The Mystery Of Mars

Carbon dioxide and oxygen are both gases found on Earth. Carbon dioxide is a greenhouse gas that is produced by various natural processes and human activities, while oxygen is essential for supporting life. Both gases play important roles in the Earth's atmosphere and are involved in various chemical reactions and cycles.

The correct answer is "Life on Earth is protected by the atmosphere." The Earth's atmosphere acts as a protective shield, shielding the planet from harmful solar radiation, extreme temperatures, and the vacuum of space. It also helps regulate temperature, provides oxygen for respiration, and filters out harmful ultraviolet radiation. Without the atmosphere, life as we know it would not be possible on Earth.

Water cannot exist as a liquid on Mars because the atmospheric pressure is too low. The low pressure causes the boiling point of water to be significantly lower than on Earth, which means that any liquid water would quickly evaporate and turn into vapor. Additionally, the extremely cold temperatures on Mars would cause any liquid water to freeze into ice. Therefore, water can only exist on Mars as either ice or vapor.

Mars is missing the air and water that would make it a livable place. This is because air and water are essential for supporting life as we know it. Without a breathable atmosphere and liquid water, it would be impossible for humans and most other organisms to survive on Mars.

The correct answer is a protective layer of air. The earth's atmosphere acts as a shield, protecting the planet from harmful solar radiation and providing a stable climate for life to thrive. It consists of various gases, such as nitrogen, oxygen, and carbon dioxide, which help regulate temperature, maintain air pressure, and support living organisms through the process of respiration. This protective layer also plays a crucial role in preventing the escape of water vapor and other essential gases into space, ensuring the sustainability of Earth's ecosystems.

The Sojourner moved around on six wheels that were at the end of flexible legs. This allowed it to navigate the rough terrain of Mars and maintain stability. The flexibility of the legs also allowed for better maneuverability and adaptation to different surface conditions.

The correct answer is that Earth has liquid water and Mars does not. This is a valid contrast because liquid water is a key characteristic of Earth, supporting the existence of life, while Mars is known to have frozen water but not liquid water on its surface.

Pathfinder carried Sojourner.

The little robot was called a "geologist" because it studies rocks and earth. Geologists are scientists who specialize in understanding the composition, structure, and history of the Earth's materials. They study rocks, minerals, and the processes that shape the Earth's surface, such as volcanoes, earthquakes, and erosion. The term "geologist" is commonly used to describe professionals who work in this field, but it can also refer to a robot designed specifically for studying rocks and earth.

An astronaut on Mars would need a spacesuit because the air is so thin. The atmosphere on Mars is much thinner than Earth's, with only about 1% of the atmospheric pressure. This means that there is not enough oxygen for humans to breathe and the lack of pressure would cause fluids in the astronaut's body to boil. Therefore, a spacesuit is necessary to provide a controlled environment with oxygen, temperature regulation, and pressure to keep the astronaut safe and alive on Mars.

Scientists guided the Viking and Pathfinder landers to gently rolling Martian plains because they wanted to avoid the risk of landing them on dangerous terrains such as the edge of a cliff or the side of a volcano. By choosing the plains, they ensured a safer landing for the landers, minimizing the chances of damage or failure.

The scientists heated samples of soil from Mars to observe if any gases were released. This was done to determine if organic molecules, which are the building blocks of life, were present in the soil. Organic molecules can release certain gases when heated, and detecting these gases would provide evidence of the existence of organic compounds on Mars.

Interplanetary dust refers to the dust particles that are found in space. These particles are typically remnants of comets, asteroids, or other celestial bodies. They are scattered throughout the solar system and can be found between planets, orbiting the Sun. Interplanetary dust plays a crucial role in various astronomical phenomena, such as the formation of planets and the creation of meteor showers. It is not limited to being visible only at night or being located at the center of planets.

A meteorite is a small body that flew through space. Meteorites are remnants of asteroids or comets that have survived their journey through Earth's atmosphere and landed on the surface. They are composed of various materials such as rock, metal, and sometimes even organic compounds. Scientists study meteorites to gain insights into the formation and composition of celestial bodies, including Mars.

The word "organic" in this sentence means "with carbon". Organic molecules are those that contain carbon atoms and are typically found in living organisms. This term distinguishes them from inorganic molecules, which do not contain carbon.