years.

    Deceleration could be accomplished without the use of substantial amounts of rocket propellant by using a magnetic sail (or “magsail”) to create drag against the interstellar medium.

    In a more ambitious approach, one could envisage a group of interstellar emigrants selecting a small ice asteroid with a mass of 30,000 tonnes and using it as propellant (together with 7,500 tonnes of uranium obtained elsewhere) for a 300 tonne spacecraft. In this case the ship could obtain a final velocity of about 7.62% light speed, and reach Alpha Centauri in about 60 years.

  • ljk September 29, 2016, 9:58

    OSIRIS-REx’s cameras see first light

    Posted By Emily Lakdawalla

    2016/09/29 08:34 UTC

    As OSIRIS-REx speeds away from Earth, it’s been turning on and testing out its various engineering functions and science instruments. My favorite proof of a happy instrument is data, especially camera data, so I’ve really been enjoying the series of “first light” images that OSIRIS-REx has been sharing over the past few weeks.

    Full article and images here:


    StowCam also took an amazing shot of the space probe’s sample return capsule:


  • ljk September 29, 2016, 11:19

    An Animated Guide to Humanity’s First Interstellar Mission

    September 27, 2016

    Video by The Atlantic


    In a 1610 correspondence to Galileo Galilei, Johannes Kepler noted, “Ships and sails proper for the heavenly air should be fashioned. Then, there will also be people, who do not shrink from the dreary vastness of space.” Now, more than four centuries later, the Russian venture capitalist Yuri Milner is applying these principles to modern day space exploration.

    Human travel to our nearest star system, Alpha Centauri, will not be possible for many years, if ever. However, in the near future, robots might be able to make the trip in an inexpensive and scalable way. Using a solar sail, a nearly weightless spaceship and a powerful beam of light, probes could travel the 4 light years to Alpha Centauri in only 20 years. The most expensive piece of equipment, the beam of light, will stay on the planet, and each spaceship will cost only as much as a smartphone. With this scalable model, our earthly civilization might someday become truly galactic.

    Authors: Caitlin Cadieux, Erica Moriarty, Ross Andersen

  • ljk September 29, 2016, 15:22

    Spiral arms: not just in galaxies

    Protoplanetary disk around a young star exhibits spiral structure

    September 29, 2016

    Astronomers have found a distinct structure involving spiral arms in the reservoir of gas and dust disk surrounding the young star Elias 2-27. While spiral features have been observed on the surfaces of protoplanetary disks, these new observations, from the ALMA observatory in Chile, are the first to reveal that such spirals occur at the disk midplane, the region where planet formation takes place. This is of importance for planet formation: structures such as these could either indicate the presence of a newly formed planet, or else create the necessary conditions for a planet to form. As such, these results are a crucial step towards a better understanding how planetary systems like our Solar system came into being.

    Full article here:


  • ljk September 29, 2016, 15:26


    Five Hundred Meter Aperture Spherical Telescope

    Image Credit & Copyright: Jeff Dai (TWAN)

    Explanation: The Five-hundred-meter Aperture Spherical Telescope (FAST) is nestled within a natural basin in China’s remote and mountainous southwestern Guizhou province. Nicknamed Tianyan, or the Eye of Heaven, the new radio telescope is seen in this photograph taken near the start of its testing phase of operations on September 25.

    Designed with an active surface for pointing and focusing, its enormous dish antenna is constructed with 4,450 individual triangular-shaped panels. The 500 meter physical diameter of the dish makes FAST the largest filled, single dish radio telescope on planet Earth.

    FAST will explore the Universe at radio frequencies, detecting emission from hydrogen gas in the Milky Way and distant galaxies, finding faint galactic and extragalactic pulsars, and searching for potential radio signals from extraterrestrials.

  • ljk September 30, 2016, 9:52

    I wonder if Rosetta is sitting on the comet somewhere or did it have enough momentum to bounce back into space?


    The probe has certainly given us plenty of comet science for decades:


    Some day researchers will be hunting down Rosetta for its valuable cargo: An etched disc containing over one thousand human languages:



    I am a bit unsure if a comet is the best place to store human knowledge for future generations, but it is still likely better than just about anywhere on Earth.

  • Harry R Ray September 30, 2016, 11:21

    There MAY(CAVEAT! CAVEAT!)be ANOTHER “Earth 2.o” LEAK, this time regarding TRAPPIST-1d! This time the “newspaper” is Sputnik France. Newspaper is in quotation marks because I am NOT certain whether this is PRINT media, or just an on-line entity. Google TRAPPIST1-d. go to page 3 and click TRAPPIST1-d hashtag on Twitter. Click sptnk.ws/cjay#TRAPPIST1-d. The article is in FRENCH. I would appreciate FEEDBACK from any reader PROFFICIENT in French ASAP!

    • ljk September 30, 2016, 14:27

      Are you referring to this article from September 14, 2016:


      • Harry R Ray October 2, 2016, 13:29

        Yes, but TRIPLE that caveat! Sputnik is a Putin pandering “independent”(HA! HA!) publication in Russia and Sputnik France is JUST their French affiliate! My guess is that they have tapped into all of the MEGA-RUMERS about TRAPPIST-1d in January and February coming from MOSTLY Russian bloggers. So, to me, anyway; there is only an OUTSIDE POSSIBILITY that they have something REALLY NEW, but, then again; I could be wrong, so it STILL should be checked out. If they DO have something, I fear that it would NOT have been leaked from someone on Guillen’s team, but; instad, would have been HACKED from their database(this ITSELF is ANOTHER issue that should be discussed on this website sometime in the future). Oh, and talking about Russians, why did their radio astronomers WITHDRAW their September 27 presentation?

        • Harry R Ray October 3, 2016, 10:41

          A quote from the “article”: Son atmosphere, raconte Astrophysical Journal Letters, contient des traces d’eau, d’oxygene et de CO2.” NOTE: NO “possible” IN BETWEEN “contient” and “des traces…”! BUT: Spitzer and Hubble are NOT sensitive enough to detect these gasses from such a small transit at such a large distance. AND: Astrophysical Journal Letters does NOT embargo major discoveries like “Nature” and “Science” do, so this should have been up on arXiv by now. Looks like it just another over-agressive attempt to gain attention.

    • DJ Kaplan September 30, 2016, 16:14

      I could do that, but I’d rather not. Let the responsible scientific organization (ESO?) release it when they are ready.

      • DJ Kaplan September 30, 2016, 16:18

        BTW, here is Sputnik France’s website:

        I don’t know what that other link is.

        • ljk October 3, 2016, 9:58

          It is the link to the actual article from that publication.

  • ljk September 30, 2016, 12:54

    This paper is currently freely available from Astrobiology magazine:


    The Case for Extant Life on Mars and Its Possible Detection by the Viking Labeled Release Experiment

    To cite this article:

    Levin Gilbert V. and Straat Patricia Ann. Astrobiology. September 2016, ahead of print. doi:10.1089/ast.2015.1464.

    Online Ahead of Print: September 14, 2016

  • ljk September 30, 2016, 12:57


    The Search for Extraterrestrial Intelligence in Earth’s Solar Transit Zone

    To cite this article:

    Heller René and Pudritz Ralph E.. Astrobiology. April 2016, 16(4): 259-270. doi:10.1089/ast.2015.1358.

    Published in Volume: 16 Issue 4: April 15, 2016
    Online Ahead of Print: March 11, 2016

    Over the past few years, astronomers have detected thousands of planets and candidate planets by observing their periodic transits in front of their host stars. A related method, called transit spectroscopy, might soon allow studies of the chemical imprints of life in extrasolar planetary atmospheres.

    Here, we address the reciprocal question, namely, from where is Earth detectable by extrasolar observers using similar methods. We explore Earth’s transit zone (ETZ), the projection of a band around Earth’s ecliptic onto the celestial plane, where observers can detect Earth transits across the Sun. ETZ is between 0.520° and 0.537° wide due to the noncircular Earth orbit. The restricted Earth transit zone (rETZ), where Earth transits the Sun less than 0.5 solar radii from its center, is about 0.262° wide. We first compile a target list of 45 K and 37 G dwarf stars inside the rETZ and within 1 kpc (about 3260 light-years) using the Hipparcos catalogue. We then greatly enlarge the number of potential targets by constructing an analytic galactic disk model and find that about 105 K and G dwarf stars should reside within the rETZ.

    The ongoing Gaia space mission can potentially discover all G dwarfs among them (several 104) within the next 5 years. Many more potentially habitable planets orbit dim, unknown M stars in ETZ and other stars that traversed ETZ thousands of years ago. If any of these planets host intelligent observers, they could have identified Earth as a habitable, or even as a living, world long ago, and we could be receiving their broadcasts today. The K2 mission, the Allen Telescope Array, the upcoming Square Kilometer Array, or the Green Bank Telescope might detect such deliberate extraterrestrial messages.

    Ultimately, ETZ would be an ideal region to be monitored by the Breakthrough Listen Initiatives, an upcoming survey that will constitute the most comprehensive search for extraterrestrial intelligence so far. Key Words: Astrobiology—Extraterrestrial life—Intelligence—Life detection—SETI. Astrobiology 16, 259–270.

  • ljk September 30, 2016, 14:06


    Sonneberg plate photometry in two colors for KIC 8462852: No dimming between 1934 and 1995

    Michael Hippke, Peter Kroll, Frank Matthei, Daniel Angerhausen, Taavi Tuvikene, Keivan G. Stassun, Elena Roshchina, Tatyana Vasileva, Igor Izmailov, Michael B. Lund

    (Submitted on 29 Sep 2016)

    The F3 main sequence star KIC 8462852 has raised interest because of its mysterious day-long brightness dips, and an unusual ~3% brightness decrease during the 4 years of the Kepler mission.

    Recently, a 0.164mag (~14%) dimming between 1890 and 1990 was claimed, based on the analysis of photographic plates, although this has been refuted.

    To resolve this controversy, we have gathered an independent set of historic data from Sonneberg Observatory, Germany. From these historic plates, we could extract 862 magnitudes in blue light, and 401 magnitudes in red light. The data cover the years 1934 to 1995 and are very evenly sampled between 1956 and 1995.

    In both colors, we find the star to be of constant brightness within 0.033mag/century (~3%). The previously claimed dimming is inconsistent with these data at the ∼5σ-level, however the recently reported modest dimming of ~3% in the Kepler data is not inconsistent with these data. We have also searched for periodicities and yearly trends in the data and find none within our limits of ~10% per year.

    Comments: Comments welcome

    Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

    Cite as: arXiv:1609.09290 [astro-ph.SR]
    (or arXiv:1609.09290v1 [astro-ph.SR] for this version)

    Submission history

    From: Michael Hippke [view email]

    [v1] Thu, 29 Sep 2016 10:29:11 GMT (2912kb,D)


    • ljk September 30, 2016, 14:11


      A first view with GAIA on KIC 8462852 – distance estimates and a comparison to other F stars

      Michael Hippke, Daniel Angerhausen

      (Submitted on 18 Sep 2016)

      Distance estimates from Gaia parallax and expected luminosities are compared for KIC 8462852. Gaia DR1 yields a parallax of 2.55±0.31mas, that is a distance of 391.4+53.6−42.0pc, or 391.4+122.1−75.2pc including systematic uncertainty. The distance estimate based on the absolute magnitude of an F3V star and measured reddening is ∼454±35pc. Both estimates agree within <1σ, which only excludes some of the most extreme theorized scenarios for KIC 8462852.

      Future Gaia data releases will determine the distance to within 1% and thus allow for the determination a precise absolute luminosity.

      Comments: Comments welcome

      Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

      Cite as: arXiv:1609.05492 [astro-ph.SR]
      (or arXiv:1609.05492v1 [astro-ph.SR] for this version)

      Submission history

      From: Michael Hippke [view email]

      [v1] Sun, 18 Sep 2016 14:22:23 GMT (394kb,D)


      • ljk October 3, 2016, 13:26

        Our galaxy’s most-mysterious star is even stranger than astronomers thought

        Monday, October 03, 2016

        Pasadena, CA— A star known by the unassuming name of KIC 8462852 in the constellation Cygnus has been raising eyebrows both in and outside of the scientific community for the past year. In 2015 a team of astronomers announced that the star underwent a series of very brief, non-periodic dimming events while it was being monitored by NASA’s Kepler space telescope, and no one could quite figure out what caused them. A new study from Carnegie’s Josh Simon and Caltech’s Ben Montet has deepened the mystery.

        Simon and Montet’s findings caused a stir in August, when they were posted on a preprint server while their paper was being reviewed. Now their work is now accepted for publication by The Astrophysical Journal.

        Full article here:


        To quote:

        “The steady brightness change in KIC 8462852 is pretty astounding,” said Montet. “Our highly accurate measurements over four years demonstrate that the star really is getting fainter with time. It is unprecedented for this type of star to slowly fade for years, and we don’t see anything else like it in the Kepler data.”

        “This star was already completely unique because of its sporadic dimming episodes. But now we see that it has other features that are just as strange, both slowly dimming for almost three years and then suddenly getting fainter much more rapidly,” Simon added.

        Astronomers were already running short of good ideas to account for the dips in KIC 8462852’s brightness, and the new results will make that task even harder. Simon and Montet think that the best proposal so far for explaining the star’s drastic six month dimming might be a collision or breakup of a planet or comet in the star’s system, creating a short-term cloud of dust and debris that blocks some starlight. However, this wouldn’t explain the longer-term dimming observed during the first three years of Kepler and suggested by measurements of the star dating back to the nineteenth century.

        “It’s a big challenge to come up with a good explanation for a star doing three different things that have never been seen before,” Montet said. “But these observations will provide an important clue to solving the mystery of KIC 8462852.”

    • Harry R Ray October 3, 2016, 16:12

      This paper was up on arXiv last week, AND ABSOLUTELY NO ONE HAS RESPONDED TO IT YET! No tweets from Jason Wright. No response from Bradley Schaefer. No blogger “debunkers” using it to drive nails into the coffin, that I can see. Is it just “shell-shock”, or is EVERYONE waiting to come out with a VERY MEASURED RESPONSE! The paper DID say that the new data is NOT inconsistant with Montet et al’s Kepler results, which have JUST BEEN ACCEPTED AND PUBLISHED!

      • Harry R Ray October 4, 2016, 9:39

        Doubts on the RELIABILITY of a systematic search of a large sample of plates from the Sonneberg Sky Patrol Archive(SSPA). ArXiv # 1610.00265. This MAY put Hippke et al’s results in doubt. Kind of ironic, as this is the argument he used against Schaefer.

        • ljk October 4, 2016, 12:14


          Sonneberg Sky Patrol Archive – Photometric Analysis

          Milan Spasovic, Christian Dersch, Christian Lange, Dragan Jovanovic, Andreas Schrimpf

          (Submitted on 2 Oct 2016)

          The Sonneberg Sky Patrol archive so far has not yet been analyzed systematically. In this paper we present first steps towards an automated photometric analysis aiming at the search for variable stars and transient phenomena like novae. Early works on the sky patrol plates showed that photometric accuracy can be enhanced with fitting algorithms. The procedure used was a manually supported click-and-fit-routine, not suitable for automatic analysis of vast amount of photographic plates.

          We will present our progress on deconvolution of overlapping sources on the plates and compare photometric analysis using different methods. Our goal is to get light curves of sufficient quality from sky patrol plates, which can be classified with machine learning algorithms. The development of an automated scheme for finding transient events is in progress and the first results are very promising.

          Comments: 4 pages, 4 figures, Proceedings Astroplate 2016, Prague, in print

          Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

          Cite as: arXiv:1610.00265 [astro-ph.IM]
          (or arXiv:1610.00265v1 [astro-ph.IM] for this version)

          Submission history

          From: Andreas Schrimpf [view email]

          [v1] Sun, 2 Oct 2016 11:55:31 GMT (705kb,D)


          • ljk October 4, 2016, 12:20


            Photometric and astrometric vagaries of the enigma star KIC 8462852

            Valeri V Makarov, Alexey Goldin

            (Submitted on 13 Sep 2016 (v1), last revised 26 Sep 2016 (this version, v2))

            We apply a PCA-based pre-whitening method to the entire collection of main Kepler mission long-cadence data for KIC 8462852 spanning four years. This technique removes the correlated variations of instrumental origin in both the detected light curves and astrometry, resolving intrinsic changes in flux and image position of less than 100 ppm and 1 mas, respectively. Beside the major dips in the light curve during mission quarters 8 and 16, when the flux dropped by up to 20%, we confirm multiple smaller dips across the time span of observation with amplitudes ranging from 0.1% to 7%. A variation of flux with a period of 0.88 d and a half-amplitude of approximately 90 ppm is confirmed in the PCA-cleaned data. We find that the phase of the wave is steady over the entire 15-month interval. We confidently detect a weak variability-induced motion (VIM) effect in the cleaned astrometric trajectories, when the moment-based centroids shift synchronously with the flux dips by up to 0.0008 pixels on the detector. The inconsistent magnitude and direction of VIM effects within the same quarter point at more than one source of photometric variability in the blended image. The 0.88 d periodicity comes from a different source, not from the target star KIC 8462852.

            We discuss a possible interpretation of the bizarre properties of the source as a swarm of interstellar junk (comets and planetoids) crossing the line of sight to the star and its optical companions at approximately 7 mas per year.

            Comments: submitted in ApJ. The most significant change with respect to previous version is a new clue discussed in Section 6 about the foreground junk hypothesis where we discuss the proximity of the target star to a filamentary H-alpha emission nebula DWB 123 possibly associated with the peculiar Simeiz 57 (Propeller Nebula) cloud, and a new Fig. 12 showing a DSS-red image of the extended area

            Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

            Cite as: arXiv:1609.04032 [astro-ph.SR]
            (or arXiv:1609.04032v2 [astro-ph.SR] for this version)

            Submission history

            From: Valeri Makarov [view email]

            [v1] Tue, 13 Sep 2016 20:15:05 GMT (1363kb)
            [v2] Mon, 26 Sep 2016 07:58:26 GMT (2460kb)


            • Harry R Ray October 4, 2016, 17:06

              With this flood of NEW INFORMATION, the situation has reached a state of NEAR TOTAL CONFUSION! Obvious incompatable data sets here, and SOME of this data will have to be PROVEN wrong before we get a clearer picture of what’s going on! WHICH DATA IS THE WRONG DATA? In my mind, ALL HYPOTHESES are OFF THE TABLE until we know for sure!

            • Michael October 5, 2016, 15:23

              ‘The 0.88 d periodicity comes from a different source, not from the target star KIC 8462852.’

              Heavier massed F-type stars can rotate quite fast, less than a day as they can have weak magnetic braking abilities.


  • ljk September 30, 2016, 14:16

    No Conclusive Evidence for Transits of Proxima b in MOST photometry:


    The Pale Green Dot: A Method to Characterize Proxima Centauri b using Exo-Aurorae:


    The Space Weather of Proxima Centauri b:


    • Sean Robert Meaney October 8, 2016, 23:34

      At 124 miles deep the ocean pressures are sufficient (2.3 gigapascals) to form oxygen-4 (oxygen-8 forms at 8 gigapascals). As oxygen is diamagnetic the solid oxygen core will add to the concentration of the electromagnetic field of Proxima B. It means that it doesnt need an Iron core because a solid oxygen core would allow Proxima B to be a Super-ocean much larger than earth with an electromagnetic field than an Iron core earth scale ocean planet. And the larger it is the greater the core water pressure. The greater the pressure the longer the oxygen chains (oxygen-8).


  • ljk September 30, 2016, 15:00

    Seth Shostak tells Stephen Hawking to relax about aliens:


    To be blunt, Hawking’s views on the subject have always seemed to come straight from his viewing of the 1996 science fiction film Independence Day. Of course because HE said it, the media listens and obeys without really thinking.

    Hawking also started saying these things about aliens back in 2010 to gain publicity for his then-new science series, Stephen Hawking’s Universe. Check out this admittedly interesting clip on the subject from it:


    What is really “amusing” is when Hawking made his pronouncements about aliens as potential invaders, most everyone automatically agreed with him because he was that really smart English cosmologist. However, when Hawking also pronounced that he did not believe in the existence of God, suddenly the general public responded that he was just some crazy scientist who didn’t know what he was talking about!

    Here are my views on Hawking and ETI:


    and here:


  • Sean Meaney October 3, 2016, 0:36

    Option B: we all accept our extinction and not let a murderous self entitled species escape its prison.

    • ljk October 3, 2016, 9:57

      Do you assume that all other beings have someone begun life as saints and angels from the get-go? Are we really that terrible, or is this just the process that all intelligent go through as they evolve? Will the Universe truly be better off without us? Would we really be able to do any real damage to something that is 13.7 billion years old and has over 100 billion galaxies?

      • Sean Robert Meaney October 8, 2016, 23:22

        It’ll make me happy…and isnt that what realy counts?

        • ljk October 10, 2016, 15:56

          Causing the extermination of our entire species, including all the good people who try to make the world a better place, would make you happy?

  • Asteroidenbergbauer October 3, 2016, 7:09
    • ljk October 3, 2016, 9:55

      What is this about? I do not want to download a file without knowing what is first, thank you.

  • ljk October 3, 2016, 11:05

    How a Couple of Guys Built the Most Ambitious Alien Outreach Project Ever

    You might think it takes vast governmental resources to launch an extraterrestrial communication effort. Nope

    By Michael Chorost


    September 26, 2016

    On May 24, 1999, a large radio transmitter in the city of Evpatoria in Ukraine turned its dish to the star 16 Cygni, 70 light-years away, and emitted a four-hour blast of radio waves. It was the beginning of the Cosmic Call, one of the most ambitious efforts ever made at sending a message to alien civilizations.

    It wasn’t a project run by NASA or some major government. It was a crowdsourced effort, put together by an unlikely team of Texan businessmen, Canadian astrophysicists, Russian scientists, and Eastern European radio engineers.

    Full article here:


    To quote:

    And Alexander Zaitsev, a prominent astronomer at the Russian Academy of Science, was glad to be involved. Zaitsev had used the Evpatoria transmitter for years to study Venus, Mars, Mercury, and several asteroids. But he also had a deep interest in SETI. He agreed to oversee the sending of the Cosmic Call from Ukraine. And with that, a DIY alien outreach project was born.

    Zaitsev had to exercise some diplomatic delicacy. In 1999 memories of the Cold War were still fresh, and there were tensions over how the Americans were intervening against the Serbs during the war in the former Yugoslavia. “[Evpatoria] is the middle of nowhere,” Chafer says. “It’s a base that was used to track Russian satellites that were used in submarine communications out of Sevastopol. It was a very highly sensitive military base.”

    So it was politically awkward for the Cosmic Call team visiting Evpatoria to be led by Americans. But one of Team Encounter’s employees was Romanian, and one of its guests was Danish. So Zaitsev decided that the Cosmic Call team was a Romanian and Danish delegation with two American observers. Chafer recalls, “[Zaitsev] gets the gold star for making it happen. I mean, literally everybody he was dealing with had a uniform on, and here comes this Danish Romanian delegation with two American visitors.”


    But the drawback of freelance projects like Cosmic Call is that there’s no institution to preserve a memory of them. The message hasn’t been particularly well-archived. (Sadly, Stéphane Dumas died unexpectedly in August 2016.) It would be embarrassing if we got a reply in 2069 and no one could remember what we had sent. All of the websites that had archived it have disappeared, except for an incomplete remnant preserved here by an Internet archive. The only documents that show the primers are PDFs buried on obscure websites. The 1999 primer is here, and both the 1999 and 2003 primers are explained here.

    So one of humanity’s most intellectually ambitious interstellar messages, and so far the one most likely to get where it’s going, was written by two people, Dutil and Dumas. There’s a lesson there. If we ever receive a message from another civilization, it may not be from a committee of its august wise heads (or whatever they have instead of heads.) It may not be from their equivalent of the United Nations or United Federation of Planets.

    A civilization modestly more developed than ours could be using Evpatoria-class transmitters for the local equivalent of high-school science projects. In other words, Earth’s long-awaited first message from aliens, if it ever comes, could basically be from a couple of guys.

  • DJ Kaplan October 3, 2016, 12:28

    Hawking ignores the huge benefits that normally accrue from cross-cultural contacts.

    • ljk October 3, 2016, 13:47

      Like I said, Hawking is obviously a very smart man, smarter than many, but it does not make him any more of an expert on ETI than the rest of us. He was clearly influenced by Independence Day, among other things.

      I am not saying that otherwise fictional scenario is impossible, but if the aliens’ goal was to remove humanity in order to get at Earth and its resources, then wouldn’t it make more sense to just drop a few space rocks on the major population centers and wait for the dust to settle? Humanity would not have a chance against such an attack and would be so devastated that the survivors would offer little to no resistance. No, instead the ID aliens hover over our major cities, zap them with big laser weapons, then send out fighter squadrons to be followed by ground troops with laser rifles. Not saying it wouldn’t work, just that there are more effective ways of conquering a planet – especially if you have the literal high ground already.

      The other attack scenario is to slam a starship into a planet at relativistic speeds. The kinetic energy alone would sterilize more of Earth’s surface in one literal whack.

      And then there is the Nicoll-Dyson beam weapon, where one does not even have to leave home to fry worlds across the galaxy….


      • DJ Kaplan October 5, 2016, 16:02

        No proof of aliens yet, but we still try to predict their motives, weaponry and tactics. :) We may be indeed gazing into a mirror, projecting our instincts into the as-yet unpeopled void…
        (Reminds me of a certain scene in Doctor Strangelove.)

        • ljk October 6, 2016, 9:06

          Some things just make sense from a practical/physics point of view, irregardless of the species. Yes aliens could behave in very different and unexpected ways, but just as the laws of physics and the makeup of the Universe is essentially the same wherever you look, it is not illogical to assume certain patterns and behaviors matching with certain situations.

          This applies to interstellar conquest as well. You can land troops and be engaged in a long, drawn out battle that will cause many casualties for the invaders, or you can drop a few big space rocks and resolve the situation in short order with little to no loss for the conqueror’s side.

          • Alex Tolley October 6, 2016, 11:06

            Don’t make the mistake of assuming sociology or even biology is as deterministic as physics. Evolution has developed many very different forms that occupy the same niche, and human cultures have developed very different ways with coping with their natural and artificial environments. It is one reason why biology is so phenomenological with so few “laws”. This is even more so in the humanities, as behaviors can be unpredictable.

            I would be very careful of ascribing human responses of known cultures to aliens.

            • ljk October 6, 2016, 13:21

              So we can expect Earth to be invaded by large-headed humanoid aliens in silver spacesuits toting laser rifles and wanting our water and cattle? Darn it….

              • Alex Tolley October 6, 2016, 16:16

                Quite the reverse, I would have said. Aliens are unlikely to be humanoid, and cattle might not even be digestible. Even humans won’t be using laser rifles, chemically propelled projectiles are much more effective killing devices. Those alien ships firing EM bolts are less effective than WWII aircraft at killing humans on the ground. (They also seem to have forgotten to turn on their computer targeting as they seem to miss a lot).

  • ljk October 4, 2016, 12:54