enow.com Web Search

Search results

1. Results from the WOW.Com Content Network

2. What causes a "falling star"? - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/questions/question12.html

   A "falling star" or a "shooting star" has nothing at all to do with a star! These amazing streaks of light you can sometimes see in the night sky are caused by tiny bits of dust and rock called meteoroids falling into the Earth's atmosphere and burning up. The short-lived trail of light the burning meteoroid produces is called a meteor.

3. StarChild: Meteoroids - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/meteoroids.html

   A meteoroid is a piece of stony or metallic debris which travels in outer space. Meteoroids travel around the Sun in a variety of orbits and at various speeds. The fastest meteoroids move at about 42 kilometers per second. Most meteoroids are about the size of a pebble. When one of these pieces of debris enters the Earth's atmosphere, friction ...

4. StarChild: Meteoroids - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level1/meteoroids.html

   A meteoroid is a piece of stone-like or metal-like debris which travels in outer space. Most meteoroids are no bigger than a pebble. Large meteoroids are believed to come from the asteroid belt. Some of the smaller meteoroids may have come from the Moon or Mars. If a meteoroid falls into the Earth's atmosphere, it will begin to heat up and ...

5. StarChild: Comets - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/comets.html

   Most comets are thought to originate in a huge cloud called the Oort Cloud. The Oort Cloud is believed to surround our solar system and reach over halfway to the nearest star, Alpha Centauri, which is 150,000 astronomical units away. Scientists think that about 100 million comets orbit the Sun. A comet has a distinct center called a nucleus.

6. What makes stars shine - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/questions/question13.html

   What makes the Sun shine? Answer: The simple answer is that deep inside the core of the Sun, enough protons can collide into each other with enough speed that they stick together to form a helium nucleus and generate a tremendous amount of energy at the same time. This process is called nuclear fusion.

7. What causes fireballs in the sky? - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/questions/question56.html

   Fireballs are really just big meteors - the result of meteoroids falling into the Earth's atmosphere and burning up. The rock that caused the "Chicago Fireball", as the March 2003 event has been called, was probably a small space rock about 1 or 2 meters wide. As it fell into the atmosphere, it heated up and eventually broke up into about 500 ...

8. What You'd See Watching a Total Eclipse - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/questions/total_eclipse.html

   The sky slowly gets dark as the Moon moves in front of the Sun. When the Moon and Sun are in a perfect line, it is called a total eclipse. These are very rare. Most people only see one in their lifetime. As the Moon passes between the Sun and the Earth, the Moon begins to block out some of the Sun's light casting a shadow on the Earth.

9. Why do stars twinkle? - NASA

   starchild.gsfc.nasa.gov/docs/StarChild/questions/question26.html

   This means that some of the light reaches us directly and some gets bent slightly away. To our eyes, this makes the star seem to twinkle. You will notice that stars closer to the horizon will appear to twinkle more than other stars. This is because there is a lot more atmosphere between you and a star near the horizon than between you and a ...

10. StarChild: Quasars

    starchild.gsfc.nasa.gov/docs/StarChild/universe_level1/quasars.html

    Quasars. Quasars give off more energy than 100 normal galaxies combined. Quasars are farther away from Earth than any other known object in the universe. Because they are so far away from us, it takes billions of years for the light they give off to reach Earth. The light stays the same, it just has to travel a long time to get to us.

11. Can you tell me about gamma-ray bursts? - NASA

    starchild.gsfc.nasa.gov/docs/StarChild/questions/question47.html

    Gamma-ray bursts (GRBs) can release more energy in 10 seconds than the Sun will emit in its entire 10 billion-year lifetime! In order to understand what a gamma-ray burst is, you must recognize gamma-rays as the most energetic form of light. Light, or electromagnetic radiation, can be thought of as coming in tiny packets of energy called photons.