One Shimmery Lake

Titan Has a Liquid Lake: is this News?  Yeah!!

A flash of sunlight glints off a lake on Titan, one of the moons of Saturn. Courtesy NASA and the Cassini Equinox Mission.

I know this hit the news a few days ago, but it’s such an historical image that I wanted to show it here.

If you’ve been buried hip-deep in holiday preparations and celebrations, you might not have known that the Cassini Equinox Mission returned an image of Titan that shows a lake of liquid something on the surface of the cloud-shrouded moon of Saturn.  That lake is called Kraken Mare.

That little flash of light you see is a specular reflection off the surface of the liquid. Specular reflections are commonly seen on Earth when the sunlight flashes off bodies of water here. But, this is not likely to be water on Titan. Kraken is a hydrocarbon lake (hydrocarbons are things like methane and ethane). It stretches across about 400,000 square kilometers (150,000 square miles) across the northern surface.

Now, the cool thing about this image (along with the flash) is that we can actually even detect that glint. Most of the time Titan is covered in clouds.  Optically it makes it very difficult to see anything on the surface, but wavelengths of infrared light get through.  As Saturn and Titan approach their spring equinox, the viewing angle is just right, and scientists using an infrared-sensitive instrument onboard the Cassini spacecraft were able to detect the glint in infrared wavelengths.  This is pretty exciting news.  It’s cool because it’s there, first of all, and second because we’ve been able to see it with special instruments.  Third, the existence of that lake will help planetary scientists understand more about the interactions between the surface and the atmosphere of Titan and the conditions that help make the existence of that lake possible. Stay tuned!

Willing Suspension of Disbelief

That 2012 Stuff

This is, as the old song says, “the most wonderful time of the year.”  If you celebrate any sort of holiday in December — from Hanukkah to Christmas to Festivus to Yuletide to Kwanzaa to many, many others, you’re familiar with wonderful traditions that celebrate something at this time of year.

There’s an astronomy component to celebrations at this time of year and it has to do with the winter solstice — the shortest day of the year and the point at which the Sun appears at its lowest point in the sky (for the northern hemisphere, anyway).  Historically, the earliest humans likely noted the position of the Sun in the sky throughout the year and devised rituals and celebrations around the solstice times (the summer solstice marks the point when the Sun is at its highest point in the sky).  Over time, as other cultures, religions, and rituals evolved, people began ascribing more mystical and ritual significance to this otherwise purely physical lineup of the Sun and Earth as Earth orbits the Sun.

I think it’s only natural that people at any age of our history would devise such rituals — although they have nothing to do with our scientific understanding of Earth’s orbit around the Sun, and the Earth’s tilt on its axis, and so forth.  They’re rituals that began as ways to help people deal with what seemed to be supernatural — i.e, the Sun’s yearly and daily path across the sky, the changing sets of star patterns we see at night throughout the year, and so forth. Charting those constellations and the motions of the Sun, Moon and planets across the backdrop of the sky was the basis for the ancient practice of astrology.   Astronomical charts came to us through those early sky mappers who were, nonetheless, adherents to mysticism, which is not a scientific way of thinking.

Science and mysticism moved apart pretty quickly when people began ascribing some powerful (but immeasurable and unprovable) influences to the constellations (which are, after all, simply random patterns of stars that we somehow recognize from our point of view on Earth as shapes of animals, people, and things), or some magical power that a planet that lies billions of miles away has on a child at birth.  Such ideas are more in the realm of human mysticism and spirituality and the forces and processes they invoke have never been detected or measured scientifically. And, in science, if it can’t be observed and measured, it’s tough to prove it exists or does what people claim it does. That’s why scientific investigations of things like ESP and astrology and crop circles and UFO “apparitions” always turn up empty — there’s nothing to measure or prove. And, just because someone says something’s mystical and wonderful and THEY can see it, doesn’t mean it exists in the reality-based world of science.

That doesn’t mean that people aren’t attracted to the mysticism that early skygazers imagined existed within the stars and planets.  Humans are born with this ability to suspend disbelief in order to believe that something exists or happened, even if it never did. Look at it this way — we read fantasy and science fiction and watch anime movies and follow Star Trek (for example) and we know that those events and people don’t exist, but we can overlook that for the sake of a good story.  Cultural star legends are built around the constellations and planets, but they’re often couched in terms of gods and goddesses, kings and queens, and mythical animals like centaurs. Those legends teach lessons and transmit cultural information. But, they have little to do with the science that explains those stars and planets.

When mysticism claims to have proofs that pretend to be science or even supplant or ignore scientific research (such as is done with modern-day astrology), then it goes too far, even for a “good story.”  One of the “good stories” I’ve been reading about lately (and it’s not even all that good since it doesn’t hang together logically as a fairy tale, let alone as good science), is about the so-called 2012 Prophecies. They conflate a  somehow-apocalyptic line-up of planets, combined with some kind of galactic beam that’s headed straight for us, along with a mysterious planet (that nobody’s observed yet, but some folks claim it exists) that’s going to shift out of its orbit and collide with Earth, into a world-bashing scenario that boggles the mind. Some Web sites that “discuss” this set of predictions also include some peripheral claims that we’ll be experiencing pole shifts, increased volcanic eruptions, psychic disruptions (well, they may be right there, but not in the way they think) and — oh my gawd — human evolution!!!

Can you stand it??

All this is being touted by a mind-boggling collection of astrologers, mystics, out-of-body proponents, crop-circle believers, amateur archaeologists, and others with little to no scientific training or understanding. Oh, and people who have books and other products to sell about this nonsense.

Apparently all this apocalyptic oogah-boogah is going to happen on the winter solstice in the year 2012. And, at the root of the thing is a claim that the whole thing was predicted by the Maya civilization that largely died out in the 1500s.  There’s even been a movie made exploiting the pseudo-scientific claims that the 2012 Apocalypse pushers are splashing all over the Web.  I heard the movie did boffo biz at the box office, and that it has great special effects.

Well, the 2012 predictions and associated pseudo-science don’t reflect reality any more than a fairy tale does. But, interestingly, the whole thing does reflect our very human propensity to suspend disbelief for the sake of a good story. It essentially combines end-of-the-world predictions (which are pretty common) with ancient religions and misunderstandings about science to create a nonsense mashup of epic proportions that sounds vaguely scientific and “woooooo” all at the same time. What’s not to like about that?

Of course, all of us who talk and write about astronomy are getting questions about this 2012 stuff. It’s inevitable — and it’s also a good chance to do a little proactive astronomy teaching and help people build up their Nonsense Detectors.  I did this with two of my cruise lectures and people seemed to appreciate the “heads-up” on the phenomenon. Of course, I think a lot of people don’t really buy into the 2012 “predictions” — but there are enough of them out there that do.

So, I and people like my friend Dr. Ed Krupp at Griffith Observatory, and many others are giving talks and writing articles and blog entries to give people the “straight skinny” on what it’s all about. I highly recommend Dr. Krupp’s article and a recorded talk he gave for the National Academies of Science on the subject. Dr. Krupp is an engaging speaker and, as one of the world’s experts on the astronomy of the Maya, is the man to talk to when it comes to what the Maya calendar says as it relates to astronomy and any s0-called “predictions” the Maya are claimed to have made. He’s also an astronomer and all-around good guy.  Check it out!

More Starbirth Than You Can Shake a Telescope At

Hubble Peers Into a Stellar Nursery

R136 in the Large Magellanic Cloud, courtesy of Hubble Space Telescope. Click to embiggen.

Every time I turn around, Hubble Space Telescope is looking at another fantastic place in the cosmos. This time, it’s a massive region of starbirth, where gigantic hot young newborn stars are crowded together in an area where there are even MORE stars are still being  created.

The scene that Hubble imaged is 30 Doradus, a starbirth nursery that’s wracked with the turbulent winds and activity that accompany the births of stars in close quarters.  The hot blue stars you see in this image are part of a cluster called R136. They are but a few million years old and lie about 170,000 light-years away in the neighboring Large Magellanic Cloud (a companion galaxy to the Milky Way).

Many of these icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun.  They may look pretty now, but in a few million years, they will have spent their nuclear fuel and will start to pop off like firecrackers in giant supernova explosions.

The clouds surrounding these stars are being carved away by relentless and prodigious amounts of ultraviolet radiation and stellar winds pouring off the hot young stellar beauties.  That action is etching away at the enveloping hydrogen gas cloud in which the stars were born — and, in the process, in some places it may well be choking off the materials that other stars that need to form in the future.

Now, the stellar winds and radiation aren’t the only action going on here. The motion of the Large Magellanic Cloud itself may have played a huge role in starting the whole star-birth process in 30 Doradus.  First, the gravitational tug of the Milky Way and the companion Small Magellanic Cloud may have acted together to push the gas clouds in the LMC together.  You need highly compressed clouds of gas and dust to start the stellar nursery chugging away cranking out new stars.

It’s also likely that when the Large Magellanic Cloud plowed through the halo of the Milky Way in the distant past, that action could also have compressed clouds of gas and dust, setting the stage for star formation. As fascinating as this is because it’s happening relatively near to our galaxy, this same scene has played itself out many times through out the early history of the universe. In distant regions where galaxies have collided, massive clusters like R136 are common and this tells us that glaaxy interactions are a great spur to star birth.  This image is a great example of studying something close to us that gives us great insight into something that happened in galaxies long ago and far, far away.