Right Now There are only 13 days before

Right Now… • There are only 13 days before final exams, meaning you have 13 days to make a significant impact on your grade. • Find your new seat. This is where you will stay until I see some major improvements.

Bell Ringer – answer based on previous knowledge • The Earth rotates on its axis once every (24 hours/365 days), making one (day/year). The Earth orbits around the Sun once every (24 hours/365 days), making one (day/year).

ASTRONOMY AND THE EARTH

Tools of Astronomy • Astronomy – study of objects beyond Earth’s atmosphere • The most useful tool for observing space is electromagnetic radiation that comes to Earth from distant objects

Tools of Astronomy • Electromagnetic (EM) radiation – form of energy that travels as a wave • Includes radio waves, microwaves, infrared, visible light, ultraviolet (UV), x-rays, and gamma rays

Tools of Astronomy • Earth’s atmosphere blocks most EM waves, so objects must be sent into space to observe these types of radiation • Examples: satellites and space stations

Tools of Astronomy • Telescopes – devices that observe radiation on Earth • Most are used in rural areas, at high elevations Keck Observatory, Hawaii

• Can be used with other pieces of equipment such as cameras Photos from Hubble Telescope

Tools of Astronomy • Refracting Telescopes – use lenses to focus light • Reflecting Telescopes – use mirrors to focus light – Most commonly-used type of telescope

Check for Understanding • How are satellites and telescopes similar? both are used to study outer space • What’s the difference between a satellite and a telescope? satellite – in space; telescope – on Earth • Which telescope uses a mirror? reflecting • Which telescope uses a lens? refracting

Units of Measurement Commonly Used in Astronomy: • Astronomical Unit (AU) = the average distance from the Sun to the Earth

Units of Measurement Commonly Used in Astronomy: • Light year = the distance that light travels in one year (nearly 6 trillion miles!) • Example: It takes over 4 years for light to travel from Earth to our next-closest star, Proxima Centauri

Earth’s Rotation • The Earth rotates (spins) on its axis once every day, about every 24 hours – Facing the Sun = day – Facing away from the Sun = night • At the equator, Earth is spinning at a rate of 1040 mph

Earth’s Rotation • Earth’s rotation is the reason why the Sun appears to rise in the east and set in the west, as well as the Moon and stars at night

Earth’s Revolution • The Earth and other planets revolve (orbit) around the Sun counterclockwise in the same plane • Ecliptic – the plane in which planets orbit around the Sun

Earth’s Revolution • The Earth completes one revolution around the Sun once every year, about 365 days

Earth’s Revolution • Earth’s axis is tilted 23. 5 o in relation to the ecliptic • This tilt causes Earth’s seasons (summer when towards the Sun, winter when the Earth is tilted _______ away it is tilted _____)

Earth’s Revolution • The Northern and Southern Hemispheres have opposite seasons • Example: December is the beginning of winter in the Northern Hemisphere and the beginning of summer in the Southern Hemisphere

Check for Understanding • How often does Earth revolve? • How often does Earth rotate? • What causes seasons?

Solstices and Equinoxes (in Northern Hemisphere specifically) • • • Summer Solstice -- June 21 (1 st day of summer) Northern Hemisphere tilted toward the Sun directly over the Tropic of Cancer (23. 5° N) Maximum amount of daylight hours (longest day) Constant daylight within the Arctic Circle (66. 6°N)

Constant Daylight • https: //www. youtube. com/watch? v=ndl. QNic Oeso

Solstices and Equinoxes • • • Winter Solstice -- December 21 (1 st day of winter) Northern Hemisphere tilted away from the Sun directly over the Tropic of Capricorn (23. 5° S) Minimum amount of daylight hours (shortest day) Constant darkness within Arctic Circle (66. 6°N)

Solstices and Equinoxes Solstice Occurs in this month 1 st day of this season Winter Solstice Dec Winter Summer June Solstice Longest Shortest North Hemi is __ of the Pole: year pointed year Away Night Daylight Summer Towards Day Night Darkness

Solstices and Equinoxes • Equinox -- equal-length days and nights (equinox means “equal nights”) • Sun is directly over the equator • Halfway between the summer and winter solstices • March and September (1 st days of spring and fall)

Solstices and Equinoxes Equinox Vernal Autumnal Occurs in this month March September 1 st day of this season Spring Fall Days are (>, <, =) to Nights = =

Precession and Nutation • Precession – the wobbling of the Earth on its axis, completing a circle every 26, 000 years

Precession and Nutation • Non-science example: spinning top • https: //www. youtube. com/watch? v=u. Vyhy. Nvl. N 3 Y

Precession and Nutation • Nutation – Earth’s wavy path as it wobbles on its axis • Mainly caused by the effects of the Moon’s orbit around the Earth

Today • Complete Vocabulary Assignment – INDEPENDENTLY, IN YOUR OWN SEAT • If you have headphones, you may listen to music • Turn into basket when you are done • I will let you look at your tests from Friday at the end of class

Good Summary for Today: • https: //www. youtube. com/watch? v=9 n 04 SEzuv. Xo

Vocabulary • Complete Vocabulary Sheet • When done, get 5 ½ sheets of paper and staple them together (Station 1) • Choose 5 of the words on your vocab and make a book about them. – Vocab Term (nice and big) – A QUALITY picture illustrating the term – A short definition IN YOUR OWN WORDS describing the term • Staple together when done

Rhyme Time • Complete the sentence: “In 14 hundred 92, Columbus sailed the ocean blue _______________” • Our brains have the ability to better retain information when it is set to songs or rhymes. • Create a couplet (2 rhyming lines) for EACH of the following topics from today’s notes: rotation, revolution, solstices, equinoxes • These couplets should have important (testable) information in them. • You DO NOT have to rhyme the key words. Example: “Equinoxes are in the spring and fall, they bring equal day and night for one and all. ”