Word: earths
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Dates: during 1990-1999
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...Spotted more than three years ago, it seemed at first to be a garden-variety star--but it wasn't. It might have turned out to be an unremarkable galaxy or quasar--but it didn't. Frustrated in their attempts to learn its nature, and even its distance from Earth, astronomers have begun to refer to the mystery object as, well, the "mystery object...
...resulting spectrum, not unlike the band of colors that appears when sunlight is passed through a prism, would tell them a lot. "Once you have a star's spectrum," says Djorgovski, "you can determine its temperature, its heavy elements and how fast it's moving with respect to Earth...
...mark an ample presence of an as yet unidentified element, and many small dips that probably represent segments of the spectrum where light has been absorbed by other elements--perhaps those in the object's outer atmosphere or in gas clouds between the object and Earth. Bewildered, the Caltech team looked for other answers. Maybe the object was a supernova, an exploding star, which often projects what Djorgovski calls a "weird-looking" spectrum. But the team observed the target a number of times over several months and noted no change. That ruled out a supernova's light, which gradually fades...
...water, everywhere ?- it?s not just a theory anymore. Astronomers have cracked open a meteorite that dates back 4.5 billion years ?- to the birth of the solar system ?- and found tiny droplets of seawater, still in liquid form and capable of answering one of astronomy?s big questions: Was Earth born with water, or was water thrust upon it? Some scientists say water was created on Earth by happy circumstance, but others insist that it was delivered on comets and meteorites ?- and therefore might have nurtured life elsewhere. "It?s no real surprise that there would be water left over...
...Until then, NASA asteroid specialist Michael Zolensky and his colleagues will have little to do except wait ?- and collect more evidence. After getting the word out to be extra careful with new meteorite finds (previous discoveries have been tainted by suspicions that they had become contaminated by water from Earth's environment), Zolensky has had another hit on a rock that touched down in Morocco. "Lo and behold, it's the same stuff in a different meteorite," he said. Everywhere indeed...