Scales of Scales of the the

UniverseUniverse

The Earth is 12,700 km in diameter.

The Sun is 1.39 million km in diameter.

Imagine the Sun is the size of the classroom.

How large would the Earth be?

The size of a grapefruit(9.2 cm diameter)or small globe

Now imagine that the

Solar System (to the

boundary of the solar

winds) is the size of

the classroom

. (200 AU

diameter)

1 Astronomical Unit = 149,597,870,700 m

or, roughly the distance between the Earth and the

sun. http://www.youtube.com/watch?v=sBap15NWmsI

How large would the sun be?How large would the earth’s

orbit around the sun be?How large would the earth be?

Sun: a grain of salt (0.46 mm diameter)

about the diameter of the tip of a toothpick

Orbit: a CD or half a roll of masking tape (10 cm diameter)

Earth: microscopic bacteria (4 micrometers – 4 millionths of a

meter)

Now imagine the solar neighborhood (the closest

stars to the sun; 65 light-years diameter) were the size of the

classroom.How big would the solar

system be?

A light-year is a measure of distance, not time.

9.4605284 × 1015 metersThe distance light travels in a

year.

A grain of salt (0.49 mm diameter)

about the diameter of the tip of a toothpick

Now imagine the Milky Way (160,000 light-years) is the size

of the classroom.How big would the solar

neighborhood be?

The Milky Way is our galaxy, made up of over 100 billion

stars.

A peppercorn (4mm diameter)about the size of a piece of gravel

Our Local Group of

Galaxies is made up of

3 spiral galaxies (Milky Way,

Andromeda –M31,

and Triangulum -M33), plus

several dwarf

galaxies

Now imagine the Local Group of Galaxies

(6.5 million light-years across) is the size of

the classroom. How big is the Milky

Way?

The size of a large

pizza (50 cm in

diameter)

A Supercluster is a cluster of clusters. The Virgo

Superclustercontains

over 1000 galaxies.

Imagine the Local

Supercluster of Galaxies (130 million light-years) is the size of

the classroom. How large is

the Local Group?

How large is the Milky

Way?

Local Group: A basketball or globe(25

cm in diameter)

Milky Way: A button

(1.25 cm in diameter)

about the diameter of a large thumbtack

It is believed

that there are over

100 billion galaxies.

The Observable Universe is 156 billion light-years in diameter.

Imagine the entire

observable universe were the

size of the classroom. How large would the

Local Supercluste

r be?How large would the

Local Group be?

Local Supercluster: A small

button (8.3 mm

diameter)about the diameter of

a large thumbtack

Local Group: A small

grain of salt (0.2mm

diameter)