NAME:
GEOL 1101 LAB7 ASTRONOMY
REMEMBER: with scientific notation, when you multiply you will add exponents and when you divide you subtract exponents
1. Define light year.
2. What are the three observations discussed in class that must be accounted for in any scientific theory on the formation of the universe?
3. How do astronomers calculate the age of the universe?
What is the current best scientific estimate of the age of the universe? ______years
4. Define galaxy.
In what galaxy is our solar system located?
Approximately how many light years across is our galaxy?
Convert this to kilometers (use scientific notation).
Extra Credit: questions 5-6 are optional, for up to 2 points extra credit on Lab Exam 2.
5. A galaxy is 150 million light years away. How many kilometers is that?
This distance is equal to how many centimeters? = ______cm
(use scientific notation and remember 1 km = 105 cm)
We can calculate the age of stars and galaxies if we know the distance from Earth and how fast they are moving away from Earth. (Age = Distance /Velocity)
6. This galaxy in question 4 is moving away from the Earth at a velocity of one billion cm/sec
(= 109 cm/sec). Calculate an approximate age of the Earth in seconds: (use scientific notation!)
Determine how many years this corresponds to:
7. Sketch and name the planets of our solar system in order from the sun. Include the asteroid belt between Mars and Jupiter and the Kuiper Belt. Indicate which are the Terrestrial and which are the Jovian planets.
The Lecture Notes on the Universe and Our Solar System will help to answer all lab questions, as well as the following websites:
WEBSITE #1:
WEBSITE #2:
8. List at least 4 differences between the Terrestrial and Jovian planets.
9. What is our evidence that Mercury does not have active volcanism or tectonics?
10. Why do we think Mercury has a large iron core?
11. Why do we think Mercury's core was at least partially liquid at one time?
12. Why is the surface temperature of Venus hotter than that of Mercury, even though Mercury is closer to the sun?
13. The largest known volcano in our solar system is on Mars (Olympus Mons). Why are such enormous volcanoes like this unable to form on Earth?
14. What is the currently accepted theory to explain why Pluto does not fit the characteristics of the Jovian planets, even though it is at the outer edges of our solar system?
15. What are thecharacteristics that make Pluto so different from the other outer Jovian planets?
16. How does a planet’s composition and density change with distance from the sun?
17. Which terrestrial planet has the lowest density? Why do you think this is?
18. What are the names of the 2 Martian Rovers from Earth that are still sending back information?
19.Which planet in our solar system has a long lived storm in its atmosphere called "the Great Red Spot"?
20. Which Jovian planet rotates about an axis that is almost parallel to the plane of the ecliptic?
(Pluto also does, but it is NOT a Jovian planet). Why do scientist think this happened?
21. All planets but one rotate about their axis in a counter clockwise manner (when viewed from above the plane of the ecliptic), which is the same direction as they rotate about the sun. Which planet rotates about its axis in the opposite direction from which it rotates about the sun? Why do scientist think this occurred?
22. What is the Intense Bombardment Period? Why don't we have evidence for this on Earth?
23. What do asteroids and meteors (called meteorites when they hit the Earth) represent?
24. How did the Earth's moon form?
How did the moons of Jupiter and Saturn form?
25. What are the lunar highlands?
26. What are the lunar maria?
27. How can we distinguish an older surface from a younger surface on another planet (or our moon)?
28. The left photo below of the moon’s surface shows several impact craters. The right photo shows a volcano on Mars. How can you distinguish an impact crater from a volcanic crater?
MOONMARS
29. The moon photo above has a “teardrop” shape crater in the lower left. Explain how this could have formed.
The sketches below show the lunar phases. Use this to help with answering questions 30 - 33.
30. What causes lunar eclipses? At what phase in the lunar cycle will they occur?
31. What causes solar eclipses? At what phase in the lunar cycle will they occur?
32. Each cycle of the moon throughout its phases lasts about 29.5 days. How many cycles occur within one year?
What do we call each cycle?
33. Below is a sketch showing the lunar phases. First, determine the location of the sun from determining what portion of the Earth is in daylight. Label the location of the sun.
Then, name the phases shown at the following locations:
A = H = G =
C = D =
Use the sketch of the Earth’s orbit around the sun below to help answer questions 34–36
34. Explain why the Earth has seasons.
35. What is the relationship between the tilt of the Earth's axis and the sun during a solstice?
36. What is the relationship between the tilt of the Earth's axis and the sun during an equinox?