Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Friday, April 15, 2016

Starshot, SETI, and the Universe

We may be within a generation of sending probes on flyby missions to other stars, high-energy jets from several distant galaxies all point in the same direction, and we're learning more about hot super-earths.

That sort of thing fascinates me, your experience may vary.

Meanwhile, SETI researchers will be checking out red dwarfs: which may be more promising places to look for neighbors than we thought.
  1. Breakthrough Initiatives' Starshot Project: Sailing to the Stars
  2. That's Odd: Aligned Galaxy Jets
  3. Too Hot for Air
  4. Still Searching for Neighbors

"...Only Two Possibilities...."



"Thar's only two possibilities: Thar is life out there in the universe which is smarter than we are, or we're the most intelligent life in the universe. Either way, it's a mighty sobering thought."
(Porky Pine, in Walt Kelly's Pogo; via Wikiquote)
I've quoted Kelly's Porky Pine before. It's among the more clear-headed things I've seen written about the possibility that we may have neighbors in this universe. (July 26, 2015; November 7, 2014)

In my considered opinion, there's life elsewhere in the universe: or not. I'd be astounded if there isn't, but right now we don't know.

As I've said before, 'is there life in the universe' isn't quite a new question.

Back in the 13th century, some European scholars had insisted that Earth had to be the only world like ours: because Aristotle said so. That's when the Church stepped in: reminding folks that God's God, and Aristotle's not. (July 31, 2015; June 27, 2014; February 23, 2014)

As it turns out, there are more worlds: some orbiting our star, plus a growing list of planets around other stars.

Aristotle has had a profound influence on Western thought, but he was wrong about our standing on the only world. I've mentioned Anaximander before: but not Democritus. They both thought there could be, and probably were, many worlds. (August 7, 2015)

As it turns out, they were right.

A recent news item involved SETI: Search for Extraterrestrial Intelligence. Maybe you've read why God's decisions don't upset or offend me.

If you have, feel free to skip down to Breakthrough Initiatives' Starshot Project: Sailing to the Stars, which doesn't involve SETI; Still Searching for Neighbors, which does; go for a walk; take a coffee break; whatever.

Order, Beauty, and Opportunities


Still with me? Thanks!

Briefly —

I think that the universe operates according to logical, knowable, physical laws. As a Catholic, I must believe that. (Catechism of the Catholic Church, 299)

I must also believe that this universe is a place of order and beauty, and can learn something about God by studying God's creation: and that studying the universe is okay. We can, using reason, see God's work in the universe. (Catechism, 32, 35-36, 301, 303-306, 311, 1704)

We're told that scientific discoveries are opportunities for greater admiration of God's greatness. (Catechism, 283)

I certainly don't have a problem with that.

1. Breakthrough Initiatives' Starshot Project: Sailing to the Stars



(From Christian Darkin/Science Photo Library, via BBC News, used w/o permission.)
("This generic artist's concept shows how a solar sail might work"
(BBC News))
"Hawking backs interstellar travel project"
Pallab Ghosh, BBC News (April 12, 2016)

"Stephen Hawking is backing a project to send tiny spacecraft to another star system within a generation.

"They would travel trillions of miles; far further than any previous craft.

"A $100m (£70m) research programme to develop the computer chip-sized 'starships' was launched by the billionaire Yuri Milner, supported by Facebook founder Mark Zuckerberg.

"Interstellar travel has long been a dream for many, but significant technological hurdles remain.

"But Prof Hawking told BBC News that fantasy could be realised sooner than we might think.

" 'If we are to survive as a species we must ultimately spread out to the stars,' he said...."
I'm not sure what Hawking meant by "if we are to survive as a species...." He might have meant that we'd die if we don't travel to the stars: or that we'll certainly reach the stars if we survive. Either way, I think he's (almost) right.

In the first case, if we stop trying to find out what's 'out there,' we'll have lost something very basic in our nature. I'll get back to that, later in this post.

In the second case, if we somehow manage to become extinct before reaching the stars — I really do not think that will happen. That's not blind optimism, and I've talked about that before. (December 24, 2015; October 25, 2015)

My attitude about Hawking's statements may be the sort of thing that happens when remarks by a theoretical physicist and cosmologist get nitpicked by a writer and artist. I talked about Hawking's support of a SETI project last year. (July 24, 2015)

Breakthrough Initiative's Starshot is "...aiming to demonstrate proof of concept for light-propelled nanocrafts. These could fly at 20 percent of light speed and capture images of possible planets and other scientific data in our nearest star system, Alpha Centauri, just over 20 years after their launch...." (News, Breakthrough Initiatives)

Starshot: This Just Might Work


Their version of Robert L. Forward's fictional beam-powered propulsion is a bit beyond today's tech: but not by much.

I talked about more-than-a-bit-beyond-today's tech like beamed-core antimatter rocket engine and Forward's gigawatt laser array, week before last. (March 25, 2016)

Current 'light sail' technology, like NanoSail-D — that's a picture of it, unfurled in an Earthside laboratory — might have to be tweaked, but it's been flight-tested.

We may — eventually — build ships with thousand-kilometer-wide sails, pushed by light from massive laser banks, focused through 10-kilometer-wide lenses, as described in Forward's Rocheworld.

Or someone may have worked the bugs out of Alcubierre warp field1 generators by then: leaving the construction of light-sail ships to hobbyists of a later era.

Or we may discover that there's something fundamentally wrong with the math of both approaches: and find another way to travel between stars.

What jumps out at me from Breakthrough Initiatives' Starshot is their proposal of an Earth-based laser array using adaptive optics to focus the beam for comparatively rapid acceleration while the tiny ships are still relatively nearby.

That would eliminate the need to keep a beam focused over 'astronomical' distances.

I'm pretty sure at least some of the small probes would still be working after their three-decade trip to Alpha Centauri.

Voyager 1 and Voyager 2, launched in 1977, are still sending back data: 39 years into their missions.

Just how the Starshot probes would transmit signals back to Earth is — a good question. One approach, I suppose, would be to design them along the lines of Rubenstein's kilobots, so they could assemble themselves into a high-gain antenna when they arrived. (August 22, 2014)

Make that before they arrive. Starshot would be a flyby mission: zipping through the Alpha Centauri system at about 20% speed of light. That's fast enough to make the trip from Earth to our sun in a skosh under 42 minutes.

My guess is that the first interstellar mission, whatever propulsion tech we use, will be a flyby. That's what we've done before, sending probes to other planets. (November 13, 2015: October 30, 2015)

I'm also quite sure that we'll want probes that can slow down and take a look around after they arrive.

Background:

2. That's Odd: Aligned Galaxy Jets



(From Prof Russ Taylor, via Royal Astronomical Society, used w/o permission.)
("An image of the deep radio map covering the ELAIS-N1 region, with aligned galaxy jets. The image on the left has white circles around the aligned galaxies; the image on the right is without the circles."
(Royal Astronomical Society))
"Astronomers in South Africa discover mysterious alignment of black holes"
News & Press, Royal Astronomical Society (April 12, 2016)

"Deep radio imaging by researchers in the University of Cape Town and University of the Western Cape, in South Africa, has revealed that supermassive black holes in a region of the distant universe are all spinning out radio jets in the same direction – most likely a result of primordial mass fluctuations in the early universe. The astronomers publish their results in a new paper in Monthly Notices of the Royal Astronomical Society.

"The new result is the discovery – for the first time – of an alignment of the jets of galaxies over a large volume of space, a finding made possible by a three-year deep radio imaging survey of the radio waves coming from a region called ELAIS-N1 using the Giant Metrewave Radio Telescope (GMRT) in India.

"The jets are produced by the supermassive black holes at the centres of these galaxies, and the only way for this alignment to exist is if supermassive black holes are all spinning in the same direction, says Prof Andrew Russ Taylor, joint UWC/UCT SKA Chair, Director of the recently-launched Inter-University Institute for Data Intensive Astronomy, and principal author of the Monthly Notices study.

" 'Since these black holes don't know about each other, or have any way of exchanging information or influencing each other directly over such vast scales, this spin alignment must have occurred during the formation of the galaxies in the early universe,' he notes.

"This implies that there is a coherent spin in the structure of this volume of space that was formed from the primordial mass fluctuations that seeded the creation of the large-scale structure of the universe...."
We've been learning quite a bit about the "large-scale structure of the universe" lately.

The more up-to-date textbooks mentioned "island universes" when I was in high school. These days they're called galaxies, astronomers have been mapping galactic clusters and superclusters, which form walls and filaments of superclusters.

The universe we're in is huge and almost unimaginably ancient: which gives some folks conniptions. I don't mind a bit, and that's another topic. (September 26, 2014; July 15, 2014)

We've been studying 'light' — microwave frequencies, actually — from the edge of the observable universe, some 46,000,000,000 light years away 'now.' (June 14, 2015)

Those light quanta have been heading our way since this universe cooled down enough to be transparent, some 380,000 years after the Big Bang.

The Big Bang was only 13,798,000,000 years ago, give or take 37,000,000. Light — radiation of any sort that we know of — travels at the speed of light. But the edge of the observable universe is about 46,000,000,000 light years away because this universe is still expanding.

Oddly enough, that expansion is speeding up, and that's yet another topic. (April 17, 2015)

That gets me back to what the Inter-University Institute for Data Intensive Astronomy's Taylor said about "...primordial mass fluctuations that seeded the creation of the large-scale structure of the universe...."

Sort of.

Black Holes and the Universe


We've been learning that big galaxies generally have really big black holes in the middle. Stuff falling toward those black holes forms an accretion disk, sort of a scaled-up version of what forms around new(ish) stars. (November 14, 2014)

That accretion disk spins — like pretty much everything else in this universe, it's a physics thing. Stuff in some accretion disks spins really fast: close to the speed of light.

When that happens, jets of stuff shoot out, parallel to the disk's spin axis. Scientists are still figuring out exactly how that works.

Pierre-Simon Laplace figured that the escape velocity for very massive stars might be greater than the speed of light, John Michell wrote about "dark stars" in 1783.

Karl Schwarzschild worked out the math for what we call the Schwarzschild radius in 1915, David Finkelstein and Charles W. Misner noticed a topological defect in the gravitational metric — that was in 1958.

Don't bother trying to remember all that: there will not be a test on this, not being a teacher any more has advantages, and that's yet again another topic.

Where was I? Primordial mass fluctuations, folks with names like Schwarzschild and Finkelstein, Quantum mechanics. Right.

I've talked about quantum gears and philosophy before: briefly. (September 26, 2014)

The point is that stuff that became those galaxies used to be a lot closer than it is now. That's (probably) why their supermassive black holes spin on pretty much the same axis.

More than you probably need to know about:

3. Too Hot for Air



(From Peter Devine, via BBC News, used w/o permission.)
"Planets stripped bare by host stars"
BBC News (April 11, 2016)

"Astronomers have confirmed the existence of planets that have had their atmospheres stripped away by their host stars.

"Planets with atmospheres that orbit too close to their host stars are bombarded by a torrent of high-energy radiation.

"The gaseous outer layers of these worlds are then stripped away, according to the international team of scientists.

"Their work appears in the journal Nature Communications...."
What's "hot" and what's not depends on context. A pop tune may be "hot," metaphorically speaking, a summer day here in Minnesota can be "hot," literally, compared to our winter weather; and we've been finding quite a few metaphorically and literally "hot" exoplanets.

I've talked about 55 Cancri e and HAT-P-11b before. (February 19, 2016; October 3, 2014)

Scientists had good reason to think that at least some planets orbiting very close to their stars might be more massive than Earth, but with no atmosphere.

Now it looks like at least some of those theories are a pretty good match with reality. That will help us understand how planets and stars form and develop.

None of which will give me brighter, whiter teeth; help me find an exciting, rewarding, career; or win the lottery. But I'm human, and I've been over that before: often. (March 18, 2016; March 3, 2016)

More:

4. Still Searching for Neighbors



(From Seth Shostak, SETI Institute; via Space.com, used w/o permission.)
("The SETI Institute's Allen Telescope Array in Hat Creek, California is now searching 20,000 red dwarf stars for signs of intelligent life."
(Space.com))
"SETI's New Alien Life Hunt Targets 20,000 Small, Dim Stars"
Mike Wall,Space.com (March 31, 2016)

"The search for intelligent aliens has expanded to include thousands of star systems very different from that of Earth.

"Scientists with the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California have just begun a two-year hunt for signs of alien civilizations around 20,000 red dwarfs — stars considerably smaller and dimmer than Earth's sun.

"Red dwarfs are promising targets for SETI scientists. They are the most common stars in the Milky Way, making up about 75 percent of the galaxy's stellar population. And because red dwarfs burn through their fuel slowly, they live a long time; on average, the Milky Way's red dwarfs are billions of years older than the sun, researchers said...."
The Space.com article included an informal, highly-unscientific poll: asking "Do you believe alien life exists elsewhere in the universe?" I was the 55,742th respondent. The results weren't terribly surprising:
  • Yes - We may not have found them yet, but they're out there.
    64% (35902 votes)
  • No - Aliens are just part of science fiction.
    20% (11277 votes)
  • I'm not sure
    15% (8563 votes)
I was in the 15% minority.

"Belief in Extraterrestrial Life:" Certainty, Uncertainty, and Religious Affiliation



(From Survata, used w/o permission.)

My guess is that a Survata poll of Americans, done in 2013 or thereabouts, is a tad more accurate. In that one, roughly a third of American Christians, Jews, Muslims, Hindus, and atheists/agnostics weren't sure about whether we have neighbors.

Interestingly, over half of "other" 'believe in the existence of extraterrestrial life.' That may help explain why some American Christians are adamant that life mustn't exist anywhere except Earth.

Like I said, I'm not sure. We either have neighbors, or we don't. Right now, we don't know, and I'm okay with that.

I hope we do have neighbors. For one thing, it would make this universe seem a bit less empty.

For another, comparing notes with folks who aren't human would be an opportunity to learn how much of 'human nature' comes from being critters with free will and bodies; and how much is strictly "human."

My guess is that we'd learn that a great many of our neighbors are fine folks: but not "human." At all. Which is why I think nearly every SETI effort makes unwarranted assumptions.

Tesla, Pulsars, and "Wow!"


SETI is part of the SETI Institute's name. (www.seti.org)

It's also a generic term, the Search for extraterrestrial intelligence's acronym. Like ancient Romans, Americans use a lot of acronyms, and that's still another topic.

I'll be talking about SETI in general. Current efforts arguably began in 1896, when Nikola Tesla said that he should be able to communicate with Martians with his wireless electrical transmission system.

He thought he had detected Martian signals in 1899, at his Colorado Springs experimental station.

I gather that Tesla's oddly-regular static might have come from Marconi's European radio experiments, static from Jupiter's plasma torus, or something else that wasn't Martians.

Or maybe someone was trying to get a distress call to the nearest rescue station — using badly-damaged equipment.

If that's the case, which I think is extremely unlikely, we'll eventually find them; or the equivalent of a SAR ship is on its way — or was here, and left.

We've had SETI false positives since then, including PSR B1919+21 (1967) and the 1977 "Wow! signal."

I gather that Susan Jocelyn Bell, a graduate student at the time, and Antony Hewish, her thesis supervisor, wanted a reason to not identify the thing as an artificial beacon. They were both professional scientists, and had careers to think of.
"...At this point, Burnell notes of herself and Hewish that 'we did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission. It is an interesting problem—if one thinks one may have detected life elsewhere in the universe, how does one announce the results responsibly?'..."
(Pulsar, Discovery, Wikipedia)
Later, after more rapidly-pulsing radiation sources showed up in other parts of the sky, they started looking more like a previously-unknown natural phenomenon.

Or maybe a network of navigation beacons. Each one pulsed at a slightly different rate: and much, much faster than a star should be able to.

Eventually we caught one slowing down, and decided that highly magnetized rotating neutron stars were the best explanation for observed data.

I'd love to think that there's a vast civilization using pulsars as a sort of galactic GPS system: but I figure the scientists are right.

The Universe, Life, and Us


Recent (1950-to-current) SETI efforts have tried detecting artificial radio signals from promising sections of the sky, from specific nearby sun-like stars, and now we're trying pretty much the same thing for red dwarf stars.

I don't think the efforts were a waste of time and effort. Folks collected a great deal of data, which should help us understand this universe.

But I'm pretty sure that there's nobody like us within several dozen light years. Whether or not we've got next-door neighbors: is another matter.

Like I've said before, SETI generally makes some whacking great assumptions. (July 24, 2015)

We use modulated radio signals for long-distance communication. We could use off-the-shelf tech to chat with folks on planets circling nearby stars: if they're there, and if they use radio, too. Maybe they do. Then again, maybe not.

Let's assume that there's a planet almost exactly like Earth orbiting Alpha Centauri A, a star that's almost exactly like ours. Almost:
  • Mass 1.100 M☉
  • Radius 1.227 R☉
  • Luminosity 1.519 L☉
    (Source: Wikipedia)
Let's also assume that the Alpha Centauri system is exactly the same age as the Solar System, about 4,540,000,000 years; and that life started on that hypothetical planet when life started here. That's a lot of assumptions.

Two more: let's assume that people (that's one) living on that Earth-analog are almost exactly as 'old' as we are (that's the other).

In other words, that they got started within 1/1000th of their world's age as we did. That's 4,540,000,000 times 0.001 = 4,540,000 years. That's a long time.

Instead, let's assume that they're 1/4,540th Earth's age old: that's 1,000,000 years.

A million years back, we were making almond-shaped stone hand axes.

If that's where our neighbors are at, they probably won't build their first radio for another 999,881 years. (June 19, 2015)

If they started 1/4,540th Earth's age before we did, they were probably using radios when we worked the bugs out of those hand axes: and are currently using whatever we'll invent a million years from now.  (June 19, 2015)

My guess is that talking drums, slit gongs, and the Inmarsat network are the not the ultimate communication technologies. (July 24, 2015)

I also suspect that people aren't necessarily as incurably chatty as we are. (January 15, 2016; July 24, 2015; June 27, 2014)

Maybe we have neighbors who have more in common, psychologically, with cats than chimps. That would go a long way toward explaining why we haven't heard anything so far. (August 2, 2015)

Cats don't have pack or herd behavior. They're smart, and social in their own way: but cats don't "act collectively without centralized direction." (Wikipedia)

This doesn't mean we should give up on looking for neighbors. I think, however, that SETI projects would be well-advised to stop looking for signals from the stars, and start looking for indirect evidence that people are at work.

That'd be something fairly small, and not acting like a natural phenomenon: an infrared source in what looks like empty space, unusual concentrations of one heavy element or molecule, and that gets me back to pulsars. (September 26, 2014)

That's assuming that people always develop and use technology on an increasingly-large scale. Maybe we haven't detected our neighbors because they're all quietly contemplating the suchness of sibilance, itemize the enigmatic, or watching the local equivalent of grass grow.

Reassuringly "Human" — and Otherwise?


Then there's physical appearance. If — and that's a big "if" — we have neighbors, we may learn that that folks who look like Mr. Chuckles there are the most reassuringly 'human' of the lot.

Whatever they look like, and however they think, if we do have neighbors — I'm pretty sure that some folks will be upset, others won't care much one way or the other, and at least one religious order — Jesuits, most likely, or their analog in the nth century — will get to work learning their language.

And that's — you guessed it — another topic. (August 2, 2015; July 18, 2014; June 27, 2014)

Had enough? If not, here's more:
1 I've talked about the Alcubierre metric before. From what I've read, some scientists and mathematicians still say an 'Alcubierre drive' shouldn't work. They could be right.

But I think it's significant that objections to building ships whose engines use the Alubierrie metric have shifted from 'it's impossible' to 'it's impractical' and 'it's dangerous.' About the latter: I'm pretty sure they're right. Any technology, from fire to sewing machines, is dangerous if we're not careful. The trick is being careful.

More of my take on fire and other dangerous technology:
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Friday, January 15, 2016

SETI: Looking for Neighbors

Some scientist think globular clusters aren't good places to look for neighbors.

Others took a fresh look at the data, crunched numbers, and pointed out that parts of globular clusters might be better spots for interstellar civilizations than the boonies where we live.

Meanwhile, someone with a lot more money than I'll ever see decided to spend some of it on a systematic search for extraterrestrial intelligence.
  1. Globular Clusters and SETI
  2. SETI, Breakthrough, and Assumptions

Flying Chicken Incubators, Invaders, and All That


I read speculative fiction back when it was called fantasy and science fiction, watched The Invaders, and enjoyed Star Trek when it was new. (September 4, 2015; September 7, 2014)

But — do I "believe in" space aliens?

No, not in the Close Encounters of the Third Kind sense.

My guess is that most folks say "UFO" these days, when talking about visits with space aliens.

The term "flying saucer" goes back to around 1947, when Kenneth Arnold said he saw nine UFOs flying near Mount Rainier.

Seeing flying saucers, having conversations with or being abducted by, aliens — interstellar pregnancy test optional — was all the rage for the next decade or so.1

Small wonder that I run into folks who dismiss the notion of extraterrestrial intelligence as nonsense: if they're feeling charitable.

Do I "believe" we're alone in the universe?

That depends on what you mean by "alone:" and "universe," for that matter.

SETI



(From SETI@Home BOINC Client software, via Wikimedia Commons, used w/o permission.)
(Screen shot of SETI@Home screensaver.)

Depending on context, SETI means Search for Extraterrestrial Intelligence; SETI Institute, an astronomical research organization; or SETI@home, software using the BOINC platform.

Seti, or Sethi, or Sethos, if you like ancient Greek, was a not-uncommon name a few millennia back. I hardly ever hear folks talking about Seti the Viceroy of Kush; commander Seti, grandfather of Seti I; Seti II; or Seti-Merenptah; now, though: and that's another topic.

Where was I? Alien abductions, old television series, public figures of Egypt's 19th dynasty. Right.

I was running SETI@home on my desktop computer, some years back. The software's demands on my system resources were minimal, and I liked the idea of helping folks search through digital haystacks in search of a needle that might not be there.

SETI@home apparently didn't find space aliens, but did identify a few spots in Earth's sky with mildly anomalous electromagnetic activity. My guess is that they're natural phenomena, not neighbors: but we'll learn something by reviewing the data and making new observations.

Maybe. It's also possible that SETI@home's data and analysis will get lost or ignored. I hope not: that was a lot of data.

Although I recognize that some organizations use SETI as part of their outfit's name, I use the term generically, meaning humanity's recent search for neighbors.

I've known a few folks who apparently really "believed in" space aliens of the 'take me to your leader' or 'we have come to lead mankind to a groovier tomorrow' variety.

I've known others who share my belief — that the universe is real, follows knowable laws, and that we may or may not share it with other creatures like us. Well, more-or-less like us.

About the universe operating according to logical, knowable, physical laws: as a Catholic, I must believe that. (Catechism of the Catholic Church, 299)

Ignoring God's wonder-filled creation is most emphatically not part of my faith. (November 6, 2015; March 29, 2015)

Alone: Or Not


I am firmly convinced that in all the vast expanse of this universe, through all the billions of years which have elapsed since it began, and until it finally ends — humanity is alone, that nobody else lives and looks at the stars, and wonders if they are alone.

Or we have neighbors.

Right now, we don't know.

Either way, I figure it's up to God whether or not we have company.

As far as I know, the Catholic Church hasn't made an official statement on this particular topic. That's hardly surprising, since we've got very little data to work with.

Besides, the general principle was addressed back in 1277, when some Aristotle fanboys said that there couldn't be any other worlds — because Aristotle said so.

Some of the 219 Propositions of 1277 have since been rescinded, but not the basic principle of 27/219: God's God, Aristotle's not. (October 23, 2015; May 8, 2015)

Getting back to those earnest folks who look to the stars in hopes that space-alien emissaries of niceness will come to solve all our problems — I think, and hope, that they're sincere. I'm also quite sure that they're wrong.

I implied earlier that I'd talk about what I mean by "alone" and "universe," and this looks like a good spot to blather on about my take on what's real and what's not.

Ladders, Angels, and (Maybe) a Multiverse


I've talked about the Scala Natura, Ladder of Nature/Creation, before. (August 2, 2015)

We've learned a bit in the two dozen centuries since Plato and Aristotle studied the nature of reality.

When the 45th century rolls by, I'm quite sure we'll have filled in some of the gaps in today's knowledge, discovered new vistas that we hadn't known about before, and that's yet another topic.

Skipping past Plato's forms, Aristotle's taxonomy, and Medieval Neoplatonism — we're learning that living creatures don't divide neatly into "plants" and "animals," for example — I think the the scala naturae, or ladder of nature, is still an adequate illustration of some very basic ideas.

Humans are living creatures with a material body: the sort we call animals. But we're not just animals. We can reason and have free will. We can decide what we do or do not do. (Genesis 1:27; Catechism, 1951, 1700-1706, 1730)

It's being rational creatures that makes us "in the image of God." (Catechism, 1730)

We may or may not learn that we share this universe with other self-willed creatures with material bodies of some sort.

On the other hand, we've known about the folks without bodies for a very long time.

Angels, like us, are intelligent and have/had free will; but they don't have bodies. They're pure spirit, not material at all. (Catechism, 328-330)

Some angels work for God, others decided to do their own thing, that lot is not safe to be around, and that's yet again another topic. Topics. (Catechism, 391-395, 409, 414, 2851-2852)

When I write about neighbors in the universe, I'm talking about folks who are self-willed creatures with a physical form.

Some of what we're learning about quantum mechanics make more sense if we assume that we're not in the only space-time continuum, and that's still another topic. (September 26, 2014)

Assumptions


Efforts at finding or contacting extraterrestrial intelligence make an assumption which I think is dubious, at best: that our non-human neighbors are pretty much just like us.

If non-human people live on another world, my guess is that they're not human: at all.

That, I think, would be a more sensible explanation than the conventionally pessimistic response to the Fermi paradox: that civilizations go into self-destruct mode as soon as they develop the sort of tech we did about fifty years ago.

I don't see why every intelligent species must be as irrepressibly chatty as we are. Then there's the assumption that everyone, everywhere, uses modulated electromagnetic signals for long-distance communication.

I've discussed Oldowan tools, slit gongs, Klemperer rosettes, and H. P. Lovecraft, before. (July 24, 2015; June 27, 2014)

1. Globular Clusters and SETI



(From Science Photo Library, via BBC News, used w/o permission.)
("Plenty of neighbours: Might clusters like this be the place to search for alien civilisations?"
(BBC News))
"Star clumps harbour 'sweet spot' in search for alien life"
Jonathan Webb, BBC News (January 7, 2016)

"Ancient, tightly packed clumps of stars found at the fringe of the Milky Way are a good bet in the search for extra terrestrial intelligence (Seti), research suggests.

"Because of their abundance of stars, these 'globular clusters' were an early favourite in the Seti field.

"But recent efforts to scour the sky for planets orbiting alien stars have had little success within star clusters.

"Now, two astronomers say there is good reason to keep up the search.

"Rosanne Di Stefano from the Harvard-Smithsonian Center for Astrophysics, US, and Alak Ray from the Tata Institute of Fundamental Research in India, have described what they call the 'globular cluster opportunity'...."
First, a quick review.

This universe began 13,799,000,000 years ago, give or take 21,000,000. Stars started forming somewhere between 150,000 and 1,000,000,000 years later. Many or most of those stars are no longer around.

The larger ones became supernovae. Others eventually became red giants. These stars produced elements heavier than hydrogen and helium. Red giants release these elements gradually, Supernovae dump their contributions into the cosmos rather abruptly.

Either way, clouds of gas and dust — including heavier elements — collapsed to form new stars: including our sun. The Solar System is about 4,600,000,000 years old now.

Life appeared on Earth at least 3,500,000,000 years back, folks were making stone tools 3,400,000 years before Darwin published "Origin of Species" — that was 156 years ago — and I've been over this before. (August 14, 2015; May 29, 2015; July 15, 2014)

'Life as we know it' depends on water, which is made of hydrogen and oxygen; and requires a wide variety of heavier elements.

Globular clusters, according to that BBC News article, are about 10,000,000,000 years old on average. Their stars generally don't have as many heavier elements as ours: but we're leaning that such stars can have rocky planets like Earth orbiting them.

Here's where it gets interesting.

Speculation



(From Science Photo Library, via BBC News, used w/o permission.)
("Back in 1974, globular cluster M13 was the target for the first deliberate radio transmission into outer space"2
(BBC News))

We're learning that a planet like Earth could be in a stable orbit in the habitable zone of a small, stable, and very old, star in a globular cluster.

If life started on such a planet, and folks more-or-less like us showed up about three and a half billion years later, like we did — that's a lot of "ifs."

But if all that happened, there could be folks living on such a world: whose ancestors started sending probes into the universe before our sun began shining.

Such a world almost certainly wouldn't exist in the most densely-packed parts of a globular cluster. Tidal/gravitational forces from passing stars would disrupt its orbit: probably. The good news is that globular clusters thin out toward the edges.
"...there is a region within these clusters, Dr Di Stefano said, where the stars are not so tightly packed that huddled, small, rocky planets would be stripped from their stars - and yet they are still close enough together that an alien civilisation might manage the leap from one to another.

"Fun speculation

" 'In this large region... planetary systems can survive, and yet it's dense enough that it may facilitate interstellar travel.'

"In fact, she added, these planets - if they do exist - could last even longer than the current age of the Universe, leaving ample time for intelligence and interstellar ambition to flourish.

"Other researchers at the conference agreed that these were interesting observations, even if the notion of ancient, star-hopping civilisations was - of course - a provocative speculation...."
(, BBC News)
The typical distance between stars in a globular cluster is around 1 light- year: that's just an average, though. (Wikipedia)

Let's say that folks whose home world orbits a star that's dimmer, cooler, and older, than ours — and is in the 'one light-year between stars' section of a globular cluster — got curious about their corner of the universe, and started sending probes out.

If they were as good at building robot spaceships as we were in 1977, they could launch something like Voyager 1. If they did, their probe could reach the closest star in a little over 2,250 years.

Outward Bound



(From Ames Research Center of the United States/NASA Photo ID: ACD97-0036-1, used w/o permission.)

Voyager 1 is currently outward bound, headed in the general direction of the constellation Camelopardalis. About 40,000 years from now, unless someone goes out to retrieve it, it'll be in the general vicinity of Gliese 445, some 17.6 light-years away.

We can't build probes that'll stay in good working order for 40,000 years, yet. But if we lived on that hypothetical planet, and knew that a probe could reach another star in a bit over two and a quarter millennia?

My guess is that some of us would be figuring out how to make a probe that would last that long.

Maybe someone already has: and has been working on 'next generation' technology since Earth's Hadean eon began.

More:

2. SETI, Breakthrough, and Assumptions



(From Wired, used w/o permission.)
"SETI Gets a $100 Million Gift"
Danielle Venton, Science, Wired (December 21, 2015)

"This summer Russian tech billionaire Yuri Milner announced he’ll fund the most extensive sweep yet for radio signals from alien civilizations. The initiative, known as Breakthrough Listen will allow SETI scientists to buy thousands of observation hours annually at some of the worlds most powerful radio telescopes. The search will scan 10 times more sky than past scouting efforts and will listen in to a larger range...."
Breakthrough Listen is one of Yuri Milner's Breakthrough Initiatives, a systematic search for other people in the universe. Breakthrough Listen's goal is to check 1,000,000 stars for artificial radio or laser signals.

They may find something — or not. My guess is "not," for reasons I discussed last year. (July 24, 2015)

It's not that I think we're alone in the universe — or that we are, and are being ignored.

Basically, I'd be astonished, and pleasantly surprised, if we pick up signal from folks who are as chatty as we are — in the next decade — using communications tech that's almost identical to what we developed over the last few decades.

Scenarios like that are fine for space opera: but my guess is that we'll find that the universe is a whole lot more interesting than what we've seen in Star Trek.

As for whether or not Mr. Milner should be supporting this effort? I figure that it's his money: and I can think of much less-productive ways he could spend it. Besides, maybe Breakthrough Initiatives will hit the jackpot.

More, mostly why I won't tell God how to run the universe:
1 If even a fraction of the 'I met space aliens' tales were true, Earth would be — in my opinion — an unaccountably popular destination for profoundly bored aliens. I've opined seriously and otherwise, on life, the universe, and everything, in other blogs:
2 M13, Messier 13, the Great Globular Cluster in Hercules is a globular cluster containing about 300,000 stars: roughly 22,200 light-years away. I don't think anyone seriously expected the message to be picked up. It was aimed at M13's current position, the signal will take tens of thousands of years to arrive where the cluster was, and — oh, well, it was a nice gesture: and serves as a demonstration that we can, in principle, send messages to folks on planets circling other stars.
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Friday, December 18, 2015

Enceladus and Kepler's Planets

Scientists following up on Kepler observations learned that a bit over half of the objects tentatively identified as giant planets are brown dwarfs or stars.

We've also learned that Saturn's moon Enceladus has a vast ocean under its icy surface: with all the ingredients needed for life.
  1. Kepler Data Analyzed: False Positives and Big Planets
  2. Enceladus Interplanetary Geyser Park and the Search for Extraterrestrial Life

Thinking and Humility


If you've read my 'science' posts before, you know why I think Earth isn't flat; the universe is billions, not thousands, of years old; poetry isn't science; and thinking is not a sin.

Basically, it's because I think God created and creates this universe: and isn't a liar. Nothing we learn about this universe can interfere with faith because both come from God. (Genesis 1:1-31; John 14:6; Catechism of the Catholic Church, 159, 279, 301)

Science and technology, studying the universe and applying that knowledge, is part of being human. We're supposed to use the brains God gave us. (Catechism, 1730, 1831, 2292-2295, 2493)

There's being humble, too. Humility, in the Catholic sense, is not cherishing delusions of inadequacy. That's being crazy, and an almost-entirely different topic.

Humility is recognizing that God's God and I'm not.
"HUMILITY: The virtue by which a Christian acknowledges that God is the author of all good. Humility avoids inordinate ambition or pride, and provides the foundation for turning to God in prayer (2559). Voluntary humility can be described as 'poverty of spirit' (2546)."
(Catechism, Glossary, H)
Accepting reality seems prudent. Insisting that God must conform to what we thought was true a few centuries or millennia back: not so much. (March 29, 2015; August 10, 2014)

Neighbors


I am quite certain that life exists elsewhere in this universe: or not. Right now, we don't know.

Finding any sort of life, like the alien equivalent of bacteria, would be a huge discovery: but the 'jackpot' would be finding neighbors.

If we meet them during the next few centuries, I think the odds are that they'll be finding us. Either way, I'm pretty sure that reactions would be mixed. (August 2, 2015)

I like Brother Guy Consolmagno's opinion about extraterrestrial life. (July 31, 2015)
"...Frankly, if you think about it, any creatures on other planets, subject to the same laws of chemistry and physics as us, made of the same kinds of atoms, with an awareness and a will recognizably like ours would be at the very least our cousins in the cosmos. They would be so similar to us in all the essentials that I don't think you'd even have the right to call them aliens."
("Brother Astronomer;" Chapter Three, Would You Baptize an Extraterrestrial? — Brother Guy Consolmagno (2000))
The idea that we have a kind of solidarity with the universe isn't new. Daniel 2:79-81, St. Francis of Assisi's Laudes Creaturarum/Canticle of the Creatures/Canticle of the Sun before, and all that. (June 28, 2015; June 15, 2014)

As for whether or not there's life on other worlds: like I've said before, that's God's decision. Not mine. (August 2, 2015)

1. Kepler Data Analyzed: False Positives and Big Planets



(From ESO/M. Kornmesser/Nick Risinger (skysurvey.org), via Space.com, used w/o permission.)
("Artist's illustration showing the giant, Jupiter-like exoplanet 51 Pegasi b, which in 1995 became the first alien world to be found around a sunlike star."
(Space.com))
"Half of Kepler's Giant Exoplanet Candidates Are False Positives: Study"
Mike Wall, Space.com (December 11, 2015)

"More than half of the giant alien planet candidates detected by NASA's prolific Kepler space telescope are false positives, a new study suggests.

"A team of astronomers followed up on 129 huge potential exoplanets spotted by Kepler using a ground-based telescope and found that 52 percent of the objects are actually stars, while another 2 percent are strange 'failed stars' known as brown dwarfs.

" 'It was thought that the reliability of the Kepler exoplanets detection was very good — between 10 and 20 percent of them were not planets,' study lead author Alexandre Santerne, of the University of Porto in Portugal, said in a statement...."
The giant planet candidates Santerne's team were checking out were something at least as massive as Jupiter. They used the radial velocity method to analyze SOPHIE data — in other words, they looked hard at wobbling stars from July 2010 through July 2015.

The stars they found are eclipsing binaries, pairs of stars orbiting each other in a plane that's really close to us, so that each star crosses in front of its partner from our viewpoint.

Brown dwarfs are more massive than the largest gas giant planet, but lighter than a star. They're not massive enough to support hydrogen-1 fusion, the thermonuclear 'fire' that heats main sequence stars.

Scientists still haven't decided where the line between gas giant planet and brown dwarf is. That's hardly surprising, since we didn't know they might exist until the 1960s, and weren't sure they really did until 1995.

Luhman16 A and B, about 6.5 light-years away, are the closest known brown dwarfs, and that's yet another topic.

Acronyms and Exoplanets


SOPHIE stands for Spectrographe pour l'Observation des Phénomènes des Intérieurs stellaires et des Exoplanètes.

In English that'd be Observation of the Phenomena of Stellar Interiors and Exoplanets, or OPSIE — which sounds odd, somehow, and that's yet again another topic. Topics.

The SOPHIE échelle spectrograph is a high-resolution echelle spectrograph at the Haute-Provence Observatory in south-eastern France. Echelle spectrograph??

An echelle spectrograph uses an echelle grating, a special sort of diffraction grating with slits spaced at intervals equal to the wavelength of light being studied. It's like a prism, only different.

Anyway, analysis of the SOPHIE data showed how fast the stars were wobbling; Kepler's data showed the orbiting objects' diameters; so when they were done, Santerne's team knew how wide and how massive the star's orbital companions were. Some were too massive to be planets.

However, that left some 46% of the possible gas giant planets that apparently are planets. That's still a lot of big planets.
"...Kepler has been an incredibly successful planet hunter. To date, the observatory has discovered 1,030 bona fide alien worlds (more than half of all the confirmed exoplanets ever found), as well as another 3,660 "candidates" that await vetting by further observation or analysis...."
(Mike Wall, Space.com)
The last I checked The Extrasolar Planet Catalog, which was December 16, 2015, scientists have confirmed more than two thousand planets orbiting other stars. That's 2,030 planets in 1,288 planetary systems: 501 in multiple planet systems.1

2. Enceladus Interplanetary Geyser Park and the Search for Extraterrestrial Life



(From Richard Bizley/SPL, via BBC News, used w/o permission.)
("The Enceladus Interplanetary Geyser Park: Might we go there someday?"
(BBC News))
"Enceladus: Does this moon hold a second genesis of life?"
Jonathan Amos, BBC News (December 11, 2015)

"The mighty Cassini probe has made many great discoveries at Saturn, but none top its extraordinary revelations at Enceladus.

"What the plutonium-powered satellite has seen at this 500km-wide, ice-crusted moon is simply astounding.

"Cassini has pictured huge jets of water vapour and other materials spewing from cracks at its south pole.

"It's quite a spectacle, and it's unique in the Solar System, according to Carolyn Porco, who runs the camera system on the big spacecraft.

" 'It became a joke on our team that we had found the Enceladus Interplanetary Geyser Park, and that future generations may go there just for vacation,' she tells me in a Discovery programme all about Enceladus which goes out on the BBC World Service on Monday.

"But researchers are not laughing when they say this little world is among the best places to search for life beyond Earth.

"The plumbing for the jets leads to a vast body of water that may be 30-40km deep in places. And Cassini's instruments have been able to show, by flying through and sampling the emissions, that the conditions and - importantly - the chemistry in this subterranean ocean could support microbial life...."
My high school science textbooks outlined what's required for life: water, rock or soil, and sunlight. Plants use water, rocks, soil, and sunlight; get eaten by animals or recycled by fungi and microbes; all of which eventually become part of the soil that plants use.

Scientists knew that some critters live at the bottom of Earth's ocean, far from any sunlight: but the ones they'd found fed directly or indirectly on organic stuff drifting down from the sunlit regions.

Then they found critters thriving around hydrothermal vents on the ocean floor. I've talked about extremophiles and looking for life in the universe before. (December 5, 2014; April 18, 2014)

If critters live in the Enceladean ocean, they may cluster around thermal vents: like deep-sea life here on Earth, where bacteria 'eat' sulfur compounds like hydrogen sulfide, producing organic stuff that's consumed by other critters.2

That's a big "if." All we have now is strong evidence that life could exist there. We'll know a bit more after Cassini's last flyby of Enceladus tomorrow, but the probe's instruments weren't designed to look for life.3

Next Enceladus Mission: ELF?



(From NASA/JPL-Caltech/SSI, via BBC News, used w/o permission.)
"...Jonathan Lunine is an interdisciplinary scientist on the Cassini mission at Cornell University in Ithaca, New York. He has a concept for a future spacecraft he calls the Enceladus Life Finder (ELF).

"This would be a smaller probe than the goliath currently orbiting Saturn, but what it would give up in size (and cost) it would more than compensate for with sophistication.

"Its instruments would be dedicated to the very specific job of analysing the contents of the jets for any chemistry associated with biology...."
(Jonathan Amos, BBC News)
Lunine's ELF would carry mass spectrometers, instruments that shoot electrons at a sample, measuring the atomic and molecular debris knocked loose.

ELF could sample spray from Enceladean geysers, detecting fatty acids, isoprenoids, and carbon isotopes used by life on Earth.

NASA turned down ELF when looking for new missions. One of the issues, apparently, was finding a power source for a Saturn-system probe. That far from the sun, solar panels would have to be huge; and plutonium batteries like the one in Cassini are rare items these days. Also expensive.

Even if ELF never gets off the ground, I'm pretty sure that someone will send a probe with similar instruments to Enceladus. Quite a few folks want to know if there's life elsewhere in the universe, and at the moment Enceladus is the most promising spot that our robot spacecraft can reach.

The south polar geysers may not be there by the time ELF or another probe arrives, though. It looks like they may have been fading since 2005. And that's still another topic. (Space.com (December 16, 2015))

More of how I see life, the universe, and all that:
1 Finding new worlds:
2 Extremophiles and extraterrestrial life:
3 Saturn's moons:
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Marian Apparition: Champion, Wisconsin

Background:Posts in this blog: In the news:

What's That Doing in a Nice Catholic Blog?

From time to time, a service that I use will display links to - odd - services and retailers.

I block a few of the more obvious dubious advertisers.

For example: psychic anything, numerology, mediums, and related practices are on the no-no list for Catholics. It has to do with the Church's stand on divination. I try to block those ads.

Sometime regrettable advertisements get through, anyway.

Bottom line? What that service displays reflects the local culture's norms, - not Catholic teaching.