Observations of the Solar System

Dwarf planets are smaller than planets. What is another way that dwarf planets are different?

• They are not spherical.

• They do not orbit the sun.

• They have large objects in their orbit.

• They move more slowly along their orbits.

As an astronomer observes an object in space that has an irregular shape, that orbits the sun in a highly elliptical orbit, and that is made of ice and rock. Which object is the astronomer most likely observing?

• moon

• comet

• asteroid

• meteoroid

Parallax can be used to determine a planet's relative distance from Earth. Which statement correctly describes parallax?

• Planets closer to Earth will appear brighter.

• Planets farther away from Earth will have a dimmer appearance.

• Planets farther from Earth will appear to have a smaller shift in position.

• Planets farther away from Earth will appear to have a greater shift in position.

The picture shows a model of the solar system. Which statement describes a limitation of the model?

• It cannot show how the planets orbit the sun.

• It cannot show the relative sizes of each planet.

• It does not show the gravitational force exerted by each planet.

• It does not show the order of the planets, from closest to the sun to farthest from the sun.

Tags

NGSS.MS-ESS1-1

NGSS.MS-PS2-4

Early astronomers noticed that some stars in the sky appeared to move together across the sky as constellations. How do astronomers today explain this motion?

• The sun's gravity keeps the stars together because they orbit the sun at the same rate.

• The stars appear to move together along a path because of Earth's rotation on its axis.

• Gravitational attraction between the stars keeps them fixed relative to each other as they move.

• The stars move around Earth in the same way, so their positions relative to each other stay the same.

Tags

NGSS.MS-ESS1-2

NGSS.MS-PS2-4

The table shows events that led to the current theory that the sun is the center of the solar system. Which sequence of events is correct?

• 1, 2, 3

• 1, 3, 2

• 2, 1, 3

• 3, 1, 2

The dotted lines in the picture show orbital paths of objects. Which object orbits object E?

• object A

• object B

• object C

• object D

Tags

NGSS.MS-ESS1-2

NGSS.MS-PS2-4

Explain retrograde motion and why it confused early astronomers as they viewed the motion of objects in the sky.

• Retrograded motion is the reversal of time in space

• The apparent backward motion of a planet.

• When the moon transits the sun casting a shadow on the earth.

• Like parallax it shifts when its farther away.

Explain how Ptolemy's concept of epicycles improved on Aristotle's model of how objects move in the solar system.

• It was able to show the order of the planets

• It showed that the sun was the center of the universe

• It was able to (incorrectly) explain the backward motion of the planets.

• He changed it to the heliocentric model

Describe Copernicus's heliocentric model of the solar system.

• It took the geocentric model and added the stars to orbit as well

• The sun was at the center with everything else orbiting it.

• The earth was finally given a moon

• Neptune and Jupiter were downgraded to dwarf planets

Tags

NGSS.MS-ESS1-2