Astronomy Chapter 4-7 Quiz

The Earth-crossing family of asteroids have orbits that bring them closer to the Sun than the Earth. These asteroids cross the Earth's orbit, making them potentially hazardous as they have the potential to collide with our planet. The term "Earth-crossing" indicates their close proximity to Earth's orbit and highlights the potential danger they pose.

The moon is a celestial body that revolves around another larger object in the solar system, such as a planet. In the case of Earth, the moon is the natural satellite that orbits around our planet. It is held in its orbit by the gravitational force between the Earth and the moon. The moon does not revolve around the Sun directly, but it is considered a satellite of the Sun-Earth system as it orbits around the Earth, which itself orbits around the Sun.

Terrestrial planets are characterized by weak magnetic fields, slower rotation, and few moons. These planets, which include Earth, Mars, Venus, and Mercury, have solid rocky surfaces and are closer to the Sun compared to the gas giants. The weak magnetic fields are a result of their smaller size and lack of a liquid metallic core, unlike the gas giants. The slower rotation is due to the conservation of angular momentum during their formation, causing them to rotate more slowly over time. Finally, the terrestrial planets have fewer moons compared to the gas giants, which have a large number of moons orbiting around them.

Comets spend most of their time at the far edges of the solar system, only rarely passing into the inner solar system. Comets are celestial bodies composed of ice, dust, and rocky material. They have highly elliptical orbits that take them far away from the Sun, where they spend the majority of their time. However, due to gravitational interactions or disturbances, some comets occasionally venture closer to the Sun and into the inner solar system. This is when they become visible from Earth as they heat up and release gas and dust, forming a glowing coma and sometimes a tail.

Jovian planets, also known as gas giants, are the correct answer because they have a lower density compared to the terrestrial planets. Jovian planets are primarily composed of gases, such as hydrogen and helium, which make them less dense. In contrast, terrestrial planets, like Earth, have a higher density due to their solid composition. Therefore, Jovian planets are the least dense among the different classes of planets.

Terrestrial planets are characterized by their slow rotation, high density, and few satellites. This is because they are composed mainly of rock and metal, which makes them denser than the gas giants. Due to their solid composition, they rotate more slowly compared to gas giants, which are mainly composed of gases. Additionally, terrestrial planets tend to have fewer satellites because their smaller size and lower gravitational pull make it more difficult for them to capture and retain moons. Therefore, the given answer "Terrestrial" accurately describes the planets that possess these characteristics.

Few meteors actually strike the Earth's surface, because most are small in size and burn up in the atmosphere.

Mars is the correct answer because it shows signs of water erosion in the past, such as ancient riverbeds and canyons. However, presently there is no liquid water on its surface due to its thin atmosphere and low atmospheric pressure, which causes water to evaporate or freeze.

The age of the Earth is estimated to be approximately 4.6 billion years. This estimation is based on various scientific methods, including radiometric dating of rocks and minerals. By analyzing the decay of radioactive isotopes, scientists have been able to determine the age of the oldest rocks on Earth and, consequently, the age of the planet itself. This estimation aligns with the geological and paleontological evidence that supports the existence of life on Earth dating back billions of years.

The greenhouse effect on Venus has raised the surface temperature by hundreds of degrees Celsius. This is due to the thick atmosphere of Venus, which is composed mostly of carbon dioxide. The carbon dioxide traps the heat from the sun, causing a runaway greenhouse effect. As a result, the surface temperature on Venus is extremely hot, reaching up to 900 degrees Fahrenheit (475 degrees Celsius). This is much hotter than the surface temperature on Earth, where the greenhouse effect is less pronounced.

The correct answer is Mercury, Venus, Earth, Mars. These are the terrestrial planets because they are rocky, solid planets that are similar in composition to Earth. They are located closer to the Sun compared to the gas giants like Jupiter and Saturn. Pluto is not considered a terrestrial planet as it is classified as a dwarf planet.

The asteroid belt is located between the orbits of Mars and Jupiter. This region is characterized by a large number of small celestial bodies, mainly asteroids, which orbit the Sun. The gravitational influence of Jupiter prevented the formation of a planet in this region, resulting in the concentration of asteroids instead. Mars, being the planet closer to the Sun, marks the inner boundary of the asteroid belt, while Jupiter, being the planet farther from the Sun, marks the outer boundary.

Venus has a hostile environment with extreme conditions. The lack of oxygen and tremendous atmospheric pressure would make it impossible for humans to survive without proper equipment. The thick atmosphere of Venus creates a greenhouse effect, leading to extremely high temperatures that can melt metal. Therefore, being stranded on Venus would result in certain death due to the lack of breathable air and the intense atmospheric pressure.

Small debris in the solar system less than 100 meters in diameter are called meteoroids. Meteoroids are fragments of asteroids or comets that orbit the sun. When a meteoroid enters the Earth's atmosphere and burns up, it is called a meteor. If a meteoroid survives the journey through the atmosphere and lands on Earth's surface, it is called a meteorite.

The correct answer is carbon dioxide. Venus has a thick atmosphere composed mainly of carbon dioxide, with traces of nitrogen and sulfuric acid. Unlike Earth, Venus does not have oxygen in its atmosphere. The high concentration of carbon dioxide in Venus' atmosphere contributes to its extreme greenhouse effect, resulting in a surface temperature that is hot enough to melt lead.

Mercury experiences highs and lows in temperature between day and night because it lacks a blanket of atmosphere. Without an atmosphere to trap and distribute heat, the surface of Mercury is directly exposed to the extreme temperatures of the sun during the day, causing it to become very hot. At night, without an atmosphere to retain any heat, the surface temperature drops drastically, resulting in very cold temperatures. This lack of atmosphere contributes to the significant temperature variations experienced by Mercury.

The correct answer is that the earth's average density is greater than the surface density. This is because the earth's core is believed to be composed mainly of iron and nickel, which are metals and have a higher density compared to the rocks and minerals that make up the earth's crust. The overall average density of the earth is therefore higher than the density of the surface materials, providing evidence that the core is metallic.

The correct answer is nearly 4 billion years old. This is determined through radiometric dating, a method that uses the decay of radioactive isotopes in rocks to estimate their age. By analyzing the ratios of certain isotopes, scientists can calculate how long it has been since the rock formed. The oldest rocks found on Earth, such as those in Western Greenland and Western Australia, have been dated to be around 3.8 to 4.4 billion years old. These rocks provide valuable insights into the early history of our planet.

Nitrogen is the chief gas in the Earth's atmosphere because it makes up about 78% of the total composition. It is an essential component for life as it is needed for the growth of plants and the production of proteins. Nitrogen is relatively inert and does not react easily with other elements, making it an important stabilizing gas in the atmosphere. Additionally, it plays a crucial role in the nitrogen cycle, where it is converted into different forms by bacteria and other organisms, ensuring the availability of nitrogen for various biological processes.

The answer states that we have learned more about the solar system in the past few decades than in all the previous centuries combined. This suggests that our understanding of the solar system has significantly advanced in recent times compared to the accumulation of knowledge over centuries.

Comets are thought to reside mainly in the Oort Cloud and Kuiper Belt. The Oort Cloud is a theoretical cloud of icy objects that is believed to surround the outermost regions of the solar system, while the Kuiper Belt is a region of the solar system beyond Neptune that is also populated with icy bodies. These two regions are considered to be the primary sources of comets, as they contain a large number of icy objects that can be gravitationally disturbed and sent into the inner solar system, where they become visible as comets.

Carbon dioxide is the correct answer because it is known to exist in the atmosphere of Mars. The polar caps of Mars are composed of a mixture of water ice and carbon dioxide ice, which freezes during the winter. This frozen carbon dioxide, also known as dry ice, sublimates and evaporates during the Martian summer, contributing to the seasonal changes on the planet. Therefore, carbon dioxide is a prominent component of the polar caps on Mars.

The term "falling star" is another commonly used term for a meteor. When we see a streak of light in the night sky, it is often referred to as a falling star, even though it is not actually a star falling from the sky. Meteors are small particles that enter the Earth's atmosphere and burn up due to friction, creating the bright streak of light that we see. This term is used because the appearance of a meteor resembles a star falling from the sky.

The correct answer is that the Moon lacks wind and running water. Wind and running water are two major agents of erosion on Earth, but they are absent on the Moon. Without these forces, the erosion rate on the Moon is significantly lower compared to Earth. The Moon's surface is mainly affected by other processes such as impact cratering from meteoroids and gradual weathering caused by temperature fluctuations.

One astronomical unit is the average distance from Earth to the Sun. This unit is used to measure distances within the solar system and is approximately 93 million miles or 150 million kilometers. It provides a standard reference point for measuring distances between celestial bodies in our solar system.

Rocky debris, typically larger than 100 meters in diameter, seen orbiting the sun are known as asteroids. These objects are remnants from the early formation of the solar system and can be found in the asteroid belt between Mars and Jupiter, as well as in other regions of the solar system. They are composed primarily of rock and metal and vary in size from small boulders to large bodies several hundred kilometers in diameter. Asteroids can pose a potential threat to Earth if their orbits bring them close to our planet, but they also provide valuable information about the history and composition of our solar system.

The age of the Moon is less than the age of the Earth. This is because the Moon is believed to have formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia. This collision occurred approximately 4.5 billion years ago, which is the estimated age of the Earth. Therefore, the Moon is thought to be slightly younger than the Earth.

Oxygen makes up 20% of the Earth's atmosphere. This means that out of all the gases present in the Earth's atmosphere, oxygen constitutes 20% of it. This is significant because oxygen is vital for many living organisms, including humans, as it is necessary for respiration. It is also involved in various other processes such as combustion. Therefore, the presence of oxygen in the Earth's atmosphere is crucial for sustaining life on our planet.

Most asteroids have orbits that lie beyond the orbit of Mars. This means that their paths around the Sun are situated further away from the Sun than Mars' orbit. Therefore, these asteroids are located in the outer regions of the solar system, beyond the orbit of Mars.

The surface pressure on Venus is much greater than that on Earth. Venus has a thick atmosphere composed mainly of carbon dioxide, which creates a strong greenhouse effect. This causes the surface temperature to be extremely high, resulting in a high atmospheric pressure. In fact, the atmospheric pressure on Venus is about 92 times greater than that on Earth, making it the highest among all the planets in our solar system.

Mercury and the Moon are both too small to retain a substantial atmosphere, which is why they are best separated from the other terrestrial planets. The lack of a substantial atmosphere is due to their small size, which means they have less gravitational pull to hold onto gases. This is in contrast to the other terrestrial planets, which are larger and have enough gravity to retain an atmosphere. Therefore, the fact that Mercury and the Moon are too small to retain a substantial atmosphere is the best explanation for why they are different from the other terrestrial planets.

When Earth crosses the orbit of a comet, it passes through the trail of debris left behind by the comet. As Earth moves through this debris field, the particles enter our atmosphere and burn up, creating a meteor shower. This phenomenon occurs because the debris, such as dust and rocks, vaporizes due to the friction with the Earth's atmosphere, producing streaks of light in the night sky.

The lack of atmosphere is the main reason for the large temperature variations on both the moon and Mercury. Without an atmosphere to trap and distribute heat, the surface of these celestial bodies is directly exposed to the sun's radiation during the day, causing temperatures to rise significantly. However, without an atmosphere to retain heat, the surface quickly cools down during the night, resulting in extreme temperature drops. This lack of atmospheric insulation leads to the significant temperature variations experienced on both the moon and Mercury.

The correct answer is carbon dioxide makes for a strong greenhouse effect. Venus has a thick atmosphere composed mainly of carbon dioxide, which traps heat and creates a strong greenhouse effect. This causes the temperature at the surface to be extremely high and relatively constant throughout the day and night. The greenhouse effect prevents the heat from escaping into space, resulting in similar temperatures at noon and midnight on Venus.

Most astronomers today favor the theory that the Moon originated as material torn from Earth by the collision of a large Mars-sized body. This theory, known as the Giant Impact Hypothesis, suggests that a massive object collided with Earth early in its history, causing debris to be ejected into space. This debris eventually coalesced to form the Moon. This theory is supported by various lines of evidence, including the similarities in isotopic compositions between the Earth and Moon, as well as computer simulations that show how such a collision could have occurred.

The correct answer is "none of the above" because all of the listed objects (asteroids, comets, and meteoroids) have the potential to collide with Earth. While the likelihood of a collision may vary, none of these objects can be ruled out as never colliding with Earth.

Nitrogen is the primary ingredient in the Earth's atmosphere. It makes up about 78% of the atmosphere, while oxygen makes up about 21%. Nitrogen is essential for life as it is a key component of proteins and nucleic acids. It is also important for the nitrogen cycle, which is crucial for the growth of plants and the balance of ecosystems.

The sun contains over 99% of the entire solar system because it is by far the largest celestial object in the system. It has a mass that is approximately 330,000 times greater than that of Earth and is responsible for the vast majority of the system's gravitational pull. Additionally, the sun's immense heat and energy radiate outwards, providing light and warmth to all the planets and other objects in the solar system. Therefore, it is safe to say that the sun dominates the solar system in terms of size, mass, and influence.

All of the factors mentioned contribute to Venus being hot. Venus is closer to the Sun than Earth, which means it receives more sunlight and heat. Additionally, Venus has a dense atmosphere that traps heat and creates a greenhouse effect, further increasing its temperature. The atmosphere is mainly composed of carbon dioxide, which is a greenhouse gas that contributes to the warming of the planet. Therefore, all of these factors combined make Venus extremely hot.

The technique of radioactive dating of rocks is used to estimate the Earth's average age. This method relies on the natural decay of radioactive isotopes in rocks, such as uranium and potassium, to determine the age of the rocks. By measuring the ratio of parent isotopes to daughter isotopes in the rocks, scientists can calculate how long it has been since the rock formed. This method is widely used in geology and archaeology to determine the age of rocks and artifacts.

In the 20th century, the carbon dioxide levels in the atmosphere have increased by 20%. This suggests that there has been a significant rise in the amount of carbon dioxide present in the Earth's atmosphere over the course of the century. This increase is likely due to human activities such as the burning of fossil fuels, deforestation, and industrial processes, which release large amounts of carbon dioxide into the atmosphere. The rise in carbon dioxide levels is a major contributor to global warming and climate change.

Droplets of sulfuric acid make up clouds of Venus. The atmosphere of Venus is composed mainly of carbon dioxide, with traces of nitrogen and other gases. However, sulfuric acid is a dominant component of the clouds on Venus. These clouds are composed of droplets of sulfuric acid that form due to the high temperatures and pressures in the atmosphere. This is why sulfuric acid is the correct answer.

Venus appears bright to the eye because its cloud cover is highly reflective. The clouds on Venus are made up of sulfuric acid and are very thick, which causes them to reflect a significant amount of sunlight back into space. This reflection makes Venus appear bright, even though it is not the closest planet to the Sun.

The atmosphere is responsible for moderating the surface environment of the Earth. It acts as a protective layer, shielding the Earth from harmful solar radiation and regulating temperature by trapping heat. The atmosphere also plays a crucial role in the water cycle, distributing moisture and influencing weather patterns. Additionally, it contains the gases necessary for life, such as oxygen and carbon dioxide, and helps maintain a stable climate. Overall, the atmosphere acts as a buffer, regulating and maintaining the conditions necessary for life on Earth.

The Milky Way Galaxy is estimated to contain a few hundred billion stars. This estimation is based on observations and calculations made by astronomers. The exact number of stars is difficult to determine due to the vastness of the galaxy and the limitations of current technology. However, studies have suggested that there could be anywhere from 100 to 400 billion stars in the Milky Way.

The earth's atmosphere helps to keep the surface warm by absorbing a large fraction of the incoming infrared radiation. Infrared radiation is a form of heat energy that is emitted by the Earth's surface and is absorbed by certain gases in the atmosphere, such as carbon dioxide and water vapor. This absorption of infrared radiation prevents it from escaping back into space, effectively trapping heat and keeping the Earth's surface warm.

The correct answer is "The earth and Venus." Both the earth and Venus are similar in size, with Venus being only slightly smaller than the earth. They are both terrestrial planets and have similar compositions and densities. Additionally, they are both located in the inner solar system, relatively close to each other in terms of distance from the sun.

Moonquakes are seismic activities that occur on the Moon. These quakes provide valuable information about the lunar interior. The fact that the Moon experiences moonquakes suggests that it has a dynamic and active interior. The presence of moonquakes indicates that the Moon might have a small, partially molten core. This suggests that there is still some residual heat within the Moon, which causes the interior to be active and potentially molten. Therefore, the correct answer is that moonquakes reveal that the Moon might have a small, partially molten core.

According to Viking orbiter results, the outer parts of the Martian pole caps consist mostly of carbon dioxide ice. This conclusion is based on the data collected by the Viking orbiter spacecraft, which observed the composition of the Martian polar caps. The presence of carbon dioxide ice is consistent with our understanding of the Martian atmosphere, which is primarily composed of carbon dioxide. Additionally, the extreme cold temperatures at the Martian poles would support the formation and preservation of carbon dioxide ice.

The given question is comparing the surface rocks on the moon with terrestrial surface rocks. The answer "older than" suggests that the surface rocks on the moon are older than terrestrial surface rocks. This implies that the moon's geological activity and processes have been occurring for a longer period of time compared to those on Earth.