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  • richardmitnick 7:42 pm on September 1, 2014 Permalink | Reply
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    Seth Shostak of SETI Institute at his Eloquent Best. 


    SETI Institute

    Seth Shostak. ’nuff said.

    SETI Institute – 189 Bernardo Ave., Suite 100
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    Phone 650.961.6633 – Fax 650-961-7099
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  • richardmitnick 7:26 am on August 22, 2014 Permalink | Reply
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    From Seth Shostak via SPACE.com: “6 Most Likely Places for Alien Life in the Solar System” 

    space-dot-com logo

    SPACE.com

    SETI Seth Shostak
    Seth Shostak, Senior Astronomer, SETI Institute

    We still don’t have hard evidence for any life that’s not of this Earth, but across our solar system there are some tantalizing possibilities for primitive life to find a haven. Some moons of Jupiter and Saturn are intriguing, and there’s also the chance for some surprises somewhere on Mars.

    Here are my top six candidates for the best spots to search for primitive alien life in our solar system.

    FIRST STOP: Enceladus

    encl

    In 2005, NASA’s Cassini spacecraft photographed geysers of frozen water spewing from cracks in Enceladus’ southern hemisphere. Scientists think reservoirs of liquid water lie beneath the frozen surface and are warmed by gravitational interactions between Enceladus and other moons around Saturn. The necessities for life are there, and maybe Enceladans are as well. The moon has a mean radius of 156.6 miles (252.1 km).

    NASA Cassini Spacecraft
    NASA/Cassini

    NEXT STOP: Mars

    mars

    Mars remains perennially popular for those hunting for otherworldly protoplasm. Particularly intriguing are the dark stripes that appear in the Martian summertime at Horowitz crater. These are likely to be salty meltwater only inches beneath Mars’ dusty epidermis. A relatively simple probe could sample this muddy environment. Mars has a diameter of about 4,212 miles (6,779 km)

    NEXT STOP: Titan

    tit

    Titan is Saturn’s largest moon and the only world in the solar system (besides Earth) known to sport liquid lakes. These are lakes of ethane and methane — liquid natural gas — endlessly topped up by hydrocarbon rain. Despite the odd ingredients and Titan’s gelid temperatures (minus 290 Fahrenheit, or minus 179 Celsius), it is a world where chemistry’s a happening enterprise. Titan possesses diameter of 3,200 miles (5,150 km).

    NEXT STOP: Europa

    europa

    Many would grant Europa a higher potential-life rating than I have, since there’s probably more liquid water here than in all of Earth’s oceans. The downside is that Europa’s vast, salty seas lie beneath roughly 10 miles of ice. Not only is it difficult get a probe beneath this icy armor, but Europa’s oceans are darker than a cave — which means photosynthesis won’t work. However, something down there may subsist on geothermal heat or complex molecules from the surface. Europa possesses a mean radius of 970 miles (1,560.8 km).

    NEXT STOP: Venus, the Hellish Planet

    venus

    A surprise entry in the exobiology sweepstakes is our sister planet, Venus, with its scorching surface temperatures (850 F, or 454 C). The planet is generally assumed to be as sterile as a boiled mule.

    But planetary scientist David Grinspoon, astrobiology curator at the Denver Museum of Nature and Science, points out that high in the Venusian atmosphere temperatures are refreshingly tolerable. Atmospheric sulfur dioxide and carbon monoxide might serve as food for floating microbes. Venus is 7,521 miles wide (12,104 km).

    NEXT STOP: Callisto and Ganymede of Jupiter

    calisto

    I considered these two moons of Jupiter together, as I feel they’re neck-and-neck candidates for biology. Like their more celebrated neighbor Europa, Ganymede and Callisto may have buried, liquid oceans. However, in the case of these two satellite siblings, briny deeps would underlie at least 60 miles (100 km) of rock. Finding inhabitants here is a shovel-ready project for our grandkids. Callisto has a diameter of more than 2,985 miles (4,800 km); Ganymede’s diameter is 3,270 miles (5,262.4 km).

    See the full article here.


    SETI Institute

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    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099

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  • richardmitnick 11:44 am on August 20, 2014 Permalink | Reply
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    From Seth Shostak of SETI Institute via Huff Post: “Forget Space Travel: Build This Telescope” 


    SETI Institute

    SETI Seth Shostak
    Seth Shostak,Senior Astronomer, SETI Institute

    The first telescopes were toys, charming amusements. Sure, there were a few practical uses, such as observing distant ships coming into harbor. Doing so allowed merchants to hurry down to the docks ahead of their telescope-free competitors, and snag all the better goods. Military commanders occasionally found telescopes handy as well. And when they weren’t being used for commerce or conflict, these simple devices were undoubtedly helpful for checking out the personal parameters of careless neighbors.

    In 1609, Galileo turned a telescope skyward — a move that no one else seems to have considered. His instruments had lenses about the size of a half-dollar coin, and magnifications that were only about 20 times. Their simple optics had more aberrations than Vlad the Impaler.

    Today, you wouldn’t give a kid a telescope this lousy, unless you’re inspiring her to forsake science in favor of a more lucrative occupation, like starching shirts. But these low-grade constructions were good enough to see the bigger moons of Jupiter, the craters of the moon, and stars making up the Milky Way. They were, despite their pitiful specifications, arguably the most important astronomical telescopes of all time.

    Modern researchers would find Galileo’s ‘scopes useful only for batting Whiffle balls. They’ve moved on to bigger and better, and today are building some truly impressive instruments: a new generation of titanic telescopes that sport primary mirrors larger than tennis courts.

    ESO E-ELT
    ESO E-ELT

    Thirty Meter Telescope
    Thirty Meter Telescope.

    Giant Magellan Telescope
    Giant Magellan Telescope

    These will snag a million times as much light as Galileo’s instrument, which is really the motivation for their construction. But, thanks to an ability to undo a lot of the distortions caused by Earth’s shuddering atmosphere [adaptive optices, active optics], these new outsized ‘scopes will be about as hawkeyed as the famed Hubble instrument — able to see detail at a level of about 0.1 seconds of arc. That’s enough to just make out a dime a dozen miles away.

    exo
    Exoplanet

    Impressive, yes, but no one cares about examining far-off dimes. What about inspecting worlds around other stars, the so-called exoplanets that dominate a lot of astronomy news these days? Well, with these new giant telescopes, any Earth-size exoplanet would be smaller than one pixel in size. It would be a thoroughly unresolved pinpoint of light.

    Useful, but not entirely gratifying.

    I think it’s fair to say that, given your ‘druthers, you’d want an instrument that could map exoplanets in the kind of detail you get with Google Earth, with enough resolution to actually see the Great Wall of the Klingons, in case they’ve built one.

    Could we construct such a telescope … ever?

    Here’s what it takes: Let’s assume that all the alien worlds you wish to view up close and personal are no more than 100 light-years away. That might sound pretty cramped to astronomy nerds, but there are probably several hundred thousand planets within that distance – enough to gratify even the most spirited voyeur.

    At 100 light-years, something the size of a Honda Accord — which I propose as a standard imaging test object — subtends an angle of a half-trillionth of a second of arc. In case that number doesn’t speak to you, it’s roughly the apparent size of a cell nucleus on Pluto, as viewed from Earth.

    You will not be stunned to hear that resolving something that minuscule requires a telescope with a honking size. At ordinary optical wavelengths, “honking” works out to a mirror 100 million miles across. You could nicely fit a reflector that large between the orbits of Mercury and Mars. Big, yes, but it would permit you to examine exoplanets in incredible detail.

    The down side is obvious: Who could ever construct such a thing? Well, fortunately, no one has to. Instead, you could field a phalanx of small mirrors in space, spread out over 100 million miles. They wouldn’t even have to maintain a fixed pattern, as long as you could accurately keep track of their relative positions.

    No huge mirror: just a manageable number of small ones. The ability to see detail would be the same. And, of course, it’s a heck of a lot easier to turn an array of small instruments to different places on the sky than to pivot a 100 million-mile monstrosity.

    Of course, there are a few small problems of principle here. You need to collect enough light to make the imaging possible, and correct for the fact that the target exoplanet is both rotating and sliding across the sky. Both problems can be dealt with, at least in theory — which suggests that they can also be dealt with in practice, given sufficient effort.

    But think of the implications. There’s a lot of talk about interstellar travel, and whether we will ever be capable of rocketing to other stars. It’s a tough thing to do.

    However, if the type of telescope described here can be built, then the tyranny of distance is vanquished. You can forget deep space probes and their long travel times. We could explore alien worlds in the comfort of our own homes, as our laptops scroll and zoom through data sets collected by a mammoth, space-based telescope array.

    It would also, quite obviously, be a whole new way to search for extraterrestrial life … just look for it, or its artifacts (like cities).

    This is, to my mind, the ultimate telescope. It’s not for our generation to build, or even the next two. But after that …?

    See the full article here.

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
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  • richardmitnick 4:59 pm on July 31, 2014 Permalink | Reply
    Tags: Seth Shostak,   

    From Seth Shostak at SETI Institute: “Why the Aliens Want Earth” 


    SETI Institute

    July 31, 2014
    SETI Seth Shostak
    Seth Shostak, Senior Astronomer, Director of SETI Research

    Expedia’s galaxy-wide website must be offering Earth at a major discount. In one movie after another, aliens decide to pass up competing Milky Way attractions — including neutron stars, antimatter clouds, hot Jupiters, and a 4 billion-trillion-trillion-ton central black hole — in favor of our planet. The small speck of rock we inhabit is more popular with tourists than Disneyland.

    Even an abbreviated laundry list of invasion films will give you the idea: Independence Day, War of the Worlds, Superman II, Mars Attacks, The Day the Earth Stood Still, Killer Clowns from Outer Space … They all share a common premise, namely that Earth is the bee’s knees, cosmically speaking.

    But really, you’ve got to wonder what would motivate creatures from other worlds to suffer a journey of hundreds of trillions of miles to visit our planet? It’s a trip so relentlessly devoid of scenery, their spacecraft wouldn’t need windows. Why bother?

    I’ve been asked this question at least a half-dozen times by Hollywood writers, and the best answer I can muster is “I don’t know.”

    My impoverished reply is clearly disappointing, and the usual response by the filmmakers is to resort to two hackneyed incentives to rope in the aliens, namely (1) a quest for natural resources, and (2) breeding experiments.

    Frankly, and not to rain on anyone’s parade, neither makes sense.

    Consider the idea that the extraterrestrials want materials for their industrial needs. It’s nice to imagine that Earth is valuable as a mining claim, but what do we have that they don’t?

    A frequent suggestion is water. But that’s silly: The universe is awash in water, thanks to the abundance of its two atomic ingredients, hydrogen and oxygen. Like Kimye and Kanye, these two elements are everywhere. Heck, there’s more water on some of the moons of Jupiter than on Earth, and no one’s going to get ruffled if you opt to remove it. But really, you can save the tanker costs by finding water in your own solar system. There’s bound to be plenty.

    Digging up other minerals and metals is similarly unnecessary and inconvenient. The entire cosmos is made of the same elements (and more or less in the same proportions) as is our local neighborhood. You don’t need to import this stuff from light-years away.

    Maybe they just need farmland? Like Captain Bligh, perhaps aliens are hoping to find a place to grow breadfruit, or whatever the galactic equivalent might be. Again, this is the kind of incentive that might work if you don’t first need to traverse interstellar space. If you do, consider building orbiting greenhouses at home. They’ll be cheaper, and the produce will be fresher. And honestly, if Earth’s countryside is that attractive, why didn’t someone plant a flag (or Klingon breadfruit) millions or billions of years ago? It seems that terrestrial real estate is a dog on the market.

    Breeding experiments are even less plausible, even if many movie-goers feel like participating. Anyone who’s made it through tenth-grade biology will recognize that breeding with other species here on Earth — all of whom are card-carrying members of the DNA club, and therefore closely related to you — is not only difficult, it’s guaranteed to be fruitless. And possibly illegal.

    Trendy scenarists will often invoke the social concern du jour, and suggest that the extraterrestrials are here to save us from ourselves. Aside from the obvious fact that they don’t know of such contemporary problems as climate change or nuclear proliferation (our newscasts haven’t reached them yet), why would they be interested? I bet the dinosaurs would have wished for a bit of alien help in giving an asteroid a nudge 66 million years ago, but it seems the extraterrestrials couldn’t be bothered. Are we that much more deserving?

    No, the bottom line is that the only truly special things about Earth are likely to be our biota and our culture. They could learn a lot about either one by merely analyzing the spectral signature of our atmosphere or tuning in to our TV broadcasts, and they would save a king’s ransom on fuel by avoiding actual travel.

    Despite the dramas played out at the local cineplex, real aliens won’t be itching to visit. What we’ve got, they’ve already seen, and the doorbell won’t ring. We’re not on their bucket list.

    See the full article here.

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments


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