Earth Science Astronomy Quiz - Review
It took over a billion years for the first life to appear on Earth and even longer for more complex life to appear.
The first life on Earth did not appear on Earth until several hundred million years after the formation of oceans and an atmosphere.
There is no evidence for life anywhere else in the solar system, only evidence of water.
Out of all the planets in the solar system, Earth has life!
Earth didn’t have life for a long time and now it does.
Our Earth is becoming less and less welcoming due to human impact, and our population is continuing to increase!
The sun is essential to our existence
White light emitted from a source initially contains many wavelengths that correspond to different colors, but we cannot see all those colors unless the light passes through a prism.
A spectroscopy telescope contains a prism that separates light into all wavelengths that are present.
If white light passes through a gas, some wavelengths will be absorbed. The wavelengths absorbed are dependent on the composition of the gas.
If white light passes through a prism after passing through a gas, the prism will separate the light into all the wavelengths that remain, allowing us to see what wavelengths that particular gas absorbs. This process can be repeated over and over and over with a known gas in a laboratory… and the light spectra will always show the same absorption as black lines. We call these absorption lines and their wavelengths are unique to each gas.
We can view the spectra of sunlight when it passes through the prism in a spectroscopy telescope and match that spectra with laboratory references in order to determine the composition of the sun. We have determined it is made of Hydrogen and Helium.
Sun's Properties
The sun could hold 1 million Earth’s.
The interior of the sun is as hot as 15,000,000 degrees C
Surface temperatures are about 5,500 C
Galileo went blind because of his observations of the sun
The sun rotates! 25 earth days for one rotation at equator. 27 earth days for rotation at poles. (not the same because it is made of gas).
The sun produces energy through nuclear fusion, whereby two Hydrogen atoms fuse together to form one Helium atom. There is a small decrease in mass during nuclear fusion, which is converted to energy.
Our Sun releases 2.41 X 1030 Mega Electron Volts of energy per second, or 2,410,000,000,000,000,000,000,000,000,000 Mega Electron Volts of energy per second. That’s more energy than the entire world uses in a whole day! And the sun releases it per second.
Stellar Evolution
Star's are formed from a stellar nebula which is a large cloud of gas and dust in interstellar space. Once they become a star the initial mass of the star determines the stages of evolution for the star.
Low mass stars (similar to the mass of our Sun) stay in the Main Sequence phase for billions of years, then they become a Red Giant where the star becomes extremely hot and extremely large and loses some mass. This happens over about a billion years. Then they lose their outer gases and very quickly shrink in size, lose half their mass and become a white dwarf.
Medium Mass stars (with a mass greater than 8 times the size of our sun but smaller than 20 times the size of our sun) will stay in Main Sequence for only hundreds of million years, then become a red giant for 5 million years, a supernova will take place, and then these stars become Neutron stars.
Large Mass Stars that are 30 times the mass of our sun and bigger will stay in the Main Sequence phase for only 5 million years or less, then they will become a red giant, then blue giant, then there is a supernova and finally they will turn into a black hole.