Astronomy test 2

Which statement about the size of the universe is true?

• Most astronomers believe the universe is expanding in size.

• Most astronomers believe the universe is shrinking in size.

• Most astronomers believe the universe is remaining the same size.

• Most astronomers believe the universe is shrinking and expanding in a cyclic pattern.

Which unit is commonly used to express distances between stars and galaxies?

• astronomical units (AU)

• kilometers (km)

• lightyears (LY)

• nanometers (nm)

Which is the correct sequence from largest to smallest?

• universe, milky way, solar system

• milky way, universe, solar system

• solar system, milky way, universe

• universe solar system, milky way

What components best define a galaxy?

• gas, dust, and billions of stars

• meteors, comets, and asteroids

• planets, moons, and a single star

• ice, rock, and dust

What is the solar system's position relative to the Milky Way galaxy?

• The solar system is located on an arm within the Milky Way galaxy.

• The Milky Way galaxy is found within the solar system near the outer planets.

• The solar system revolves in and out of the Milky Way galaxy.

• The Milky Way is a cluster of stars near, but separate from, the solar system.

A researcher studies the light emitted by a distant star. The researcher finds that light received from the star falls slightly closer to the red end of the electromagnetic spectrum when compared to a similar source closer to Earth. The researcher claims that the star is moving from Earth. Is the researcher correct?

• No. All hot stars emit red-colored light.

• es. All moving objects emit red-colored light.

• No. The red-colored light emission is due to the composition of the star.

• Yes. Light from any object moving away from Earth shifts to red-colored light.

A student creates a model by placing raisins in bread dough and allowing the dough to rise for several hours. The student sketches the model before and after the dough rises. The student claims that the model accurately describes the motion of the galaxies in the universe. What evidence from the model supports the student's claim?

• As the dough rises, the size of the raisins increases, resembling the expansion of galaxies.

• As dough rises, the distance between the raisins decreases, indicating that the galaxies will collide.

• As the dough rises, the size of the raisins decreases, resembling the emission of light from stars.

• As the dough rises, the distance between the raisins increases, indicating that the galaxies are moving apart.

A student reads a list of several measurements. Which measurements are used as evidence of the age of the universe?

• 1 and 2

• 2 and 3

• 1, 2, and 3

• 1, 2, and 4

Meteorites are particles of dust or rock that pass through Earth's atmosphere. Which reason best explains why meteorites are seen as brief streaks of light?

• They are produced by the Sun and are made up of flaming gases.

• They reflect the Sun's light as they enter Earth's atmosphere.

• They give off cool vapors as they enter Earth's atmosphere.

• They burn up due to friction as they enter Earth's atmosphere.

Astronomers use telescopes that measure the radiation from objects in space to detect the object's size and distance. The Chandra X-ray telescope is designed to get information from some of the hottest objects that emit X-rays. Where are telescopes like Chandra located to capture the sharpest images?

• on mountain tops

• on satellites

• in deserts

• in rural observations.