Download 2b Astronomer space units

Astronomer’s Tools
Discovery Through Technology
Humans have created many tools to help explain
the mysteries of the universe.
Sun dials
 help tell time each day
Merkhet
• to chart astronomical
positions and predict
the movement of
stars
Quadrant
• Measures stars height
above the horizon
Astrolabe
• Make accurate charts of
Stars
Cross-staff
• Measures angle between
the moon and any given
star
Telescope
• Study planets and stars
Today, super-powerful optical and radio telescope’s operating from
earth, satellites orbiting around Earth, and sophisticated spacebased telescopes have shown us the immensity of objects in space
and of distances across the universe.
Astronomical Units
(AU)
 Used to measure distance
in our solar system
 One AU is equal to the
distance from the center
of Earth to the center of
the Sun (149 599 000
km)
Light Years
 Used to calculate distances
outside the solar system
 It equals the distance light
travels in one year
• (300 000 km/s = 9.5 trillion
km)
If you wanted to
wind a string 1
Light-year long
around Earth’s
equator, you would
have enough string
to wrap it around
236 million times!
Light from the sun
takes about 8
minutes to reach
earth
Ancienct Myia(45 min)