Science On Sphere
The Sun is not a ball of gas, but it is plasma. Plasma is a state of matter where it is so hot that protons lose their electrons. In a star, these two protons fuse together, and one gives off a neutrino, forming a proton fused with a neutron, which is called deuterium. The deuterium bonds with another proton and gives off gamma radiation, forming He3. He3 forms with another He3, each losing a proton in the process to form He4, or Alpha Particle. These reactions all give off energy, but the most important one is the formation of He3, where it gives off light energy.
Solar flares affect infrastructure; however, we have an ozone layer to protect us from the charged particles. The Sun has sunspots on its surface, where the temperatures are cooler. The sunspots are similar to clouds, and they get bigger and bigger until at the end of 11 years, they disappear. They are generally 3-4 times the size of earth.
Aurora Borealis are formed by the radiation from solar flare hitting the earth’s magnetosphere. The magnetosphere protects the earth from getting exposed to radiation. There are different colors in Aurora Borealis the different elements in the atmosphere have different masses. When it hits hydrogen, it turns pink. When it hits oxygen, it turns yellow and green.
- Formation of the solar system
Our sun was formed from a nebula, when a bunch of gas became more compressed and hotter. After the sun had been formed, the solar wind blew the lighter metals and materials further away from the sun. The inner, more solid planets formed, and the outer planets are less dense, therefore larger. Jupiter formed first, and during its formation, it had more massive gravity, so it attracted more materials from other not yet formed planets.
- Got bombarded during its formation and its surface was thrown off its surface, decreasing its size
- Said to be similar to Earth regarding size and mass
- Its surface is very hot, around 462 degrees
- It has a very dense atmosphere, about 90 atmospheric pressure
- Greenhouse effect. The atmosphere in Venus that contains carbon dioxide creates a greenhouse effect that causes the planet to be very hot
- Venus was taught to be twins with earth, but it is more like the opposite
- One day on Venus is 200 earth days; this is because Venus turns very slowly
- Surface thrown away, due to its lack of an atmosphere
- During its formation, Jupiter stripped away its material, resulting in its small size
- It is 1300 times of Earth and has a famous Big Red Spot that is 400 year old on-going storm.
- Galilean moons are important as Galileo Galilei discovered them, he proved that there were objects orbiting star stuff as well, thus proving the geocentric model wrong
- There was a comet that hit Jupiter in 1994. It broke into 21 pieces as it fell due to the gravitational force of Jupiter, and they were not absorbed by Jupiter. If the comet had hit earth instead, it would have wiped out life on earth. Hence many people believe the dinosaurs were killed by a similar comet.
- It is a Gas giant and the biggest planet in the Solar System
- It was formed first, allowing it to strip materials from other planets around it, resulting in its size
- Its rings mostly consist of ice and dust, resulting in it being more reflective and thus observable easily from Earth.
- It consists of mostly hydrogen, thus resulting in it being less dense compared to water
- Uranus & Neptune
- Contains a large volume of Methane
- Methane absorbs red light, causes Uranus and Saturn to appear Blue
- Dark side of the Moon
- Tidal Locking
- Black spots on Moon
- Called the “8 oceans”, these are large and flat and thus thought to contain water. However, it was due to a meteorite that hit Earth and caused large pieces from Earth to fly to the moon and cause these craters
- Conversely, on the other side of the moon, it is much smoother and only smaller craters can be found as the large pieces from Earth could not reach the other side of the moon and only meteors could hit this side of the moon and thus cause these smaller craters.
- Size of Planets
- When the sun is formed, Solar winds blow the lighter and less dense materials such as water, ice, and dust
- When planets form, the heavier and denser materials are nearer to the sun and form smaller planets
- The lighter and less dense materials are further away from the sun form larger and less dense planets
Visit to Central Weather Bureau - Space Weather (Group 2)
A1. What are CMEs?
- CME stands for Coronal Mass Ejection. The CMEs are releases of huge plasmas from the Sun, typically from groups of sunspots which are related to frequent solar flares.
A2. Are they different from Solar Flares? (x only)
300 - 800 metres per second, taking up to 3 - 4 days to reach Earth.
Speed of light, reaching Earth in only 8 minutes.
Effects on Earth
The energy from a flare can disrupt the radio waves in the atmosphere, leading to degradation or even temporarily disrupting navigation and communications signals.
It can mess with Earth’s magnetic fields, creating currents that drive particles down toward Earth's poles. Aurora (a.k.a Northern / Southern Lights) is then formed when these particles are mixed with nitrogen and oxygen. However, these magnetic charges can affect our technologies, for example, radios transmit static, and GPS coordinates stray by a few yards. The magnetic oscillations can also create electrical currents in utility grids on Earth that can overload electrical systems when power companies are not prepared.
Minutes to hours
Hours to day
A3. How do they affect communication systems on Earth?
- Minimally, it causes radio transmissions inaudible. Larger scale Solar Flares (class X) and CMEs are examples of critical “attacks” from the sun. In the modern world, the Global Positioning System (GPS) is a widely used service. It is used in vehicles such as cars to navigate to other places in a certain region.
- On a larger scale, airplanes and ships do use the GPS as they have to navigate to different countries, hence being vital for pilots and captains. When a large scale solar flare or a CME occurs, the GPS may fail and this is how it could affect such as communication system on earth.
B1. Why does the Aurora Borealis occur in the North & South poles?
- The charged particles blown by the solar wind gets deflected by the Earth’s magnetic field. However, the magnetic field is weaker on the North and South pole and therefore some particles are able to enter the Earth’s atmosphere and collide with the gas particles forming the lights during an Aurora Borealis.
B2. How many different colours appear in the Aurora Borealis?
- Red, Yellow, Green, Blue and Violet.
B3. What do the different colours represent?
- Red represents Carbon Dioxide and high altitude Oxygen. Purplish-Red or Blue represents Nitrogen. Yellowish-Green represents Oxygen