Why Comets Are Important - NASA Solar System Exploration
2000年6月7日 · What Are Comets? * Comets are small, fragile, irregularly shaped bodies composed of a mixture of grains and frozen gases. They have highly elliptical orbits that repeatedly bring them very close to the Sun and then swing them deeply into space, often beyond the orbit of Pluto.
In Depth | Our Solar System – NASA Solar System Exploration
Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids.
In Depth | 1P/Halley – NASA Solar System Exploration
Comet Halley moves backward (opposite to Earth's motion) around the Sun in a plane tilted 18 degrees to that of the Earth's orbit. Halley's backward, or retrograde, motion is unusual among short-period comets, as its greatest distance from the Sun (aphelion) is …
Why Comets Are Like Deep Fried Ice Cream - NASA Solar System …
2015年2月10日 · The result is a crunchy comet crust sprinkled with organic dust. "A comet is like deep fried ice cream," said Murthy Gudipati of NASA's Jet Propulsion Laboratory in Pasadena, California, corresponding author of a recent study appearing in The Journal of Physical Chemistry.
Hubble's Messier Catalog – NASA Solar System Exploration
2018年3月19日 · Occasionally, however, a comet will sweep past the Sun that is bright enough to be seen during the daytime with the naked eye. One such instance occurred in 1744. Comet Klinkenberg-Chéseaux, discovered by three amateur astronomers in late 1743, grew steadily brighter as it approached the Sun.
Stardust Comet P/Wild 2 - NASA Solar System Exploration
The comet itself, not coming very close to the sun, will not develop spectacular tails like Halley, but will look more like a fuzzy blob. It will be visible to amateur astronomers for about 6 months, while it is brighter than 13th magnitude.
In Depth | 2P/Encke – NASA Solar System Exploration
Comet 2P/Encke is a small comet. Its nucleus measures approximately 2.98 miles (4.8 kilometers) in diameter, which is about a third of the size of the object hypothesized to have led to the demise of the dinosaurs.
In Depth | Perseids – NASA Solar System Exploration
The Comet. The pieces of space debris that interact with our atmosphere to create the Perseids originate from comet 109P/Swift-Tuttle. Swift-Tuttle takes 133 years to orbit the Sun once. It was Giovanni Schiaparelli who realized in 1865 that this comet was the source of the Perseids. Comet Swift-Tuttle last visited the inner solar system in 1992.
In Depth | Oumuamua – NASA Solar System Exploration
The object, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date.
Comet Wild 2 Is Unique Because - NASA Solar System Exploration
2000年6月7日 · Since it is the escaping gases that drive the dust particles from the nucleus (solid part of the comet), the comet no longer creates the long beautiful dust tail that we can see in the sky. Since Wild 2 has passed the sun only a few times, it still has most of its dust and gases -- …