ScienceIQ.com

NASA Spacecraft Reveals Surprising Anatomy Of A Comet

Findings from a historic encounter between NASA's Stardust spacecraft and a comet have revealed a much stranger world than previously believed. The comet's rigid surface, dotted with towering pinnacles, plunging craters, steep cliffs, and dozens of jets spewing violently, has surprised scientists. 'We thought Comet Wild 2 would be like a dirty, ...

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AnatomyOfAComet
Astronomy

Big Fish

The phrase 'big fish eat little fish' may hold true when it comes to planets and stars. Perhaps as many as 100 million of the sun-like stars in our galaxy harbor close-orbiting gas giant planets like ... Continue reading

BigFish
Geology

Crater Lake

Crater Lake: overwhelmingly yet sublimely beautiful. Moody. At times brilliantly blue, ominously somber; at other times buried in a mass of brooding clouds. The lake is magical, enchanting - a remnant ... Continue reading

CraterLake
Astronomy

Cosmos Provides Astronomers with Planet-Hunting Tool

If only astronomers had a giant magnifying glass in space, they might be able to uncover planets around other stars. Now they do -- sort of. Instead of magnifying a planet, astronomers used the ... Continue reading

PlanetHuntingTool
Mathematics

Who Invented Zero?

Many concepts that we all take for granted sounded strange and foreign when first introduced. Take the number zero for instance. Any first-grader can recognize and use zeros. They sound so logical and ... Continue reading

WhoInventedZero

It's Dusty Out There

ItsDustyOutThereThere is no lower limit to the size of the solid particles that move around the Sun. Small asteroids grade downward into large meteoroids and then into smaller pebbles and so on down to the tiniest particles of dust. The most numerous particles are the smallest ones. A particle larger than a millimeter (about one twenty-fifth of an inch) in diameter is a relative rarity in space, but even smaller particles exist by the uncountable billions. There are enough of them to reflect sunlight in a faint glow, called the zodiacal light. Unlike planets and other large objects, dust particles are not permanent residents of the solar system. They spiral slowly inward toward the Sun. Over a million years or so, a typical particle will fall into the Sun, so that the current dust population must consist of fairly new arrivals, presumably shed from comets.

Because interplanetary dust particles may be actual samples of comets, strenuous efforts have been made to collect them. Many efforts failed because of the rarity of the particles and the contamination of collecting devices by terrestrial dust. Recently, however, extraterrestrial dust particles have been successfully trapped with collectors mounted on high-flying aircraft. The yield has been small so far: only about a hundred particles a few thousandths of a millimeter across. But recently developed instruments are so sensitive that even these tiny objects can be usefully studied. They are definitely extraterrestrial, for their chemical composition is like that of common meteorites (and not like that of the Earth), but they are fluffy, fragile objects, each particle a mosaic of millions of tiny crystals.

As we look ahead to the reappearance of Halley's Comet, we are continuing to collect and study the dust that may have been shed by comets in the past. Perhaps when Halley does appear, we may be able to do more than just look at it. We may be able to collect and analyze the very dust that it sheds as some of those tiny fragments drift down to our planet.