Solar Activities

1. Plages - Bright regions seen in the solar chromosphere.

2. Filaments - Filaments are large regions of very dense, cool gas, held in place by magnetic fields. They usually appear long and thin above the chromosphere.

3. Prominences - A Prominence is an elongated structure full of material hundreds of times cooler and denser than the surrounding corona.

4. Solar flares - Solar flares are huge explosions on the surface of the sun, throwing out massive amount of material as matter is heated to millions of degrees in a few minutes. It can last from minutes to hours.

5. Solar wind - A tenuous flow of gas and energetic charge particles which streams from the sun. 

6. Sunspots

• Sunspots appear as dark spots on the surface of the sun.

• Temperatures in the dark centers of sunspots drop to about 3700 K (compared to 5700 K for the surrounding photosphere).

• Sunspots are magnetic regions on the sun with  magnetic field strengths thousands of times stronger than the Earth’s magnetic field.

Earth as the only planet which life exist

Earth’s conditions are ideal for life.

1. Liquid water and all the other requirements for life exist on Earth. Temperature is just right for liquid water to remain.

2. The atmosphere of Earth is a complex system which is made up of Nitrogen, Oxygen, Argon, Carbon Dioxide and water vapor. This structure and continuous process of the atmosphere control the life on Earth. Life is also affect atmosphere both its variation and stability.

3. The atmosphere contain right amount of oxygen.

4. Earth is the only planet where gaseous oxygen is found. Because Earth has plants that do photosynthesis. There’s no other natural process that will put significant amount of oxygen in to a planet’s atmosphere.

5. But we does not mean that to exist life in any planet need to have oxygen.

6. Ozone layer of atmosphere is thick enough to protect life from harmful radiation and small objects from space.

Requirements for Life

We really don't know the conditions required for life in general. We only know what is required for life like us.

1. Liquid water -habitability is basically determined by liquid water as it is an excellent solvent for chemicals & provide medium for chemical reactions of living beings. But some life forms might be based on other liquids.

2. Elements or Organic compounds - life on Earth is made up of complex molecules based on Carbon. Carbon is the only atom capable of forming large complex molecules.

3. Energy source - Energy source need for synthesize complex organic molecules.

4. Atmosphere - To support liquids on its surface atmosphere is needed.

5. Temperature -temperature of planet mainly depend on the distance from sun. Support life in a planet needs temperature within 0-1000C with a pressure is at least 10mbars.

6. Protection from harmful radiation - For example, Ozone layer around Earth act as a protective cover from radiation.

7. Stability -conditions must be stable to initiate and exist life. it takes time for life to form and then evolve to complex forms capable of intelligence.

8. A suitable planet - not so small or not so large. if it is so small, loses its atmosphere. If it is massive, becomes “gas giants”.

9.  Disaster avoidance -collision with large asteroid, explosion of supernova very nearby can destroy life.