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.
Asteroids, Comets & Meteors - NASA Solar System Exploration
Don’t let the name fool you. Our solar system’s small bodies – asteroids, comets, and meteors – pack big surprises. These chunks of rock, ice, and metal are leftovers from the formation of our solar system 4.6 billion years ago.
In Depth | Our Solar System - NASA Solar System Exploration
Introduction. The planetary system we call home is located in an outer spiral arm of the Milky Way galaxy. 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.
Planet Compare - NASA Solar System Exploration
2025年1月9日 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
Stardust Findings Suggest Comets More Complex Than Thought
Minerals formed near the sun or other stars were in the samples returned to Earth by the Stardust spacecraft in January 2006. The findings suggest materials from the inner regions of the solar system could have traveled to the outer reaches where comets formed.
In Depth | 1P/Halley – NASA Solar System Exploration
Halley's Connection to Meteor Showers. Each time Halley returns to the inner solar system its nucleus sprays ice and rock into space. This debris stream results in two weak meteor showers each year: the Eta Aquarids in May and the Orionids in October.
In Depth | 2P/Encke – NASA Solar System Exploration
Discovery. Comet 2P/Encke was first discovered by Pierre F. A. Mechain on Jan. 17, 1786. Other astronomers located this comet in subsequent passages, but these sightings were not defined as the same comet until Johann Franz Encke calculated its orbit.
In Depth | Vega 1 – NASA Solar System Exploration
2025年1月9日 · Goals: The Soviet Union's twin Vega spacecraft were designed primarily to deliver advanced landers and balloons to Venus, but the return of comet Halley to the inner solar system provided an opportunity for additional science. Accomplishments: Both Vega 1 and its twin Vega 2 were tremendously successful. After successfully delivering its payload at Venus, …
RPS 3D Viewer - NASA Solar System Exploration
2025年1月9日 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
In Depth | Perseids – NASA Solar System Exploration
About the Meteor Shower. The Perseid meteor shower, which peaks in mid-August, is considered the best meteor shower of the year. With swift and bright meteors, Perseids frequently leave long "wakes" of light and color behind them as they streak through Earth's atmosphere.