American Museum of Natural History
- What is a Star?
- Lives of Stars
- Our Star: the Sun
- Space weather: Storms from the Sun
- Interferometry: Sizing up the Stars
- Neil deGrasse Tyson on Finding Krypton
- Stars Glossary
- Quiz: Stars
- Exploration Questions: Stars
- Answers to Exploration Questions: Stars
1. What causes a star to form? What causes it to die?
Answer: A star forms in a huge cloud of gas and dust. Over time, gravity causes the cloud to contract. As the gas becomes denser, the pressure and temperature increase. As the cloud pulls in more gas and dust, its mass, pressure, and temperature continue to increase until nuclear fusion begins. The star shines through nuclear fusion until it runs out of fuel and dies.
2. Hayden Planetarium Director Neil deGrasse Tyson advised DC Comics on an episode in which Superman uses a powerful telescope to watch the destruction of his home planet Krypton. Is it really possible to look back in time by looking through a telescope? Why or why not? Why did Dr. Tyson suggest a star 27 light-years away?
Answer: Yes, whenever you view an object in space, you’re looking back in time — and the farther the object, the further back in time you’re looking. That’s because light takes time to travel from that object to your telescope, and you see the object as it appeared when light left that object. All the stars we see are light-years away, so we see them as they looked years ago. Dr. Tyson chose a star that was 27 light-years away because he predicted that Superman would be about 27 years old, and he left the planet as a baby.
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- You know how the space dust is making?(0 votes)
- Space dust is dust which exists in space. It is for the most part a type of small dust particles which are a few molecules to 0.1 µm in size. A smaller fraction of all dust in space consists of larger refractory minerals that condensed as matter left the stars. It is called "stardust" and is included in a separate section below. The dust density in the local interstellar medium of the Local Bubble is approximately 10 to power -6 × dust grain/m3 with each grain having a mass of approximately 10 to power -17 kg.
Space Dust Is generally Known as "Cosmic Dust"(0 votes)