What are the Odds?

So, you’re standing there on the golf course at the last hole, waiting to sink your final putt of the game. The other members of your foursome have finished and it’s up to you to go for par. You bend over and take a practice putt, concentrating on the lie, the break, the distance to the hole, the wind speed, the time of day—all the factors that influence your putts.

Suddenly from out of nowhere comes a burned-out little piece of slag. It whooshes past your head and lands directly in the cup for a hole-in-one, shattering into pieces as it does so.

I logged into a discussion board earlier today and found the members all chattering up such a scenario, based on a story on today’s CNN.com: Space Station Cosmonaut ‘go’ for golf stunt.

Of course, being the pragmatic scientist (and former golfer) that I am, I felt constrained to point out that such a cosmic hole in one is pretty unlikely to happen. The biggest reason is that the golf ball is going to burn up in the atmosphere on its way down to Earth’s surface. Anything that’s left is going to be ash, or less.

But, just for fun, let’s imagine that some piece of the golf ball survives the trip. While the odds are against this happening, think about the variables in the problem.

First there’s the composition of the golf ball, which we assume meets at least some of the standards of the Royal and Ancient Golf Club of St. Andrews and the U.S. Golfing Association (which appears to be a world-wide standard). (Those standards are laid out here, if you’re interested.) The golf ball to be hit from the station will weigh considerably less than most regulation balls, coming in at only 3 grams, while regulation balls are heavier, but cannot weigh more than 45.9 grams.

Then, there’s the whole question of the construction of the golf ball to be used. It’s not mentioned in the story. However, a typical golf ball has a hard rubber core, a wound secondary layer (usually some kind of polymer), and a hard outer covering made of some kind of plastic. You know what happens to plastics when they are heated, so imagine this 3-gram ball slicing through our atmosphere, and the kind of friction it will encounter. (And, keep in mind that an incoming meteor (a rock!) of the same size as a golf ball is likely to burn up (although maybe not completely, depending the variables of its flight and its composition) on its way in.)

Other variables? We know the speed of the space station from which the golf ball will be hit, the rotation speed of Earth, the size and weight of the golf ball, and the gravitational pull it will feel as it comes down. What we don’t know is the strength of the cosmonaut’s swing, the direction he’ll hit it in, or whether or not he’ll slice it and send the ball whacking off some piece of the space station, thus changing its trajectory entirely. (Which reminds me of the last golf scramble I played in. My younger brother was part of the foursome and he has a hell of a swing. He stepped up to the tee, sliced the ball, sending it underneath the golf cart, where it swirled around and came shooting out the other side and hit a tree. Not only were WE staggering around laugh so hard it hurt, but the foursome of doctors behind us was howling in laughter, too. But I digress.)

A fun thought problem, but in reality the”Whack a Golf Ball off the Space Station” thing is just what CNN says it is—a publicity stunt to commemorate Alan Shepard whacking golf balls across the surface of the Moon during Apollo 14. It’s pretty unlikely that anybody on Earth will do more than hear about it on the evening news late on Thanksgiving Day this year.

But, if you’re a science teacher or somebody who likes to pose thought problems to people, this story might be a good way to teach a few basics in physics or strike up a heated discussion at a party.

Travel Pages Posted

In other news, we finally got our web pages up describing our trip to Australia and the tour of astronomy installations we made. While this was primarily a business trip, we did manage to have some fun and see some great stuff along the way. So, in the grand tradition of all those “What I did on my trip” stories, here’s a link to our trip pages:
Australia Trip Pages.

Snakes on a (Galactic) Plane

While we’re waiting for the IAU to decide on the latest planet definitions, let’s turn our attention to a pair of constellations that lie in the southern part of the northern hemisphere sky at this time of year (mid to late summer): Ophiuchus and Serpens. They both lie near the plane of the galaxy, and believe me, finding a play on the words in the name of a popular movie and relating it to astronomy has been bugging me for days!

So, work with me here. It’s been a long, hot summer. You wanna see some other kinds of snakes on a plane? Step outside tonight, face south and look around for the familiar teapot of Sagittarius or the S-shaped sweep of Scorpius. Ophiuchus is just above the heart of the Scorpion, the red star Antares.

Courtesy of StarrySkies.com (and a link to a fine, large sky chart).

This chart shows you the general outlines of Ophiuchus and his ophidian companion. One half of the snake (Serpens Cauda) points toward Aquila the Eagle (with the bright star Altair), and the other half of the snake (Serpens Caput) points toward Corona Borealis (the northern crown).

So, that’s the snake part. To get the plane part, just scan the sky with binoculars (or your naked eye if you happen to have good dark skies) and you’ll be looking at the plane of the Milky Way, and in particular, you’ll be looking toward the center of our galaxy. What more could you ask for, and it’s not even scary!

It Makes Plutonic Sense

By now you’ve probably read a bunch of stories in the media about how Pluto is still a planet, how astronomers have decided it’s the head of a new class of planets called “plutons” and how millions of school children will be relieved to know that everything they were taught in school about planets isn’t wrong. Of course, that’s not the only news coming out of the International Astronomical Union meeting in Prague this week, but it seems to be the story the mainstream media has latched onto with great gusto.

On Tuesday, CNN’s lead science story focused on how Pluto could shortly lose its planet status. I thought they were sort of jumping the gun, since I’m pretty sure they had the same advance embargoed press release that I did, explaining the IAU’s proposed new classifications for planets. (Embargo means that the news is released early so that the media can prepare stories, but they can’t print or release the story until a specific time. In this case, the news was sent out early Tuesday for release at 2 AM Eastern Daylight Time in the United States). So, they had all day yesterday to put together some story that would prepare people for the proposal by the IAU to keep Pluto as a planet AND make some new classifications of planets (including the Sun) that would help us understand the nature of the largest bodies that orbit stars.

To be fair, CNN’s story today (go to CNN.com) leads the news on the website, with a real emphasis on how our perceptions of the solar system have changed with discoveries of new solar system bodies.

Still, it’s tough to blame the media for latching onto a story that’s easy to tell in screaming headlines: Pluto Might Not be a Planet: Children Everywhere Dismayed! It’s got drama, science, crying children, duelling scientists: what’s not to like?

Maybe I’m tough on the media; I was trained as a science journalist and have worked in astronomy research, so I can see both sides of the story. Rarely does the whole story get into the papers. For one thing it’s just too tough for the average reporter to take a complex science topic and write about it well. There ARE good science writers out there, but they’re not as common at media outlets as we’d like to think. And they have to report on all science, not just astronomy. But, since astronomy is a science that can take you pretty easily into all sciences, and because it excites people’s imaginations so well, I’d sure like to see better reporting on it.

But, I digress. There are several REAL stories here about Pluto and the planets. One of them is that astronomy has always been at least one part observation, one part theory, and one part classification of what we’ve observed. Rethinking our definition of “planet” is actually a long-overdue move on the part of astronomers. Back when our telescopes could barely show us even such giants as Jupiter and Uranus, it was pretty easy to classify planets into the scheme we used for hundreds of years. Now that we have telescopes (both on Earth and in orbit) that can show us mere specks of ice and rock in orbit in the most distant reaches of the solar system, as well as giant planets (and some not-so-giants) around faraway stars, the business of classifying what we see got more complex. Pluto has always been called a planet, but in recent years we’ve found objects that are bigger than Pluto, albeit farther away. What to call them? And if they’re planets, what’s that make Pluto? The situation needed clarification.

So, the IAU (which was charged by the world’s astronomers to come up with a solution) proposed that we refine our classifications of what planets are. Their decision, which still has to be voted on by the astronomers meeting in Prague, clarifies the parameters for what’s a planet and what isn’t by applying some easy-to-understand definitions.

What they’ve done is to keep Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune as “classical planets.” But these aren’t the only planets. There’s a new class of them out there, of which Pluto is the king: the “plutons.” This is what astronomers will now call the rapidly growing class of worlds being discovered in the outer reaches of the solar system. This includes Pluto and Pluto-like objects. You may have read about the discovery of some of these plutons in the past few years, like the one called Quaoar. Ceres, formerly called a minor planet, is also part of this group. These plutons likely outnumber the classical planets by many orders of magnitude because there are so many of them out there. We haven’t discovered them all, but they are part of the solar system’s most distant population of objects, which astronomers are exploring with stronger and better telescopes each day.

So, the story here is that Pluto’s still a planet, for sure. But, in coming up with the new classification, astronomers are doing what they’ve always done when their technology improves and shows them more variety in the universe: they find new ways to describe the new objects. We did it with galaxy types, we did it with star types, we’re doing it with cluster types, and now we’re doing it with planet types. And that’s the way science often works. New types give new understanding and help resolve old disputes. While not all astronomers are going to completely agree with the IAU’s proposal, I think most of them recognize that somebody had to bring some order out of the chaos introduced by the discovery of so many new objects out on the frontiers of the solar system.