The Universe — Topic 7 Test (Grade 8)

When the Hubble Space Telescope (1990) and the Spitzer Space Telescope (2003) were launched, astronomers gained new ways to observe the universe. Which statement best explains how different types of telescopes provide different forms of data, with examples?

• Telescopes all detect the same kind of light, so newer ones only improve image sharpness.

• Different telescopes detect different parts of the electromagnetic spectrum; for example, Hubble collects optical images while Spitzer observes infrared sources hidden by dust.

• Space telescopes work only in Earth’s atmosphere, so they mainly record weather patterns.

• Newer telescopes are larger, so they only measure the brightness of nearby stars more precisely.

The James Webb Space Telescope (JWST), launched in 2018, is a large telescope that cannot function well in the sun’s glare, so its orbit keeps it in Earth’s shadow. It is not an optical telescope but picks up different types of ________ waves that objects in space give off.

• electromagnetic

• sound

• heat

• seismic

The Giant Metrewave Telescope detects radio waves from space. Radio waves have a ________ wavelength than light waves.

• shorter

• longer

Stephen is learning about telescopes and electromagnetic radiation. What type of electromagnetic radiation can be seen without additional equipment?

• ultraviolet radiation

• visible light

• x-rays

• gamma rays

The galaxy NGC 7513 is very similar to our galaxy and is a spiral galaxy. Scientists have observed a ________ when looking at its emission spectra, indicating it is moving farther away from Earth.

• blueshift

• redshift

• doppler effect

• radio wave

Cosmic background radiation was discovered while studying the origin of the universe. Which statement best communicates its significance to our understanding of how the universe began?

• It proves that the universe is static and unchanging.

• It is leftover microwave radiation from the early hot, dense universe, providing strong evidence for the Big Bang and a map of early density fluctuations.

• It shows that stars form only through nuclear fusion in present-day galaxies.

• It indicates that the universe has been collapsing for billions of years.

Julissa reads about four theories of universe expansion and prefers the coasting model. Why might she prefer the effects of the coasting model over the other models?

• Growth continues to grow at a steady rate.

• Growth begins to slowly decelerate before shrinking.

• The universe begins to shrink quickly.

• The universe continues to expand until density gets too low.

Andromeda Galaxy is headed toward the Milky Way. Does its light show a redshift or a blueshift, and how would the emission lines appear on an emission spectrum?

• Redshift; emission lines shift toward longer wavelengths on the red side.

• Blueshift; emission lines shift toward shorter wavelengths on the blue side.

• No shift; emission lines remain at rest wavelengths.

• Redshift; emission lines become broader but do not move.

Scientists have evidence that the universe is expanding but are unsure about the future. Which possibility indicates the model in which, in the future, the universe will begin to slowly decelerate the speed of expansion before shrinking in size?

• Recollapsing Universe

• Critical Universe

• Coasting Universe

• Accelerating Universe

Scientist have found that helium and hydrogen make up most of the matter in the universe. Why is this important evidence for the Big Bang?

• These elements from only in planets.

• These elements formed later inside stars.

• These elements formed during the early universe.

• These elements form when galxies collide.