Solar System Scale and Physical Properties
Contrasts the inner terrestrial planets with the outer gas giants
Inner planets are smaller, denser and rockier.
What is the direct physical cause of the daily 24-hour cycle of day and night on Earth?
Earth's rotation on its central axis
How much of the total spherical surface of the Moon is illuminated by sunlight at any given moment?
50%
Which celestial alignment is required for a solar eclipse to occur on Earth?
Sun – Moon – Earth
What two physical factors determine the strength of the gravitational force between two celestial bodies?
Mass and distance
Saturn is located approximately 1,430,000,000 kilometers from the Sun. Given that 1 AU equals roughly 150,000,000 kilometers, what is Saturn's distance in Astronomical Units?
9.53 AU
During the month of December, which condition is observed worldwide?
The Northern Hemisphere experiences winter while the Southern Hemisphere experiences summer.
Which sequence lists lunar phases in the correct chronological order as seen from Earth?
New Moon → Waxing Crescent → First Quarter → Waxing Gibbous
An observer on Earth watches the lit portion of the Moon grow larger each night. Which term describes this progression?
Waxing
Jupiter has a lower density than Mercury because Jupiter is composed mainly of ___________.
Gas
An Astronomical Unit (AU) is defined as the average distance between which two celestial objects?
Earth and the Sun
At what angle is Earth's rotational axis tilted relative to the plane of its orbit around the Sun?
23.5°
Although the Moon takes 27.3 days to revolve once around Earth, a complete cycle of lunar phases requires 29.5 days. What causes this time difference?
Earth travels along its orbit around the Sun while the Moon revolves around Earth.
During which phase of the Moon can a lunar eclipse occur?
Full Moon
On an equinox, which of the following statements is true for observers located across the globe?
Day and night are approximately equal in duration everywhere on Earth.
The Sun contains approximately what percentage of all mass in our solar system?
99.8%
When the Northern Hemisphere tilts fully toward the Sun it is known as the June _______________
Solstice
Why is the exact same side of the Moon always facing Earth?
The Moon's period of rotation equals its period of revolution around Earth.
Define umbra as it relates to a lunar eclipes
The central, darkest part of the Earth's shadow where direct sunlight is completely blocked
If a new dwarf planet is discovered orbiting the Sun at an average distance of 45 AU, how would you predict that it's orbital period (year length) would compare to that of Neptune's?
Its orbital period (year length) will be longer than Neptune's orbital period
A student represents Earth using a 1-centimeter marble. Based on true planetary ratios, which object best represents the diameter of the Sun?
A 109-centimeter sphere
Why does the Northern Hemisphere experience higher average surface temperatures during summer than during winter?
Solar radiation strikes the surface at a steeper angle, concentrating energy over a smaller area.
during which phase of the moon do observers on Earth see the right half of the visible lunar disk illuminated.
First Quarter
Why does an eclipse NOT happen twice every month during every New Moon and Full Moon?
The Moon's orbit is tilted approximately 5° relative to the plane of Earth's orbit.
How does the orbital speed of Neptune compare to that of Mercury, and what physical principle explains this difference?
Neptune orbits slower because the Sun's gravitational attraction decreases with distance.