The strangest star in the galaxy

Ever heard of Eta Carinae?

If there was a contest for the weirdest known astronomical object in the Milky Way, Eta Carinae would certainly be in the top ten.  It's a binary star system in the constellation Carina, one member of which is a luminous blue variable, unusual in and of itself, but its behavior in the last hundred or so years (as seen from Earth; Eta Carinae is 7,500 light years away, so of course the actual events we're seeing took place 7,500 years ago) has been nothing short of bizarre.  It's estimated to have started out enormous, at about two hundred solar masses, but in a combination of explosions peaking in the 1843 "Great Eruption" it lost thirty solar masses' worth of material, which has been blown outward at 670 kilometers per second to form the odd Homunculus Nebula.

After the Great Eruption, during which it briefly rose to a magnitude of -0.8, making it the second-brightest star in the night sky, it faded below naked eye visibility, largely due to the ejected dust cloud that surrounded it.  But in the twentieth century it began to brighten again, and by 1940 was again visible to the naked eye -- and then its brightness mysteriously doubled again between 1998 and 1999.

Which is even more mind-blowing when you find out that the actual luminosity of the combined Eta Carinae binary is more than five million times greater than that of the Sun.

This comes up because the Hubble Space Telescope has provided astronomers the clearest images of Eta Carinae and the Homunculus Nebula they've yet had, and what they're learning is kind of mind-blowing. Here's one of the best images:

[Image is in the Public Domain, courtesy of the NASA Hubble Space Telescope]

There are a lot of features of these photographs that surprised researchers.  "We've discovered a large amount of warm gas that was ejected in the Great Eruption but hasn't yet collided with the other material surrounding Eta Carinae," said astronomer Nathan Smith of the University of Arizona, lead investigator of the study.  "Most of the emission is located where we expected to find an empty cavity.  This extra material is fast, and it 'ups the ante' in terms of the total energy of an already powerful stellar blast....  We had used Hubble for decades to study Eta Carinae in visible and infrared light, and we thought we had a pretty full account of its ejected debris.  But this new ultraviolet-light image looks astonishingly different, revealing gas we did not see in either visible-light or infrared images.  We're excited by the prospect that this type of ultraviolet magnesium emission may also expose previously hidden gas in other types of objects that eject material, such as protostars or other dying stars; and only Hubble can take these kinds of pictures."

One of the most curious things -- one which had not been observed before -- are the streaks clearly visible in the photograph.  These are beams of ultraviolet light radiating from the stars at the center striking and exciting visible light emission from the dust cloud, creating an effect sort of like sunbeams through clouds.

Keep in mind, though, how big this thing is.  The larger of the two stars in the system, Eta Carinae A, has a diameter about equal to the orbit of Jupiter.  So where you're sitting right now, if our Sun was replaced by Eta Carinae A, you would be inside the star.

The question most people have after learning about this behemoth is, "when will it explode?"  And not just an explosion like the Great Eruption, which was impressive enough, but a real explosion -- a supernova.  It's almost certain to end its life that way, and when it does, it's going to be (to put it in scientific terms) freakin' unreal.  Even at 7.500 light years away, it has the potential to be the brightest supernova we have any record of.  It will almost certainly outshine the Moon, meaning that in places where it's visible (mostly in the Southern Hemisphere) for a time you won't have a true dark night.

But when?  It's imminent -- in astronomical terms.  That means "probably some time in the next hundred thousand years."  It might have already happened -- meaning the light from the supernova is currently streaming toward us.  It might not happen for thousands of years.

But it's considered the most likely star to go supernova in our near region of the galaxy, so there's always hoping.

[Nota bene: we're in no danger at this distance.  There will be gamma rays from the explosion that will reach Earth, but they'll be pretty attenuated by the time they get here, and the vast majority of them will be blocked by our atmosphere.  So no worries that your friends and family might be at risk of turning into the Incredible Hulk, or anything.]

So that's our cool scientific research of the day.  Makes me kind of glad we're in a relatively quiet part of the Milky Way.  Eta Carinae, and the surrounding Carina Nebula (of which the Homunculus is just a small part), is a pretty rough neighborhood.  But if it decides to grace us with some celestial fireworks, it'll be nice to see -- from a safe distance.

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Orphan stars

Here in the twenty-first century, it's easy to deride the ancients for their belief that the Earth was the center of the cosmos, and everything revolved around it.

After all, that's certainly what it looks like.  We still talk about the Sun "rising" and "setting" -- even though we know the Earth orbits the Sun, the terms are a convenient way to describe our experience.  (Well, to be absolutely accurate, the Earth and the Sun both orbit their common center of gravity, but the Sun is so much more massive that to say the Earth orbits the Sun is substantially accurate.)

Even after Copernicus showed that the heliocentric model is correct, it still left us to explain the apparent motion of the stars.  As we gradually learned more, we found that we are far from the center of the universe; we orbit a rather ordinary star in the outer reaches of a rather ordinary galaxy.  It still boggles my mind that they figured this last part out.  Not only are we at the periphery of the Milky Way, and therefore seeing it edge-on, a lot of the bright central bits are obscured by dust.  But even so, we've now amassed enough data to understand that the Milky Way is a barred spiral galaxy, and even to map out its main features.

If ever there was an image you need to study in detail, this is it.  Take a look at the original, close up.  The Solar System is in the Orion Arm, directly down from the center of the galaxy.  The thing that blew me away is the circle marked "Naked Eye Limit" -- literally every star you have ever seen without the use of a telescope is in that little circle.  [Image licensed under the Creative Commons Pablo Carlos Budassi, Milky way map, CC BY-SA 4.0]

And if you want to feel even smaller, the Milky Way is just one of a hundred thousand galaxies in the Laniakea Supercluster, which stretches over a distance of 520 million light years.  And weirdest of all, the entire supercluster's center of gravity is at a point called "the Great Attractor," but we can't see what's there because it's on the other side of the Milky Way's center.  If there's actually something there holding the entire Laniakea Supercluster together, it's currently hidden, and will be for another hundred million years -- at which point the Solar System will have made a half-revolution around the Milky Way and will be able to see what, if anything, is out there.

The reason this topic comes up is a recent survey by the Hubble Space Telescope that found good evidence that there are stars -- and therefore probably associated planetary systems -- out there in the space between the galaxies.  It picked up "intracluster light," a faint glow produced by these unaffiliated stars.  What was fascinating and unexpected is that when you look at progressively more distant regions of space -- and thus, back further in time -- the amount of that ghostly glow doesn't change, which implies that earlier models attributing these orphan stars to the chaos resulting from galactic mergers or close side-swipes can't be true.  It looks like there have always been stars floating out there between galaxies.

Think about what it'd be like to live on a planet around one of those.  Remember the circle on the map marked "naked eye limit?"  Within the naked eye limit of a planet around one of those orphans, there would be nothing.  The skies would be pitch black... until the telescope was invented.  And then, what a surprise they'd get!  (If they'd even think of inventing the telescope -- why would you, when it appears that there's nothing up there to see?)

"We don't exactly know what made [the orphan stars] homeless," said astrophysicist James Jee of Yonsei University, who co-authored the study.  "Current theories cannot explain our results, but somehow they were produced in large quantities in the early universe.  In their early formative years, galaxies might have been pretty small and they bled stars pretty easily because of a weaker gravitational grasp."

More data should come in from the newly-deployed James Webb Space Telescope, and that may clarify this fascinating conundrum.

The ancients found it unsettling that we might not be at the center of the universe, and later that the universe is astonishingly larger than they ever dreamed.  Me, I find it reassuring.  My own little petty day-to-day concerns and worries seem like nothing at all on the scale of the Laniakea Supercluster.  Looking up on the next clear night, remember that little circle marked "naked eye limit" -- and think about what there is up in the night sky that you're not seeing.

Including the ghostly light of millions of orphan stars, lost in the deeps of interstellar space.

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A window on deep time

The ultimate speed limit in the universe -- unbreakable, as far as our current understanding of science goes -- is the speed of light, 3x10^8 meters per second.

Most people think of spaceships when this comes up, and certainly it's easy to conceptualize this in terms of objects moving.  What might be less intuitive is that this speed limit also applies to the movement of information.  If an event occurs, the soonest we can know about it is the amount of time it takes for light to get from there to here.  So -- to use an oft-cited, if a little ridiculous, example -- if the Sun were to disappear, we wouldn't know about it for 8.317 minutes, because the Sun is 8.317 light-minutes from Earth.

So we're always looking into the past, and the farther away something is, the farther into the past we're looking.  You see the Sun as it was a little over eight minutes ago.  The distance between the Earth and Mars varies, given that both are in elliptical orbits around the Sun and moving at different angular velocities, but on average Mars is a bit under thirteen light-minutes from us, which is why the Mars rovers had to be able to sense their environment and function independently.  If here on Earth we saw through its camera that the rover was heading toward the edge of a cliff, and we sent a message saying "Stop!  Turn around!", it would be far too late.  Not only would that image have taken (again, on average) thirteen minutes to get to us, it would take another thirteen minutes for our command to get back to it.  By that time, it would be a heap of scrap metal on the bottom of the cliff.

And so on.  We see the nearest star to the Sun, Proxima Centauri, as it was 4.3 years ago.  The brightest star in the night sky, Sirius, in the constellation of Canis Major, is 8.6 light years away.  Vega, brightest star in the constellation Lyra -- the one made famous as the home of the super-intelligent aliens in the movie Contact -- is twenty-five light years away.  When we see the other side of our own galaxy, we're seeing what it looked like around a hundred thousand years ago (at which point we were in the middle of an ice age, and our distant ancestors were just on the point of leaving the African savanna).  The nearest galaxy to the Milky Way, the Andromeda Galaxy, is 2.5 million light years away -- when the light from it left its source, there weren't any modern humans, and the species Homo habilis had just mastered the use of tools.

But this ultimate speed limit means there's also a limit to how far away we can see.  The Big Bang is estimated to have happened 13.8 billion years ago, so the Cosmic Microwave Background Radiation -- the remnant radiation from only a short time after the universe formed -- has been traveling toward us for 13.8 billion years, and represents the most distant thing it's even theoretically possible to see.  There is certainly stuff farther away from us than that; for one thing, in the intervening 13.8 billion years, the universe has been continuously (although not uniformly) expanding, so the radius of the universe is way bigger than 13.8 billion light years.  But whatever is farther away than that is completely out of our reach, no matter how good our telescopes get.  Our knowledge of anything beyond the distance limit imposed by the speed of light is zero, and always will be.

That doesn't mean we can't see a long way, though.  Last week in Nature it was announced that the Hubble Space Telescope had captured a photograph of the most distant star ever seen, at 12.9 billion light years away.  The image was distorted by gravitational lensing, when the light from a luminous object passes through a region of space warped by a large mass, but the astronomers are saying the source is too small to be a galaxy or star cluster.  We know how far away it is because of its red shift, the stretching of the wavelength of light when its source is moving away from us, combined with Hubble's Law, which connects the amount of red shift with the object's distance.

The image containing Earendel [Image is in the Public Domain courtesy of NASA/JPL]

The astronomers named the star Earendel -- an Old English word meaning "morning star."  If you immediately thought of J. R. R. Tolkien when you saw this, so did I; the name of the character Eärendil in The Silmarillion was pilfered directly from Old English, of which Tolkien was a noted scholar.  Tolkien said he was struck by the word's "great beauty," and adopted it into his conlang Quenya (one of the Elvish languages in his stories).  In Quenya, Eärendil means "lover of the sea," but interestingly, at the end of The Silmarillion, when Morgoth is defeated, the last remaining Silmaril -- the phenomenally beautiful jewels created by the Elf Fëanor, that were the cause of the entire conflict in the book -- is taken by Eärendil up into the sky, where it becomes the "morning star," or Venus.  So the myth and Tolkien's story come full circle.

In any case, the fact that we can see something that far away is kind of astonishing.  When the light Hubble captured from Earendel left its surface, it was 8.4 billion years before the Earth would form.  In fact, Earendel almost certainly doesn't exist any more; the current guess is that it is (or was) a supergiant, meaning it had high temperatures and luminosity, and would have burned through its fuel long ago.  What's left of it is almost certainly a black hole.  But when that occurred is impossible to know, as the light released when it went supernova still hasn't gotten here.

But still, this is an incredible window on deep time.  I have to wonder what other amazing images we'll get to see soon when the new James Webb Space Telescope, which has better resolution than Hubble, starts sending us data this summer.  I think we've only begun to explore what is out there in the far reaches of the universe, and the far distant past.

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Knockin' on heaven's door

It's been awhile since we've have a truly goofy claim to consider, so to take a brief diversion from more serious issues, today I bring you:

NASA space telescopes have photographed the Celestial City of New Jerusalem, as hath been prophesied in the scriptures.

I wish I was making this up.  The claim appeared on the ultra-fundamentalist site Heaven & Hell, and the post, written by one Samuel M. Wanginjogu, reads like some kind of apocalyptic wet dream.

It opens with a bang.  "Despite new repairs to the Hubble Telescope," Wanginjogu writes, "NASA refuses to release old photos or take new ones of Heaven!"

Imagine that.

He goes on to explain further:

Just days after space shuttle astronauts repaired the Hubble Space Telescope in mid December, the giant lens focused on a star cluster at the edge of the universe – and photographed heaven! 

That’s the word from author and researcher Marcia Masson, who quoted highly placed NASA insiders as having said that the telescope beamed hundreds of photos back to the command center at Goddard Space Flight Center in Greenbelt, Md., on December 26. 

The pictures clearly show a vast white city floating eerily in the blackness of space. 

And the expert quoted NASA sources as saying that the city is definitely Heaven “because life as we know it couldn’t possibly exist in icy, airless space. 

“This is it – this is the proof we’ve been waiting for,” Dr. Masson told reporters. 

“Through an enormous stroke of luck, NASA aimed the Hubble Telescope at precisely the right place at precisely the right time to capture these images on film.  I’m not particularly religious, but I don’t doubt that somebody or something influenced the decision to aim the telescope at that particular area of space.

“Was that someone or something God himself?  Given the vastness of the universe, and all the places NASA could have targeted for study, that would certainly appear to be the case.”

Unsurprisingly, NASA researchers have "declined to comment."

Then we get to see the photograph in question:

After I stopped guffawing, I read further, and I was heartened to see that Wanginjogu is all about thinking critically regarding such claims:

I am not an expert in photography, but if you scrutinize the photo carefully, you find that the city is surrounded by stars if at all it was taken in space...  If the photo is really a space photo, then it could most likely be the Celestial city of God because it is clear that what is in the photograph is not a star, a planet or any other known heavenly body.

Yes!  Surrounded by stars, and not a planet!  The only other possibility, I think you will agree, is that it is the Celestial City of God.

Wanginjogu then goes through some calculations to estimate the size of New Jerusalem:

If an aero plane [sic] passes overhead at night, you are able to see the light emitted by it.  If that aero plane [sic] was to go higher up from the surface of the earth, eventually you won’t be able to see any light from it and that is only after moving a few kilometers up.  This is because of its small size.  Yet our eyes are able to see, without any aid, stars that are millions of light years away.  This is because of their large size. 

The further away an object is from the surface of the earth, then the bigger it needs to be and the more the light it needs to emit for it to be seen from earth.

The city of New Jerusalem is much smaller than most of the stars that you see on the sky.  To be more precise, it is much smaller than our planet earth.  Remember that here we are not talking of the entire heaven where God lives but of the City of New Jerusalem.  The city of New Jerusalem is currently located in heaven.  Of course, heaven is much larger that the city itself.  The photo seems to be of the city itself rather than the entire heaven.

Some solid astrophysics, right there.  He then goes on to use the Book of Revelation to figure out how big the city prophesied therein must be, and from all of this he deduces that the Celestial City must be somewhere within our Solar System for Hubble to have captured the photograph.  He also uses the testimony of one Seneca Sodi, who apparently saw an angel and asked him how far away heaven was, and the angel said, "Not far."

So there you have it.

The best part, though, was when I got about halfway through, and I found out where Wanginjogu got the photograph from.  (Hint: not NASA.)  The photograph, and in fact the entire claim, originated in...

... wait for it...

... The Weekly World News.

Yes, that hallowed purveyor of stories about Elvis sightings, alien abductions, and Kim Kardashian being pregnant with Bigfoot's baby.  Even Wanginjogu seems to realize he's on shaky ground, here, and writes:

This magazine is known to exaggerate stories and to publish some really controversial articles.  However, it also publishes some true stories.  So we cannot trash this story just because it first appeared in The Weekly World News magazine.  It is worthwhile to consider other aspects of the story.

He's right that you can't rule something out because of the source, but this pretty much amounts to something my dad used to say, to wit, "Even stopped clocks are right twice a day."   But suffice it to say that here at Skeptophilia headquarters we have considered other aspects of the story, and it is our firmly-held opinion that to believe this requires that you have a single scoop of butter-brickle ice cream where the rest of us have a brain.

Anyway, there you are.  NASA photographing heaven.  Me, I'm waiting for them to turn the Hubble the other direction, and photograph hell.  Since that's where I'm headed anyway, might as well take a look at the real estate ahead of time.

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The advancement of technology has opened up ethical questions we've never had to face before, and one of the most difficult is how to handle our sudden ability to edit the genome.

CRISPR-Cas9 is a system for doing what amounts to cut-and-paste editing of DNA, and since its discovery by Emmanuelle Charpentier and Jennifer Doudna, the technique has been refined and given pinpoint precision.  (Charpentier and Doudna won the Nobel Prize in Chemistry last year for their role in developing CRISPR.)

Of course, it generates a host of questions that can be summed up by Ian Malcolm's quote in Jurassic Park, "Your scientists were so preoccupied with whether they could, they didn't stop to think if they should."  If it became possible, should CRISPR be used to treat devastating diseases like cystic fibrosis and sickle-cell anemia?  Most people, I think, would say yes.  But what about disorders that are mere inconveniences -- like nearsightedness?  What about cosmetic traits like hair and eye color?

What about intelligence, behavior, personality?

None of that has been accomplished yet, but it bears keeping in mind that ten years ago, the whole CRISPR gene-editing protocol would have seemed like fringe-y science fiction.  We need to figure this stuff out now -- before it becomes reality.

This is the subject of bioethicist Henry Greely's new book, CRISPR People: The Science and Ethics of Editing Humans.  It considers the thorny questions surrounding not just what we can do, or what we might one day be able to do, but what we should do.

And given how fast science fiction has become reality, it's a book everyone should read... soon.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Rings in the sky

Sometimes I enjoy mysteries just because they're mysteries.

I ran across an astronomical curiosity yesterday that I'd never heard of before, and one that has had no convincing explanation; a ring galaxy.  The most famous example is "Hoag's Object," a ring galaxy discovered by astronomer Arthur Hoag.  It's about six hundred million light years away -- so not exactly in our neighborhood -- but that hasn't stopped the Hubble Space Telescope from getting an amazing photograph of it:

Hoag's Object [Image is in the Public Domain, courtesy of NASA]

As you can see, it's a torus (donut) of stars with a bright, dense cluster in the middle, and a gap where there's not much in the way of anything.  The estimate is that it's a hundred thousand light years across, so a bit larger than the Milky Way.

The curiosity is the gap.  It's hard to imagine what would cause this arrangement of matter; the stars in the ring must be orbiting fast enough to compensate for the gravitational pull of the stars in the center, but why were there none orbiting with the right velocity to end up in between?  My first thought was that it might be something similar to what caused Cassini's Division in the rings of Saturn, but when I looked into this, it turns out that the physicists don't know what caused that, either.

Various ideas were fielded to explain the odd structure.  Hoag himself thought at first that it was a case of gravitational lensing -- the bending of light when it passes through a strong gravitational field between the emitter and observer.  Sometimes, if the heavy object causing the bending is right between the two, light passing around it gets deflected into a bullseye shape called an Einstein ring (because the great man predicted the effect before it was observed):

[Image is in the Public Domain courtesy of NASA]

Even though the two photographs look superficially alike, the explanation was discarded when it was found that the ring of Hoag's Object showed no distortion on a smaller scale, and also the ring and the bright spot at the center had exactly the same degree of red shift, which would not be the case if the light emitted by it had passed through a strong gravitational field.

Other explanations were also proposed and discarded.  Perhaps it was caused by a collision between galaxies -- but there's no evidence of that, and the object's amazing symmetry argues against its having been the product of a chaotic merger.  Another was that it was the result of bar instability, which is when the matter distribution of a barred spiral galaxy results in a gravity field that is insufficient to keep the whole thing together, resulting in the furthest ones getting flung outward in an ever-increasing bubble.  But the almost perfectly spherical nature of the center of Hoag's Object caused astrophysicists to dismiss that explanation, too.

Long story short, we still have no idea how Hoag's Object formed, or even what exactly it is.  Other ring galaxies are known, but they're extremely rare, accounting for less than one in a thousand observed galaxies.  Another curiosity is that the stars in Hoag's Object are all very young, very hot blue-white stars -- but no one knows if that's relevant or a coincidence.

So we're left with a mystery.  I will say, however, that whatever it is, Hoag's Object is beautiful.  The idea that even our best scientists can't explain it adds to the mystique.  And it further reinforces something I've said many times; if you get interested in science, you'll never be bored.  There will always be questions to answer.

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Long-time readers of Skeptophilia have probably read enough of my rants about creationism and the other flavors of evolution-denial that they're sick unto death of the subject, but if you're up for one more excursion into this, I have a book that is a must-read.

British evolutionary biologist Richard Dawkins has made a name for himself both as an outspoken atheist and as a champion for the evolutionary model, and it is in this latter capacity that he wrote the brilliant The Greatest Show on Earth.  Here, he presents the evidence for evolution in lucid prose easily accessible to the layperson, and one by one demolishes the "arguments" (if you can dignify them by that name) that you find in places like the infamous Answers in Genesis.

If you're someone who wants more ammunition for your own defense of the topic, or you want to find out why the scientists believe all that stuff about natural selection, or you're a creationist yourself and (to your credit) want to find out what the other side is saying, this book is about the best introduction to the logic of the evolutionary model I've ever read.  My focus in biology was evolution and population genetics, so you'd think all this stuff would be old hat to me, but I found something new to savor on virtually every page.  I cannot recommend this book highly enough!

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

The strangest star in the galaxy

Ever heard of Eta Carinae?

If there was a contest for the weirdest known astronomical object in the Milky Way, Eta Carinae would certainly be in the top ten.  It's a binary star system in the constellation Carina, one member of which is a luminous blue variable, unusual in and of itself, but its behavior in the last hundred or so years (as seen from Earth; Eta Carinae is 7,500 light years away, so of course the actual events we're seeing took place 7,500 years ago) has been nothing short of bizarre.  It's estimated to have started out enormous, at about two hundred solar masses, but in a combination of explosions peaking in the 1843 "Great Eruption" it lost thirty solar masses' worth of material, which has been blown outward at 670 kilometers per second to form the odd Homunculus Nebula.

After the Great Eruption, during which it briefly rose to a magnitude of -0.8, making it the second-brightest star in the night sky, it faded below naked eye visibility, largely due to the ejected dust cloud that surrounded it.  But in the twentieth century it began to brighten again, and by 1940 was again visible to the naked eye -- and then its brightness mysteriously doubled again between 1998 and 1999.

Which is even more mind-blowing when you find out that the actual luminosity of the combined Eta Carinae binary is more than five million times greater than that of the Sun.

This all comes up because the Hubble Space Telescope has just sent astronomers the clearest images of Eta Carinae and the Homunculus Nebula they've yet had, and what they're learning is kind of mind-blowing.  Here's one of the best images:

[Image is in the Public Domain, courtesy of the NASA Hubble Space Telescope]

There are a lot of features of these photographs that surprised researchers.  "We've discovered a large amount of warm gas that was ejected in the Great Eruption but hasn't yet collided with the other material surrounding Eta Carinae," said astronomer Nathan Smith of the University of Arizona, lead investigator of the study.  "Most of the emission is located where we expected to find an empty cavity.  This extra material is fast, and it 'ups the ante' in terms of the total energy of an already powerful stellar blast....  We had used Hubble for decades to study Eta Carinae in visible and infrared light, and we thought we had a pretty full account of its ejected debris.  But this new ultraviolet-light image looks astonishingly different, revealing gas we did not see in either visible-light or infrared images.  We're excited by the prospect that this type of ultraviolet magnesium emission may also expose previously hidden gas in other types of objects that eject material, such as protostars or other dying stars; and only Hubble can take these kinds of pictures."

One of the most curious things -- one which had not been observed before -- are the streaks clearly visible in the photograph.  These are beams of ultraviolet light radiating from the stars at the center striking and exciting visible light emission from the dust cloud, creating an effect sort of like sunbeams through clouds.

Keep in mind, though, how big this thing is.  The larger of the two stars in the system, Eta Carinae A, has a diameter about equal to the orbit of Jupiter.  So where you're sitting right now, if our Sun was replaced by Eta Carinae A, you would be inside the star.

The question most people have after learning about this behemoth is, "when will it explode?"  And not just an explosion like the Great Eruption, which was impressive enough, but a real explosion -- a supernova.  It's almost certain to end its life that way, and when it does, it's going to be (to put it in scientific terms) freakin' unreal.  Even at 7.500 light years away, it has the potential to be the brightest supernova we have any record of.  It will almost certainly outshine the Moon, meaning that in places where it's visible (mostly in the Southern Hemisphere) for a time you won't have a true dark night.

But when?  It's imminent -- in astronomical terms.  That means "probably some time in the next hundred thousand years."  It might have already happened -- meaning the light from the supernova is currently streaming toward us.  It might not happen for thousands of years.

But it's considered the most likely star to go supernova in our near region of the galaxy, so there's always hoping.

(Nota bene:  we're in no danger at this distance.  There will be gamma rays from the explosion that will reach Earth, but they'll be pretty attenuated by the time they get here, and the vast majority of them will be blocked by our atmosphere.  So no worries that your friends and family might be at risk of turning into the Incredible Hulk, or anything.)

So that's our cool scientific research of the day.  Makes me kind of glad we're in a relatively quiet part of the Milky Way.  Eta Carinae, and the surrounding Carina Nebula (of which the Homunculus is just a small part), is a pretty rough neighborhood.  But if it decides to grace us with some celestial fireworks, it'll be nice to see -- from a safe distance.

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This week's Skeptophilia book recommendation is pure fun for anyone who (like me) appreciates both plants and an occasional nice cocktail -- The Drunken Botanist by Amy Stewart.  Most of the things we drink (both alcohol-containing and not) come from plants, and Stewart takes a look at some of the plants that have provided us with bar staples -- from the obvious, like grapes (wine), barley (beer), and agave (tequila), to the obscure, like gentian (angostura bitters) and hyssop (Bénédictine).

It's not a scientific tome, more a bit of light reading for anyone who wants to know more about what they're imbibing.  So learn a little about what's behind the bar -- and along the way, a little history and botany as well.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Trip to the stars

Because the news down here on Earth in the last few days is making me angry, frustrated, depressed, or all three simultaneously, in today's post I'm going to go to my Happy Place, which is: outer space.

This all comes up not only because of the goings-on I'm exposed to every time I read the news, but because of a loyal reader of Skeptophilia who sent me a link to a wonderful article by Nola Taylor Redd in Astronomy magazine online entitled, "The Outer Solar System Keeps Getting Weirder."  In it we find out that recent research has shown that our home system is not nearly as orderly or predictable as we thought it was back when I was in grade school and remembering the mnemonic "My Very Educated Mother Just Served Us Nine Pies" gave you all of the planets in order, and that was pretty much that.

First, we have the discovery of a small icy planet (or dwarf planet; the astronomers aren't exactly sure yet) called L91, which has a highly elliptical orbit varying from 50 Astronomical Units (an AU is the average distance from the Sun to the Earth) to 1,430.  Not only does L91 have an odd orbit, the orbital trajectory isn't stable.  "Its orbit is changing in quite a remarkable way," said astrophysicist Michele Bannister of Queen's University Belfast at the American Astronomical Society’s Division for Planetary Sciences Conference in Pasadena, California.  "There are minute changes in the object’s orbit that could come from the passing gravity of other stars or interactions with the hypothetical Planet Nine."

Artist's conception of the Sun as viewed from Sedna (a dwarf planet three times more distant than Neptune) [image courtesy of the Wikimedia Commons]

I remember when the whole Planet Nine thing first was proposed, right around the time I was an undergraduate student of physics at the University of Louisiana.  Two of my teachers, Daniel Whitmire and John Matese, had proposed the periodic disturbance of comets in the Oort Cloud by a large planet outside the orbit of Pluto as a mechanism for periodic mass extinctions (the idea being that the planet, as it passes through the Oort Cloud, interacts gravitationally with the comets, slingshotting some of them in toward the inner Solar System, and increasing the likelihood of an impact with the Earth and a resultant catastrophe for us Earthlings).  Apparently, Whitmire and Matese are still at it, and have been vindicated at least so far as the existence of Planet Nine; earlier this year Konstantin Batygin of the California Institute of Technology announced independent evidence of a large planet that was perturbing the orbit of dwarf planets in the distant reaches of the Solar System.

So that's pretty cool.  I mean, not the comets striking the Earth and obliterating everything part, but the odd stuff in the far reaches of the Solar System part.

To further explore my Happy Place, I then went to the Hubble Telescope image gallery, and found the following extremely cool photographs, further emphasizing that although things can get ugly down here on Earth, we live in a gorgeous universe.  Here are a few of my favorites.  All images are courtesy of NASA/Hubble Space Telescope and are in the public domain.

A supernova in the galaxy NGC3021

The Helix Nebula

A supernova remnant in the constellation Cassiopeia

The Sombrero Galaxy, NGC 4594

The Whirlpool Galaxy, M51

There.  I don't know about you, but I feel much better now.  The idea that there are billions of stars out there, many of which probably host intelligent life, is a real source of comfort to me.  Especially considering that just by the law of averages, some of them must get by without doing the stupid stuff we do down here on Earth.

Knockin' on heaven's door

Because yesterday's post -- which was about a bunch of sinkholes in the Siberian tundra being evidence of aerial dogfights between rival alien space fleets -- wasn't ridiculous enough, today I bring you:

NASA space telescopes have photographed the Celestial City of New Jerusalem, as hath been prophesied in the scriptures.

I wish I was making this up.  The claim appeared on the ultra-fundamentalist site Heaven & Hell, and the post, written by one Samuel M. Wanginjogu, reads like some kind of apocalyptic wet dream.

It opens with a bang.  "Despite new repairs to the Hubble Telescope," Wanginjogu writes, "NASA refuses to release old photos or take new ones of Heaven!"

Imagine that.

He goes on to explain further:

Just days after space shuttle astronauts repaired the Hubble Space Telescope in mid December, the giant lens focused on a star cluster at the edge of the universe – and photographed heaven! 

That’s the word from author and researcher Marcia Masson, who quoted highly placed NASA insiders as having said that the telescope beamed hundreds of photos back to the command center at Goddard Space Flight Center in Greenbelt, Md., on December 26. 

The pictures clearly show a vast white city floating eerily in the blackness of space. 

And the expert quoted NASA sources as saying that the city is definitely Heaven “because life as we know it couldn’t possibly exist in icy, airless space. 

“This is it – this is the proof we’ve been waiting for,” Dr. Masson told reporters. 

“Through an enormous stroke of luck, NASA aimed the Hubble Telescope at precisely the right place at precisely the right time to capture these images on film. I’m not particularly religious, but I don’t doubt that somebody or something influenced the decision to aim the telescope at that particular area of space. 

“Was that someone or something God himself? Given the vastness of the universe, and all the places NASA could have targeted for study, that would certainly appear to be the case.”

Unsurprisingly, NASA researchers have "declined to comment."

Then we get to see the photograph in question:

After I stopped guffawing, I read further, and I was heartened to see that Wanginjogu is all about thinking critically regarding such claims:

I am not an expert in photography, but if you scrutinize the photo carefully, you find that the city is surrounded by stars if at all it was taken in space...  If the photo is really a space photo, then it could most likely be the Celestial city of God because it is clear that what is in the photograph is not a star, a planet or any other known heavenly body.

Yes!  Surrounded by stars, and not a planet!  The only other possibility, I think you will agree, is that it is the Celestial City of God.

Wanginjogu then goes through some calculations to estimate the size of New Jerusalem:

If an aero plane [sic] passes overhead at night, you are able to see the light emitted by it. If that aero plane [sic] was to go higher up from the surface of the earth, eventually you won’t be able to see any light from it and that is only after moving a few kilometers up.  This is because of its small size. Yet our eyes are able to see, without any aid, stars that are millions of light years away. This is because of their large size. 

The further away an object is from the surface of the earth, then the bigger it needs to be and the more the light it needs to emit for it to be seen from earth. 

The city of New Jerusalem is much smaller than most of the stars that you see on the sky. To be more precise, it is much smaller than our planet earth.  Remember that here we are not talking of the entire heaven where God lives but of the City of New Jerusalem. The city of New Jerusalem is currently located in heaven.  Of course, heaven is much larger that the city itself. The photo seems to be of the city itself rather than the entire heaven.

Some solid astrophysics, right there.  He then goes on to use the Book of Revelation to figure out how big the city prophesied therein must be, and from all of this he deduces that the Celestial City must be somewhere within our Solar System for Hubble to have captured the photograph.  He also uses the testimony of one Seneca Sodi, who apparently saw an angel and asked him how far away heaven was, and the angel said, "Not far."

So there you have it.

The best part, though, was when I got about halfway through, and I found out where Wanginjogu got the photograph from.  (Hint: not NASA.)  The photograph, and in fact the entire claim, originated in...

... wait for it...

... The Weekly World News.

Yes, that hallowed purveyor of stories about Elvis sightings, alien abductions, and Kim Kardashian being pregnant with Bigfoot's baby.  Even Wanginjogu seems to realize he's on shaky ground, here, and writes:

This magazine is known to exaggerate stories and to publish some really controversial articles.  However, it also publishes some true stories.  So we cannot trash this story just because it first appeared in The Weekly World News magazine. It is worthwhile to consider other aspects of the story.

So this pretty much amounts to something my dad used to say, to wit, "Even stopped clocks are right twice a day."  But suffices to say that we have considered other aspects of the story, and it is our firmly-held opinion that to believe this requires that you have a single scoop of butter-brickle ice cream where the rest of us have a brain.

Anyway, there you are.  NASA photographing heaven.  Me, I'm waiting for them to turn the Hubble the other direction, and photograph hell.  Since that's where I'm headed anyway, might as well take a look at the real estate ahead of time.