Astron 103

Question 1

Mercury’s Composition and Rotation

Answer 1

Mercury has a molten core but rotates slowly, which contributes to its weak magnetic field and the absence of Van Allen belts.
The planet exhibits ice at its poles, similar to the Moon, in permanently shadowed craters. Despite the lack of atmosphere, which hinders heat transfer, there’s significant temperature variation between day and night due to this.

Question 2

Planetary Differentiation and Magnetic Fields

Answer 2

Planetary differentiation refers to the variation in planetary composition and size, including the presence of an iron core and rotation affecting the existence of magnetic fields.
The molten iron cores are crucial for generating magnetic fields. Despite its slow rotation, Mercury manages to maintain a magnetic field.

Question 3

Venus

Answer 3

Leading theory: 2 mini venuses collided, combining into new venus, which rotates other way/upside down.
Venus is noted as being very similar to Earth but significantly different due to factors like its intense greenhouse effect, craters, volcanoes, and its unique rotation pattern which is both upside-down and backwards.
Venus has a lot of CO2- traps a lot of heat, any water evaporated and heightened effects of the greenhouse effect
Because it has similar gravity to Earth but is closer, gas can stay trapped, forming a thick atmosphere
Venus has no small craters because its atmosphere is so thick, meaning any small meteorites get slowed down by the gases and burn up even more than on Earth, only big asteroids can get through
Enough dense gas
Venus generates its magnetic field from the interaction of the Sun’s solar wind with the planet’s ionosphere, the atmospheric region filled with charged atoms
Venus has a very slow orbit and little movement in the core to cause no magnetic field like Earth

Question 4

Thermal Expansion and Contraction on Mercury

Answer 4

Mercury’s iron core experiences significant contraction with temperature changes, more so than its rocky crust, leading to surface features like lobate scarps indicating compression.

Question 5

Planetary Mass and Atmospheres

Answer 5

Heavier planets with denser cores tend to retain more heat and have thicker atmospheres. The presence of a magnetic field influences the atmosphere’s retention and protection against cosmic rays and solar wind

Question 6

Mercury’s Spin-Orbit Resonance

Answer 6

Unlike the Moon, which is tidally locked to Earth, Mercury is in a 3:2 spin-orbit resonance with the Sun. This means it completes three rotations on its axis for every two orbits around the Sun, contributing to temperature extremes.

Question 7

Observations of Mercury

Answer 7

Radar observations have confirmed the presence of water ice in Mercury’s permanently shadowed polar craters, believed to originate from cometary impacts.

Question 8

Van Allen Belts

Answer 8

Regions of energetic charged particles that are trapped by Earth’s magnetosphere. The belts are made up of billions of particles from the sun that become trapped in Earth’s magnetic field

Question 9

Mars

Answer 9

Solid core, no magnetic field,
use to but solidified in last billion years due to cooling
Mars has moons, understand that they are potentially comets or asteroids due to their abnormal shape and size
We think once had active molten core, is small and leads to small magnetic field
Causes volcanic activity (giant volcano)
Phobos and Deimos are Mars’s “moons” but they are more likely asteroids that got caught in its orbit, did not form from collision like our moon

Question 10

Why don’t Venus and Mercury have moons

Answer 10

proximity to the sun

Question 11

Escape Velocity

Answer 11

v=√3kt/m, mv2=3kT
T=temp of gas particles
M=mass
V=escape velocity

Question 12

Isotopes

Answer 12

of a particular element, it’s just a variation with a different number of neutrons

Question 13

Dust on the moon

Answer 13

from an observer’s experience, we want to put telescopes up there, also because its tidally locked. Moondust sticks to everything and is sharp

Question 14

Outer gas giants

Answer 14

have very strong magnetic fields
each of the gas giants has a core that is partially liquid metallic hydrogen. As this material circulates, it generates electrical energy, which creates the magnetic field

Question 15

Expeditions

Answer 15

Moon, Mars, Apollo
Why bother going to mars,
Artemis 1, officially Artemis I and formerly Exploration Mission-1, was an uncrewed Moon-orbiting mission. As the first major spaceflight of NASA’s Artemis program, Artemis 1 marked the agency’s return to lunar exploration after the conclusion of the Apollo program five decades earlier.
Have not done much with Venus due to the heat