Universe Quiz
Questions: 16 · 10 minutes
1. A star’s brightness drops slightly at regular intervals, with each drop having a similar shape. Which explanation are astronomers likely to investigate?
An orbiting planet passing in front of the star
The star repeatedly moving behind the center of its galaxy
The star temporarily stopping nuclear fusion at fixed intervals
Earth’s atmosphere permanently absorbing part of the starlight
2. Which comparison between a solar system and a galaxy is accurate?
A solar system is organized around one or more stars, while a galaxy contains vast numbers of star systems
A solar system contains galaxies, while a galaxy contains only one star
A galaxy is the orbit of one planet, while a solar system is a cluster of galaxies
A solar system and a galaxy are two names for the same type of structure
3. Two stars are viewed without significant intervening dust. One appears blue and the other red. What can be inferred most directly from their colors?
The blue star must be physically larger
The blue star is necessarily closer to Earth
The blue star must be older
The blue star has a hotter surface
4. The Moon is positioned roughly between Earth and the Sun, and its Earth-facing side is mostly unilluminated. Which phase is occurring?
Full moon
First quarter
Third quarter
New moon
5. What is the cosmic microwave background?
Visible light reflected from dust at the edge of the Solar System
Microwave signals produced mainly by modern technology on Earth
Faint radiation left from the universe’s early hot state
Radiation emitted only from the immediate surroundings of black holes
6. Astronomers find an overall pattern in which more distant galaxies generally have greater cosmological redshifts. What does this pattern support?
Space has been expanding, stretching light as it travels
Earth occupies the fixed center from which every galaxy was launched
Light naturally loses energy because it becomes tired over long journeys
All distant galaxies contain cooler stars than nearby galaxies
7. Which alignment is required for a lunar eclipse?
Earth, Moon, Sun, with the Moon between Earth and the Sun
Moon, Sun, Earth, with the Sun between the Moon and Earth
Earth and Moon at right angles to the Sun
Sun, Earth, Moon, with Earth between the Sun and Moon
8. A spacecraft near a planet is given enough sideways speed that, while falling under gravity, it continually misses the surface. What is it doing?
Hovering because gravity has stopped affecting it
Moving in a straight line while the planet follows beneath it
Orbiting the planet along a curved path
Escaping the planet because any sideways motion defeats gravity
9. A star’s spectrum contains a distinctive pattern of dark absorption lines. What can astronomers infer most directly from that pattern?
The exact number of planets orbiting the star
Which chemical elements are present in the star’s outer layers
The shape of the star’s magnetic field at every depth
The star’s precise age without using any other information
10. What process supplies most of the energy radiated by a star such as the Sun?
Nuclear fusion in its core
Chemical burning across its visible surface
Friction caused by planets orbiting around it
Radioactive decay occurring mainly in its atmosphere
11. What does a light-year measure?
The time Earth takes to complete one orbit of the Sun
The time required for sunlight to reach the outer planets
The amount of light a star produces during one year
The distance light travels through a vacuum in one year
12. Several stars form a familiar constellation pattern in Earth’s sky. What does that pattern usually tell us?
Every star in the pattern formed at the same time
The stars appear in related directions but may lie at very different distances
The stars are all close together in three-dimensional space
The stars are planets reflecting light from a shared sun
13. Earth is closer to the Sun during part of the Northern Hemisphere’s winter than during its summer. What primarily causes the seasons?
Regular changes in the Sun’s energy output
Earth’s orbit alternately speeding up and slowing down
Earth’s axial tilt changing sunlight angle and day length through the year
The Moon changing how much sunlight reaches each hemisphere
14. A star is 100 light-years from Earth. When you observe it tonight, what are you seeing?
The star as it will appear 100 years in the future
Light that left the star about 100 years ago
The star’s present state with a delay only in measuring its distance
Light reflected from the star by objects between it and Earth
15. What is the event horizon of a black hole?
The solid surface where matter lands after entering a black hole
A boundary beyond which nothing, including light, can escape to the outside universe
The ring of material that every black hole must visibly possess
The maximum distance from which a telescope can detect a black hole
16. Which description best matches what astronomers mean by the universe?
Only the region of space that current telescopes can observe
The collection of stars and gas contained within the Milky Way
All space and time, together with their matter, energy, and physical contents
The Solar System and the empty space immediately surrounding it