Milky Way

1. Sun's Corona hotter than surface

1.1. Surface is 6,000 kelvins, corona is 1 million kelvins

1.2. magnetic fields are stronger, corona is hotter

1.3. atronomers don't have tools to measure magnetic field strength, so they use math

1.4. other ways of measuring coronal heating is observation of other stars

2. Milky Way Formed

2.1. collapse of gas clouds

2.2. supernova explosion

2.3. absorbing pristine intergalactic gas

3. Milky Way's atmosphere

3.1. galaxy's atmosphere is called intersteller medium

3.2. intersteller medium is a mixture of temperature, diversity, density, and ionization

3.3. Supernova explosions blow giant bubbles

4. Stardust

4.1. from forming a star a dust grain evaparotes and could form a rocky planet, asteriod or become part of star later

4.2. silicate dust grains could form a clump then a comet

4.3. comets are about 4.6 billion years old, so the dust grains are about 10 billion years old

5. Milky Way is alive

5.1. HVCs show us that our galaxy is still growing

5.2. Milky Way was surrounded by intergalactic galaxies

5.3. Next 10 billion years in the future the Milky Way will suck up more galaxies

6. Most of Milky Way has no life

6.1. Needs available materials

6.2. Needs to be away from cosmic threats

6.3. The regular universe is less habitable than the Milky Way.

7. Andromeda Galaxy

7.1. Sister Galaxy of Milky Way

7.2. Collision course with Andromeda Galaxy

7.3. Spiral Galaxy

8. Zone of avoidance

8.1. Galaxies are everywhere except region of Milky Way

8.2. Zone of Avoidance is full of dust and stars

8.3. many ways to see through the zone of avoidance such as: by eye, infarred, wavelenghs, 21-centermeter spectral line, and x-rays