Astronomy y8 Flashcards
Why is there day and night?
As the Earth rotates on its axis, we will at one point, be facing the sun (day) and face away from the sun (night).
Why are there seasons?
Seasons are caused by the tilt of the Earth’s axis, if it’s tilted toward the sun, it’s Summer, if tilted away, it’s Winter.
What is equinox? When in the year does it occur?
An equinox is when the sun is directly above the equator - meaning the day and night are the same length - around March 21st (vernal) and September 23rd (autumnal)
What is solstice? When in the year does it occur?
A solstice is the shortest or longest day of the year - around June 20th (Summer) and December 21st (Winter)
How does the length of day vary throughout they year? Why?
Summer days are longer then Winter days because in the Summer, the Sun rises earlier and sets later because when tilted toward the sun, the angle is more perpendicular.
What is the difference between waxing and waning?
Waxing - getting larger
Waning - getting smaller
Why do we see different amounts of light from the moon?
The positions of the Earth, moon and Sun all change the amount of light we see from the moon
Why is the ‘half moon’ called the first quarter?
You only see one side of the moon, so when you see half of a half of the moon, it is a quarter.
What is the moon’s effect on Earth’s tides?
The moon exerts tidal force on the Earth, which is different all around the globe, and when the moon, Earth and Sun are all perfectly around, a spring tide happens, where the Earth is being stretched out into an oblong by both, causing extreme tides. Neap tides are made by the moon being perpendicular to the Earth, working against the sun’s gravity, more or less squashing Earth.
What is the sun and how big is it?
The sun is a star with a radius of 696,340 km.
How can the sun be viewed safely?
By using a solar filter or projecting its image
What process occurs in the sun to form light and heat energy?
nuclear fusion reactions in the sun release a lot of energy in the form of heat and light
What is the order of the planets?
Mercury, Venus, Earth, Mars, (asteroid belt), Jupiter, Saturn, Uranus, Neptune
what is the spacing of the planets
four rocky planets close together, then big, gaps, only getting bigger
What is the difference between a planet, minor planet and dwarf planet?
A planet is a large, spherical object that dominates its orbit, a minor planet is a small celestial body orbiting the sun that isn’t a comet and a dwarf planet is an object that has enough mass to become nearly round, but doesn’t dominate its orbit.
