The University of Texas at Arlington

The University of Texas at Arlington

UTA Planetarium

UTA Planetarium

Ask the Astronomer Q&A

Tag: "hydrogen"

  • How is Hydrogen used in everyday life?
  • Hydrogen has many uses. NASA uses liquid Hydrogen as rocket fuel. Hydrogen is also used to generate electricity. Engineers are working on creating a Hydrogen fuel cell to power our cars. It is used in a variety of applications in industry, including as a coolant. It is even important in the semiconductor industry.

    (Tags:  hydrogen  nasa)
  • I've heard people say Jupiter is a failed star since its made up of mostly Hydrogen and Helium like a star is. I know a Brown Dwarf is essentially a failed star, so would that make it correct to think of Jupiter as a Brown Dwarf? If not, why?
  • Jupiter is not a failed star or a Brown Dwarf. It is a gas giant planet. Brown Dwarfs are objects that are between 10 and 100 times more massive than Jupiter. They are not large enough to sustain Hydrogen fusion in the cores, this is why they are sometimes called failed stars. In order for Jupiter to be considered a Brown Dwarf it would need to get at least 10 times more mass than it currently has.

    (Tags:  brown dwarf  hydrogen  jupiter  star)
  • Is everything we see in the universe on fire or able to be seen because it is reflecting light from something on fire?
  • The answer kind of depends on what you are referring to. Take the planets of our solar system for example. They do not create their own light, they are just reflecting the Sun’s light back to us, the same is true for our Moon. On the other hand, the Sun, stars, galaxies and nebulae are all creating their own light. But I wouldn't say that they are on fire. It is true that astronomers talk about stars “burning” but we aren't referring to a fire like you may create in your fireplace or grill. What’s actually happening is Hydrogen atoms in the center of the star (like our Sun) are fusing to form Helium atoms. This creates an incredible amount of heat and light. The Sun is more than 10,000 degrees Fahrenheit!

    (Tags:  hydrogen  light  milkyway galaxy  moon  planet  star  sun)
  • What is the possibility of dropping U-238 into Jupiter, for example, to trigger the proton-proton chain reaction? Or, the CNO cycle (carbon-nitrogen-oxygen) to turn all the gas giants into mini-Suns? After all, U-238 has a half life of 4.5 Billion years, and we have a surplus of U-238!
  • Although it may allow us to get rid of our Uranium, this wouldn't work to create another Sun. Atoms bombs like those made with U-238 create fission reactions, which are the opposite of fusion reactions. In fission, you are breaking apart an atom and creating smaller ones – and a lot of energy! In fusion, like within a star, 2 small atoms are joining together to make a larger atom – and again a lot of energy. So, sending our atom bombs to Jupiter would only blow it up, not start a fusion reaction. The only way to start a fusion reaction is to add more mass. To make Jupiter into a small brown dwarf star, we would need to add about 9 more Jupiter’s worth of Hydrogen to the planet. To make a Sun-sized star out of Jupiter, we would have to add 100 more Jupiter’s worth of Hydrogen. That’s a lot of Hydrogen!

    (Tags:  brown dwarf  hydrogen  jupiter  sun)