Answer: is constant
Explanation:
In order to analyze the velocity of the stars within a galaxy, the <u>galaxy rotation curves</u> (developed by the American astronomer Vera Rubin) are used. These graphs are elaborated as a scatter diagram in which the orbital velocity of the stars present in a galaxy is represented on the Y axis and the distance of these stars to the center of the galaxy on the X axis.
Thanks to this diagram, it has been possible to observe a characteristic behavior in the rotation speed of the stars (and gas) present in the galaxies, which differs from the rules of the orbital movement of the planetary systems postulated by Newton and Kepler.
This means that in these galaxy rotation curves it has been observed that the rotation speed of stars and gas is "constant", regardless of the distance to the center of the galaxy. This discrepancy and these results were then used to demonstrate the existence of dark matter in the universe.
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Desert. lots and lots of desert. all desert
The area was once a forest.
The area was uplifted.
The area was buried in sediment.
The area was probably covered by water.
Petrification of a dead plant or animal organisms occurs when rock mineral displaces the organic elements in the structure of the biotic matter or these minerals seep in between the spaces and pores within the dead plant or organism and become part of the material.
Explanation:
Petrification occurs under high pressure. This is why this process occurs in the crust after layers of sediments create enough pressure on the dead organic matter buried in with the sediments. This phenomenon commonly begins on the ocean floor where dead marine life sinks to the bottom and is buried by sediments over many years.
Occasionally, tectonic plate forces uplift these petrified fossils from deep in the crust exposing them on the surface like in this case.
Learn More:
For more on petrification check out;
brainly.com/question/11767037
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