Transcript Components of the Universe

The Sun

The sun is a medium size
star

It appears larger than the
other stars because of its
relative nearness to the
earth

It consists of about 70%
Hydrogen, 28% Helium and
2% of metals such as iron
Size

The sun is 1,390,000 km in diameter
 You could fit 1 million earths inside the sun
The planet Venus just passing in front of the Sun
Our Sun is so large ….
it would take 108 Earths laid side-by-side to go
across the Sun’s diameter
Characteristics of the Sun –
Relative Sizes
Mass

The mass of the
Sun is about 2 x
1030 kilograms

It is one of the larger
stars in our Milky
Way galaxy

The mass of the
Sun is over 300,000
times greater than
that of the Earth
Distance

The Sun is 149,600,000 km
(92 million miles) from the
Earth
 Since the speed of light is
303,000 km/sec (186,000
miles/second), it takes the
light slightly over 8 minutes
to get from the Sun to the
Earth
Inside our Sun a Deeper Look
Temperature

Its temperature is
extremely hot, with the
surface being about
5000° C and the center
core at 15,600,000° C

The high temperature in the core, along with
extreme pressure from the Sun's mass, result in
nuclear fusion reactions

Nuclear fusion converts hydrogen to helium
producing energy
Importance of the Sun

Without the Sun, the
Earth would not be able
to support life

It is the main source of
energy for earth

It provides light and heat

It’s necessary for plants
to carry out
photosynthesis
The Sun Song
- kidsknowit
The sun song
Importance of the Sun
– 5min
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The Milky Way

The Milky Way is a cluster of
stars, called a galaxy

It contains hundreds of billions
of stars

If you traveled at the speed of
light for about 2 million years,
you would reach the next galaxy
– the Andromeda Galaxy

There are billions of galaxies in
the universe
Light Years Explained
Distance to Stars

Astronomers use light-years and
astronomical units to measure
distance
 A light-year is the distance that
light travels in one year
 In space, light travels at a speed
of 300,000 km per second

A light year is about 9.5 million
million km (9,460,730,472,580.8)
 About 6 trillion miles
For Example
Measuring the Universe - discove

If you ride your bike at 10 kilometers per hour,
it would take you 1 hour to go to a mall 10km
away

You could say that the mall is 1 bike-hour away
Actual Distance from the Sun to the Earth
How long does it take light to get
from the Sun to the Earth?
8 minutes
It takes 16 minutes to go there and back
Stars

Betelgeuse:
 427 light years

Rigel:
 773 light years

Orion Nebula:
 1600 light years
Key Idea
The light-year is a unit of
distance, not time!
The Milky Way Galaxy is about 100,000 light
years across
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Nearby Stars:
Name
Distance from Earth
Sun
93 million miles (8 light min)
Proxima Centauri
4.22 Light Years
Alpha Centuri A,B
4.39 Light Years
Barnards Star
5.94 Light Years
Wolf 359
7.8 Light Years
Lalande 21185
8.3 Light Years
Sirius A,B
8.6 Light Years
How Fast Can We Get There?
Destination
Jet
(960 km/h)
Rocket
(40,000km/h)
Sunbeam
(300,000 km/sec)
Moon
16.5 days
9.4 hours
1.2 seconds
Sun
17 years, 8
months
4 months
8.5 minutes
Jupiter
74 years, 3 mos
1 year, 9 months
35 minutes
Alpha Centauri
(nearest star)
4.8 million years
114,155 years
4.2 years
-------------------
-------------------
109 years
Center of the
------------------Milky Way Galaxy
-------------------
38,000 years
Andromeda
Galaxy
-------------------
-------------------
2.2 million years
Hubble Galaxies
-------------------
-------------------
400 million years
Monocerus
Nebula
Astronomical Unit

The distance of the Sun to the Earth is called an
Astronomical Unit (AU) and is sometimes used to
denote large distances that are less than a light
year

A light year is
about 63,241.1
astronomical
units
Sun to Earth Distance
1 Astronomical
Unit (AU)
93,000,000 Miles
Body
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
AU
0.39
0.72
1.0
1.5
5.2
9.5
19.2
30.1
39.5