The diagram below shows reference lines on a standard spectrum and a spectrum from a distant galaxy moving away from Earth. If the spectral lines produced by the light from a distant galaxy are:

• shifted toward the blue, the galaxy is moving away from us

• shifted toward the red, the galaxy is moving towards us

• shifted toward the blue, the galaxy is stationary

• are shifted toward the red, the galaxy is moving away from us

Answer explanation

The spectral lines from a distant galaxy are shifted toward the red due to the Doppler effect, indicating that the galaxy is moving away from us. This redshift is a key evidence for the expansion of the universe.

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-3

The diagram below represents the Milky Way Galaxy. Which letter best represents the location of the Earth's solar system?

• A

• B

• C

• D

Answer explanation

The Earth's solar system is located in the Orion Arm of the Milky Way, which corresponds to letter C in the diagram. This position is between the center and the outer edge of the galaxy.

Tags

NGSS.MS-ESS1-2

The diagram below shows the standard dark-line spectrum for an element. The spectral lines of the same element are observed in light from four distant galaxies. Which spectral lines most likely represent the galaxy farthest from the Earth?

• A

• B

• C

• D

Answer explanation

Spectral lines shift towards the red end of the spectrum for galaxies moving away from Earth, known as redshift. The lines in choice D are the most shifted, indicating it is the galaxy farthest from Earth.

Tags

NGSS.HS-ESS1-2

Background radiation detected in space is believed to be evidence that

• the Universe is contracting

• the Universe began with a primeval explosion

• all matter in the Universe is stationary

• galaxies are evenly spaced throughout the Universe

Answer explanation

Background radiation, known as cosmic microwave background radiation, supports the Big Bang theory, indicating the Universe began with a primeval explosion, rather than contracting or being stationary.

Tags

NGSS.HS-ESS1-2

The symbols below represent the Milky Way galaxy, the solar system, the Sun, and the universe. Which arrangement of symbols is most accurate?

• A

• B

• C

• D

Answer explanation

Choice A accurately represents the hierarchical structure: the universe contains galaxies, the Milky Way contains solar systems, and the solar system contains the Sun. This reflects the correct spatial relationships among these entities.

Light and other forms of electromagnetic radiation are given off by stars using energy released during

• nuclear fusion

• conduction

• convection

• radioactive decay

Answer explanation

Light and other forms of electromagnetic radiation from stars are produced through nuclear fusion, where hydrogen atoms combine to form helium, releasing energy in the process. This energy manifests as light and heat.

Tags

NGSS.HS-ESS1-1

Which star is cooler and less luminous than the Sun?

• Proxima Centauri

• Pollux

• Rigel

• 40 Eridani B

Answer explanation

Proxima Centauri is a red dwarf star, cooler and less luminous than the Sun, with a surface temperature around 3,000 K compared to the Sun's 5,800 K. The other options, Pollux, Rigel, and 40 Eridani B, are all hotter and more luminous.

Which diagram shows the position of the Earth relative to the Sun's rays during a Winter day in the Northern Hemisphere?

• A

• B

• C

• D

Answer explanation

During winter in the Northern Hemisphere, the Earth is tilted away from the Sun, resulting in lower sun angles and shorter days. Diagram D accurately depicts this position, showing the Sun's rays hitting the Northern Hemisphere at a slant.

Tags

NGSS.MS-ESS1-1

Which diagram shows the position of the Earth relative to the Sun's rays during a Summer day in the Northern Hemisphere?

• A

• B

• C

• D

Answer explanation

During a Summer day in the Northern Hemisphere, the Earth is tilted towards the Sun, allowing direct sunlight to hit the region. Diagrams A and C correctly depict this position, showing the Sun's rays hitting the Northern Hemisphere directly.

Tags

NGSS.MS-ESS1-1

During which season is the Earth TILTED away from the sun?

• Summer

• Fall

• Winter

• Spring

Answer explanation

The Earth is tilted away from the sun during winter in the Northern Hemisphere, resulting in shorter days and colder temperatures. This tilt causes the sun's rays to hit at a more oblique angle, leading to winter conditions.

Tags

NGSS.MS-ESS1-1