A
*What causes the moon's phases?
Changes in how much of the sunlit side of the moon faces Earth
*The 3 criteria to be considered a planet
Spherical shape, revolve around a star, and clear its orbital path/neighborhood
*What is the next life cycle stage of our star, a medium star (the Sun)?
Red giant stage
*Which direction does a comets tail always face and why?
Away from the sun because of solar wind.
*One astronomical unit (AU) average about how many km?
150 million km
*Which layer of the sun is visible during an eclipse?
Corona
*Terrestrial (inner) planets all have what in common?
A hard, rocky surface. Thinner atmosphere. Smaller size. Fewer moons.
*When is a star thought to be born?
When a protostar reaches a temperature high enough for nuclear fusion to begin
*What days mark the beginning of seasons in the northern hemisphere?
Summer solstice (June 22). Winter solstice (Dec. 22). Spring equinox (March 22). Autumnal equinox (Sept. 23)
*Seasons are caused by what?
The Earth's tilted axis
*What are the different types of eclipses and their parts?
Solar eclipse (earth-moon-sun). Lunar eclipse (sun-earth-moon). Umbra (darkest shadow/ total eclipse). Penumbra (lighter shadow/ partial eclipse).
* What is the imaginary line that the Earth rotates around?
Axis
*Describe the relationship between the angle of sunlight hitting the Earth and the concentration of light heating the Earth.
Sunlight is more concentrated at the equator because it hits the Earth at a 90 degree angle. Because the Earth is spherical, sunlight hits other parts of the earth at a non-perpendicular angle. At these angles, sunlight is less concentrated.
*Where are meteors found?
Burning up in the atmosphere
*What are seasonal stars only visible during certain times of the year?
Their visibility depends on Earth's position relative to the sun.
*What 2 properties effect the gravitational force between objects?
Distance and mass
*Which planet has the hottest surface temperature and is referred to as Earth twin because of its size?
Venus
*Explain Earth's rotation.
The Earth spins in a counter-clockwise direction on its imaginary axis. It takes 24 hours to complete one rotation.
*Objects made of ice, gas, and dust that orbit the sun are called?
Comets
*What is a science phenomenon?
A naturally occurring event
*What tide occurs when the moon, sun, and Earth are in a straight line?
Spring tide
*Why is Pluto considered a dwarf planet?
It has not cleared its orbit around its neighborhood. It is found in the Kuiper Belt.
*What are the layers of the sun, from outside to inside?
Corona, chromosphere, photosphere, convective zone, radiative zone, core.
*Why can we see circumpolar stars all year?
They reside high above Earth's orbital plan.
*Why do the planets remain in orbit around the sun?
Gravity and inertia