Three Comet Close Encounters 2017-2018
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Three comets will have close encounters with the Earth over the next 2 years; they are the subject of the 4*P Coma Morphology Campaign, an observing program being run by the Planetary Science Institute. All three comets are very small, ranging in size from 1.2 – 1.4 kilometers in diameter, and are classified as Near-Earth Objects (NEOs) due to their proximity to the Earth. Their comas and tails may not be visible to the naked eye (I hesitate to speculate with them being comets and all…), but they will be observable with binoculars and telescopes, and should be good targets for amateurs and professionals alike. The Planetary Science Institute is running this observing campaign nearly identically to what they carried out for Comet ISON (C/2012 S1); they are requesting un-enhanced continuum (dust) images, as well as gas (e.g., CN) images with good signal-to-noise ratio, More photography requirements and info can be found at the campaign website: http://www.psi.edu/41P45P46P “Observations with sufficient signal-to-noise that could be … Continue reading

Across the Universe: Gift of Tongues
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This column first ran in The Tablet in May, 2012 “Men of Galilee, why are you standing there looking at the sky?” We heard that reading a week ago, celebrating the feast of the Ascension. At least, I think that’s what I heard; [in 2012], it was in Japanese, in the small cathedral in Niigata, during an international meeting on asteroids, comets, and meteors. Why do we astronomers stand about, looking at the sky? We heard a number of reasons. One scientist described Nasa’s ambitions to send astronauts to asteroids passing near the Earth. Their expressed reasons involve science (where do asteroids, and we, come from?); resources (commercial efforts to exploit asteroids); and planetary safety (how do we nudge an asteroid out of a collision path with Earth?). The unspoken motivation is political: astronauts at an asteroid is the kind of project that is both exciting and achievable, a reason for voters to support NASA’s budget. We know right now … Continue reading

Across the Universe: Everything You Know Is Wrong
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Pluto continues to make the news… this column dates from November, 2004, in the Tablet. The latest news from out where Pluto orbits has brought to my mind that ‘60s satire of TV science shows, “Everything You Know Is Wrong.” Readers of this column may remember how surprised we were last spring [2004] to find an object, since named Sedna, orbiting nearly twice as far from the Sun as any previously discovered solar system body. That far away, it must be pretty big to reflect even the meager bit of sunlight that we see glancing off its surface; perhaps as big as Pluto itself? How big? That depends on how bright its surface is. We know from their motions how far away from the Sun (and us) Sedna and the other Trans-Neptunian Objects (TNOs) lie. And we can measure how much light from them reaches our telescopes. For a given brightness, that amount of light could mean they were very … Continue reading

Comet 67P/Churyumov–Gerasimenko Before Perihelion
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For the first time in human history, a spacecraft has observed a comet nucleus become active as it reaches perihelion – the point in its orbit when it is closest to the Sun. The Rosetta spacecraft rendezvoused with comet 67P/Churyumov–Gerasimenko in August of 2014, and has watched the comet become active in recent weeks as it neared the Sun. These images, and the science being returned from the Rosetta mission are nothing short of spectacular. Hats off to the ESA and Rosetta mission team! Read the full story here: Rosetta’s big day in the Sun Mission Timeline: Here … Continue reading

Across the Universe: Deep Impact
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This article from The Tablet was first published in June, 2005, a mere ten years ago, just before the “Deep Impact” probe hit. The flyby of the comet then, parallels the flyby of Pluto by New Horizons next month. It’s interesting to see what we were hoping to learn… how little we knew; how little we know. The folks who work out the celestial mechanics of space probes are a clever bunch, with a techie’s sense of humor. A few years ago, the NEAR spacecraft arrived at asteroid Eros on Valentine’s Day. The ill-fated Beagle 2 probe was designed to land on Mars on Christmas morning (not the only present that Christmas to arrive broken, I suspect). And this year [2005], on the Fourth of July, an American probe called “Deep Impact” hopes to make a splash as dramatic as any fireworks display by plunging at 37,100 kilometers per hour – London to New York in nine minutes – into the nucleus of the comet Temple … Continue reading

Across the Universe: The Exploding Centaur
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This column first appeared in The Tablet in April, 2006 It was April Fool’s Day at the Vatican’s telescope in southeastern Arizona, and we’d had three nights of cloudy weather. This night looked promising, however. Bill Romanishin, our colleague at the University of Oklahoma, had given us a list of Kuiper Belt Objects to observe, orbiting out beyond Neptune. Included were some Centaurs, objects that some day might become comets plunging close to the Sun. At the telescope, I was with Steve Tegler from Northern Arizona University. Along with each object, we also observed bits of blank sky, so we could find and remove all the dust spots on the images; and fields of stars whose colours and brightnesses were already well known, so that we could calibrate our objects against these known standards. Around midnight, about halfway into a field of standard stars, Steve looked over his list again and remembered, “Oh, Bill wanted us to try 60558. It’s a Centaur … Continue reading

Open Thread #2: The Messier Marathon
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Lisa Tobias, who also provided our first open thread, expands further on the Messier Marathon that she mentioned there. I know a lot of amateur astronomers and a few professional ones. When you ask, they almost always they’ll you how they have loved the stars since they were kids and how they were so excited when they opened their first telescope box (probably a Wal-Mart special with more power than Galileo ever hoped for). That wasn’t me. I always enjoyed looking at the stars, but that’s all I did. Walking in and out to the car or sitting by the fire at camp; that was enough. I just looked up and imagined. Maybe it was Halley’s Comet that ruined it for me. I was only about 9 when the comet came through, but my school (which was located in the country surrounded by horse farms and corn fields) made a big event to go out and observe the comet. I … Continue reading

Br Guy Diary: February 22, 2015
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This week has been a week of travel, with a bit of science and a lot of outreach. I experience a blizzard in Boston and warm, dry days in California; talked about Vesta and ET’s; and met some alpacas… I arrived in Boston for the Boskone SF convention just before the snow. I also got a morning’s work in, speaking with Cy Opeil at Boston College. He has a lab set up that we’re collaborating with to measure meteorite thermal and physical properties at temperatures down to near absolute zero. The convention was a whirlwind – and that was just the blizzard outside! I actually never left the hotel, given the weather, which meant I stayed warmer than I usually do at that convention. Monday my flight left on time, and so by Monday evening I was in Merced, California, where over the next three days I gave four presentations at the University of California Merced. Great students, great conversations. I’ve … Continue reading

Across the Universe: The best way to travel
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First published in The Tablet in January, 2007   Dark and dreary, January is a time to take off to new and exotic climes; or at least, to daydream about such trips. My own January voyage was a visit to my old hometown, snow-dusted Detroit, to attend a science fiction convention. But a panel discussion at that meeting, “Travel Destinations of the Solar System,” challenged us to imagine really exotic localities. Where among the planets would we love to go? And what it would be like to be standing there, in person? Panelist Bill Higgins, a radiation physicist at Fermi Lab in Chicago, regularly presents spaceflight results as a Nasa “Solar System Ambassador” at events like this. He described how Pluto and its moon Charon orbit each other while locked in a spin state that keeps each body always facing the other. “What if we could stretch a “beanstalk” across the 17,000 km gap between them?” he asked. “We could … Continue reading

Across the Universe: Stardust messages
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First published in The Tablet in January, 2006   Thirty years ago, when I was a doctoral student at the University of Arizona, our campus in Tucson lay beneath the landing path of the Davis-Monthan Air Force Base and every few minutes our planetary science classes would be interrupted by the roar of a jet fighter. But an occasional plane would cross overhead with a different sound… an odd, almost quiet whine. Looking up you’d see the large black cruciform, long straight wings and a thin fuselage, of a U-2 spy plane. For twenty years they’d flown photography missions over Soviet Russia and other cold war hotspots. But one U-2 was different. Rather than spooky black, it was painted pure white. And instead of air force emblems, it flew NASA insignia. A visitor to our Lunar and Planetary Laboratory, Don Brownlee from the University of Washington, explained those flights to us. With boyish enthusiasm – he looked like a teenager, though … Continue reading

Philae Lander Completes Main Science Mission Before Entering Hibernation
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Rosetta’s lander has completed its primary science mission after nearly 57 hours on Comet 67P/Churyumov–Gerasimenko. So much hard work.. getting tired… my battery voltage is approaching the limit soon now pic.twitter.com/GHl4B8NPzm — Philae Lander (@Philae2014) November 14, 2014 After being out of communication visibility with the lander since 09:58 GMT / 10:58 CET on Friday, Rosetta regained contact with Philae at 22:19 GMT /23:19 CET last night. The signal was initially intermittent, but quickly stabilized and remained very good until 00:36 GMT / 01:36 CET this morning. In that time, the lander returned all of its housekeeping data, as well as science data from the targeted instruments, including ROLIS, COSAC, Ptolemy, SD2 and CONSERT. This completed the measurements planned for the final block of experiments on the surface. In addition, the lander’s body was lifted by about 4 cm and rotated about 35° in an attempt to receive more solar energy. But as the last science data fed back to … Continue reading