An Introduction to Space

Hiya!

A bit of late night physics is what we all need once in a while, space can also be very fascinating when you can experience it first hand (just look out at the stars!) If this work gets too much just don't forget to give yourself some space. Comical. Happy reading!

Much of space physics is a very ambiguous as no-one really knows what's deep past our atmosphere- although technologies can help us make educated predictions as to how the galaxies came about. The Milky Way is our galaxy which contains billions of different stars at different stages of the life cycle of the star (below). Our sun is among the billions of stars. Due to its enormity, the Sun has a large gravitational field which keeps the planets, asteroids, dwarf planets and meteorites in orbit around it. In orbit this matter travels at a constant speed but at a continuously changing velocity (as the magnitude remains the same, the direction of the force changes). The planets in orbit are:

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

As the different planets lie at different distances to the sun, their conditions and temperatures are very different. Their distances also mean that the further away the planet is, the longer the orbit is; Mercury's orbit is 88 days long compared to Neptune's orbit of 165 years. So how are these powerful stars formed?

No joke took this picture this afternoon, I must be getting
 better at this whole picture thing (yes there is a filter, yes I'm aware I'm amazing)

All stars, big and small, are formed in the same way;

1. A nebula (cloud of hydrogen gas and dust) pulls slowly together under the force of its own gravity. As this happens, the gravitational potential energy in the nebula transfers into kinetic energy. As the dust and gas continue to combine, the nebula spins at high speeds and forms a hot, dense 'baby star' called a protostar.
2. When the core becomes hot enough nuclear fusion of hydrogens starts to occur which induces the formation of helium gas. The star is now a hot, dense centre of hydrogen and helium gas.
3. For millions of years, nuclear fusion reactions occur radiating the energy released as light and heat (as transfers). This is where all of the living Earth's energy comes from.
4. Eventually, the hydrogen store will run out and the star will (as I put it "have a mid-life crisis") expand to form either a red giant or a red supergiant (larger stars)
5. Lower mass stars like our sun will turn into red giants. After swelling and cooling, they will become a hot dense white dwarf and glow. Eventually, they will stop glowing and become a dead, black dwarf.
6. Higher mass stars (bigger than our sun) will expand and eventually explode as a supernova. Supernovae are large explosions that create and distribute all the elements formed in the star. Elements heavier than iron cannot be formed in a main sequence star and are formed through further fusion in the supernova. 
7. (High mass star continued) Once the supernova has exploded, it can become either a really dense neutron star or a black hole 

This isn't relevant to space but it's a reminded to live on the wild side,
 have fun and remember the sky is your limit, unless you're an astronaut. If so, you're pretty cool. (Paul Wellez)