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Astr nomy. Part 1 – Earth in the Universe. The Big Bang Video. The Big Bang Theory. The universe started with a concentrated area of matter and energy. 15-20 billion years ago. Then, it exploded and has been expanding ever since. The Big Bang Theory.
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Astr nomy Part 1 – Earth in the Universe
The Big Bang Theory • Theuniversestarted with a concentrated area ofmatterand energy. • 15-20billion years ago. • Then, itexplodedand has beenexpandingever since.
The Big Bang Theory • Matter began toclumptogether formingstarsand galaxies. • The universe continued to expand and is stillexpandingtoday.
Regents Question Which celestial feature is largest in actual size? (1) the Moon (2) the Sun (3) Jupiter (4) the Milky Way Answer is… 4
Universe Expansion • How do we know the universe is expanding? • Pg.14in the ESRT shows theelectromagneticspectrum. • Notice that in thevisiblespectrum there are all the colors of therainbow.
Pleaseanswer the questions on the Electromagnetic spectrum ½ sheet.
Universe Expansion • When looking at the visible spectrumwavelengthsare shifted either to theblueend (shorter wave) or theredend (longer wave). • This shift in wavelengths is called theDoppler Effect. • If they are shifted towardsred, they are movingawayfrom you. • If they are shifted towardblue,they are comingtowardsyou.
Universe Expansion • When scientists look at the universe, they see ared shift.This proves it is movingawayfrom us, thus, expanding!
Red Shift Light from galaxies moving away Earth Science Rocks Notice the shift towards red
Blue Shift Light from galaxies moving toward us Earth Science Rocks Notice the shift towards blue.
Galaxies • A galaxy is a collection of billions ofstarsand gas and dust. • Our solar system is part of theMilkyWay Galaxy. • The Milky Way is aspiral-shapedgalaxy.
Regents Question The Milky Way Galaxy is best described as (1) elliptical (2) circular (3) irregular (4) Spiral Answer is… 4
Stars Earth Science Rock • A star is usually a large ball ofgasheld together bygravity. • Energy is producedbynuclear fusion– combination ofnucleiof smaller elements to form nuclei of larger elements.
Regents Question Which star color indicates the hottest star surface temperature? (1) blue (2) yellow (3) white (4) Red
Regents Question Which star color indicates the hottest star surface temperature? (1) blue (2) yellow (3) white (4) Red Answer is… 1
Regents Question In the main sequence, compared to the surface temperature and luminosity of massive stars, the smaller stars are (1) hotter and less luminous (2) hotter and more luminous (3) cooler and less luminous (4) cooler and more luminous Answer is… 3
DENEB 1.What is the most massive star on the chart? ________________________________ 2. What is the temperature and luminosity of the Sun? __________________ and ________________ 3. What group is a star in during a late stage? ________________________________ 5,600 ºK Luminosity = 1 White Dwarfs
3300ºK 4. What is the temperature and luminosity of Betelguese? ___________________ and ___________________ 5. What color would a star be if it was 15,000ºK? ________________________________ 6. What group of star is Albebaran in? ________________________________ 200,000 Blue White Giants
2800ºK Red 7. What temperature and color is Proxima Centauri? __________________ and __________________ 8. Massive stars are (more / less) luminous. (Circle one) 9. Name a White Dwarf star. __________________ 10. What stage are Main Sequence stars in? _______ Procyon B or Eridani B Early
Our Solar System • Thesolar systemis thesunand all objects thatorbitthe sun under itsgravitationalinfluence. • Our solar system has1 sun and 8planets.
Regents Question The Sun’s position in space is best described as the approximate center of (1) a constellation (2) the universe (3) the Milky Way galaxy (4) our solar system Answer is… 4
Regents Question Compared to Earth’s solar system, the universe is inferred to be (1) younger and larger (2) older and larger (3) younger and smaller (4) older and smaller Answer is… 2
Page 15: ESRT Pluto? New Chart in your ESRT… Sorry Pluto…
Using the data table on page 15 of your ESRT, answer the following questions. 1. What is the period of rotation of Mercury? _____________________________ 2. What is a year on Mars?__________________________________________ 3. Which planet has the most eccentric orbit? ___________________________ 4. Which has the least eccentric orbit? ____________________________ 5. What is the diameter of Jupiter?__________________________ 6. What is a day on Saturn?__________________________________________ 59d 687 d Mercury Venus 142,984 km 10 h 14 min
Venus Jupiter 7. Which planet has the longest period of rotation?__________The shortest?_________ 8. Which planet is the most dense?_____________The least?____________ 9. How far from the sun is Venus?__________________ 10. How far from Earth is our Moon?______________________________________ 11. What is the mass of Neptune ?____________________ 12. What is the radius of Saturn?_______________________________ Earth Saturn 108.2 million km 0.386 million km 4,498.3 million km 60,268 km
Regents Question Which event takes the most time? • one revolution of Earth around the Sun (2) one revolution of Venus around the Sun (3) one rotation of the Moon on its axis (4) one rotation of Venus on its axis Answer is… 1
Eccentricity and Ellipses • Anellipseis an oval shape. • Earth’sorbitaround the sun is an ellipse. • Within an ellipse, there are twofixedpoints calledfoci. • In our solar system, thesunisALWAYSONE of those foci.
Eccentricity and Ellipses • Thedegree of flatnessor “ovalness” of an ellipse is measured byeccentricity. • This formula is on page1of your ESRT!
Eccentricity and Ellipses • The moreovalthe orbit is, the moreeccentricit is, or the higher the eccentricity. Increasing Eccentricity
Eccentricity and Ellipses • Calculating Eccentricity: Major Axis X X Foci 1 Foci 2
You can make an ellipse with 2 tacks and a string. The tacks are the “foci”, and if you put them further apart, the ellipse is more “eccentric” (one tack makes a circle). An ellipse is an example of a “conic section”. Circles and hyperbolas are others. All are possible forms for orbits.
Eccentricity and Ellipses • Calculating Eccentricity: • When you measure those 2 distances and calculate them, you willNEVERget higher than1!! • The closer to 1 you are theMOREoval or eccentric the orbit. • The closer to 0 you are theLESSoval or eccentric the orbit.
Regents Question Which planet’s orbit around the Sun is most nearly circular? (ESRT 15) (1) Mercury (2) Pluto (3) Neptune (4) Venus Answer is… 4 No More Pluto
Gravitational Force • Thecloser2 objects are to each other, thegreaterthegravitationalpull between them. • Therefore, during theperihelion– when Earth iscloserto the sun, there is agreatergravitationalpull between it and the sun. • This makes the Earthspeed upa bit in itsorbitaround the sun during that time.