Question

You surveyed the Universe by taking a cosmic zoom in which each field of view was 100 times wider than the previous field of view. Astronomers use the metric system because it _________ calculations and use scientific notation for very large or very small numbers. The Solar System includes the _____ at the center, all of the _________ that orbit around it—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune—plus the _________ of the planets and all other objects bound to the Sun by its _________. You live on a planet, Earth, which orbits our star, the Sun, _______ a year. As Earth rotates once a day, you see the Sun rise and set. The Moon is only ________ the diameter of Earth, but the Sun is about _______ times larger in diameter than Earth—a typical size for a star. The _______________ ________ (AU) is the average distance from Earth to the Sun. Mars, for example, orbits 1.5 AU from the Sun. The _________ _______ (ly) is the distance light can travel in 1 year. The nearest star is 4.2 ly from the Sun. Many stars seem to have planets, but such small, distant worlds are difficult to detect. Nevertheless, thousands have been found after almost 30 years of searching by astronomers. So far, only a few of those planets have been determined to be Earth-like in terms of size and temperature. ___________ contain many billions of stars. Our Galaxy is about 80,000 ly in diameter and contains more than 100 billion stars. The Milky Way, the hazy band of light that encircles the sky, is the Milky Way Galaxy seen from inside. The Sun is just one of the billions of stars that fill the Milky Way Galaxy. Some galaxies, including our own, have graceful _______ _______ bright with stars, but some galaxies are plain clouds of stars. The Solar System consists of the Sun plus __________ planets, including Earth. Our Galaxy contains our Solar System plus billions of other stars and whatever planets orbit around them. The Universe includes everything that there is: billions of galaxies, each containing billions of stars and, presumably, billions of planetary systems. Our Galaxy is just one of billions of galaxies that fill the Universe in great clusters, _____________, filaments, and walls—the largest structures in the Universe.

Answer 1

Astronomers use the metric system for calculations and scientific notation for large or small numbers. The solar system includes the Sun at the center, planets, moons, and other objects bound by gravity. The Universe is made up of billions of galaxies, each containing billions of stars and possibly planetary systems.

Step-by-step explanation:

Astronomers use the metric system because it simplifies calculations and use scientific notation for very large or very small numbers. The Solar System includes the Sun at the center, all of the planets that orbit around it—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune—plus the moons of the planets and all other objects bound to the Sun by its gravity. You live on a planet, Earth, which orbits our star, the Sun, once a year. As Earth rotates once a day, you see the Sun rise and set. The Moon is only about one-fourth the diameter of Earth, but the Sun is about 109 times larger in diameter than Earth—a typical size for a star. The Astronomical Unit (AU) is the average distance from Earth to the Sun. Mars, for example, orbits 1.5 AU from the Sun. The light-year (ly) is the distance light can travel in 1 year. The nearest star is 4.2 ly from the Sun. Many stars seem to have planets, but such small, distant worlds are difficult to detect. Nevertheless, thousands have been found after almost 30 years of searching by astronomers. So far, only a few of those planets have been determined to be Earth-like in terms of size and temperature. Galaxies contain many billions of stars. Our Galaxy is about 80,000 ly in diameter and contains more than 100 billion stars. The Milky Way, the hazy band of light that encircles the sky, is the Milky Way Galaxy seen from inside. The Sun is just one of the billions of stars that fill the Milky Way Galaxy. Some galaxies, including our own, have graceful spiral arms bright with stars, but some galaxies are plain clouds of stars. The Solar System consists of the Sun plus eight planets, including Earth. Our Galaxy contains our Solar System plus billions of other stars and whatever planets orbit around them. The Universe includes everything that there is: billions of galaxies, each containing billions of stars and, presumably, billions of planetary systems. Our Galaxy is just one of billions of galaxies that fill the Universe in great clusters, superclusters, filaments, and walls—the largest structures in the Universe.