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: Heavenly Visitors
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This column first ran in The Tablet in December 2006 The reporter from the BBC was shocked that I wasn’t shocked: Could the seeds of life have come to Earth from outer space? He was interviewing me about a new [in 2006] discovery published in Science. In a meteorite retrieved from a frozen lake in northern Canada, researchers found chemical compounds that could be the precursors of life, sitting in small round voids that could have served as the templates for early cells. Meteorites are my business, and the scientists cited are colleagues and friends of mine, but even so I couldn’t understand why a BBC reporter in London was trying to interview me. The data are new and intriguing, yes, but it’s hardly a new idea. For more than 150 years, meteorites have been known to contain organic chemicals. “But doesn’t the stuff of life coming to us from off the Earth contradict the Church’s teaching that only Earth is … 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: Dawn of My Belief
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This column first ran in The Tablet in June 2011 As a graduate student in 1976 I gave a paper to the Meteoritical Society about a theory that I (and my thesis advisor) had developed concerning a rare class of meteorites which appeared to be bits of lava from the surface of an asteroid. While most asteroids are collections of metal and rock, we knew that some of them must have melted; for one, asteroid Vesta’s infrared colors exactly matched the spectra of these basaltic meteorites. Our work determined that for every gram of lava in these meteorites, there should have been another nine grams of residue in its parent asteroid. After my talk, a grand old man of the field approached me. “If these meteorites come from an melted asteroid,” he asked, “lavas flowing to the top and residue in the center, then once it was broken into meteorites, shouldn’t we have we seen nine times as many meteorites from … 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

Across the Universe: Treasure from Heaven
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This column first ran in The Tablet in May, 2009 Above the Arizona sky the night of October 5, 2008, a faint moving dot of light was captured in the Skywatch telescope. Soon its orbit was calculated, showing that this newly discovered asteroid, 2008 TC3, had only 20 hours left before it was to hit the Earth. Two dozen teams of astronomers made every possible use of that time, measuring its colors and changing brightness as it spun across the sky, and further refining its orbital path. On the morning of October 7 (local time), a tumbling lump the size of a white van struck the sky over northern Sudan. Seven months later, in a quiet conference room in Prague, Peter Jenniskens told a rapt audience of bolide and meteorite specialists (I was one) the story of what happened next. Through e-mails to friends and colleagues, this Dutch-American meteor specialist had made contact with a geologist at the University of … Continue reading

Across the Universe: Touch the Sky
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This column first ran in The Tablet in April, 2010 Next summer [2011], the “Dawn” spacecraft will go into orbit around Ceres and Vesta, biggest and brightest of the asteroids. (Indeed they are so much larger than the other asteroids that they may be better classified as dwarf planets.) These bodies have been well studied by telescope for more than 200 years – Ceres was discovered on New Year’s Day, 1801, by the Sicilian priest-astronomer Giuseppe Piazzi – but seeing them remotely is nothing like getting a close-up view. [In April of 2010], a team of scientists and engineers met in Rome to prepare for Dawn’s arrival, and they spent a morning visiting our observatory in Castel Gandolfo. For reasons ranging from the way they reflect infrared light to the conclusions of computer models for their chemical evolution (including work I was involved with more than thirty years ago), we believe that certain meteorites in our collections are actual samples of … Continue reading

Across the Universe: The Still Voice in the Chaos
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This column first appeared in The Tablet in January, 2010. During the Apollo 17 walk on the Moon, the astronauts collected a rock for the specific purpose of providing samples to pass out to nations around the world. About 200 Apollo 17 samples were distributed in this way. But Robert Pearlman, who runs the space-news website collectspace.com, wrote in 2010 that NASA can now account for only 61 of them. (The one sent to the Vatican resides in our display case at the Vatican Observatory.) I’m not surprised; keeping track of samples is harder than it looks. The humor of the “Night at the Museum” movies comes from the conceit that the specimens in a museum’s display cases are alive, that they get up and move around during the night. Every collector knows that feeling. It’s surprisingly hard to keep our collections in order. One of the little breakthroughs in my own research was finding that a simple measurement of a … Continue reading

Across the Universe: Words that Change Reality
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My columns for The Tablet often act as a diary of sorts, recording important events in science or in my own life. Such is this column, which first ran in September, 2006. Ten years ago last month [2006], Dave McKay and his colleagues at Nasa’s Johnson Space Center in Houston announced that a meteorite, believed to have come from Mars, showed evidence of microbial life. Their interpretations are still widely disputed by the meteoritics community. But, oddly, their announcement resulted in one major change of attitudes. Before, there were still skeptics who were not sure that those rocks came from Mars; now, as the skeptics argue about the putative biogenic grains found in it, no one doubts the Martian origin anymore! Some of us can only be skeptical of one thing at a time, I guess. Still, what you call the meteorite doesn’t really change its nature. Either it is, or it is not, from Mars. Either it is, or … Continue reading

Across the Universe: Help My Unbelief
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This column was published in The Tablet in August, 2007 We believe in things we don’t see — like electrons, or black holes — because they let us make sense of things we do see. But sometimes we don’t believe, even when we see. The question of what we believe, and why we believe in it, struck me particularly this past week [2007] at the annual meeting of the Meteoritical Society. A French mathematician has analyzed the dates meteorites have been seen to fall over the past 200 years and found clear trends, at the 90% confidence level: more meteorites than usual tend to fall every 3 years, every 10 years, and every 17 years. His analysis is standard, straightforward stuff; but I don’t believe it. Nor did anyone else in the audience. Two hundred years just doesn’t seem long enough to show such periodicities. And we’ve been burned before with theories that had only a 10% formal chance of … Continue reading

Across the Universe: Off The Beach
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This column first appeared in The Tablet in August 2004. Scientists have a reputation of being nerds with no social skills, and yet like actors and athletes we spend most of our careers working in teams. It’s a rare scientific paper that has only one author. This social aspect of science is especially clear at the annual meetings of scientific organizations. Obviously meetings are important for practical reasons. If you don’t tell anyone what you’ve done, you might as well not have done it. If you don’t know what others are doing, you can’t pitch in to help the field along. And if we didn’t have meeting deadlines to meet, we’d never get the work done! But meetings are also attractive precisely because they are social events. The first week of August [2004] found me in a resort hotel on the beach of Rio de Janeiro with two hundred other meteorite specialists, listening to a hundred talks and joining in … Continue reading

Across the Universe: Key to the Sea and Sky
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This column first ran in The Tablet in July 2007   In Alicante, on Spain’s Mediterranean coast, a group of us planetary astronomers held a workshop on how asteroids respond to the massive collisions that can lead to their catastrophic disruption. Just north of us, in Valencia, sailors from Switzerland and New Zealand were vying for the America’s Cup. The connection between elegant million dollar yachts and exploding asteroids is the equations of fluid dynamics. I’ve loved sailing since my childhood; I spent my summers capsizing sailboards on Lake Huron and my winters reading too much Arthur Ransome. As a student in the early 1970s I competed on MIT’s sailing team (the Charles River was indeed “dirty water”), and attended lectures in their ocean engineering department on the challenges of designing the best shape for a hull that could slip through the water with a minimum of friction while still providing the resistance to leeward slip that lets a sailboat claw … Continue reading