All questions of Beyond Earth for Class 6 Exam

Option B, Revolution

Our Solar System is located in the Milky Way Galaxy.

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

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

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

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

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.

Understanding Venus' Visibility
Venus, often referred to as the "Evening Star" or "Morning Star," is one of the brightest objects in the night sky. Its visibility throughout the year can be attributed to its position relative to the Earth and the Sun.
Why Venus is Visible at Dawn or Dusk
- Orbit and Position: Venus orbits the Sun at a distance closer than Earth. This means that it is often situated between the Earth and the Sun, making it visible during certain times of the day.
- Phases of Venus: Similar to the Moon, Venus goes through phases. During its cycle, it can be seen just before sunrise (dawn) or just after sunset (dusk), depending on its position in its orbit.
- Brightness: Venus reflects sunlight effectively, making it exceptionally bright, which contributes to its visibility at these times.
Comparison with Other Times
- Midnight: At midnight, Venus is usually on the opposite side of the Sun, making it difficult to observe.
- Noon: During midday, the Sun's brightness overshadows Venus, rendering it invisible to the naked eye.
- Throughout the Day: Although Venus can occasionally be seen during the day, it is not consistently visible due to the Sun's glare.
Conclusion
In summary, Venus can be observed most of the year primarily at dawn or dusk, making option 'C' the correct choice. Its unique position in the solar system allows it to shine brightly during these times, captivating skywatchers around the globe.