Sizes and scales in Astronomy

1mm

1cm

Earth: radius 6,400km equivalent to 0.5mm

Jupiter 70,000km

Sun 700,000km

Earth 6,400km

Jupiter 70,000km

Distance from Earth to Sun is 149,600,000km = 1AU(12m)

SunEarthJupiter

1 AU4 AU

Heliopause – 100 AU (1.2km)

Pluto’s Orbit – 40 AU

6km

100km

1500km

3000km

Solar System Proxima Centauri <1.3 pc = 268,000AU>

20,000km

Stars Nearer than 5 pc: 70

Solar System

200 AU equivalent to 1mm (Earth is size of atom);1 pc equivalent to 1m

Rescale:

Stars within 5 pc

Milky way: 300,000pc across (300km)

Milky Way

30 galaxies, 10,000km across

Rescale:

Milky Way

300,000pc equivalent to 10cm- Solar system smaller than size of atom- Earth 1,000 times smaller than the smallest sub-atomic particle known

Local GroupLocal Supercluster (Virgo, 2000 galaxies)

Observable Universe: 96,000,000,000pc across