Chapter 7 - Astronomy Flashcards
Who was the first to create a calendar
The Mesopotamian civilization, that had evidence of astronomical observations. They had a very detailed somewhat accurate calendar.
Why are calendars useful ?
They allowed early civilizations to predict yearly occurring event, such ad flood or avalanches. And they allowed people predict when were the best times to hunt or harvest.
How long is 1 earth year ?
365.24 days
Rotation - earth
The earth rotates on an axis of 23.5 degrees, it takes 1 days for the earth to rotate fully on its axis
Revolution - earth
The earth revolves around the sun.
Why do we have seasons ?
We have seasons b/c of the earths tilt, in the winter the northern hemisphere is tilted away from the sun and in the summer tilted towards the sun.
What is the name of our galaxy ?
The Milky Way
What are the names of our planets
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
-Uranus - Neptune
Mercury - atmosphere
No atmosphere to close to the sun
Venus - atmosphere
Sulfur and CO2 and N2
Earth - atmosphere
O2 N2 CO2 H2O
Jupiter - atmosphere
H+ + He+ - fusing hydrogen and helium
Saturn - atmosphere
H+ + He+
Uranus - atmosphere
Methane
Neptune - atmosphere
Methane
Celestial object
Any object that exist in space.
Astronomer
A scientist who studies astronomy.
Astronomy
The study of the night sky.
Revolution
The time it take for an object to go orbit another object.
Rotation
The turning of an object around an imaginary axis running through it.
Constellation
A group of stars that seem to from a distinctive pattern in the sky.
Asterism
A prominent group of stars that have a name but smaller than a constellation
Apparent magnitude
A star brightness as seen from earth.
Comet
An object composed of rocky material, ice and gas, normally come from the Kuiper Belt or Oort Cloud. The tails are never facing the sun.
Comet tails
Comets have 2 tails, the blue tail is made of gas and is also called the ion tail because the gases have been ionized by the sun radiation and the white tail is the sunlight reflecting of the particles that have been released.
Asteroid
An object that ranges in size and generally originates from the asteroid belt.
Meteoroid
A piece of rock moving through space.
Meteorite
A meteoroid that was large enough to pass through earths atmosphere with ought being burned up.
Meteor
A meteoroid that hits earth atmosphere and is burns up.
Planet
Is an object that orbits 1 or more stars, is spherical and does not share its orbit with another object.
Solar system
A groups of planets that circle 1 or more stars.
Retrograde motion
The movement of an object in the sky moving from east to west and making a look to catch up with the other planets.
Orbital radius
The average distance between the sun and the object orbiting it.
Lunar eclipse
The phenomenon in which the full moon passes into the earths shadow. ( the earth is between the sun and the moon.
A lunar eclipse generally happens 2 weeks before of after a solar eclipse.
Solar eclipse
The phenomenon which is when the new moon passes in front of the sun, the moon and cast its shadow on the earth.
Gravitational force
The force between all masses in the universe.
Light year
The distance that light travels in a year, (9.46 x 10[12]).
The velocity of light is 300 000 km/s, ( kilometres per second)
Astronomical unit
1 astronomical unit is the distance between the earth and the sun,(149, 600 000)
Latitude
The location below or above the equator.
Tides
The rising and falling of the oceans water, this golems become of the Moon orbits around the earth.
Solstice
A solstice is the shortest (winter) or longest day of the year.
Equinox
An equinox is when the southern and northern hemisphere both of the same amount of daylight and night time.
The closest star to our earth
Alpha Centauri
What is the northernmost star
Polaris
Ancient Chinese
Saw the Big Dipper as a chariot for the emperor of heavens.
The Early Egyptians
Saw the leg and thing of a bull.
The Early oboriginal cultures
Saw a bear and some hunter and in early autumn thy believed that the bears wounds would bleed o. The trees changing the colours of the leaves.
Ptolemy
He proposed the geocentric model that last for 1400 years.
Galileo
Discovered that we orbited the sun.
Copernicus
Proposed the heliocentric model.
Satellites
Is an object that moves around another bigger object. Most satellites at man made but moons can be a natural satellite too.
Satellites orbit
Low earth orbit
Medium earth orbit
High earth obit
Satellite used
Satellite can be used to monitor weather. Navigation and communications, agriculture and the minister different airspace’s.
