Mars
Definition
Mars is the fourth planet from the sun and the second-smallest planet in our solar system. It is a cold, dry, and dusty place with a thin atmosphere. Mars is also the only planet in our solar system besides Earth that has signs of liquid water on its surface.
Mars is a terrestrial planet, which means that it is made up of rock and metal. It is about half the size of Earth, and its gravity is only about 38% of Earth's gravity. The surface of Mars is covered in craters, volcanoes, and canyons.
The atmosphere of Mars is very thin, about 1% as thick as Earth's atmosphere. This means that there is no liquid water on the surface of Mars. However, scientists have found evidence that there may be liquid water underground.
Mars has two moons, Phobos and Deimos. Phobos is about 17 miles wide, and Deimos is about 12 miles wide. Both moons are very small and irregular in shape.
Scientists are still learning about Mars. We may one day find evidence that Mars once had life, or even that it could support life today. Mars is a fascinating planet, and it is one of the most promising places in our solar system to look for signs of life beyond Earth.
How can the word be used?
The astronauts will be travelling to Mars in the next decade.
Different forms of the word
Noun:
- The fourth planet from the sun in our solar system.
- The Roman god of war.
Adjective:
- Relating to Mars, the planet or the god.
Verb:
- To travel to or land on Mars.
Etymology
The word "Mars" comes from the Latin word "Martis", which was the name of the Roman god of war.
The word "Mars" was first used in English in the 14th century. It was originally used to describe the planet, but it soon came to be used in a more general sense to describe anything that was related to war or violence.
Question
What do you know about Mars?
AQA Science Exam Question and Answer
Question:
Discuss the geological features of Mars that suggest its past potential for liquid water and the search for signs of ancient life on the planet. How have rovers and orbiters contributed to our understanding of Mars' history and the possibility of habitability? Provide examples of key discoveries and their implications.
Answer:
Mars, the fourth planet from the Sun, has long captured the curiosity of scientists due to its potential for hosting liquid water and the possibility of ancient life. Geological features on Mars provide intriguing evidence of its watery past. Valleys, riverbeds, and the presence of ancient shorelines suggest that liquid water flowed on its surface in the past. One of the most significant discoveries is the confirmation of polar ice caps primarily composed of water ice.
Rovers and orbiters, such as the Mars rovers Spirit, Opportunity, and Curiosity, along with the Mars Reconnaissance Orbiter, have revolutionised our understanding of the Red Planet. The rovers have explored Martian terrain, discovering features like sedimentary rocks that suggest the presence of ancient lakes and rivers. Curiosity's detection of organic molecules in Martian rocks further adds to the intrigue of possible past life.
Additionally, the identification of recurring slope lineae (RSL) - seasonal dark streaks on slopes - raised questions about their origin, potentially involving salty liquid water seeping from the subsurface.
The Mars Reconnaissance Orbiter has provided detailed images of surface features, aiding scientists in deciphering the planet's history. High-resolution images of layered sediments, deltas, and alluvial fans hint at a dynamic past shaped by flowing water.
Overall, these findings suggest that Mars might have been habitable in its distant past. While the search for direct evidence of ancient life is ongoing, the combined efforts of rovers and orbiters have significantly expanded our understanding of Mars' geological history and the potential for habitability.