1.
Our sun is
Correct Answer
B. A star
Explanation
The correct answer is "a star" because our sun is a massive ball of gas that produces light and heat through nuclear fusion. It is classified as a G-type main-sequence star, commonly known as a yellow dwarf. The sun is not a planet because it does not orbit around another celestial body, and it is not the largest star as there are other stars in the universe that are much bigger in size.
2.
The brightest star in our sky is
Correct Answer
C. Sirus
Explanation
Sirus is the correct answer because it is the brightest star in our sky. It is part of the constellation Canis Major and is easily visible from Earth. Sirus is also known as the "Dog Star" and has a high luminosity, making it appear very bright to observers.
3.
How does the Andromeda galaxy compare with the Milky Way?
Correct Answer
A. The Andromeda galaxy is a spiral galaxy with almost twice as many stars as there are in the Milky Way.
Explanation
The correct answer states that the Andromeda galaxy is a spiral galaxy with almost twice as many stars as there are in the Milky Way. This means that the Andromeda galaxy has a larger number of stars compared to the Milky Way, making it more massive. The fact that it is a spiral galaxy suggests that it has a distinct shape with a central bulge and spiral arms, similar to the Milky Way.
4.
What happens when a massive star cools and collapses?
Correct Answer
B. When a massive star cools and collapses, it becomes a black hole
Explanation
When a massive star cools and collapses, it becomes a black hole. This is because as the star runs out of fuel and is no longer able to sustain nuclear fusion, it can no longer counterbalance the inward pull of gravity. The star then collapses under its own weight, forming a region of spacetime with an extremely strong gravitational pull from which nothing, not even light, can escape. This is what we call a black hole.
5.
What do planets and stars have in common?
Correct Answer
C. Planets and stars form at the same time and from the same gasses.
Explanation
Planets and stars form at the same time and from the same gases. This means that both planets and stars are formed from the remnants of a nebula, which is a cloud of gas and dust in space. As the nebula collapses under its own gravity, it begins to spin and flatten into a disk shape. Within this disk, clumps of gas and dust come together to form protoplanets or protostars. Eventually, the protoplanets accrete more material and become planets, while the protostars continue to grow and eventually ignite nuclear fusion to become stars. Thus, both planets and stars share a common origin and are formed from similar gases.
6.
How do scientists hope to find out if there is life on other planets?
Correct Answer
B. They hope to find out by using radio telescopes to listen for signals of life there.
Explanation
Scientists hope to find out if there is life on other planets by using radio telescopes to listen for signals of life there. Sonar telescopes are used to detect underwater objects and are not suitable for detecting signals from other planets. Quasars are extremely distant and powerful sources of energy, and observing them does not provide direct evidence of life on other planets. Radio telescopes, on the other hand, can detect radio signals that may indicate the presence of intelligent life.
7.
What makes the sun an unusual star?
Correct Answer
A. The sun is an unusual star because it does not have any nearby stars circling it as most stars do.
Explanation
The given answer correctly states that the sun is an unusual star because it does not have any nearby stars circling it as most stars do. This is true because the sun is a solitary star, meaning it does not have a companion star in a binary system like many other stars in the universe. Most stars are part of binary or multiple star systems, where two or more stars orbit around a common center of mass. However, the sun is a single star and does not have any other stars orbiting around it.
8.
What happens when a supernova collapses suddenly?
Correct Answer
C. When it suddenly collapses, it becomes a neutron star that spins and gives off a beam of X-ray radiation.
Explanation
When a supernova collapses suddenly, it becomes a neutron star that spins and emits a beam of X-ray radiation. This occurs because the collapse of the supernova causes the core to become extremely dense, with protons and electrons combining to form neutrons. The resulting neutron star is incredibly compact and has a strong gravitational pull, causing it to spin rapidly. As the neutron star spins, it emits beams of X-ray radiation from its magnetic poles, which can be detected from Earth.
9.
Hercules is
Correct Answer
C. A constellation
Explanation
Hercules is a constellation. Constellations are groups of stars that form patterns or shapes in the sky as seen from Earth. Hercules is one of the 88 recognized constellations and is named after the mythical hero Hercules. It is located in the northern sky and can be seen during certain times of the year.
10.
What galaxy do we live in?
Correct Answer
C. Milky Way
Explanation
The Milky Way is the correct answer because it is the galaxy in which our solar system is located. It is a barred spiral galaxy that contains billions of stars, including our Sun. The name "Milky Way" comes from the hazy band of light that can be seen in the night sky, which is caused by the combined glow of countless stars and other celestial objects in our galaxy.
11.
Over millions of years, gravity pulled the gas and dust particles together. Another word for particle is
Correct Answer
C. A small bit
Explanation
The correct answer is "a small bit" because particles refer to tiny pieces or fragments of matter. In the context of the question, gas and dust particles were pulled together by gravity over millions of years, indicating that these particles were small in size. Therefore, "a small bit" is a suitable synonym for particle in this scenario.
12.
The star is visible when the X-rays are "on". If something is visible, you can
Correct Answer
A. See it
Explanation
The correct answer is "see it" because visibility refers to the ability to perceive something with the eyes. In the given context, the star is visible when the X-rays are "on," indicating that it can be seen. The other options, touch it and taste it, are not relevant to the concept of visibility.
13.
What is a globular cluster?
Correct Answer
B. Thousands or millions of stars close together
Explanation
A globular cluster refers to a large group of thousands or millions of stars that are densely packed together. These stars are held together by their mutual gravitational attraction, forming a spherical or globular shape. Globular clusters are typically found in the outer regions of galaxies and are some of the oldest objects in the universe. They are distinct from open clusters, which are smaller and more loosely bound groups of stars.
14.
A nebula is
Correct Answer
A. A cloud of gas and dust
Explanation
A nebula is a cloud of gas and dust in space. It is formed from the remnants of dying stars or from the collapse of interstellar gas and dust. Nebulas can vary in size and shape, and they often serve as the birthplace of new stars. The gas and dust within a nebula can come together under the force of gravity, forming dense regions where stars are born. Therefore, the correct answer is "a cloud of gas and dust."
15.
Stars that are sometimes bright but sometimes dim are called variable stars. Variable means
Correct Answer
B. Changeable
Explanation
Variable stars are called so because their brightness changes over time. Unlike constant stars that maintain a consistent level of brightness, variable stars can go through periods of being bright and then become dim. This changeability in their brightness is what defines them as variable stars.