The following data for the Sun and the four inner planets of the Solar System have been observed. Mean Distance from the Sun (million kilometers) Diameter (kilometers) Sun 1,400,000 Mercury 58 4,900 Venus 108 12,100 Earth 150 12,800 Mars 228 6,800 In a simplified model of the Solar System, the planets revolve around the Sun in circular orbits, all in the same plane. Each planet has a different period of revolution. Also, each planet is a sphere that rotates about an axis through its center, but with a different period of rotation. In this model the axis of rotation of each planet is perpendicular to the plane of the orbit.
1. Draw a sketch showing how Earth and Venus can be 258 million kilometers apart and explain how
Scoring Guide Score & Description Complete Student demonstrates both an understanding of the changing alignment of planets as they move around the Sun and an ability to find a possible location of two planets when they are a specified distance apart. Student response contains a sketch that shows Earth and Venus at opposing ends of their respective orbits and provides a correct explanation of the sketch, referring to the different rates at which planets move around their orbits. Partial Student response contains a sketch that shows Earth and Venus on opposing sides of their respective orbits, but does not include a correct explanation of the sketch. OR The sketch is incorrect or missing, but the response contains an explanation recognizing that Earth and Venus do not stay fixed relative to each other but travel at different rates around their orbits. Unsatisfactory/Incorrect Student response does not show a sketch with Earth and Venus at opposing ends of their respective orbits, and there is no explanation about the differing rates at which planet move around their orbits.
Complete - Student Response Scorer Comments: Student response correctly shows Earth and Venus at opposite sides of the Sun, and explains that this alignment is possible because the two planets revolve at differing rates.
Scorer Comments: Student response correctly shows Earth and Venus at opposite sides of the Sun, and explains that this alignment is possible because the two planets revolve at differing rates. Partial - Student Response
Scorer Comments: Student response correctly shows Earth and Venus at opposite sides of the Sun. The explanation describes the picture drawn, and does not say anything about the rates of revolutions of the planets. Scorer Comments: Student response shows Earth and Venus in incorrect positions. The explanation shows
understanding that the relative positions of Earth and Venus vary due to their different rates of revolution. Unsatisfactory/Incorrect - Student Response Scorer Comments: Student response shows Earth and Venus in incorrect positions, and provides an irrelevant explanation that they are in non-overlapping orbits.
Scorer Comments: Student response shows Earth and Venus in incorrect positions, and provides an irrelevant explanation about elliptical orbits.
2000 National Performance Results Score Percentage of Students Unsatisfactory/incorrect 43% Partial 36% Complete 5% Omitted 15% Off task 2% Note: These results are for public and nonpublic school students. Percentages may not add to 100 due to rounding. The Fields of Science: Earth & Space Sciences (Sub content classification: Earth in Space) Knowing and Doing Science : Conceptual Understanding
The Fields of Science Earth & Space Sciences This question measures basic knowledge and understanding of the following: Earth in Space setting of the Earth in the solar system; setting and evolution of the solar system in the universe (not in grade 4); tools and technology that are used to gather information about space; apparent daily motions of the Sun, the Moon, the planets, and the stars; rotation of the Earth about its axis, and the Earth's revolution around the Sun; tilt of the Earth's axis that produces seasonal variations in climate; and earth as a unique member of the solar system that may be approximated in other galaxies in the universe, and that evolved at least 4.5 billion years ago. Knowing and Doing Science Conceptual Understanding Conceptual understanding includes the body of scientific knowledge that students draw upon when conducting a scientific investigation or engaging in practical reasoning. Essential scientific concepts involve a variety of information, including facts and events the student learns from both science instruction and experiences with natural environment; and scientific concepts, principles, laws, and theories that scientists use to explain and predict observations of the natural world.