Lecture 11 Flashcards Preview

AST205 > Lecture 11 > Flashcards

Flashcards in Lecture 11 Deck (31):
1

What is microlensing and what did it discover?

It involves using gravity bending light around large objects to see faraway objects and was used to discover a planet

2

Where do we typically use microlensing?

Baade's window

3

What is unique about the planet discovered through microlensing?

It is circumbinary (going around a binary star system)

4

What are the lunar maria?

Smooth, dark areas (created by early volcanism)

5

Why are there ridges on the moon?

Lava contracting, not tectonics!

6

What terrain does mercury have?

Some smooth areas punctuated with craters

7

What is the largest impact crater on Mercury?

Caloris Basin

8

What was the first man-made device to enter the atmosphere of another planet?

Venera (entered venus)

9

How do we see through Venus's clouds?

Radar mapping (bright areas = rugged landscape)

10

What are Venus's coronae?

Rising magma pushing through and breaking crust

11

What are Venus's major topographical structures?

Volcanoes (dormant), impact craters, extensive tectonic movement

12

Why does lava flow so far on Venus?

The surface is very hot

13

Does venus have plate tectonics?

No actual plates, but the surface appears to have been drastically reshaped years ago; the Lithosphere resists change due to lack of water

14

What is the Gutenberg low-velocity zone?

Area just beneath lithosphere where there is a drastic seismic change

15

What is the astenosphere?

A moldable layer right below the lithosphere, which allows the plates to slide around on top

16

Who first suggested continental drift?

Wegener

17

What is the explanation for continental drift?

Sea-floor spreading

18

What is subduction?

Where one plate slides underneath another

19

What causes lava?

The friction of subduction

20

How do we know earth's magnetic field reverses every thousand or so years?

Geomagnetic reversals are recorded in the sea-floor spreading

21

Who first discovered canals on mars?

Schiaperelli

22

Who first thought earth and mars were similar?

Herschel

23

How first interpreted the martian landscape as having life?

Lowell

24

What are two mars missions?

Spirit & Opportunity, Curiosity

25

Which hemisphere of Mars has fewer volcanoes and more cratering?

The southern hemisphere

26

What is a large crater on mars?

Hellas Basin

27

What is the largest volcano in the solar system?

Olympus Mons on Mars

28

How did martian rock get to earth?

An impact

29

What is the Tharsis bulge?

A large martian volcanic feature

30

What is the evidence of tectonic activity on mars?

Valles Marineris on Mars

31

How do we know Mars had water?

Found in soil by Curiosity, seen in polar ice caps, riverbeds, erosion of craters by water, "Muddy" craters