Across the Universe: Clouds of witnesses
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This column first ran in The Tablet in September, 2016 Scientists communicate with images. We want to know not simply one value, but how each value compares with other values measured in other situations: other times, other samples, other planets. Picturing our data as spots on a grid is worth a thousand numbers. At the 2016 meeting of the Meteoritical Society in Berlin, every paper relied on images with specks of many colors (each color also a different shape, for the the color-blind) representing different sets of data. No number is perfect; no single measurement is perfect. We repeat each measurement tens, hundreds, thousands of times. If you were to plot each measurement you’d get a cloud of dots and hope that the truth is somewhere within that cloud. The better your precision, the tighter your cloud, the better you can guess where the truth may lie. Instead of plotting all the thousands of individual measurements, though, it’s usually sufficient to … Continue reading

Dusted by stars
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I have had Jon Larsen’s  In Search of Stardust on my stack of books to read because last spring the upper division research methods course I taught did an experiment to measure the heat capacities of meteorites, using the method developed by the Vatican Observatory’s Guy Consolmagno, SJ and Bob Macke, SJ and colleagues. The students were curious about the astrochemistry context (where do the samples come from, how can you distinguish regular rocks from these stony aliens) and I’ve been collecting resources for this coming spring when a new batch of students will make these measurements. I tend to think of meteor strikes as spectacular and rare events, fireballs roaring through the sky that finally come crashing to earth.  Still they aren’t as rare was you might think — tens of thousands of meteorites weighing as much or more than a euro coin hit the earth’s surface each year, most of them landing in the water.  It gives me a visceral … Continue reading

Across the Universe: Pennies from heaven
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A slightly shorter version of this column first ran in The Tablet in August 2012 Scientists who do experiments need material to experiment on. Thirty years ago, a grad student friend of mine ran into a problem researching motor skill development in infants because there were too many other students in her field writing theses, and not nearly enough infants available in her university town with parents willing to have them studied. (Ironically, my friend was herself pregnant at the time. Her baby, now grown, defended her own psychology dissertation in the fall of 2012; she’s now a psychology professor herself. And a mom, as well.) In meteoritics we cannot advertise for samples, much less produce them ourselves. We have to wait for our subject matter to fall, like manna, from the heavens. In 2012, however, we were fortunate to have two fascinating new meteorites land at our feet. They were each the subject of special sessions at the annual … Continue reading

Across the Universe: Hidden inclusions
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This column first ran in The Tablet in July 2013 I was in a state of high excitement (or what passes for such when you’re sixty years old): the Pope was coming to lunch with our Jesuit community at the Vatican Observatory! Meanwhile, I was also preparing a paper for the annual Meteoritical Society meeting, and I had just noticed a wonderful correlation in my data. These sorts of insights are as rare as Papal visits… if indeed I had really made one. I’ve been studying iron meteorites; and it’s been hard work. For one thing, they are, quite literally, hard – lumps of nickel-iron, too hard to cut up easily to see what’s inside. I’ve seen iron meteorites being cut at the Smithsonian in Washington, DC; their saw sits in a room the size of gymnasium, makes an awful racket, and spews water everywhere. (The water cools the meteorite while a diamond-encrusted wire scrapes through it.) When you do … Continue reading

Across the Universe: Rocket Science
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This column first ran in The Tablet in April 2012 “This isn’t rocket science…” It’s a common reproach, heard when we make a simple task too complex. Of course, making a rocket work is not science; it’s engineering. The difference between the two is like the difference between theology and liturgy. Both are important, and each informs the other, but it’s dangerous (in both directions) to substitute the one for the other. Another flaw in the cliché is that it assumes launching a rocket is the height of complexity. In fact, it’s a well-understood piece of engineering. Today’s rockets are marvelous pieces of machinery, and getting it right can indeed be harder than it looks (see the recent failure of North Korea’s attempt). But the basic principles are nothing new. The rockets that lift supplies to the International Space Station today are Soviet designs dating from the cold war, more than half a century old. The issue, as the North Koreans … Continue reading

Across the Universe: Touched by Heaven
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This column first ran in The Tablet in January 2014 On February, 15, 2013 [one year before this column first ran], a twenty-meter chunk of space rock hit the Earth over Chelyabinsk, Siberia. Shining brighter than the sun, its fall was recorded by video cameras as far as 700 km away. Thousands of people in Chelyabinsk ran to their windows to see what that bright light was; a few moments later, the impact’s sonic boom arrived and shattered those windows. More than 1500 people were hurt by flying glass and debris. Seventy kilometers west of Chelyabinsk, an eight meter wide hole was found in the ice of Lake Chebarkul; last summer, a half-ton meteorite was recovered from the lake bottom. It’s not every day that a rock with half a megaton of energy hits the Earth above a major city (a million people live in Chelyabinsk). But near earth asteroids are hardly rare. The Minor Planet Center in Cambridge, Massachusetts, keeps … Continue reading

Across the Universe: The New Paganism
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The following column was published in The Tablet in November 2009 You will know the end-times by their signs, we’re told in the Gospel readings at this time of year. Given the nature of those signs, mostly dramatic events in the sky, you can imagine the kinds of questions that are typically addressed to those of us who study meteorite falls. The apocalyptic visions in the Gospels bear a certain resemblance to our understanding of the destruction that an asteroid impact would produce. Is it mere coincidence? Do I have any advice for the fearful? Yes: read the Gospel passages in their context as lessons on how to live, not how we’ll die. Meanwhile, quit smoking and wear your seat belt. That said, what does science tell us about the end of the world? We know that our solar system has a finite lifetime. Stars like our Sun can only shine for about ten billion years before they run out of … Continue reading

Across the Universe: Featureless Features
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At the end of September 2016, Rosetta finally ended its mission by crashing into its comet. This column, about an earlier aspect of the Rosetta mission, first appeared in The Tablet in October 2010   Back in July [2010], ESA’s Rosetta spacecraft, en route to a comet rendezvous in 2014, flew past asteroid Lutetia, a 100 km pile of rock orbiting between Mars and Jupiter. The result of that encounter was a hot topic of both the European Planetary Science Conference in Rome in September and a meeting of American planetary astronomers in Pasadena in October [2010]. Studying asteroids has always been challenging. Even in the largest telescopes they’re mere dots of light, too small to show any shapes, much less surface details. We can only infer their nature from the most subtle of hints: how their brightness varies as they spin, how much infrared light they radiate, their visible and infrared colours. Minerals that contain iron oxide or water reveal themselves by … Continue reading

Across the Universe: Stellar Round Up
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This column first appeared in The Tablet in October 2008 Black Mesa, Oklahoma sounds like the setting for a Hollywood Western. It looks like one, too. Every year at the Okie-Tex Star Party, three hundred amateur astronomers camp out for a week with their telescopes there, in hopes of dark dry skies. Some of their “amateur” instruments are larger in aperture than the telescopes of the Vatican Observatory in Castel Gandolfo. The miracle of computerized fabrication and the modern Dobsonian mount (a way of holding a telescope in place that replaces complex hardware with simple Teflon pads) has brought the cost of quality optics to the point where the price of a large telescope can be less than that of a small automobile. My GPS unit directed me as far as Boise City, two hours north of Amarillo, Texas; after that, I was following roads too small for most maps. I was there to give a series of talks during … Continue reading

Across the Universe: Taking the Heat
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This column from The Tablet first ran in September 2011 Science is a marriage of theory and experiment. Sometimes the marriage is literal. The colleagues I visited this month [2011] at Louisiana State University, Brad and Martha Schaefer, have been married 30 years; she’s a whiz in the lab, he’s a math guru. The three of us have been looking for a quick and non-destructive way to measure the heat absorbed in a meteorite when it is raised from the cold temperatures of space to the temperature where water melts. Meteoritic material is typical of the rocky stuff mixed with ice in the moons of Jupiter and Saturn; if those moons melt, the molten regions could be oceans of life beneath their icy crusts. Indeed, Jupiter’s moons deflect its magnetic field in just the way you’d expect from deep internal oceans; and, more dramatically, we actually see geysers spurting out the surface of the Saturn moon, Enceladus. If you want … Continue reading

Get ready the Perseids are coming
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About 30 years ago we had a holiday in a remote location in the West of Ireland. The house was high on a grassy ridge on Bolus Head looking over St Finian’s Bay in Co Kerry. From this vantage point the 350 million year old Skellig Rocks rose like stegosaurus plates from the Atlantic Ocean. They were 16 kilometres out to sea but their jagged presence dominated the view to the South. It was early August and when darkness fell the predictable blinking of a distant lighthouse was the only manmade object discernible at sea level in the blackness. One moonless evening, the sky was crystal clear, the summer triangle was dramatically intersected by our galaxy’s river of stars, so much more touchable than the suburban view. I lay on the sun dried grass looking for Perseids, one, two, three, four, five, six, plus several in the corner of my eye within a few minutes. Time to take action, I … Continue reading

Across the Universe: Grain of truth
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This column first ran in The Tablet in June, 2010. Travel, a favorite summer pastime, carries with it certain social perils. After I came back from my Peace Corps service, it was astonishing how often I would find myself uttering “when I was in Africa…” as every conversation would seem to trigger some memory I just had to share. Ten years later I added “when I was in Antarctica” to my repertoire. Thank God for patient friends. I recall telling a colleague about a star-gazing trip I was planning to Australia in August. He lamented that his only trip there was cloudy the entire week, so he didn’t get a chance to see any of the southern stars. “The only time I remember ever getting to see the Southern Cross was out Shuttle’s porthole…” One-upped by an astronaut! (Thanks, Tom Jones.) But even my astronaut friend has not had a voyage like the space probe Hayabusa. Launched by the Japanese Space Agency in … Continue reading