We just sent a message to try to talk to aliens on another world

Nov 16, 2017

By Dan Falk

Are you there, aliens? It’s us, Earth. Astronomers have sent a radio message to a neighbouring star system – one of the closest known to contain a potentially habitable planet – and it’s nearby enough that we could receive a reply in less than 25 years.

“I think that’s an unlikely outcome, but it would be a welcome outcome,” said Douglas Vakoch, president of Messaging Extraterrestrial Intelligence (METI) International. METI is an offshoot of the more familiar SETI – the Search for Extra-Terrestrial Intelligence.

The target star is GJ 273, also known as Luyten’s star, a red dwarf in the northern constellation of Canis Minor, just 12 light years away. In March of this year it was discovered to have two planets. One of them, known as GJ 273b, orbits within the star’s “habitable zone” and could potentially harbor liquid water, and perhaps life.

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13 comments on “We just sent a message to try to talk to aliens on another world

  • @OP- Are you there, aliens? It’s us, Earth. Astronomers have sent a radio message to a neighbouring star system.

    Actually Earth has been ablaze with radio signals for decades!

    The night side is also lit up like a Xmas tree around all built up areas!

    Astronomers are even considering putting observatory telescopes on the far side of the Moon, to screen their equipment from Earth-generated electronic interference!

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  • ET coms from advanced civilisations won’t be at conventional broadcast frequencies, <10 Gigahertz but at ten thousand Terrahertz and beyond. This clears much of the background noise and creates super directable beams. Messaging from advance civilisations will take the form of brief transmissions indexed at source through microradian angles or millions of targetted destinations with quite short transmission times and modulation data at 100s of Tb/s. Repeated.

    It may be a quite a while before we can do any of this (transmit, receive, detect/decode) at these frequencies and data rates (our X-ray lasers are crap.) I think this usefully excludes us from the club for a while.

    Who broadcasts with high powered radio these days? Fairly shortly we will have nothing above a few watts…

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  • @OP – “I think that’s an unlikely outcome, but it would be a welcome outcome,” said Douglas Vakoch, president of Messaging Extraterrestrial Intelligence (METI) International.

    I have serious misgivings about the activities of SETI enthusiasts!

    Apart from the unlikelyhood of finding intelligent life, anywhere near the Solar System, in the unlikely event that we found a very advanced civilisation who had extensive mastery of space travel, they would probably take one look at the warring, conflicting human populations, – unsustainably and ruthlessly exploiting resources on Earth – and then quarantine the planet! – or send in the pest controllers, to eliminate a destructive invasive species so as to prepare the Earth for sustainable colonisation!

    On the other hand, if the aliens were more based on the exploitative human model, and have asset-stripped their own planetary system(s) to destruction, they may turn up looking for another system to asset-strip, so as to re-provision their fleet of starships and move on!

    Neither of these scenarios, make advertising our presence a good idea!

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  • I’m not actually worried by asset strippers. All we’ve got is startdust, like them. What we may have is stuff we’ve created and if we can’t even broadcast efficiently in the quiet channels then that is unlikely.

    I strongly expect seriously advanced civilisations to be perspective taking and moral and will be interested to learn our journey to see if we might invent useful things given the meandering path and neural legacy. We don’t sneer at cetaceans gossiping behind the backs of others. Ant poetry would be gobsmacking to discover.

    I just think SETI is fatuous right now and based on a 1950’s view of alienhood.

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  • phil rimmer #4
    Nov 17, 2017 at 9:32 am

    I’m not actually worried by asset strippers.
    All we’ve got is startdust, like them.

    I’m not so sure about that! – Bearing in mind that the Milkyway is a composite of swallowed satellite galaxies!


    Systematic Variations in Age and Metallicity Along the Early-Type Galaxy Sequence

    A composite model–including variations in age and metallicity, as well as a wavelength-independent effect such as homology breaking–is presented which can fit all four observed properties.
    This model implies that the most luminous early-type galaxies contain the oldest and most metal-rich stars, while the lowest luminosity galaxies formed the bulk of their stars as recently at z_f~1.


    Metallicity of the Stars at the Galactic Center

    In contrast to the previous studies, the authors found that the 83 stars exhibited a wide range of metallicities, from a tenth of solar metallicity all the way to super-solar metallicities.

    The abundances of the low-metallicity stars they found are consistent with globular cluster metallicities, suggesting that these stars (about 6% of the sample) may have arrived in the nuclear star cluster as a result of the infall of globular clusters.
    The super-solar metallicity stars were likely formed closer to the galactic center or from the disk.

    The authors point out that current models of the star formation history and initial mass function of the nuclear stellar cluster — which typically assume a uniform population of stars with roughly solar metallicity — may need to be revisited in light of these results.

    These studies indicate that stars migrate within galaxies.

    There may be infall within spirals, or some being thrown further out by gravitational interactions at the centre, or by mergers of galaxies.

    DEFINITION:- https://en.wikipedia.org/wiki/Metallicity

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  • Good point, Alan.

    The hyper intelligent aliens might simply go to the source of their needs. Stellar spectra are the original broadcast data.

    I still think, though, their interest in us will be if we invent anything of value.

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  • Here is one of the links which was lost from my previous comments.


    The first known asteroid to visit our Solar System from interstellar space has been given a name.

    Scientists who have studied its speed and trajectory believe it originated in a planetary system around another star.

    The interstellar interloper will now be referred to as ‘Oumuamua, which means “a messenger from afar arriving first” in Hawaiian.

    The name reflects the object’s discovery by a Hawaii-based astronomer using an observatory on Maui.

    It was discovered on 19 October this year by Rob Weryk, a postdoctoral researcher at the University of Hawaii Institute for Astronomy.

    Weryk and fellow Institute for Astronomy researcher Marco Micheli realised it was going extremely fast (with enough speed to avoid being captured by the Sun’s gravitational pull) and was on a very eccentric trajectory taking it out of our Solar System.

    In a paper submitted to Astrophysical Journal Letters, they argue that its size, rotation, and reddish colour are similar to those of asteroids in our Solar System.

    Measuring about 180m by 30m, it resembles a chunky cigar.

    “The most remarkable thing about [‘Oumuamua] is that, except for its shape, how familiar and physically unremarkable it is,” said co-author Jayadev Rajagopal from the US National Optical Astronomy Observatory (NOAO).

    If planets form around other stars the same way they did in the Solar System, many objects the size of ‘Oumuamua are predicted to be slung out in the process.

    “U1 may provide the first direct evidence that planetary systems around other stars ejected objects as they formed,” said Dr Rajagopal.

    The object has also been given the more formal designation of 1I/2017 U1 by the International Astronomical Union (IAU), which is responsible for naming celestial bodies.

    The “I” in this formal name stands for “interstellar” object, similar to the “C” and “A” in the designations for comets and asteroids, respectively.

    ‘Oumuamua is the first object to carry the “I” in front of its name.

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  • As I said earlier, we should be grateful that this is an asteroid and not a planet – with all orbital disruption the greater gravity that would bring to the Solar-System!


    An asteroid that visited us from interstellar space is one of the most elongated cosmic objects known to science, a study has shown.

    Discovered on 19 October, the object’s speed and trajectory strongly suggested it originated in a planetary system around another star.

    Astronomers have been scrambling to observe the unique space rock, known as ‘Oumuamua, before it fades from view.

    Their results so far suggest it is at least 10 times longer than it is wide.

    That ratio is more extreme than that of any asteroid or comet ever observed in our Solar System.

    Using observations from the Very Large Telescope in Chile, Karen Meech, from the Institute for Astronomy in Honolulu, Hawaii, and colleagues determined that the object was at least 400m long, rapidly rotating and subject to dramatic changes in brightness.

    These changes in brightness were the clue to ‘Oumuamua’s bizarre shape.

    “Looking at the asteroid light curve database, there are five objects (out of 20,000) that have light curves that would suggest a shape up to an axis ratio of about 7-8 to 1,” Dr Meech told BBC News.

    “Our errors are very small, so we are confident this is really elongated. Also, one has to realise we don’t know where the rotation pole is pointed. We assumed that it was perpendicular to the line of sight. If it were tipped over at all, then there are projection effects and the 10:1 is a minimum. It could be more elongated!”

    “We also found that it had a reddish colour, similar to objects in the outer Solar System, and confirmed that it is completely inert, without the faintest hint of dust around it,” Dr Meech said.

    These properties suggest that ‘Oumuamua is dense, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over long periods of time.

    Although ‘Oumuamua formed around another star, scientists think it could have been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our Solar System.

    “For decades we’ve theorised that such interstellar objects are out there, and now – for the first time – we have direct evidence they exist,” said Thomas Zurbuchen, associate administrator for Nasa’s science mission directorate in Washington DC.

    “This history-making discovery is opening a new window to study formation of solar systems beyond our own.”

    If planets form around other stars the same way they did in the Solar System, many objects the size of ‘Oumuamua should get slung out into space. The interstellar visitor may provide the first evidence of that process.

    As regards how ‘Oumuamua became so elongated, Dr Meech explained: “There has been speculation among various team members about this. Sometimes very elongated objects are contact binaries… but even so, the pieces would be longer than most things in the Solar System, and our analysis shows that it is rotating fast enough that they should not stay together.

    “One of our team wondered if, during a planetary system formation, if there was a large collision between bodies that had molten cores, some material could get ejected out and then freeze in an elongated shape.

    “Another team member was wondering if there could be some process during the ejection – say if there was a nearby supernova explosion that could be responsible.”

    The cosmic interloper was discovered by Rob Weryk, a postdoctoral researcher at the Institute for Astronomy and a co-author of the new study, which is published in Nature journal.

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  • https://www.nature.com/news/exoplanet-hunters-rethink-search-for-alien-life-1.23023

    Exoplanet hunters rethink search for alien life

    Many are starting to argue that the standard definition of habitability — having liquid water on a planet’s surface — is not the factor that should guide exoplanet exploration. Instead, the scientists say, the field should focus on the chances of detecting alien life, should it exist.

    I think liquid water somewhere on the planet remains a key issue! The concept of self replicating molecules without a suitable working solvent, is a non-starter!

    “Planets can be habitable and not have life with any impact,” Desch told researchers at the meeting.

    That is certainly true. Any chemistry extracting energy to power life will build up residues over time.

    It turns out that water worlds may be some of the worst places to look for living things.

    I am highly sceptical of such claims. The average depth of water or the average concentration of minerals is irrelevant to abiogenesis. The LOCAL conditions are what is important!

    One study presented at the meeting shows how a planet covered in oceans could be starved of phosphorus, a nutrient without which earthly life cannot thrive.

    I think this is a blinkered view, based on Earth’s rain-based water cycle, to the exclusion of consideration to other mechanisms. It also assumes that extra-terrestrial oceans would be salty enough to inhibit the solution of phosphates! (see the @ arstechnica link on moons at the end of this comment!)


    @ pnas. link – The magnitude of this heat loss requires that the entire volume of the oceans circulates through the midocean ridges in approximately 10 million years. Seawater interaction with volcanic rocks at near 400°C results in substantial chemical flux and makes an important contribution to buffering the composition of some elements in seawater. Cations from seawater (Mg+2, Ca+2, and Na+) form hydroxyl-bearing alteration minerals in the volcanic rocks, releasing hydrogen ion to solution. The hot, acidic altered-seawater releases metals (Fe, Mn, Zn, and Cu) and reduced sulfur (H2S) from the volcanic rock; these are transported by hydrothermal solutions to the seafloor and form metallic mineral deposits.

    Seafloor hydrothermal vents support ecosystems with enormous biomass and productivity compared with that observed elsewhere in the deep oceans. What is the energy source that fuels these oases of life, and what adaptations allow them to exist in these extreme environments?

    Oxidation/reduction (redox) reactions are key to supporting chemosynthesis. The atmosphere and hydrosphere are relatively oxidizing with an abundance of potential electron acceptors (O2, SO4=, and NO3-). In contrast, the basaltic rocks that form the oceanic crust are relatively reduced because of the abundance of ferrous iron. High-temperature fluid/rock interaction forms reduced gases (H2S, H2, and CH4) that dissolve in hydrothermal fluid.

    @ Exoplanet hunters rethink link – On Earth, rainwater hitting rocks washes phosphorus and other nutrients into the oceans. But without any exposed land, there is no way for phosphorus to enrich water on an aqua planet over time, Fisher reported at the Laramie meeting.

    This fails to take into account the high temperatures, pressures and chemical reactions involved at hydrothermal vents.
    It also assumes salty oceans on exoplanets inhibiting solution of phosphates, when it is the rainwater cycle running over exposed land, which produces the salty oceans on Earth which inhibit the solution of phosphates.

    @ pnas. link -Classification of the hyperthermophiles has provided new insights into evolution and the origin of life. All but two of the hyperthermophilic genera are classified by ribosomal RNA analyses as Archaea (formerly Archaebacteria), which are the second domain of prokaryotic life, in addition to the bacteria (7). Interestingly, by these phylogenetic analyses, the hyperthermophilic archaea and the two hyperthermophilic bacteria are the most slowly evolving within their domains, suggesting that life may have first evolved when the Earth was much hotter than it is now. Such a thesis is very controversial (8) but indicates that extant life forms are largely the result of temperature adaptations to lower (below hyperthermophilic) temperatures.

    Evolution gives no clue, however, as to how life can thrive near and above 100°C. Most microbes, and all eukaryotic cells, cannot survive at temperatures much above 50°C, because of the general instability of biological molecules. The three-dimensional structures of most enzymes and proteins are lost at temperatures much above 70°C, and the double-helical structure of DNA has a comparable lack of stability in in vitro studies. There are also a wide variety of ubiquitous metabolites that are rapidly hydrolyzed at temperatures above 90°C. How do hyperthermophilic cells circumvent these problems?

    Although there are some examples of modified pathways and unusual enzymes in hyperthermophiles (9, 10), in general their biochemistry closely resembles that of the mesophilic world. Yet, most enzymes from hyperthermophiles are extremely stable at high temperatures, showing optimal catalytic activity above 100°C with virtually no activity at ambient temperature.

    They contain exactly the same 20 amino acids as enzymes from conventional organisms, so why are they so stable?

    The following quote from the “planet hunters”, shows a pre-occupation with seeking analogies with present-day conditions on Earth, and little regard for the above quoted conditions likely to bring about abiogenesis and life, around hydrothermal vents!

    @ Exoplanet hunters rethink link – There would be no ocean organisms, such as plankton, to build up oxygen in the planet’s atmosphere, she says — making this type of world a terrible place to find life.

    Deep sea organisms using chemosynthesis at hydrothermal vents, don’t need sunlight in surface waters, or photosynthesis, and they don’t produce oxygen!

    Other work concludes that a planet swamped in even deeper water would be geologically dead, lacking any of the planetary processes that nurture life on Earth.

    This would depend on initial energy of planetary formation, and any internal heat generated by friction from tidal forces – arising from spin, or a non-circular orbit. (As in the case of moons of Jupiter and Saturn.)

    The Earth-Moon system is a very rare planetary formation which confers very long-term stabilities in comparison to other planets with small moons or no moons.


    @ arstechnica link – And that something is almost certainly a salty ocean of liquid water. The charged particles in this ocean could respond to Jupiter’s magnetic field and produce an opposing force, limiting its effect on the aurora. While models of the moon suggest that the oceans can’t be that close to the surface, the new results indicate the ocean has to be less than 330 km deep. The thickness of the ocean isn’t clear; it could either be broad and not very salty or thinner with levels of dissolved minerals.

    @ arstechnica link -Combined with the recent results from Enceladus, these latest findings show that, in the words of Heidi Hammel of the Association of Universities for Research in Astronomy, “we live in a wet solar system.” Earth and Mars clearly have water, as do at least two of Jupiter’s moons and two of Saturn’s. Voyager also found evidence of cryovolcanism on Neptune’s moon Triton.

    Clearly liquid water is an issue, but pockets of it, or oceans, do not need to be on a planet’s or moon’s surface, if chemosynthesis is involved!

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  • Further to #10

    Alan4discussion #10
    Nov 23, 2017 at 7:52 am

    Exoplanet hunters rethink search for alien life

    Many are starting to argue that the standard definition of habitability — having liquid water on a planet’s surface — is not the factor that should guide exoplanet exploration. Instead, the scientists say, the field should focus on the chances of detecting alien life, should it exist.

    There are two VERY different specification issues involved here!

    One is the chemistry, temperature range, and planetary stability over a very long geological time scale, to enable the evolution of alien life.

    The other is the relatively short geological time, where a planet or moon, has stability, resources, energy inputs, and a climate and temperature range, conducive to supporting safe human colonisation or bases!

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  • https://hydrothermalventszcrenshaw.weebly.com/black–white-smokers.html

    Black Smokers vs. White Smokers

    There are two main types of hydrothermal vents.
    “Black smokers” are another name for the most common type.
    They are named for the black colored water that comes out of them, like the picture on the left.
    The different colors are due to different minerals being dissolved in the water.
    The black “smoke” is caused the presence of iron and sulfur, which combine to become iron monosulfide, which has a black color.
    When the iron monosulfide solidifies, it created the black chimneys.

    “White smokers” are the cooler cousins of black smokers.
    These vents release cooler water then “black smokers”.
    These vents contain more barium, calcium and sillicon.
    These elements also have a white color, causing the white “smoke”, as seen on the right.
    White smokers also create white chimneys, which are usually smaller.

    Although both “black smokers” and “white smokers” are different colors and have different elements, they both are breeding grounds for a unique ecosystem that can be found nowhere else on Earth.

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  • @ Exoplanet hunters rethink link
    There would be no ocean organisms, such as plankton,
    to build up oxygen in the planet’s atmosphere, she says —
    making this type of world a terrible place to find life.

    Not if the information below is correct! – or the geological record of the Earth’s early atmosphere is correct!
    Life evolved on Earth, long before photosynthetic organisms produced an oxygen rich atmosphere!


    Deep sea vents are home to a host of curious creatures including a crab fondly known as ‘The Hoff’, which farms bacteria on its hairy body, and the tube worm Riftia, which are found in thickets at the base of hydrothermal vents.
    These worms thrive here because they have bacteria working with them to produce sugars and other substances needed for growth, but how do they do this so far from the sun?
    After all, there’s no light for photosynthesis this far under the ocean, as it only penetrates through the first few hundred metres.

    Instead, the bacteria use hydrogen sulphide to produce their sugars. Organisms that do this are known as chemoautotrophs.
    What light is to plants, hydrogen sulphide is to chemoautotrophs, giving them a way to take carbon from their surroundings and turn it into something useful.
    By combining oxygen in the water with hydrogen sulphide from the vent (oxidising it) the bacteria produce energy, sulphur and water.
    This energy can be used to create sugars for growth, making them the primary producers of the deep ocean.
    It’s these same bacteria that ‘The Hoff’ scrapes off his hairy body for dinner!

    Because they can withstand the high temperatures at hydrothermal vents, the bacteria found there are known as hyperthermophiles, which roughly translates as ‘extreme heat loving organism’.
    It’s thought that life originated in an environment similar to that at hydrothermal vents (although there are many hypotheses for how life originated) as 3.8 billion years ago, the oceans would have been much hotter than they are today.
    They may even have approached 100 °C after major asteroid impacts! In such an environment, early life would have been hyperthermophilic too.

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