1.
What type of galaxy is our Milky Way?
Correct Answer
B. A spiral galaxy
Explanation
Our Milky Way is classified as a spiral galaxy. This classification is based on its shape, which resembles a flat disk with spiral arms extending from a central bulge. Spiral galaxies are characterized by their distinct spiral structure, containing young stars, gas, and dust in their arms. They also have a central bulge that contains older stars. The classification of the Milky Way as a spiral galaxy is supported by observations of its structure and the presence of spiral arms.
2.
Which of these planets is the largest?
Correct Answer
D. Jupiter
Explanation
Jupiter is the largest planet in our solar system. It has a diameter of about 143,000 kilometers, which is more than 11 times the diameter of Earth. Its massive size is due to its composition, primarily made up of hydrogen and helium gasses. Jupiter's immense gravity also contributes to its size, allowing it to gather and hold onto a large amount of gas and other materials. Its size and gravity make Jupiter a dominant force in the solar system, with a strong influence on the orbits and dynamics of other planets and celestial bodies.
3.
What is the ultimate fate of our sun?
Correct Answer
B. White dwarf
Explanation
The ultimate fate of our sun is to become a white dwarf. This is because after exhausting its nuclear fuel, the sun will expand into a red giant, shedding its outer layers and leaving behind a dense core. This core will then gradually cool down and become a white dwarf, a small, hot, and extremely dense stellar remnant that will slowly fade away over billions of years. A black hole is formed from the collapse of a massive star, while a fireball is not a scientifically recognized term for the fate of a star.
4.
How much of the galaxy can you see in the night sky?
Correct Answer
C. 0.000003%
Explanation
The answer 0.000003% suggests that only a very small portion of the galaxy can be seen in the night sky. This is because the night sky is limited to what is visible from Earth, and the galaxy is vast, consisting of billions of stars, planets, and other celestial objects. Therefore, the percentage is extremely low, indicating that only a tiny fraction of the galaxy can be observed from our perspective on Earth.
5.
How many galaxies are there in the observable universe?
Correct Answer
B. 200 billion
Explanation
There are approximately 200 billion galaxies in the observable universe. This estimate is based on observations made by telescopes and other astronomical instruments. The observable universe refers to the portion of the universe that we can see from Earth, and it is constantly expanding as light from distant objects reaches us. The vast number of galaxies in the observable universe shows the immense scale and diversity of the cosmos.
6.
Light in one year approximately travels 9,460,000,000,000 km.
Correct Answer
A. True
Explanation
Light in one year travels a distance of 9,460,000,000,000 km. This is because light travels at a speed of approximately 299,792 kilometers per second. In one year, there are 31,536,000 seconds. Multiplying the speed of light by the number of seconds in a year gives us the distance traveled by light in one year, which is 9,460,000,000,000 km. Therefore, the statement is true.
7.
The Andromeda galaxy is 1,200,000 light-years away from us.
Correct Answer
B. False
Explanation
The Andromeda galaxy is not 1,200,000 light-years away from us. This statement is false. The Andromeda galaxy is actually about 2.537 million light-years away from Earth. It is the closest spiral galaxy to our Milky Way galaxy and can be seen with the naked eye from Earth.
8.
The smallest planet in our solar system is:
Correct Answer
D. Mercury
Explanation
Mercury is the correct answer because it is the smallest planet in our solar system. It has a diameter of about 4,879 kilometers, making it slightly larger than Earth's Moon. Mercury is even smaller than some moons in the solar system, such as Jupiter's moon Ganymede and Saturn's moon Titan. Its small size is one of the reasons why Mercury has a weaker gravitational pull compared to larger planets like Jupiter and Saturn.
9.
The coldest planet in our solar system is:
Correct Answer
A. Uranus
Explanation
Uranus is the correct answer because it is the coldest planet in our solar system. It has a minimum temperature of -224 degrees Celsius (-371 degrees Fahrenheit), making it colder than Neptune, Venus, and all other planets in our solar system. Uranus' extreme coldness is due to its distance from the Sun and its unique composition, which includes a thick atmosphere of hydrogen and helium.
10.
Who first proposed that the galaxy was expanding?
Correct Answer
C. Hubble
Explanation
Hubble was the first to propose that the galaxy was expanding. His observations of the redshift of light from distant galaxies led him to conclude that the universe is expanding, which became known as Hubble's Law. This discovery revolutionized our understanding of the universe and laid the foundation for the Big Bang theory. Einstein, Kepler, and Maxwell made significant contributions to physics and astronomy, but they did not propose the expansion of the galaxy.