How are galaxies important to our existence?
Galaxies recycle material from one generation of stars to the next, and without this recycling we could not exist..
How long does it take for the celestial sphere to spin in one complete cycle *?
The Celestial Sphere
The stars appear to be attached to a giant celestial sphere, spinning about the celestial poles, and around us, once every 23 hours and 56 minutes..
What best describes what we mean by the universe?
The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy..
What would make parallax easier to measure?
Using the previous example, Cassini knew that by increasing the distance between his two measurements (effectively increasing the space between his "eyes") he could get a larger parallax angle which is easier to measure..
When did our solar system begin to form?
Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust.
The cloud collapsed, possibly due to the shockwave of a nearby exploding star, called a supernova.
When this dust cloud collapsed, it formed a solar nebula – a spinning, swirling disk of material..
Where did the heavier elements that made up 2% of our solar nebula come from?
Heavier elements were formed in the cores of stars found in the early universe and through their explosions as supernovae.
It took many billions of years of star formation and supernovae to produce a sufficient amount of heavy elements to begin to form solar systems that included rocky planets similar to Earth..
- Answer: This statement does not make sense because it uses the term light-year as a length of time, rather than as a distance.
- The age of the solar system is estimated to be ~4.6 billion years old.
The age of the universe is ~13.8 billion years old. - The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.
