Mercury

Question 1

which planets are terrestrial planets?

Answer 1

mercury, venus, earth, mars

Question 2

which planets are inferior planets? why?

Answer 2

mercury and venus, they orbit the sun closer than the Earth.

Question 3

What is the mass of mercury compared to earth?

Answer 3

0.555 x

Question 4

what is the radius of mercury and the radius compared to earth?

Answer 4

2440 km

0.38 x

Question 5

what is the surface gravity compared to earth?

Answer 5

0.38 x

Question 6

what is the albedo of mercury?

Answer 6

9%

Question 7

what is the elongation of mercury? what does this have to do with visibility?

Answer 7

28 degrees

only seen in twilight and not black sky

Question 8

does mercury have phases ?

Answer 8

yes but 1/140th apparent size of moon on the sky

Question 9

how many days does it take mercury to orbit the sun?

Answer 9

88 days

Question 10

what is the mean orbital radius of mercury ?

Answer 10

0.39

Question 11

what is the eccentric orbit of mercury?

Answer 11

perhelion 0.308 AU (46 mil km)

Aphelion 0.467 AU (70 km)

Question 12

does mercury keep the same face towards the sun? yes or no and why?

Answer 12

no, disproved by W.E howard 1962.
Radio observations showed warm side (sunward) 400 degrees as expected but dark side was -170 degrees cold. Not as cold as if never faced sun.

Question 13

what is the rotation period of mercury in days?

Answer 13

59 days

Question 14

why does mercury make 3 rotations every 2 orbits? explain

Answer 14

rotation period is exactly 2/3 of orbital period. Caused nu combination of elliptical orbit and asymmetric planet density

Question 15

what is the implications of perihelion because mercury is denser on one side?

Answer 15

tidal forces will try to keep the denser side facing towards or away from sun at perihelion.
tidal forces balanced, no tendancy to slow rotation down to synchronous

Question 16

why did mercury’s spin slow?

Answer 16

tidal forces tugged rotation and slowed it down. If orbit was more circular- synchronous rotation.

Question 17

what did mariner 10 reveal in regards to craters?

Answer 17

more widely separated with more smooth space between them. Less surface gravity on mercury than moon so ejecta travels more.

Question 18

what did mariner 10 reveal in regards to extensive and prominent cliffs (scarps)?

Answer 18

they were not seen elsewhere- caused by shrinking of crust after hardening, making it shrivel and crack

Question 19

Mariner 10 revealed the large impact crater on mercury. What is its name and what its its features?

Answer 19

Caloris Basin. concentric rings around it.

Question 20

when does caloris basin point directly towards the sun?

Answer 20

every other perihelion

Question 21

what may the caloris basin of caused?

Answer 21

the one side of mercury being denser

Question 22

what is the weird terrain?

Answer 22

rippled appearance may of been created by seismic waves.

Question 23

because mercury has a high overall density, what could this mean?

Answer 23

large dense core like earth that is partially liquid

Question 24

what is the magnetic field of mercury compared to earth ?

Answer 24

1%

Question 25

does mercury have an atmosphere?

Answer 25

no atmosphere because gravity is too low and too hot

Question 26

when was the messenger launched?

Answer 26

3 august 2004

Question 27

what did messenger show?

Answer 27

improved surface, new details of caloris basin. discovery of volcanoes.

Question 28

when did the messenger crash into mercury?

Answer 28

april 2015