Untitled Flashcards Set

Please Grade 9 Science Test: Astronomy

Part A: Reviewing Key Terms (1 mark each) Fill in the blanks with the correct term.

The Mesopotamians were the first civilization for whom we have evidence of detailed astronomical observations.
Earth rotates on its axis and revolves around the Sun.
Groups of stars that seem to form distinctive patterns are called constellations.
During a solar eclipse, the new Moon completely blocks the Sun.
A planet is a celestial object that orbits one or more stars, is spherical, and does not share its orbit with another object.
Retrograde motion is the apparent motion of a planet opposite to the usual east-to-west motion.
A meteoroid that survives impact with the atmosphere and reaches the ground is called a meteorite.

Part B: Knowledge and Understanding (3 marks each) Answer the following questions in complete sentences.

Recording the movement of stars in the night sky was important to early sky watchers for navigation, calendar creation, and religious or agricultural purposes.
The Moon has phases because it orbits Earth, changing the portion of its sunlit side that we see from Earth.
The phases shown in the diagram correspond to waxing crescent, first quarter, and waxing gibbous.
You cannot see the new Moon because its sunlit side is facing away from Earth.
A total solar eclipse from the Moon would look like Earth completely covering the Sun, with a bright ring of atmosphere (Earth's atmosphere) around it.
The solar system consists of the Sun, eight planets, their moons, and other celestial bodies such as asteroids and comets.
The distances in the solar system are not measured in light-years because they are much smaller than interstellar distances, which require a more practical unit like astronomical units (AU).
The average distance between Earth and the Sun is called an astronomical unit (AU).
The classification of inner and outer planets is based on their location relative to the asteroid belt.
The outer planets are large, made mostly of gas, have rings, and have many moons.
Pluto is different from the eight planets because it is much smaller, has an irregular orbit, and does not clear its orbit of other debris.
Shooting stars are caused by meteoroids burning up as they enter Earth's atmosphere.
Asteroids are large rocky bodies orbiting the Sun, while meteoroids are smaller fragments of asteroids or comets.
A comet is a small icy celestial body that orbits the Sun. It has two tails—one made of gas and one of dust—caused by solar wind and radiation.

Part C: Thinking and Investigation (4 marks each) Answer the following in detailed explanations.

A person living in a lunar colony would experience long days and nights since the Moon's rotation period is equal to its revolution period around Earth.
(Student should create a table with planetary facts such as mass, diameter, moons, atmosphere, etc.)
Studying objects in the Oort Cloud and Kuiper Belt helps astronomers understand the formation of the solar system by analyzing leftover materials from the early solar system.
Solar events like solar flares can cause disruptions to Earth's power grids and satellite communications.
Solar flares are associated with sunspots, which are cooler regions on the Sun’s photosphere.
The solar nebula theory is supported by evidence such as protoplanetary disks around young stars, the orderly motion of planets, and the composition of asteroids and comets.

Part D: Astronomy and the Universe (3 marks each) Fill in the blanks with the correct term.

Light from a star is a form of electromagnetic radiation.
Reflecting telescopes use mirrors to collect light, and refracting telescopes use lenses to collect light.
Sunspots are dark areas on the Sun’s surface.
A(n) galaxy is a huge collection of stars, planets, gas, and dust held together by gravity.
The galaxy that includes our solar system is called the Milky Way.
The study of how the universe began and evolved is called cosmology.
According to the Big Bang theory, the universe began from an incredibly dense state.
The leftover radiation from the big bang is called the cosmic microwave background radiation.
Edwin Hubble discovered that galaxies are moving away from us, leading to the conclusion that the universe is expanding.
The fact that the universe is expanding suggests that it started from a single point, supporting the Big Bang theory.
Two spinoff technologies from space exploration are GPS and MRI imaging.
Astronomers used observational evidence such as redshift in galaxies, cosmic microwave background radiation, and element abundances to support the Big Bang theory.