Astronomy Final Exam Review: The Answers

Astronomy 2014

1. What are the wavelengths of the EM Spectrum? List from longest to shortest and give examples.

Radio waves, Microwaves, Infrared, Visible Light, Ultraviolet, X-rays, Gamma rays

2. How can you remember them in order? ~~~Longest to shortest~~~

R -obertM -ightI -nspectV -eryU -nusualX -traG -arages

3. Heat energy is what type of radiation?

THERMAL

4. In what wavelengths of the EM Spectrum does our Sun emit?• Can we see it? Yes, so…

Visible

• Does it have a temperature? Yes, so… Infrared

• Does it give off radiation than burn us? Yes, so…Ultraviolet (UV)

5. What is the approx. speed of light?

300,000 km/second

6. Explain spectroscopy and what its used for in astronomy.

Spectroscopy: process of obtaining spectra of light and analyzing it

Used in astronomy to determine chemical composition, motion, and temperature of objects in space

7-8. Wave SpeedWavelength x Frequency = Wave speed

9-11. What is Doppler Shift/Effect?Effect that shifts the wavelengths of objects that are moving toward or away from the observer

REDSHIFT: Away from observer = waves “stretched” (lengthened)

BLUESHIFT: Toward observer = waves “squished” (shortened)

IMPORTANT for determining temperature and speed/direction of an object in space

12. Line-graph Spectra

13. ID’ing chem comp from spectra.

Be able to match up the lines – one on the test is easy!

14. Explain the process of time monitoring.

Observing an astronomical object over a period of time and recording changes in its brightness

15. The First Telescopes…• Refracting = Lens, Galileo 1609• Reflecting = Mirrors, Newton 1672

LENS

FOCUSEYEPIECE

FOCUS: area inside of a telescope where light comes to a point to create an image

16-17. Radio Telescopes

Main Components: • Radio Antenna• Dish• Receiver

Radio telescopes are not affected by weather conditions

18-19. Light Curve GraphsDiagram that graphs brightness as it relates to time (such as the one to the right)

A supernova would look like…A steep “peak” that drops back down quickly over a short time period

20. Explain the process of interferometry.

Series of instruments used to account for error caused by light pollution and turbulence of the Earth’s atmosphere

21. Hubble

Observes in Infrared, Visible, and Ultraviolet

22-24. Light Pollution, Turbulence, and Ground Based Observation

22. They distort images: light pollution makes sky hazy and turbulence bends light and makes stars “twinkle”

23. Best: rural (desert), Worst: urban (D.C.)

24. They are unaffected by the disrupting factors of light pollution and Earth’s atmosphere.

25. Space Probes

Any mission with an unmanned vehicle that travelled great distances to collect information and send back data

26. Describe the Giant Impact Theory.

• Current, accepted theory for how the Moon formed

• A very young Earth was impacted by a Mars-sized object. The impact send debris into space that then orbited Earth and eventually condensed to form the moon

27. Sea of Tranquility

• Type of Feature: Lunar Maria

• Significance: Site of Apollo landing

28. Exosphere

Atmosphere of the moon is an exosphere(Thin layer of gas)

29. Lunar Geology

Moon Rocks are:• Igneous• Made of Basalt

30. How does the moon influence tides on Earth?

Gravitational force of Moon causes tides

31. Water on the moon

Yes, at the poles.

Discovered by lunar probe recently

May have come from comets/other impacts.

32. Why does the moon turn red in a lunar eclipse?

The moon appears red due to the refracting of light waves within Earth’s atmosphere.

33. Synchronous Rotation

We only ever see one side of the moon from Earth because the moon and Earth spin on their axises at the same rate of motion.

34. Umbra and Penumbra

UMBRA

PENUMBRA

35. Eclipse DiagramsEclipse Type: SOLAR

What’s Happening? The moon passes between the Earth and Sun, and casts its shadow onto Earth

Eclipse Type: LUNAR

What’s Happening? The Earth passes between the Moon and Sun, and casts its shadow onto Moon

36. Our Solar System

• 8 planets

• Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

37. Terrestrial Planets

• Terrestrial = Earth-like• Mercury, Venus, Earth, Mars• Elemental Comp: oxygen and silicon• Dense, rocky, metal core, few/no moons • Mercury and Venus have NO MOONS

38. Jovian Planets

• Jovian = Jupiter-like• Jupiter, Saturn, Uranus, Neptune• Elemental Comp: Hydrogen and Helium• Cold, strong magnetic fields, many moons, fast

rotational periods

39. Dwarf Planets

• Pluto, Ceres, Eris, Makemake, Haumea, and Sedna

• Different from a regular planets because it has not cleared similarly sized objects from its “neighborhood”

40. Asteroids

Most asteroids (75%) are CARBONACEOUS

41. TNO’s

• Trans-Neptunian Object – Object that crosses in and out of Neptune’s orbit

42. Kuiper Belt v. Oort Cloud

• Kuiper Belt: area of icy objects near the orbit of Neptune where Pluto and Eris are located

• Oort Cloud: where comets originate

43. Reclassification of Pluto

Pluto was reclassified because: the discovery of Eris, which is another Kuiper Belt object that larger than Pluto

44. Ceres

Was originally classified as an asteroid, but was reclassified as a dwarf planet

45. Pluto and Charon

Have a binary relationship

46. Define the unit of measurement AU.

1 AU = Distance from Earth to the Sun

47. What process is occurring and how is it significant to stars?

Nuclear Fusion ofHydrogen + Hydrogen = Helium

…releases ENERGY

48. What is a protostar?

An early-stage, still-forming star that has not yet reached sustained nuclear fusion at its core

49. Jean’s Instability Criteria

The maximum mass and length of a cloud of hydrogen gas where it will become unstable and collapse under its own gravity

50. Star formation for a regular mass star

BEGINS IN Nebula

THENProtostar, Main Sequence Star, Red Giant, Planetary Nebula, White Dwarf

51. Two Life Cycle Paths of Stars

DETERMINED BY STAR’S MASS

• Regular Mass Star (Main Sequence)

• High Mass Star (Super Giant)

52. Explain the White Dwarf Limit.

No white dwarf star can be larger than 1.4MSUN because at larger than this mass, the electrons within the star would be moving at impossibly fast speeds

53. How does a high-mass star’s life end?

SUPERNOVA: the core of a supergiant collapses when it is overwhelmed by pressure that has built up

54. Main Sequence

In the main sequence, a star’s temperature is directly related to brightness

55. Black Hole Emissions

• Stellar (Regular): X-Rays

• Supermassive: X-Rays and Gamma Rays

56. How does temperature relate to color in main sequence stars?

• Hottest Stars are BLUE

• Coolest Stars are RED

57. Stellar Classes

Hottest to Coolest:O, B, A, F, G, K, M

The Sun is a G Class star.

58. Layers of Our SunCHROMOSPHERE

PHOTOSPHERE

CORE

SOLAR PROMINENCE

SUN SPOTS

CORONA

CORONA: outer most layer of the sun’s atmosphere

59. Definition of “alive”

Object that…• possess an ordered structure • uses energy • respond to the environment • goal of reproduction

60. Kingdom Archaea and Microbial Alien Life

These single-celled organisms are capable of living in extreme environments and can undergo chemosynthesis

61-62. SETI and ET Research

61. SETI is a project established for the purpose of searching for and communicating with intelligent extraterrestrial life.

62. Best technology for possible communicating with intelligent ET life is radio-astronomy

63. Drake Equation

Equation that determines the mathematical probability that intelligent life exists within our solar system

Additional Study Points

Objectives from Classwork• What is atomic mass?

• What is a “rover”?

• Phases of the Moon

Additional Study Points Cont.

Objectives from Projects & Labs• What is an H-R Diagram? What does it show?

• What topic did you do your astronomical tool project on?

• What topic did you do your solar system tourism project on?

• How are objects in our solar system classified?