The Moon and Planets; Small Bodies in the Solar System

Question 1

Describe the causes and effects of the atmospheric greenhouse effect and global warming

Answer 1

Sunlight heats the ground (which emits infrared radiation). Certain molecules absorb the radiation so the Earth doesn’t cool off because it can’t escape. Water vapor and CO2 block the infrared radiation because they’re greenhouse gases. Humans add CO2 to the atmosphere= warmer temperature= Global Warming

Question 2

Describe the impact of human activity on our planet’s atmosphere and ecology

Answer 2

Global Warming

• Climate Change
• Melting icecaps
• Rising sea levels

Question 3

Explain the scarcity of impact craters on Earth compared with other planets and moons

Answer 3

Earth was heavily impacted by craters just as much as the Moon. Craters destroyed by active geology. Plate tectonics renews the crust. Objects burn up in the Earth’s atmosphere. Erosion

Question 4

Describe the evidence for recent impacts on Earth

Answer 4

1) Tunguska River in Siberia but no craters (if it penetrates the Earth it would be classified as a crater) because it only damaged the surface
2) Arizona called the Meteor Crater

Question 5

Detail how a massive impact changed the conditions for life on Earth, leading to the extinction of the dinosaurs

Answer 5

Mass extinction: more than half of the species on our planet died out
Chicxulub: crater that killed the dinosaurs. Airborne material blocked out sunlight. Other results such as the fires and acidic rains led to the extinction of the dinosaurs

Question 6

Discuss what has been learned from both manned and robotic lunar exploration

Answer 6

Manned- terrestrial planets

Robotic- (terrestrial and) jovian planets

Question 7

Explain the process of impact crater formation

Answer 7

The projectile penetrates 2-3x its own diameter before stopping; energy as a shock wave and heat
Crater size is usually 10-15x greater the diameter of the projectile

Question 8

Characterize the orbit of Mercury around the Sun

Answer 8

Highest average orbital speed

Question 9

Describe Mercury’s structure and composition

Answer 9

The smallest terrestrial planet and planet overall
Greater density than the Moon= made up of 2 very different elements (mass: up to 60% iron-nickel, the rest being silicates)
Weak magnetic field (part of the core is liquid to create the field)

Question 10

Explain why it’s difficult to learn about Venus from Earth-based observation alone

Answer 10

Surface is not visible b/c of clouds

Question 11

Compare the basic physical properties of Earth, Mars, and Venus, including their orbits

Answer 11

All about the same size

All terrestrial planets- mostly solid

Question 12

Provide an overview of the composition of the giant planets

Answer 12

Material: gas (mostly hydrogen and helium), ice, rock (less abundant than ices)
Gas giants- Jupiter and Saturn
Ice giants- Uranus and Neptune (interiors contain more ice)

Question 13

Describe typical orbits of asteroids

Answer 13

Ellipse oribit like all the planets. Some are in the KB (outside of the solar systeml has the comets, asteroids, and other small bodies of ice adn rock)

Question 14

Characterize the general physical appearance of comets

Answer 14

Comet: small chunk of icy material that develops an atmosphere as it approaches the Sun (has a very faint nebulous tail). Not spectacular; very faint. Appear at unpredictable times. Visible for a couple weeks to months

Question 15

Explain what a meteor is and why it is visible in the night sky

Answer 15

What: a small piece of solid matter that enters Earth’s atmosphere and burns up, popularly called a shooting star because it is seen as a small flash of light. a small rocky or metallic body in outer space.

Why: It’s heating up and it’s getting hot as it’s traveling through the air.

Question 16

Describe the origins of meteor showers

Answer 16

Ash, dust, debris from the comets/rock/asteroids. Falling fast which makes it appear on fire and glowing like.

Many meteors appearing to radiate from one point in the sky; produced when Earth passes
through a cometary dust stream.

A sudden burst of meteor activity usually lasts several hours. Often named by the constellation from where the radiant is located

Question 17

Explain how the study of meteorites informs our understanding of the age of the solar system

Answer 17

Includes oldest and most primitive material

Classifications of meteorites: iron, stones, and stony-irons (obvious which type they fall into)

Question 18

Describe the motion, chemical, and age constraints that must be met by any theory of solar system formation

Answer 18

Motion constraints: most planets rotate in the same direction as they revolve. Most moons orbit counterclockwise. Besides comets and other TNOs motion is defined by a disk or frisbee shape. Exceptions include the retrograde rotation of Venus

Chemical constraints: Jupiter and Saturn have the same compositions (mostly hydrogen and helium). Comets in the Oort cloud and TNOs in the Kuiper belt are icy, asteroids are rocky w/ dark, carbon-rich material. Temperature sequence with planets’ position to the Sun. Exception w/ water on Earth and Mars.

Age constraints: radioactive dating. Age of building blocks= age of planetary system

Question 19

Summarize the physical and chemical changes during the solar nebula stage of solar system formation

Answer 19

The solar system formed about 4.5 B years ago. Rotating cloud of vapor and dust collapsed under its own gravity, making the material fall towards the center and become more hot and concentrated. Solar nebula began to rotate faster due to angular momentum. Faster materials collapsed into a disk to revolve around the center, which explains the motions of the solar system. When gravitational energy faded tha nebula cooled, but the center formed a star where it maintained its own energy. Turbulent motions and magnetic fields drained its angular momentum and therefore its spin. Some material fell into the growing star and the disk stabilized. Disk cooling produced compounds (liquids and solids) from gases. First solid materials were metals and rock-forming silicates. Temperature sequence (cool temp= oxygen could combine w/ hydrogen to form water= ice)

Question 20

Explain the formation process of the terrestrial and giant planets

Answer 20

Terrestrial: Grains condensed to form planetesimals
Accretion: when planetesimals are large enough to attract their neighbors gravitationally and grow in the process
Protoplanets: not quite ready for primetime planets
Planetesimals accelerate to combine with the protoplanet, heating the protoplanet
Planetary differentiation: heavier materials sink to the bottom and lighter materials float to the top

Giant: Protoplanets attracted gas. Heated by contraction, but were too small to raise core temperatures. Gradually cooled. Less gas was captured by Uranus and Neptune which is why they have icy and rocky cores.

Question 21

Describe pseudoscience and give some examples

Answer 21

Pseudoscience is an idea of different methods and concepts that falsely use science as validation of its effectiveness

Examples: astrology, numerology, hypnosis

Question 22

Explain what scientists mean by a hypothesis, theory, and law

Answer 22

Hypothesis: an explanation that can be tested over and over again. They explain the “how”
Theory: an explanation of a phenomenon supported by facts. Theories start out as hypotheses. They explain the “why”. Cannot turn into a law
Law: principles that can be used to predict processes in the natural world. They explain the “what”

All based on observations

Question 23

Explain why science poses no threat to religion and how many scientists can be – and are – very religious as well

Answer 23

Science and religion have coexisted for a while. About 40% of scientists are religious. Only a very small percentage of religious people are “anti-science”.

Question 24

Explain the northern lights

Answer 24

The direction of the solar wind is changed by the Earth’s magnetic field and is funneled into the North and South poles. The solar wind molecules crash through the atmosphere and excite the electron molecules. These electrons move up (absorb light) and down energy levels to emit light, which produce the lights we see at the North pole.

Question 25

Where are most of the asteroids in our solar system?

Answer 25

Between Mars and Jupiter; the asteroid belt

Question 26

Kuiper Belt

Answer 26

a disk of debris at the edge of our solar system; beyond Neptune

Question 27

What kind of object is Pluto?

Answer 27

Kuiper belt object

Question 28

Oort cloud

Answer 28

sphere of widely spaced comets; the large spherical region around the Sun from which most “new” comets come; a reservoir of
objects with aphelia at about 50,000 AU

Question 29

Describe Venus’ atmophere

Answer 29

Most of the atmosphere is CO2. It’s the hottest planet because of the greenhouse effect, which means it has few craters. It spins backwards.

Question 30

What is the “Runaway Greenhouse” effect?

Answer 30

The greenhouse effect on Earth worsens to the point it looks like Venus

Question 31

Why does Io have volcanic activity?

Answer 31

As Io revolves around Jupiter it’s closeness determines its volcanic activity. As Io gets closer to Jupiter, Jupiter’s tides evoke more heat from Io, but as Io gets farther away there is less volcanic activity.

Question 32

Describe the criteria of a planet

Answer 32

1) Orbits a star
2) Approx. round
3) Not a star or moon
4) Nothing big in its orbit

Question 33

Describe a comet

Answer 33

a “dirty snowball”; 2 tails: gas and dust. The solar wind blows gases out. The closer to the Sun the longer the tail. The position of the comet in its orbit depends on where it is in its tail development.

Question 34

Asteroid

Answer 34

a stony or metallic object orbiting the Sun that is smaller than a major planet but that shows no
evidence of an atmosphere or of other types of activity associated with comets

Question 35

Near-Earth Asteroid (NEA)

Answer 35

an Earth-approaching asteroid, one whose orbit could bring it on a collision course
with our planet

Question 36

Near-Earth object

Answer 36

a comet or asteroid whose path intersects the orbit of Earth

Question 37

Nucleus (of a comet)

Answer 37

the solid chunk of ice and dust in the head of a comet

Question 38

Exoplanet

Answer 38

a planet orbiting a star other than our Sun

Question 39

Iron meteroite

Answer 39

a meteorite composed primarily of iron and nickel

Question 40

Stony meteorite

Answer 40

a meteorite composed mostly of stony material, either primitive or differentiated

Question 41

Stony-iron meteorite

Answer 41

a type of differentiated meteorite that is a blend of nickel-iron and silicate materials