Untitled Flashcards Set
ASTRONOMY UNIT 5 REVIEW
SOLAR SYSTEM OVERVIEW
1. What percentage of the Solar System’s total mass is the Sun? Over 99.8%
2. Which planets are the Terrestrial Worlds? Mercury, Venus, Earth, and Mars
3. Of the Gas Giants, which are actually closer to being Ice Giants? Neptune and Uranus
4. What Solar System region shows the limit of what orbits the Sun? Oort Cloud
5. Where are the Asteroid and Kuiper Belts?
The Asteroid Belt is located between the orbits of Mars and Jupiter.
The Kuiper Belt is a region beyond Neptune's orbit, extending from about 30 to 55 astronomical units (AU) from the Sun.
6. Natural satellites that orbit the planets/dwarf planets are called what? Moons
INNER SOLAR SYSTEM WORLDS
1. Which of the planets is the only one without an atmosphere? Mercury
2. What explains how Mars is destroying its Moon and how Saturn got its rings?
Mars' Moon Phobos is being destroyed due to tidal forces exerted by Mars. As Phobos spirals inward, it will eventually break apart, potentially forming a ring system around Mars in about 20 to 40 million years28.
Saturn's Rings are believed to have formed from the destruction of an icy object, possibly a moon. One theory suggests that a moon called Chrysalis was torn apart by Saturn's gravity about 100 million years ago, contributing to the formation of the rings.
3. If you were to try and send humans to this planet, it would kill them. Venus
4. Once the Sun expands into a Red Giant, which planets will be within the new Goldilocks
Zone? Mars
5. Of the four terrestrial worlds, which is NOT named after a God? Earth
6. Where is Olympus Mons, and why is it special?
Olympus Mons is located on Mars. It is special because it is the largest known volcano in the Solar System, with a height of approximately 27 km (17 miles) above the Martian surface and a base diameter of over 600 km (373 miles). Its size and shape make it a unique geological feature.
OUTER SOLAR SYSTEM WORLDS
1. Where does the word Jovian come from? Latin genitive form of luppiter, meaning Jupiter.
2. Which of the planets can be considered a failed star? Jupiter
3. What is the most volcanically active body in the Solar System? Lo a moon of jupiter
4. Why is Titan so interesting to us?
Titan, a moon of Saturn, is interesting because it has a thick atmosphere and lakes of liquid methane on its surface, making it a unique environment in the Solar System. It also offers insights into the early Earth's atmosphere and potential for life beyond Earth.
5. How was Neptune discovered?
Neptune was discovered on September 23, 1846, by Johann Gottfried Galle, using mathematical predictions made by Urbain Le Verrier and John Couch Adams. They noticed discrepancies in Uranus' orbit, suggesting the presence of another planet beyond it.
6. Which planet has the most extreme seasons, and what is causing it?
Uranus has the most extreme seasons due to its highly tilted axis of about 98 degrees. This tilt causes extreme variations in sunlight exposure between its poles and equator, resulting in dramatic seasonal changes.
DWARF PLANETS AND OTHER REGIONS
1. Why can’t Moons be Dwarf Planets?
The latter is the point of contention, as any moons or rings are technically "in its local area". Dwarf planets are said to have not accomplished this last step. So any object that is round, orbits the sun, and has dust floating around it is a dwarf planet.
2. What percentage of the Asteroid Belt is Ceres? 35%
3. Pluto has a special relationship with what?
Pluto's unusual binary relationship with its largest moon, Charon.
4. Of the five dwarf planets, Ceres is notable because it has what?
first dwarf planet to receive a visit from a spacecraft.
5. What primarily makes up the Asteroid and Kuiper Belts respectively. Rock and stone
6. Which dwarf planet made Pluto lose its status as a planet? Neptune
LAWS OF PLANETARY MOTION
1. Who was Kepler’s teacher? Tycho brahe
2. Which planet’s orbit did Kepler have to try and explain? Mars
3. What periods does a planet move the fastest and the slowest with respect to its star? Fastest when it is close to the star and slow when it is far from it.
4. What does the First Law say?
each planet's orbit about the Sun is an ellipse.
5. What is the relationship between a planets period and its distance from the star?
the farther a planet is from the Sun, the longer its orbital period.
6. Tycho and Kepler had differing views on what?
Tycho Brahe and Johannes Kepler had fundamentally differing views on astronomy, particularly regarding their approaches to scientific inquiry and the nature of planetary motion.
PLANET 9 AND EXOPLANETS
1. Is Planet 9 real? No but is believed to possibly exist.
2. What are the different ways to find exoplanets through gravity?
Radial Velocity, Gravitational Microlensing, Transit Timing Variations (TTV), Astrometry, Pulsar Timing.
3. What is the relationship between the brightness of a star and the dip when a planet passes
in front of it?
The bigger the planet, the bigger the dip in brightness.
The smaller the star, the bigger the dip for a given planet size.
The dip is measured as a percentage of the star's total brightness.
Typical dips range from about 1% for a Jupiter-sized planet to 0.01% for an Earth-sized planet orbiting a Sun-like star.
The dip's size doesn't depend on how far the planet is from its star.
4. What particular type of exoplanet could we consider dangerous? Why?
Dangerous exoplanets are those with extreme conditions that make them utterly inhospitable to life as we know it. These include "Hot Jupiters" that orbit very close to their stars and can be hot enough to vaporize metals, planets around pulsars that are bombarded with intense radiation, tidally locked planets with extreme temperature differences between their day and night sides, worlds with violent weather like glass rainstorms or incredibly strong winds, and super-dense rocky planets. These exoplanets are considered dangerous due to their scorching temperatures, deadly radiation levels, violent atmospheric conditions, or unstable environments that would be instantly lethal to humans or any Earth-like life forms.
POSSIBLE SHORT ANSWER QUESTIONS
1. What are the conditions that a Celestial Body must satisfy to be a planet?
a) It must orbit the Sun.
b) It must have sufficient mass to achieve hydrostatic equilibrium, resulting in a nearly round shape.
c) It must have cleared the neighborhood around its orbit
2. Why are Neptune and Uranus considered Ice Giants?
They are compositionally different from gas giants like Jupiter and Saturn.
They contain a higher proportion of heavier elements such as oxygen, carbon, nitrogen, and sulfur.
Their mantles are largely composed of compressed, slushy water and ammonia.
They have proportionally larger rocky, icy cores compared to their gaseous content
3. What are the differences between the conditions for a planet and dwarf planet, and why
can’t a dwarf planet be a moon?
Planets have cleared their orbital neighborhoods, while dwarf planets have not.
Dwarf planets must not be satellites (moons) of other bodies
4. Describe how Mercury became so dense despite being the smallest planet.
Mercury's high density, despite being the smallest planet, is primarily due to its large iron-rich core, which makes up about 60% of its volume. This unusual composition is likely the result of a past event, possibly a massive collision that stripped away much of its rocky mantle. Theories explaining Mercury's density include:
The Giant Impact Hypothesis: A significant collision may have removed lighter elements from Mercury's outer layers.
Solar effects: Intense heat from the Sun may have caused volatile element depletion.
Gravitational compression: Mercury's proximity to the Sun could have contributed to its dense structure