安裝中文字典英文字典辭典工具!
安裝中文字典英文字典辭典工具!
|
- RPS 3D Viewer - NASA Solar System Exploration
NASA’s real-time science encyclopedia of deep space exploration Our scientists and far-ranging robots explore the wild frontiers of our solar system
- Planet Compare - NASA Solar System Exploration
NASA’s real-time science encyclopedia of deep space exploration Our scientists and far-ranging robots explore the wild frontiers of our solar system
- The Sun By the Numbers - NASA Solar System Exploration
The Sun is the star at the heart of our solar system Its gravity holds the solar system together, keeping everything – from the biggest planets to the smallest bits of debris – in its orbit
- In Depth | Our Solar System – NASA Solar System Exploration
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 Beyond our own solar system, there
- In Depth | Earths Moon – NASA Solar System Exploration
The brightest and largest object in our night sky, the Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate It also causes tides, creating a rhythm that has guided humans for thousands of years The Moon was likely formed after a Mars-sized body collided with Earth several billion years ago Earth's Moon is the only
- Mars By the Numbers - NASA Solar System Exploration
Mars is the fourth planet from the Sun, and the seventh largest It’s the only planet we know of inhabited entirely by robots
- Stardust | JPL | NASA
The first such opportunity will occur April 20, 1999 when Stardust comes within 3 5 million miles of the Orionid meteor stream The Orionid meteors, left in the wake of Comet Halley, can be seen from Earth each October
- Asteroids, Comets Meteors - NASA Solar System Exploration
Asteroids and comets – and the meteors that sometimes come from them – are leftovers from the formation of our solar system 4 6 billion years ago
|
|
|