Chapter 8: Space Sciences Flashcards
How long ago was the initial “big bang”
15-20 billion years ago
What is a pre-solar nebula?
an interstellar cloud of dust and gasses
what did our solar system look like 5 billion years ago?
a big cloud of dust particles
what held all the interstellar dust particles together
their own gravity
What do scientists believe that the pre-solar nebular was made up of?
99% helium and hydrogen and 1% heavier elements
How did the protosun or protostar develop out of the clouds of gasses?
the gravity would have increased and pulled particles into the centre to form the beginning of a star
What happened in the very centre of the protosun?
the gravity got so strong, and the pressure so high, that hydrogen & helium began fusing (joining)– NUCLEAR FUSION
Did all the dust in the nebula for the sun?
no, some formed swirling rings of gas that eventually cooled and became rocky planets, gas giant planets, dwarf planets, asteroids, meteoroids and comets.
What is the distance from the earth to the sun?
149 600 000 km
What percentage of the total mass of our solar system is taken up by the sun?
98.6% of the mass of the solar system is the sun
What type of star is the sun?
a yellow dwarf star
How many years would it take to get to the sun in a regular airplane traveling 900km/hr?
19 years
How many minutes does it take for light to travel from the sun to earth?
9 minutes
What are the elements that make up the sun
72% hydrogen
26% helium
2% other elements
How come the sun shines?
as it converts hydrogen into helium, in a process called fusion, energy is released
In what way does the energy released from the sun support life on earth?
plants convert the sun’s energy via photosynthesis, and the sun drives our weather and climate
For how many years more will the sun last?
5 billion. It is about 1/2 way used up
When the hydrogen at the sun’s core runs low, what type of star will it evolve into ?
a Red Giant which is an expanded star
Once the sun is at the end of its life cycle, it will cool and become what type of star?
a White Dwarf star