Notes 2 Exam Flashcards
What are the general properties of the motions of the planets that any theory of the origin of the solar system must explain?
- Planets are isolated objects. The distance between the planets increases with distance from the sun. 2. The orbits of the planets are nearly circular.
- The orbits of planets are nearly in the same plane.
- Planets orbit in the same direction as the Sun’s rotation axis.
- The planets’ rotation axes are about the same as the Sun’s.
- Moons rotate in the same direction as the parent planet’s spin.
- Planets are differentiated: Terrestrial and Jovian classification.
- Asteroids are very old
- Comets are old, icy, not in the ecliptic, and at large distances from the Sun
What defines density?
density is mass divided by volume and the units used here gram per meter-cubed is g/m3
Which component of the solar system has an icy composition?
comets
How do the densities of the terrestrial and Jovian planets compare?
Terrestrial are denser than Jovian
Which planets are the Jovian planets?
Jupiter, Saturn, Uranus, Neptune
How has our understanding of the solar system and exo-solar planets changed over time?
we knew nothing before and now know a lot
Which planets have rings?
Jupiter, Saturn, Uranus, and Neptune
Why doesn’t Earth itself provide many clues to the origin of the solar system?
not much data to go on, all eroded.
only one aspect of the solar system.
In light of modern solar system theory, why do the orbits of the planets all lie in nearly the same plane?
During the Solar System’s formation, the planets formed out of a disk of dust which surrounded the Sun.
What happens when a solar nebula contracts?
It forms a star
What was the primary role of dust in the formation of the solar system?
Dust acted as condensation nuclei; platforms to which other particles could attach and form larger particles of matter.
What’s the most common element in Earth’s atmosphere?
Nitrogen
What defines a solar system object?
Distance from the sun:
● the orbit period (the time the planet takes to go around the Sun once),
● mass (the amount of matter the planet possesses),
● radius (size of the planet),
● number of moons (a moon is a natural satellite),
● escape velocity
● rotation period
● average density (density is mass divided by volume and the units used here gram per meter-cubed is g/m3)
What two conditions are required for a planet to have a magnetic field?
The core of the planet must be a ferromagnetic material (like nickel-iron), and the core must be molten so that the mobile fluid will generate the field through dynamo action.
What causes the tides?
Gravitational interaction between Earth and Moon
How many stars are in our solar system?
One
Which planet spins backwards on its axis?
Venus
How are the contents of our solar system classified?
-One star, the Sun (see Notes 3) ● 8 Planets: the Terrestrial planets and Jovian planets ● Interplanetary matter (Moons 170+, asteroids, comets, and meteoroids) ● Asteroids: 6 more than 300 kilometers(km) in diameter and over 7 thousand smaller ones ● Comets: about 3 km in diameter (rock/ice nucleus) ● Meteoriods: Countless “broken” pieces of asteroids or comets. Less than 100 meters (m) diameter.
Between which 2 planets is the asteroid belt located?
Mars and Jupiter
What causes the seasons?
tilt of its rotational spin and its eccentric orbit
Which planets have seasons?
with tilts, Uranus, mars, earth
At least how old must our solar system be? Write in scientific notation.
4.5 x 10^9
What is the importance of interplanetary matter?
Interplanetary material gives clues about the very young, forming Solar System. This matter is relatively un-evolved since it was made. Asteroids, meteoroids, and comets are like relics of the past
What is interplanetary matter?
Sizes range from dust particles to 100’s of km in diameter, D.
Asteroids: D >~100m Meteoroids: D < 100 m
Comets: D= 1-10 km
How did Mercury’s location in the solar system affect its composition?
It is rich in metals because only metals could survive the high temperatures near the sun
What factor caused different planets to form out of different types of material?
temperature
What is a distinguishing characteristic of planetesimals which was critical to the formation of the planets?
They were large enough so that their gravity could attract more material and grow still larger.
What is the name of the theory that is currently used to describe the formation of the solar system?
nebular theory
Which planets are characterized by deep atmospheres, many satellites, and a solar-like elemental abundance?
Earth
The most abundant element in the solar system is ____.
hydrogen
The second most abundant element in the solar system is ____.
helium
Although Mars and Mercury are nearly equal in size, Mars has more mass in its atmosphere because Mars is _____.
cooler
A solid object from outer space that lands on the surface of any solar system object is known as a ______.
meteorite
The age of the solar system is determined by the dating of ___.
rocks (meteors, asteroids, and comets)
The Jovian planets are thought to have ___ cores.
rocky ice
The principle difference in composition between the Sun and the gas-giant planets on one hand, and the terrestrial planets on the other, is the lack of (the low abundance of) the two elements _____, in the terrestrial planets.
hydrogen and helium
The ____ planets are relatively slow rotators, are dense and have few satellites.
Terrestrial
Which planet has an average density less than that of water (density of water is 1000 kg/m3)?
Saturn
Which planets are about 1/2, 1, and 11 Earth radii in size?
Mars, Venus, Jupiter
Which planets have no known moons?
Mercury and Venus
Which 2 planets are approximately four times the size of the Earth?
Uranus, neptune
Weak magnetic fields, slower rotation, and few moons characterize which of the following, the terrestrial or Jovian planets?
Earth, Mercury, Venus, and Mars
