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Ambition – Respect - Excellence
Ardrossan Academy
Dead Earth
Subtopic – SPACE – LIFE ON OTHER WORLDS
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Ambition – Respect - Excellence
Lesson Title:
Life on Other Worlds
Learning Intention:.
To research conditions on other planets and moons to decide if it could support life
Activity: Internet research
I will be successful if I can : Summarise the conditions on another planet or moon, decide whether or not it could support life, and explain my decision.
OTHER WORLDS
• Our Solar system has a single star, eight planets and over 170 known moons.
• As far as we know, only the Earth has life of any kind.
• What is so special about the Earth?
WHAT DO WE MEAN BY ‘LIFE’?
• Human beings are the most complex living things on Earth
• But living things on Earth also include plants, animals, bacteria, fungi
WHAT DOES ‘LIFE’ NEED?
• All living things on Earth need three things to survive
• Liquid water• A source of energy• A protective environment
• These depend on• Temperature• Sunlight• Atmosphere & material of
the planet
THE HABITABLE ZONE
• The temperature on Earth is ideal for water to exist in liquid form
• Closer to the Sun it is too hot• Farther from the Sun it is too
cold• This puts Earth in the
‘Habitable Zone’ for the Sun
WATER AND LIFE
• Liquid water is needed for many of the chemical reactions that support life
• It also provides a habitat for many living things
• The water cycle is vital to provide fresh water for living things
OTHER FEATURES
• The Earth also has an atmosphere rich in oxygen, though many living things – especially plants do not need oxygen to live
• The Earth’s magnetic field also protects us from harmful particles and radiation from the Sun
LIFE ON OTHER WORLDS
• Astronomers have been searching for planets orbiting other stars since the invention of telescope
• The first EXOPLANET was discovered in 1994
• The number now known is almost 2000
LIFE ON OTHER WORLDS
• Very few of these 2000 exoplanets are in the habitable zone for their stars
• Those that are may not have ideal conditions for life
• If there is life on these planets, it may be very simple – e.g bacteria