Unit 1 Week 1 Quiz

Explanation
The correct answer is that the universe is everything that exists. This means that it encompasses not only our planet and the other planets that orbit the sun, but also includes all galaxies, stars, and other celestial bodies. The universe is vast and infinite, containing all matter, energy, space, and time. It is the entirety of all known and unknown elements, forces, and phenomena.

Explanation
The Earth is one of 8 planets circling the sun, which is correct as there are indeed 8 planets in our solar system. We can estimate that there are at least 100 billion billion stars, which is also correct as there are billions of galaxies, each containing billions of stars. Our sun is a medium hot yellow star, which is true as it falls into the category of a G-type main-sequence star. The Milky Way is a spiral-shaped galaxy, which is accurate as our galaxy is indeed a spiral galaxy.

Explanation
The Milky Way, along with approximately 30 other galaxies, forms a cluster in space. This suggests that there are several galaxies grouped together in a specific region of the universe. The number 30 indicates the approximate quantity of galaxies in this cluster, highlighting the significant presence of other galactic bodies alongside the Milky Way.

Explanation
The correct answer is the distance between the earth and the sun. An Astronomical Unit (AU) is defined as the average distance between the earth and the sun, which is approximately 93 million miles or 150 million kilometers. It is used as a standard unit of measurement in astronomy to represent distances within our solar system.

Explanation
One AU (Astronomical Unit) is a unit of measurement used in astronomy to represent the average distance between the Earth and the Sun. It is approximately equal to 93 million miles. This distance is used as a reference point for measuring distances within our solar system. Therefore, the correct answer is 93 million miles.

Explanation
A light year is a unit of measurement used in astronomy to represent the distance that light travels in one year. Since light travels at a speed of approximately 299,792 kilometers per second, multiplying this speed by the number of seconds in a year gives us the distance covered by light in one year. Therefore, the statement "A light year is the distance light travels in a year" is true.

Explanation
A light year is not 4.9 million miles. It is actually the distance that light travels in one year, which is approximately 5.88 trillion miles.

Explanation
The Milky Way is indeed 100,000 light years across. This means that it would take light 100,000 years to travel from one end of the Milky Way to the other. The Milky Way is a barred spiral galaxy, and it is estimated to contain between 100 and 400 billion stars. Its immense size makes it one of the largest galaxies in the known universe.

Explanation
The statement "Everything in the universe is moving" is true because movement is a fundamental characteristic of the universe. From the smallest particles to the largest galaxies, everything is in a constant state of motion. This movement can be observed at various scales, such as the rotation of planets, the orbit of celestial bodies, and the expansion of the universe itself. Additionally, at the atomic and subatomic level, particles are constantly vibrating and interacting with each other. Therefore, it can be concluded that everything in the universe is indeed moving.

Explanation
Edwin Hubble is the correct answer because he is known for presenting the first evidence that showed the existence of other galaxies outside our own in 1924. Hubble's observations and measurements of galaxies, particularly the Andromeda galaxy, provided evidence that these celestial bodies were separate entities from our Milky Way galaxy, thus confirming the existence of other galaxies in the universe. His work revolutionized our understanding of the cosmos and laid the foundation for modern cosmology.