Discovery Channel


Asteroids range in size from pebbles to 934km across
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Observing Space

Introduction

Telescopes

Invisible Astronomy

Section 1.4

Section 1.5

Section 1.6

Section 1.7

Section 1.8

Section 1.9

Section 1.10

Section 1.11

Section 1.12

Section 1.13

Section 1.14

Section 1.15

Exploring Space

Introduction

Pioneers

Shuttles

Launchers

ISS

USA in Space

UK in Space

China in Space

France in Space

Russia in Space

The X-Prize

Section 2.12

Section 2.13

Section 2.14

Section 2.15

Planets

Introduction

Mercury

Venus

Earth

Mars

Jupiter

Saturn

Uranus

Neptune

Pluto

Section 3.11

Section 3.12

Section 3.13

Section 3.14

Section 3.15

Moons

Section 4.1

Section 4.2

Section 4.3

Section 4.4

Section 4.5

Section 4.6

Section 4.7

Section 4.8

Section 4.9

Section 4.10

Section 4.11

Section 4.12

Section 4.13

Section 4.14

Section 4.15

Stars

Introduction

The Sun

Sirius

Canopus

Alpha Centauri

Arcturus

Others

Section 5.8

Section 5.9

Section 5.10

Section 5.11

Section 5.12

Section 5.13

Section 5.14

Section 5.15

Comets, Meteors & Asteroids

Deep Impact Mission

Section 6.2

Section 6.3

Section 6.4

Section 6.5

Section 6.6

Section 6.7

Section 6.8

Section 6.9

Section 6.10

Section 6.11

Section 6.12

Section 6.13

Section 6.14

Section 6.15

Galaxies

Section 7.1

Section 7.2

Section 7.3

Section 7.4

Section 7.5

Section 7.6

Section 7.7

Section 7.8

Section 7.9

Section 7.10

Section 7.11

Section 7.12

Section 7.13

Section 7.14

Section 7.15

The Universe

Section 8.1

Section 8.2

Section 8.3

Section 8.4

Section 8.5

Section 8.6

Section 8.7

Section 8.8

Section 8.9

Section 8.10

Section 8.11

Section 8.12

Section 8.13

Section 8.14

Section 8.15

Eclipses

Solar Eclipse

Lunar Eclipse

Lunar Eclipse 2008

What Eclipses Have Taught Us

Significant Eclipses in History

The Blood Red Moon

Section 9.7

Section 9.8

Section 9.9

Section 9.10

Section 9.11

Section 9.12

Section 9.13

Section 9.14

Section 9.15

Amazing Facts

Section 10.1

Section 10.2

Section 10.3

Section 10.4

Section 10.5

Section 10.6

Section 10.7

Section 10.8

Section 10.9

Section 10.10

Section 10.11

Section 10.12

Section 10.13

Section 10.14

Section 10.15

Play: Comet Impact

Section 11.1

Section 11.2

Section 11.3

Section 11.4

Section 11.5

Section 11.6

Section 11.7

Section 11.8

Section 11.9

Section 11.10

Section 11.11

Section 11.12

Section 11.13

Section 11.14

Section 11.15

Space Blog

Section 12.1

Section 12.2

Section 12.3

Section 12.4

Section 12.5

Section 12.6

Section 12.7

Section 12.8

Section 12.9

Section 12.10

Section 12.11

Section 12.12

Section 12.13

Section 12.14

Section 12.15

Section 13

Section 13.1

Section 13.2

Section 13.3

Section 13.4

Section 13.5

Section 13.6

Section 13.7

Section 13.8

Section 13.9

Section 13.10

Section 13.11

Section 13.12

Section 13.13

Section 13.14

Section 13.15

Section 14

Section 14.1

Section 14.2

Section 14.3

Section 14.4

Section 14.5

Section 14.6

Section 14.7

Section 14.8

Section 14.9

Section 14.10

Section 14.11

Section 14.12

Section 14.13

Section 14.14

Section 14.15

Section 15

Section 15.1

Section 15.2

Section 15.3

Section 15.4

Section 15.5

Section 15.6

Section 15.7

Section 15.8

Section 15.9

Section 15.10

Section 15.11

Section 15.12

Section 15.13

Section 15.14

Section 15.15

The Universe

The Universe

We don’t know how big our universe is, because it is just too immense to measure. It could be infinitely large, or there could be other universes.

If you imagine our galaxy as the size of the USA, the Solar System would be the size of a five pence piece and the Sun just a speck of dust. So, imagine how enormous the Universe is!

The ‘big bang’ theory tries to explain how the Universe began. We know that the Universe is expanding and cooling and that it was once a much more hot and hostile environment. Astronomers have reasoned that it is therefore logical to assume that it all started with a very powerful fireball, which stretched to form the Universe around 13 billion years ago.

Photos: Hubble

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