Day 3 lecture notes

 

Gavin

Day 3 Summary

            We started off by talking about exploration, sending a person into space, the Moon.  The first contact between two separate species was when Christopher Columbus traveled across the Atlantic Ocean to North America.  We talked about putting a man on the Moon and how currently there is a machine exploring Mars.

Chapter 2 started off with what the night sky looks like.  We can see over 2000 stars on a visible night.  A group of people put together constellations to create quadrants of the universal map.  No one part of the Earth can see the entire sky; you would have to travel the world to get a view of the celestial sphere.  Stars rise and set because the Earth rotates making it seem like the starts are moving from east to west.  Stars near the north celestial pole do not rise or set; they remain above the horizon and make daily counterclockwise circles around the north celestial pole, called circumpolar.

            With the Earth tilted axis combined with orbiting the Sun creates the seasons.  During the winter months that part of the Earth is pointed away from the sun making the days shorter with fewer rays directly received.  During the summer months, that part of the Earth is pointed toward the sun creating longer days with more rays directly received.

            The Moon orbits the Earth.  We see the Moon in different phases depending on its position relative to the sun as it orbits Earth.  When the Moon is between the Sun and earth we cannot see any of the light being reflected.  When the Earth is between the Sun and Moon we can see all the light that is reflected, and as the Moon moves around the Earth we can see various phases.  During an eclipse either the Moon is completely in the Earth’s shadow or the Moon is casting a direct shadow on Earth.