Heavens above! The Sun

The Sun is the centre of our Solar system. Without this star the impact on our planet and all others would be dramatic and devastating to life as we know it. It is estimated that within one week the temperature on Earth would drop to 0°C (32°F) and within 12 months would be -101°C (- 150°F). The Earth would become an ice world perhaps with only limited basic life forms existing around geothermal vents. Without the Sun’s gravitational pull the planets of the solar system would drift into the void of space.

The Earth orbits the sun at 67,000 mph so if the Sun disappeared our planet would hurtle into space in a straight line at the same speed! Assuming it didn’t hit any other planets, asteroids or comets it would continue to travel through space. It could possibly get picked up into another star’s gravitational pull but no one really knows what would happen. So for the time being let’s just hope that the Sun’s enormous energy continues to provide the perfect temperature to ensure water remains liquid on earth and plants can continue to photosynthesise and its gravitational pull keeps us from flying into space and the unknown.

Quick Facts…

Equivalent size (if the Earth was the size of a cherry tomato!): A Giant Pumpkin

Equator circumference: 4,379,000 km (2,720,984 miles)

Radius /Diameter: 695,700 km (432,287 miles)/1,391,400 km (864,574 miles)

Made of: The star that we know as The Sun started as a cloud of dust and gas. As in the creation of all stars each particle in the cloud had a tiny gravitational pull. They were drawn together getting increasingly heavy until it collapsed in on itself and its core heat increased. This process continued until it became hot enough to result in nuclear fusion. The force of this continuing reaction is held in place by the inward pressure of the star’s gravity and is relatively stable. So essentially our Sun is a ball of hydrogen, helium and plasma with a temperature of 15 million °C at its core.

Features: The Sun is currently a Yellow Dwarf and is considered to be a medium size star. Although it is not solid, it still rotates, taking about 27 earth days to turn on it axis. As the surface of the Sun is heated to around 5,500 °C some of the charged particles escape into space. This is called solar wind. When these particles hit the earth’s atmosphere auroras occur – The Northern Lights. Similarly solar flares from the surface can interfere with satellites, phones, satnav and televisions! The light from the sun takes about 8 minutes to reach earth.

Mythology: Around the world and in many ancient civilisations it was believed that The Sun was a God. As the Sun is needed to grow food and to sustain life this is not surprising. The Ancient Egyptians called their sun god Ra. The Greeks worshipped Helios, the Romans had Sol and the Celts revered Lugh. There are many more that you can learn about with a little research!

Next time we will look at the first of the planets of the Solar System – but can you remember the order?

By Pam Waggott

References: www.solarsystem.nasa.gov www.funkidslive.com www.nhm.ac.uk www.businessinsider.com