1. Standard 1 Objective 2 Study Notes Astronomy 2

2. 1 _____ is the most likely destination for manned _________ and surface exploration because it has some conditions ______ to Earth. Mars voyages similar

3. 2 Liquid water and oxygen/carbon dioxide in the atmosphere are conditions on _______ that support the ____________. Earth biosphere

4. 3 The _______ solar system object is the _____.Sunlargest

5. 4 The ______ ______ and heat from the newly formed sun affected the composition of the inner planets of the solar system by causing them to lose most of their ______ ________. solarwind lighterelements

6. 5 A rock sample containing Strontium 30 is tested and ___% of the original Strontium remains. The Strontium 30 has undergone two _________. 25 half-life’s

7. 6 The ____ of the solar system is estimated by scientists by dating __________ elements. age radioactive

8. 7 A spherical region that surrounds the solar system and that contains billions of ______ is the ______ cloud. comets Oort

9. 8 A _______ is made up of______, dust and gas bound together by gravity. galaxystars

10. 9 A rotating cloud of ____ and _____ from which Earth’s solar system formed is called the _______ _______. gasdust solarnebula

11. 10 The two inner planets most ______ in size, mass, and ________ are Venus and _______. alike densityEarth

12. 11 The _____ dense planet in the solar system is ________. least Saturn

13. 12 The factors that contribute to _________ daily temperature fluctuation of about 600°C are the planet’s slow rotation and its ______ proximity to the sun. Mercury’s close

14. 13 _______ volcanoes are larger than those of Earth because Mars has no moving ________ plates. Mars’s tectonic

15. 14 Small bodies that _____ planets are called ______. orbit moons

16. 15 About ___% of all matter contained in the solar nebula now exists in the _____. 99 sun

17. 16 When early Earth’s atmosphere formed, _______ and _________ gases were lost because Earth’s gravity was too _____. helium weak hydrogen

18. 17 ______ is NOT considered a major planet by astronomers. Pluto

19. 18 _______ is a planet that experiences a runaway ___________ effect. Venus greenhouse

20. 19 The right combination of ___________, water, and _______ supports _____ on Earth. temperature oxygen life

21. 20 _________ is a planet that is similar to ______ in terms of its size and mass. Neptune Uranus

22. 21 The _____ atmosphere developed when many ________ eruptions released large amounts of gases in a process called outgassing. early volcanic

23. 22 The ________ belt can be found between the two planets Mars and Jupiter. asteroid

24. 23 A ____-_____ the distance light travels in a year. lightyear

25. 24 From _________ to the largest in size would be the Solar System, Milky Way Galaxy, and the ________. smallest Universe

26. 25 ___________ substances are used by scientists to measure the ____ of Earth because they give off radiation at a predictable, steady ____. Radioactive age rate

27. 26 The _____ abundant atmospheric gases found on the outer planets are _________ and _______. most hydrogen helium

28. 27 The solar system is much _______ than the ______ _____ galaxy. smaller Milky Way

29. 28 _____ is most like Earth because it has an __________ and moderate ____________. Mars temperaturesatmosphere

30. 29 The Earth’s atmosphere and the _______ Earth is from the sun combine to create an _______ rich atmosphere. distance oxygen

31. The End!!!