Word: dust
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Dates: during 2000-2009
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Soil: Paint dust, leaded-gas exhaust and industrial sources add to naturally occurring lead...
...probably flowed billions of years ago on the surfaces of Mars, and maybe Venus as well - came from icy comets, raining down on the newborn planets. As for where the comets came from, it's long been assumed that they formed directly out of clouds of interstellar gas and dust. That's why scientists are so interested in them: by studying comets, they figured they could get a handle on material that's been unchanged for billions of years...
...simple. Published in the Aug. 30 issue of Nature, the paper shows that the creation of a comet is probably a much more complicated process than anyone thought. The evidence comes from the Spitzer Space Telescope, which uses infrared-sensitive cameras to peer through the shroud of dust that surrounds newly forming planetary systems to see what's going on inside. In one such system, known as IRAS 4B, about 1,000 light-years from Earth, astronomers from the University of Rochester have detected a disk-shaped knot of material that will one day emerge as a suite of planets...
...Rochester astronomers are right, the idea that comets are pristine remnants of the material from which our solar system originally formed isn't going to hold up. Indeed, last year, comet-dust particles brought back by NASA's Stardust mission showed that the particles had been heated to high temperatures sometime in their lives, which implied that at least the dust in comets might not be primordial. And now it looks like the ice in them isn't either...
Boeing says it isn't sweating the A350. First, it has a five-year technology lead over the A350-900. "When all the dust settles, the important thing is that we keep progressing," says Bair. "They will figure it out, but we will be five and six years into knowing what we know and be that much better at it." And the 47-strong customer base that Boeing has for the 787 shows validation of the company's vision and its intent to dislodge Airbus' grip on the medium-range market. Boeing is trying to make the 787 easier...