Postcards from deep space

It's way too easy to let yourself get caught up in all the ugliness in the news.

Scandals, allegations of crimes of all sorts by various public figures, humanitarian crises, ecological damage done by people who seem to have no real care for the long-term habitability of the Earth.  Hypocrisy, dishonesty, corruption.

Pretty dark stuff, and to judge by the news, it's about all humanity has to offer.

So today I'm going to write about something hopeful -- an indication that we have the capacity for a whole lot of positive things.  Curiosity, innovation, teamwork, and a deep-seated determination to understand the universe we live in.

Ultima Thule is the popular (but unofficial) designation of the object that is, much more prosaically, called MU-69.  It's far out in space by anyone's standards, circling the Sun at an average distance of 44 AU (astronomical units, the average distance from the Earth to the Sun).  By comparison, Neptune -- the outermost actual planet -- orbits at about 30 AU.  Even Pluto (which was downgraded from "planet" to "dwarf planet" status a few years back) orbits at an average 39.5 AU.

So if you reached Pluto, you'd still have a distance of four times the Earth to the Sun to cover before you'd be within hailing distance of Ultima Thule.

And it's not a large object, making me wonder how the hell anyone saw it in the first place.  It's highly oblong, with a long axis of about 33 kilometers and a short axis of 19 kilometers.  So that's the first amazing thing; using the Hubble Space Telescope, we spotted an object only a little more than twice the size of Manhattan Island from a distance of 6.5 trillion kilometers.

Then, astronomers decided it'd be a good place to visit, based on its position with respect to the trajectory of the New Horizons probe, which had sent back stunning photographs of Pluto in 2015.  So off the little spacecraft went, to visit one of the most distant objects known in the Solar System.

The photographs coming back are amazing.  It was known that Ultima Thule was oddly shaped, but as the probe approached, it became clearer and clearer that it was just an oval.  Some of the earliest photographs made it look like a spinning bowling pin.  When it got closer, we were able to see that it was shaped more like a snowman, leading to the inference that it was formed by the collision of two roughly-spherical bodies.  The impact must have been remarkably gentle; too fast, and it would have shattered one or both of the objects.  Instead, they appear to have spiraled in toward one another until finally they kissed -- and stuck together.

[Image courtesy of NASA/JPL]

Astronomers are understandably thrilled by this opportunity to study an object close-up that is observable only as a 26th-magnitude speck of light from our position here on Earth.  Astrophysicist and former member of Queen Brian May wrote a song for the occasion, called "New Horizons," celebrating our perpetual drive for extending what we know about the universe.  (This isn't the first time May has worked his scientific background into his music.  One of Queen's best, and most under-appreciated, songs is the bittersweet and poignant "'39," which has as its basis the bizarre effects of near-lightspeed travel -- especially time dilation, which describes how fast travel slows down the passage of time, so that if you were to leave behind your loved ones and travel near the speed of light, you'd age only a year while the loved ones you left behind would age decades.  If you haven't heard it, click the link -- it's fantastic.)

NASA has promised better photographs as more data comes streaming in from the probe, but the ones they've already gotten are pretty amazing.  When you're looking at them, keep in mind that you're looking at something out there spinning space, half again as far from the Sun as the planet Neptune, and be amazed.

So let's take a break from the constant stream of negativity and vitriol, and consider what incredible journeys we can take into wonderment and beauty, journeys that have taken us into the farthest reaches of the Solar System and beyond.  As we sit down here, engaged in our petty squabbles and petty rhetoric, an intrepid little probe is out there relaying back information about are on the very edges of what we know.  And that, I think, is something about which humanity should rightly be proud.

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Carl Zimmer has been a science writer for a long time, and his contributions -- mostly on the topic of evolution -- have been featured in National Geographic, Discover, and The New York Times, not to mention appearances on Fresh Air, This American Life, and Radiolab.  He's the author of this week's Skeptophilia book recommendation, which is about the connections between genetics, behavior, and human evolution -- She Has Her Mother's Laugh: The Powers, Perversions, and Potentials of Heredity.

Zimmer's lucid, eloquent style makes this book accessible to the layperson, and he not only looks at the science of genetics but its impact on society -- such as our current infatuation with personal DNA tests such as the ones offered by 23 & Me and Ancestry.  It's a brilliant read, and one in which you'll learn not only about our deep connection to our ancestry, but where humanity might be headed.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

Polygons on Pluto

When NASA's New Horizons probe made a flyby of Pluto last summer, it sent back remarkably detailed photographs of this strange frozen dwarf planet, so distant that even one of the fastest man-made vehicles took nine years to get there.  Naturally, it's taken scientists a while to explain what the photographs contained, given our prior lack of knowledge of Pluto's composition.

One of the most curious features noticed were more-or-less straight-sided "polygons" in a region called "Sputnik Planum."  There's no doubting that the pattern is peculiar:

[image courtesy of NASA/JPL]

And of course, all it takes is "peculiar observation" added to "scientists haven't explained this yet" to send the woo-woos of the world off into a dizzying spiral of completely loony speculation.

Here are a few suggestions as to what the "polygons" might be:

• the rubble-strewn walls of an ancient alien city
• a secret base on Pluto designed (possibly with alien help) by NASA.  If you buy this one, then New Horizons was not a research mission, but was going to reestablish contact with people who are already there
• evidence that Pluto is actually the fabled planet Nibiru
• the encampments of a hostile force from another solar system

Apropos of the last one, it didn't take long for someone to remember that Pluto has been identified as the site of H. P. Lovecraft's world "Yuggoth," home to sentient fungus-beings who are able to switch personalities with human beings and keep our consciousness stored in what amount to high-tech tin cans.

So okay.  Let's start with the fact that H. P. Lovecraft's story "The Whisperer in Darkness" is labeled "fiction."  As far as the rest of the hypotheses (I hate to dignify them with that name), allow me simply to say that if I were looking for a place to build a base, Pluto would not be my first choice.  For one thing, I hate cold weather, and Pluto's average surface temperature is -229 C.  Plus, it doesn't appear to have much of an atmosphere, and I kind of like going outside without putting on a space suit.

Additionally, we just got word a couple of days ago from actual scientists (i.e. people who prefer evidence and logic than talking out of their asses) that they now have a good working explanation for the polygons.  Planetary astronomers Andrew J. Dombard and Sean O'Hara of the University of Illinois have proposed that the pattern can be explained by vigorous convection -- what we are seeing are the tops of Rayleigh--Bénard convection cells, which occur when a fluid is heated from below.  (This is what causes the pattern you observe if you carefully add cream to hot coffee without stirring.)

"Evidence suggests this could be a roiling sea of volatile nitrogen ice," Purdue planetary scientist Jay Melosh explained.  "Imagine oatmeal boiling on the stove; it doesn't produce one bubble for the entire pot as the heated oatmeal rises to the surface and the cooler oatmeal is pushed down into the depths, this happens in small sections across the pot, creating a quilted pattern on the surface similar to what we see on Pluto.  Of course, on Pluto this is not a fast process; the overturn within each unit happens at a rate of maybe two centimeters per year."

So once again, we have a cool explanation of an odd natural pattern, without any recourse to aliens, conspiracies, Nibiru, or Yuggoth.  All of which reminds me of the wonderful quote from Tim Minchin: "Throughout history, every mystery ever solved has turned out to be... not magic."

Message in a bottle

The possibility of communicating with an alien race has been a mesmerizing idea for decades.  Even if the science fiction movies of the 1950s mostly depicted aliens as bug-eyed dudes with rubber masks who were intent on destroying civilization as we knew it, the fact that there were so many such movies indicates the level of fascination we had even back then.

Then came the 60s, and Lost in Space, which was so abysmally bad as to be comical, but which had one episode in the first season called "The Sky is Falling" that transcended the idea of extraterrestrial-as-monster; it featured a family of silent aliens (who, to save on makeup and costumes, looked like humans in vaguely Ancient Greek clothing) who were thought to be hostile -- until it turned out that all they wanted was to keep their family members safe, and to meet friendship with friendship.  It was a unique approach back then, and stands out in my mind as one of the best episodes they ever did (not that there was all that much competition in that regard).

Although we've had other horrific concepts of creatures from other planets -- Starship Troopers, Alien, and The Invasion of the Body Snatchers, to name three -- they're counterbalanced by stories like Close Encounters of the Third Kind and, most strikingly, Star Trek: First Contact, which featured a scene that still strikes me as one of the coolest visual images ever -- the first time a human, physicist Zefram Cochrane, shakes hands with a Vulcan:

My thought, when I saw this movie in the theater when it first came out, was, "This would be the coolest thing ever."

Unfortunately, given the distances involved, it's unlikely that we'll ever be visited -- or that we'll ever visit another star system ourselves.  That doesn't mean we can't communicate, though; all it means is that we have to do it a different way.

The idea of sending a message to the stars is near and dear to the heart of journalist Jon Lomberg, who helped Carl Sagan in the design of the golden disks that were sent up on the Voyager missions in 1977.

This time, though, Lomberg wants to go one step further -- he wants to send a detailed digital message from Earth to the New Horizons probe, currently somewhere out past the orbit of Pluto, with the idea that the probe will then carry the message into space.  Where it is possible that it could be intercepted by an intelligent race of extraterrestrials, and the message decoded.

Lomberg wants contributions of what to say -- so he started a site called One Earth: New Horizons Message where people can submit what they'd say to an intelligent alien if they were in Zefram Cochrane's shoes.  "This will be a message from and to the Earth," Lomberg said.  "The very act of creating it will be a powerful reminder that we all share the same, small planet.  We are truly one Earth."

Which is just immensely cool.  I don't know if I'll submit anything -- I don't know that I can come up with anything profound enough to warrant saying to an alien race, and honestly, in Cochrane's place, I'd probably have been so gobsmacked that I would not have been able to get out anything more articulate than "Ub... ub... ub... ub... ub."  But I encourage you to go to the site if you can think of something better than that.  Maybe your submission will be chosen for transmission to New Horizons, where it will then be stored in memory more or less indefinitely.

And perhaps, one day, the probe will be picked up by a passing spaceship, and the message in a bottle decoded.  You have to hope it'll work out better in the end than it did for the alien race in one of the all-time best episodes that Star Trek: The Next Generation ever did, "The Inner Light."  (I've seen this one several times and still cry like a little girl at the end every single time.  If you've seen it, don't lie -- you do, too.)

So that's today's cool science stuff.  If you decide to submit something, post it here in the comments.  Not only are the aliens eagerly awaiting your message, I have to admit to some curiosity, myself.

Postcards from Pluto

I spend a lot of time, here at Skeptophilia, railing at unscientific, irrational views of the world.  Today, I'd like to celebrate a major accomplishment of humanity: this morning, virtually as I'm writing this, the NASA spacecraft New Horizons is making the closest-ever pass of a spacecraft to Pluto.

The magnitude of this feat isn't obvious at first.  Pluto is a small target -- its radius is estimated at about 1,180 kilometers -- and it's so far away that it's hard to picture.  Pluto's average distance from the sun is about 6,000,000,000 kilometers, although its orbit is so eccentric that it varies from a perihelion of 4.4 billion to an aphelion of 7.3 billion kilometers.  So how amazing a feat is this?

Let me give you an analogy.  This is like hitting an object the size of a tennis ball with an object the size of a speck of dust -- from 175 kilometers away.

Thus far, the information that has been coming back has been breathtaking.  Already we have seen that the surface of the planet is rusty-red in color and has a pattern on its surface shaped like a heart; that it seems to have ice caps of some sort; and that on its surface is a mysterious dark formation that's been nicknamed "The Whale," whose structure is as yet undetermined  We stand to learn more about Pluto's composition and history, and the characteristics of its moon Charon -- which, at a radius of about 630 km, is over half as big as the planet itself.  (In fact, astronomer Neil deGrasse Tyson tweeted this weekend, "Pluto’s primary moon Charon is so large that their mutual center-of-mass lies not within Pluto but in empty space.")

Pluto, as seen from New Horizons on July 11, 2015 [image courtesy of NASA]

But even tiny Pluto -- one-sixth the mass of the Earth's Moon, and one-third its volume -- has four other moons.  They've been named Styx, Nix, Kerberos, Hydra, after other denizens of the Greek underworld (Charon, you'll remember, is the ferryman who brings dead souls across the River Styx).  Its surface seems to be made predominantly of various kinds of ice, including frozen nitrogen, methane, and carbon monoxide.  It's lightweight for its size -- its density is only about 2 grams per cubic centimeter, only twice the density of liquid water -- leading astronomers to conjecture that it has a rocky core, and a mantle composed primarily of liquid water and water ice.  If this is correct, Pluto may have the highest percentage composition of water of any object in the Solar System.

Pluto and Charon -- July 11, 2015 [image courtesy of NASA]

And the fun won't end with its closest pass this morning.  The probe is designed to keep sending back data for another sixteen months.  After that, it will continue sailing out of the Solar System, following Voyager 1, which was launched in 1977, and now zooming out into interstellar space, some 12 billion kilometers away.

Some naysayers -- and there are more than you'd think -- have asked why we put time, effort, and (lots of) money into such endeavors.  So we find out the composition of a celestial body five-some-odd billion kilometers away from us.  So what?  What good does it do us?

I think the reason is that knowledge, in and of itself, is a worthy goal.  Always looking at the profit motive -- what benefit will it bring? -- is ignoring the fact that the inspiration gained from reaching for, and achieving, a lofty goal has a worth that can't be measured in dollars.  How many young minds were inspired by previous successes in pure science -- the discovery of how DNA works, the first humans to reach the Moon, the uncovering of countless bizarre fossil animals by paleontologists, the first manned submarine to descend into the Marianas Trench?

And what did those minds go on to accomplish?

I look at the images coming back from New Horizons with nothing but a sense of wonder and curiosity.  Such missions represent one of humanity's most fundamental drives; the thirst for knowledge.  So when you see the images that are coming back from the furthest reaches of the Solar System, don't just think of them as pictures of a distant denizen of our Solar System.  Think of them as symbols of the highest aspirations of the human mind and spirit.