All questions of Beyond Earth for Class 6 Exam

Option B, Revolution

Excessive artificial light from urban areas causes light pollution, making it difficult to see stars.

Stars emit their own light through nuclear fusion, while planets do not emit their own light and only reflect the Sun's light.

The IAU has defined 88 constellations to organize the night sky into distinct regions.

What is an Asteroid?
An asteroid is defined as a small rocky object orbiting the Sun. Here’s a deeper look into this fascinating celestial body:
Characteristics of Asteroids:
- Asteroids are primarily found in the asteroid belt, which is located between the orbits of Mars and Jupiter.
- They vary in size, from a few meters to hundreds of kilometers in diameter.
- Most asteroids are irregularly shaped, unlike planets that are generally spherical.
Composition:
- Asteroids are composed of various materials, including rock, metal, and sometimes even ice.
- Their composition can provide valuable insights into the early solar system and the formation of planets.
Orbiting the Sun:
- Asteroids revolve around the Sun, similar to planets, but they follow more eccentric and varied orbits.
- They do not have atmospheres, and their surfaces are often covered with craters due to collisions with other objects.
Difference from Other Celestial Bodies:
- Unlike comets, which are icy bodies with bright tails, asteroids do not exhibit tails and are primarily made of rock and metal.
- They are also distinct from natural satellites (moons), which orbit planets rather than the Sun directly.
In summary, asteroids are small rocky objects that orbit the Sun, making option 'A' the correct answer. Understanding asteroids helps us learn more about our solar system's history and formation.

Orion is easily identified by the three stars in a row that form Orion's Belt.

Natural satellites, such as the Moon, are objects that orbit a planet.

Introduction to Mars
Mars is commonly referred to as the "Red Planet" due to its distinctive reddish appearance, which is visible even from Earth. This unique coloration is primarily caused by iron oxide, commonly known as rust, covering its surface.
Characteristics of Mars
- Color and Appearance:
The surface of Mars is rich in iron, which gives it a reddish hue. This is why it stands out in the night sky.
- Surface Features:
Mars boasts the largest volcano in the solar system, Olympus Mons, and a canyon system, Valles Marineris, that dwarfs the Grand Canyon.
Atmosphere of Mars
- Thin Atmosphere:
Mars has a very thin atmosphere, composed mainly of carbon dioxide, with traces of nitrogen and argon. This makes it inhospitable for human life.
- Temperature:
The average temperature on Mars is about -80 degrees Fahrenheit (-62 degrees Celsius), making it much colder than Earth.
Exploration of Mars
- Mars Rovers and Missions:
Numerous missions have been sent to Mars, including rovers like Curiosity and Perseverance, which help scientists study its geology and search for signs of past life.
- Future Missions:
Future missions aim to explore the potential for human habitation, further enhancing our understanding of the planet.
Conclusion
Mars, or the Red Planet, continues to captivate scientists and space enthusiasts alike. Its intriguing features and potential for exploration make it a key focus in the study of our solar system.

Comets are composed of dust, ice, and gases, and form a glowing coma and tail when they approach the Sun.

The Sun is the main source of heat and light, providing the energy necessary for life on Earth.

Stellarium is a popular app that helps users identify stars, constellations, and planets using their mobile devices.

Why Nubra, Ladakh Has Bright Stars
Nubra Valley in Ladakh is renowned for its breathtaking night skies filled with countless bright stars. The visibility of these stars can be primarily attributed to minimal light pollution.
Minimal Light Pollution
- Light pollution refers to the excessive or misdirected artificial light that brightens the night sky, making it harder to see stars.
- In Nubra Valley, the population is sparse, and there are few artificial lights. This allows the natural brightness of the stars to shine through without interference.
- Areas with significant urban development, such as cities, have numerous streetlights and buildings that obscure the view of the night sky.
Altitude and Clear Skies
- Nubra Valley is situated at a high altitude, which contributes to clearer atmospheric conditions.
- The thin atmosphere at higher elevations has less dust and other particles that can scatter light, allowing for a clearer view of celestial bodies.
Natural Environment
- The region is surrounded by majestic mountains and has minimal vegetation that could obstruct the view of the sky.
- This natural environment enhances the stargazing experience, allowing for a more vivid display of stars and constellations.
Conclusion
In summary, the thousands of bright stars visible in Nubra, Ladakh, are primarily due to minimal light pollution, along with the high altitude and clear skies of the region. This unique combination creates an ideal setting for stargazing, making Nubra a remarkable destination for those who appreciate the beauty of the night sky.

Understanding the Water Cycle
The phenomenon driven by the Sun that involves the continuous movement of water on, above, and below the surface of the Earth is known as the water cycle.
Key Stages of the Water Cycle:
- Evaporation:
- Water from oceans, rivers, and lakes heats up due to the Sun's energy and transforms into water vapor, rising into the atmosphere.
- Condensation:
- As the water vapor rises, it cools and condenses to form clouds. This process is crucial for the formation of precipitation.
- Precipitation:
- When the clouds become heavy with water droplets, they release this water back to the Earth in the form of rain, snow, sleet, or hail.
- Collection:
- The precipitation collects in bodies of water like rivers, lakes, and oceans, where the cycle begins anew. Some water also seeps into the ground, replenishing groundwater supplies.
Importance of the Water Cycle:
- Supports Life:
- The water cycle is essential for all living organisms. It provides fresh water for drinking, agriculture, and sanitation.
- Climate Regulation:
- It plays a crucial role in regulating the Earth's climate by distributing heat and moisture around the planet.
- Ecosystem Balance:
- The cycle maintains the balance of ecosystems by ensuring that plants and animals have access to water.
In summary, the water cycle is a vital system driven by solar energy, ensuring the continuous movement and recycling of water, supporting life, and regulating climate.

Although the Sun is just one star among many, it appears larger because it is much closer to Earth compared to other stars.

Our Solar System is located in the Milky Way Galaxy.

The inner planets (Mercury, Venus, Earth, and Mars) are rocky with solid surfaces, while the outer planets are primarily gaseous.

A constellation is a group of stars that form a recognizable pattern, often based on mythology or stories.

Polaris, the Pole Star, remains almost stationary in the sky, making it a reliable indicator of the North direction.

The Astronomical Unit (au) is the standard unit used to express distances within our Solar System, roughly equal to the distance between the Earth and the Sun.

Ancient sailors used the stars as navigational aids to determine their direction and guide their voyages.

The Milky Way is the galaxy that contains our Solar System, composed of billions of stars and other celestial objects.

Comets consist of dust, gas, rocks, and ice. When they approach the Sun, the heat causes the ice to evaporate, creating a glowing coma and tail.