lect03 04

Lecture 3Discovering the Universe for yourself: 

Lecture 3 Discovering the Universe for yourself Outline Patterns in the sky Main points in the sky Phenomena involving the Sun and Moon Chapter 2.1  2.4

Constellations: 

Constellations Patterns of stars seen in the sky About 50 of them were named by ancient Greeks and Romans There are 88 constellations defined in 1920’s Coordinates on Earth

Constellation of Orion: 

Constellation of Orion

Winter triangle: 

Winter triangle

Celestial Sphere: 

Celestial Sphere North celestial pole South celestial pole Celestial equator

Celestial sphere: 

Celestial sphere

Sun within our Galaxy: 

Sun within our Galaxy

Appearance of the Milky Way: 

Appearance of the Milky Way

The closest galaxy (Messier 31): 

The closest galaxy (Messier 31)

Dome of the Sky: 

Dome of the Sky

Daily star paths: 

Daily star paths

Seasonal changes in the sky : 

Seasonal changes in the sky

Annual change of the Sun altitude : 

Annual change of the Sun altitude

The Moon: 

The Moon

The Euler crater: 

The Euler crater

Appearance of the Moon: 

Appearance of the Moon 5 4 3 2 1 1 – Waxing crescent 2 – First quarter 3 – Full moon 4 – Third quarter 5 – Waning crescent Phase diagram

Question of the Lecture: 

Question of the Lecture In the morning you see that the visible face of the Moon is half light and half dark. Is this a first or third quarter? It is a third quarter, because a new moon first appears in the evening.

Lunar eclipses: 

Lunar eclipses

Types of lunar eclipses: 

Types of lunar eclipses Total eclipse – the Moon passes through the Earth’s umbra Partial eclipse – part of the Moon passes through the Earth’s umbra Penumbral eclipse – the Moon passes only through the Earth’s penumbra

The Moon (summary): 

The Moon (summary) Mean distance from Earth – 384,000 km Diameter – 3460 km Mass – 0.01 Earth’s mass Phase cycle – 29.53 days First landing – Soviet spacecraft Luna2 in 1959 6 manned expeditions in 1969  1972 http://www.badastronomy.com/bad/tv/foxapollo.html http://pirlwww.lpl.arizona.edu/~jscotti/NOT_faked/ (the latter is the best viewed by Internet Explorer)

People on the Moon: 

People on the Moon

Solar Eclipses: 

Solar Eclipses

Types of Solar eclipses: 

Types of Solar eclipses Total eclipse – the whole solar disk is behind the Moon (a region of ~270 km in diameter) Partial eclipse – only part of the Sun is blocked from view (~7,000 km) Annular eclipse – a ring-like area of sunlight surrounds the Moon

Saros cycle: 

Saros cycle Eclipse seasons – 2 periods of the year when the nodes of the Moon orbit are aligned with the Sun No more that 7 eclipses a year: 5 solar + 2 lunar or 4 solar + 3 lunar Saros cycle is the period of recurrence of eclipse patterns (18 years and 11 1/3 days)

Map of solar eclipses: 

Map of solar eclipses

The Ancient mystery of the planets: 

The Ancient mystery of the planets

Slide27: 

Summary You can enhance your learning by observing some of the reviewed phenomena by yourself It is convenient to understand what we see in the local sky using the concept of a celestial sphere Complex phenomena in the sky challenged our ancestors and helped drive the development of science and technology