Unit E Section 1.2 Flashcards
If you used a plane to get from Earth to the Sun, how long will it take?
traveling at about 965 km/h, the flight would last close to 17 years.
How many km is the Earth from the Sun?
149 599 000 km
What are Sundials used for?
measure the passage of time.
What is merkhet?
- Ancient Egyptians invented the device
- to chart astronomical positions and predict the movement of stars.
What is a quadrant?
- A tool designed by Egyptian astronomers
- to measure a star’s height above the horizon.
What is an astrolabe?
- Arabian astronomers
- to make accurate charts of star positions.
What is a cross-staff?
In-14th century, astronomer Levi ben Gurson
-to measure the angle between the Moon and any
given star
What were the devices and tools astronomers used to discover more about outer space?
quadrant astrolabe cross-staff early telescope merkhet
What is the telescope?
late 16th century
revealed exciting details about Earth’s closest planetary neighbours, and showed the existence of other neighbours in our solar system
What is the Sun to the galaxies?
that our Sun is only an average star, lying in a small corner of
an average galaxy that is one among billions of other galaxies.
What are the two new units to measure in outer space?
- The astronomical unit (AU)
- Light-years
What is the Astronomical Unit?
is used for measuring “local” distances, those
inside our solar system.
What does one AU equal?
One AU is equal to the average distance from the
center of Earth to the center of the Sun (149 599 000 km)
What do the Astronomical Unit for?
Astronomers use this when describing the positions of the planets relative to the Sun.
What are Light-years used for?
The vast distances beyond the solar system, out to stars and galaxies
What do light-years equal to?
It equals the distance that light travels in one year
Light travels at a speed of 300 000 km/s. In a year, that adds up to about 9.5 trillion km.
What is the distance of the next nearest star
to Earth after the Sun?
4 light-years
Earth compared to Jupiter and Jupiter compared to Earth:
Earth is about 1/1000 the volume of Jupiter,
Jupiter is about 1/1000 the volume of the Sun.
How long for the light to reach from the sun to earth?
Light from the Sun takes about 8 min to reach Earth.
Why is it that when you look at an object in space, you are seeing it as it was at an earlier time?
That’s because it takes time for the light from the object to travel to Earth across the great distance in space.
The farther out into the universe we are able to look, the deeper into the past we see
