asteroid:
beam spreading: the way light spreads out when it strikes the surface of Earth at an angle less than 90 degrees.
Smaller angles (Sun is lower in the sky) = more beam spreading.
Higher angles (Sun is higher in the sky) = less beam spreading.
Smaller angles (Sun is lower in the sky) = more beam spreading.
Higher angles (Sun is higher in the sky) = less beam spreading.
VOCABULARY
altitude - the distance above Earth’s surface
astronomical unit (abbreviated "AU"): the average distance between the Earth and the Sun, about 150 million km.
1 AU = 150 million km.
2 AUs = 2 X 150 million km = 300 million km.
When talking/writing about large distances, like we find in a solar system, it's sometimes more
convenient to use AU's than kilometers.
axis of rotation: an imaginary line through a planet's poles that it rotates around. Earth's axis is tilted 23.5
degrees from straight up and down.
You can see what the Earth would look like if you changed the tilt by clicking here.
On the animation page, slide the "obliquity" to change the tilt.
("Obliquity" is just a fancy word that relates to the tilt.)
bird’s-eye view: a view of Earth’s surface looking straight downward from above.
comet:
cosmos: another word for universe
crescent Moon: less than half full. The shape of the Moon just after and just before the new Moon phase. You can see less than half the
face.
dwarf planet:
eclipse:
ejecta: the material displaced from the land when a crater is formed
full Moon: the face of the Moon is completely lit. Happens after the waxing gibbous phase. From Earth you see a bright circle in the sky.
galaxy:
gibbous Moon: more than half full. The shape of the Moon just before and just after the full Moon phase.
Kuiper Belt:
latitude: the angular distance north or south from Earth’s equator. Measured from 0 - 90 degrees. It starts
at the equator, so anywhere on the equator is 0 degrees latitude.
light year (abbreviated "ly"): the distance light travels in 1 year. It's a common unit for measuring distances
outside our solar system.
1 ly = about 9.5 trillion km; that's 9,500,000,000,000 km in 1 year or 300,000 km in 1 second! Yikes!
longitude: the distance measured on Earth's surface east or west of the prime meridian. Measured from 0 -
180 degrees. It starts at the Prime Meridian, which runs through Greenwich England. So Greenwich,
England and anywhere directly north or south of Greenwich is at 0 degrees longitude.
Still confused about latitude/longitude? Latitude/longitude practice can be found by clicking here.
lunar eclipse:
meteor:
meteorite:
meteoroid:
New Moon: the new Moon is not visible from Earth because the lit side is facing away from Earth.
revolution: moving around another object. It takes the Earth 1 year (365.24 days) to make one complete revolution
around the Sun.
rotation: spinning on an axis, like a top. It takes the Earth 1 day (24 hours) to make one complete rotation.
satellite:
solar angle: the angle that light strikes the surface of Earth at a given location. Highest solar angle is 90 degrees. Lowest is 0 degrees. Higher solar angles = more direct and concentrated sunlight.
solar eclipse:
solstice: a day of the year when Earth's North Pole is tilted away from the Sun
waning: the Moon's shape is becoming less lit.
waxing: the Moon's shape is becoming more lit.
universe:
astronomical unit (abbreviated "AU"): the average distance between the Earth and the Sun, about 150 million km.
1 AU = 150 million km.
2 AUs = 2 X 150 million km = 300 million km.
When talking/writing about large distances, like we find in a solar system, it's sometimes more
convenient to use AU's than kilometers.
axis of rotation: an imaginary line through a planet's poles that it rotates around. Earth's axis is tilted 23.5
degrees from straight up and down.
You can see what the Earth would look like if you changed the tilt by clicking here.
On the animation page, slide the "obliquity" to change the tilt.
("Obliquity" is just a fancy word that relates to the tilt.)
bird’s-eye view: a view of Earth’s surface looking straight downward from above.
comet:
cosmos: another word for universe
crescent Moon: less than half full. The shape of the Moon just after and just before the new Moon phase. You can see less than half the
face.
dwarf planet:
eclipse:
ejecta: the material displaced from the land when a crater is formed
full Moon: the face of the Moon is completely lit. Happens after the waxing gibbous phase. From Earth you see a bright circle in the sky.
galaxy:
gibbous Moon: more than half full. The shape of the Moon just before and just after the full Moon phase.
Kuiper Belt:
latitude: the angular distance north or south from Earth’s equator. Measured from 0 - 90 degrees. It starts
at the equator, so anywhere on the equator is 0 degrees latitude.
light year (abbreviated "ly"): the distance light travels in 1 year. It's a common unit for measuring distances
outside our solar system.
1 ly = about 9.5 trillion km; that's 9,500,000,000,000 km in 1 year or 300,000 km in 1 second! Yikes!
longitude: the distance measured on Earth's surface east or west of the prime meridian. Measured from 0 -
180 degrees. It starts at the Prime Meridian, which runs through Greenwich England. So Greenwich,
England and anywhere directly north or south of Greenwich is at 0 degrees longitude.
Still confused about latitude/longitude? Latitude/longitude practice can be found by clicking here.
- You can click any place on the globe to instantly move the lat/long to that location.
- You can click and drag to watch the latitude/longitude lines change as you move the cursor.
- To rotate the globe hold SHIFT + click and drag anywhere on the globe
lunar eclipse:
meteor:
meteorite:
meteoroid:
New Moon: the new Moon is not visible from Earth because the lit side is facing away from Earth.
revolution: moving around another object. It takes the Earth 1 year (365.24 days) to make one complete revolution
around the Sun.
rotation: spinning on an axis, like a top. It takes the Earth 1 day (24 hours) to make one complete rotation.
satellite:
solar angle: the angle that light strikes the surface of Earth at a given location. Highest solar angle is 90 degrees. Lowest is 0 degrees. Higher solar angles = more direct and concentrated sunlight.
solar eclipse:
solstice: a day of the year when Earth's North Pole is tilted away from the Sun
waning: the Moon's shape is becoming less lit.
waxing: the Moon's shape is becoming more lit.
universe: