Unit E - Space Exploration Flashcards
(36 cards)
What are five examples of celestial bodies?
- Sun
- Moon
- Stars
- Constellations
- Planets
What are five examples of celestial bodies?
- Sun
- Moon
- Stars
- Constellations
- Planets
What did the First Nations people of the Pacific Northwest believe about the night sky?
They thought the night sky was a pattern on a great blanket overhead. The blanket, they believed, was held up by a spinning “world pole,” the bottom of which rested on the chest of a woman underground named Stone Ribs.
What is the geocentric model?
The geocentric model is where the Earth is the centre of the universe.
What is the heliocentric model?
The heliocentric model is where the sun is the centre of the universe.
What is an ellipse?
The orbital paths of planets travelling around the the sun.
What is the astronomical unit?
A measure of distance used to describe the position of planets relative to the sun.
What is a light year?
The distance that light travels in one year (approx. 9.5 trillion km).
Why are we “looking into the past” when we look at stars?
That is because it takes time for the light from the object to travel to Earth across the great distance in space.
What is a star?
A hot glowing ball of gas that gives off tremendous light energy.
What information does the colour of a star indicate about the star?
The colour of a star depends on it’s surface temperature. Very hot stars look blue and cooler stars look red.
What is the cycle of a star?
sun-like stars→red giant→white dwarf→black dwarf
NEBULA↑or →massive stars→red supergiant→supernova→ neutron star or black hole
Explain the birth, life, and death of a star.
NEBULAE INTERSTELLAR MATTER PROTOSTAR SUN-LIKE (in terms of mass) MASSIVE MAIN SEQUENCE RED GIANT RED SUPERGIANT WHITE DWARF BLACK DWARF SUPERNOVA NEUTRON STAR BLACKHOLE
What are constellations?
THe groupings of stars that form patters in the night sky. Officially there are 88 constellations.
What are asterisms?
A distinctive star grouping that is not one of the 88 recognized constellations. For example the Big Dipper, which is part of the Ursa Major.
What is a galaxy?
A grouping of millions or billions of stars, gas, and dust, held together by gravity.
Describe a spiral galaxy.
Viewed from above or below the plane, a spiral galaxy appears to have long curved arms radiating out from a bright central core. Young stars provide most of the light in the arms. Older stars provide most of the light in the central region.
Describe a elliptical galaxy.
An elliptical galaxy has a shape similar to that of a football or egg and is made up mostly of old stars.
Describe and irregular galaxy.
An irregular galaxy has no notable shape and tends to be smaller than the other two galaxy types. A mixture of old and young stars is found in irregular galaxies.
The protoplanet hypothesis is a model for explaining the birth of a solar system. List the three steps that describe this process.
- A cloud of gas and dust in space begins swirling.
- Most of the material (more than 90%) accumulates in the centre, forming a star (like the sun).
- The remaining material accumulates in smaller clumps circling the centre. These form the planets.
What are four important points about the sun?
The temperature at the surface of the sun is about 5500 degrees celsius, while the core is close to 15 000 000 degrees celsius.
The sun releases charged particles that flow out in every direction. This SOLAR WIND passes Earth at an average speed of 400 km/s.
The sun, like most stars, is made up of two main gases, hydrogen and helium.
The sun is almost 110 times wider than Earth, and if the sun was a hollow ball, almost a million earths would be required to fill it.
Describe Mercury.
Inner Planet.
Mass is less than Earth.
Average surface temperature is greater than Earth.
Has zero moons.
Period of rotation is 59 days.
Period of orbit around the sun is 88 days.
Describe Venus.
Inner Planet.
Mass is less than Earth.
Average surface temperature is greater than Earth.
Has zero moons.
Period of rotation is 243 days.
Period of orbit around the sun is 225 days.
Describe Earth.
Inner Planet.
Has one moon.
Period of rotation is 24h.
Period of orbit is 365 days.
