All questions of Earth and its Natural Satellites for Class 5 Exam

There are 8 planets in solar system excluding Pluto.first is mercury,second is Venus.lke this is given below
mercury
Venus
earth
Mars
Jupiter
Saturday
Uranus
Neptune

The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at 0.1654 g, with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density.

The Moon orbits Earth at an average distance of 384,400 km (238,900 mi), or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period of 29.5 days, the amount of visible surface illuminated by the Sun varies from none up to 100%, resulting in lunar phases that form the basis for the months of a lunar calendar. The Moon is tidally locked to Earth, which means that the length of a full rotation of the Moon on its own axis causes its same side (the near side) to always face Earth, and the somewhat longer lunar day is the same as the synodic period. However, 59% of the total lunar surface can be seen from Earth through cyclical shifts in perspective known as libration.

The most widely accepted origin explanation posits that the Moon formed 4.51 billion years ago, not long after Earth, out of the debris from a giant impact between the planet and a hypothesized Mars-sized body called Theia. It then receded to a wider orbit because of tidal interaction with the Earth. The near side of the Moon is marked by dark volcanic maria ("seas"), which fill the spaces between bright ancient crustal highlands and prominent impact craters. Most of the large impact basins and mare surfaces were in place by the end of the Imbrian period, some three billion years ago. The lunar surface is fairly non-reflective, with the reflectance of lunar soil being comparable to that of asphalt. However, due to its large angular diameter, the full moon is the brightest celestial object in the night sky. The Moon's apparent size is nearly the same as that of the Sun, allowing it to cover the Sun almost completely during a total solar eclipse.

Both the Moon's prominence in Earth's sky and its regular cycle of phases have provided cultural references and influences for human societies throughout history. Such influences can be found in language, calendar systems, art, and mythology. The first artificial object to reach the Moon was the Soviet Union's uncrewed Luna 2 spacecraft in 1959; this was followed by the first successful soft landing by Luna 9 in 1966. The only human lunar missions to date have been those of the United States' Apollo program, which landed twelve men on the surface between 1969 and 1972. These and later uncrewed missions returned lunar rocks that have been used to develop a detailed geological understanding of the Moon's origins, internal structure, and subsequent history. The Moon is the only celestial body visited by humans.

Hottest part of the sun is the Core.

Core of the Sun:
- The core of the Sun is the innermost layer of the Sun.
- It is the hottest part of the Sun.
- The temperature in the core is about 15 million degrees Celsius.
- At this temperature, nuclear fusion occurs, which is the process of combining hydrogen atoms to form helium atoms.
- This process releases a tremendous amount of energy in the form of light and heat.
- The energy is then transported to the other layers of the Sun through a process called radiation.

Atmosphere, Corona, and Mantle:
- The atmosphere of the Sun is the outermost layer and is the least hot part of the Sun.
- The corona is the outermost layer of the atmosphere and is hotter than the atmosphere.
- The mantle is the layer between the core and the atmosphere and is also cooler than the core.

GSAT-3, also known as EDUSAT, was a communications satellite which was launched on 20 September 2004 by the Indian Space Research Organisation. EDUSAT is the first Indian satellite built exclusively to serve the educational sector. It is mainly intended to meet the demand for an interactive satellite-based distance education system for the country.

EDUSAT carries five Ku band transponders providing spot beams, one Ku band transponder providing a national beam and six extended C band transponders providing national coverage beams.

EDUSAT was successfully launched into a Geosynchronous Transfer Orbit (GTO) on the first operational launch of the Geosynchronous Satellite Launch Vehicle, which flew from the First Launch Pad at the Satish Dhawan Space Centre in Sriharikota. EDUSAT was initially placed into a transfer orbit with a perigee of 180 kilometres (110 mi) and an apogee of 35,985 kilometres (22,360 mi) and a period of 10.5 hours, inclined at 19.2 degrees to the equator.

EDUSAT was decommissioned in September 2010 and relocated to a graveyard orbit.

Fault

A fault is a break or fracture in the Earth's crust where tectonic plates come into contact with each other. It is a type of geological feature that occurs due to the movement and interaction of these massive plates. Faults play a significant role in shaping the Earth's surface and are responsible for earthquakes and the formation of mountains.

Types of Faults

There are three main types of faults:

1. Normal Fault: A normal fault occurs when the hanging wall (the block of rock above the fault) moves downward relative to the footwall (the block of rock below the fault). This type of fault is commonly associated with tensional forces, where the crust is being pulled apart.

2. Reverse Fault: A reverse fault occurs when the hanging wall moves upward relative to the footwall. It is caused by compressional forces, where the crust is being pushed together.

3. Strike-Slip Fault: A strike-slip fault occurs when the blocks of rock move horizontally past each other, with very little vertical movement. This type of fault is associated with shear forces, where the crust is being pushed in opposite directions.

Earthquakes and Faults

Faults are closely related to earthquakes. When the stress on a fault exceeds the strength of the rocks, it causes them to rupture, resulting in an earthquake. The release of energy during an earthquake causes the ground to shake and can lead to the destruction of buildings and infrastructure.

The movement along a fault can occur gradually over time, known as aseismic creep, or it can be sudden and release a large amount of energy, resulting in a seismic event. The point within the Earth where the earthquake originates is called the hypocenter or focus, while the location on the surface directly above it is called the epicenter.

Impact on Landforms

Faults also play a crucial role in the formation of mountains. When tectonic plates collide, the rocks get pushed together, causing them to buckle and fold. The pressure can build up to a point where the rocks along the fault break, and one block moves relative to the other. This movement uplifts the crust, creating a mountain range.

Conclusion

In summary, faults are breaks or fractures in the Earth's crust where tectonic plates interact. They are responsible for earthquakes, the formation of mountains, and the shaping of the Earth's surface. Understanding faults and their movements is essential for studying the dynamic nature of our planet and mitigating the risks associated with earthquakes.

Introduction:
The day when we cannot see the moon in the sky is called a "New Moon Day." It is an important concept in astronomy and occurs approximately once a month.

Explanation:
New Moon:
- A new moon occurs when the moon is positioned between the Earth and the Sun, with the side of the moon facing the Earth being completely dark.
- During this phase, the illuminated side of the moon is not visible from Earth because the sunlight is only reaching the side facing away from us.
- As a result, the moon appears to blend in with the dark night sky, making it invisible to the naked eye.

Phases of the Moon:
- The moon goes through different phases as it orbits around the Earth.
- The four main phases of the moon are the new moon, first quarter, full moon, and third quarter.
- These phases occur due to the changing positions of the moon, Earth, and Sun.

Full Moon Day:
- A full moon occurs when the moon is on the opposite side of the Earth from the Sun, and its entire illuminated side is visible from Earth.
- On a full moon day, the moon appears as a complete circle in the sky.
- This phase is often associated with cultural and religious festivals in various parts of the world.

Crescent Moon Day and First Quarter Moon Day:
- A crescent moon occurs when only a small part of the illuminated side is visible, appearing as a thin sliver or crescent shape.
- The first quarter moon occurs when half of the illuminated side is visible, resembling a semi-circle.
- These phases are different from a new moon day because they involve some visibility of the illuminated side.

Conclusion:
In summary, the day when we cannot see the moon in the sky is called a "New Moon Day." It occurs when the moon is positioned between the Earth and the Sun, causing the illuminated side to face away from us. On this day, the moon appears invisible as it blends in with the dark night sky.

Corona
The thin layer of air around the sun is called the corona. The corona is the outermost layer of the sun's atmosphere and is composed of extremely hot ionized gas. It is only visible during a total solar eclipse when the moon blocks out the bright light of the sun, allowing the fainter corona to be seen.

Characteristics of the Corona:
- The corona has a temperature of over a million degrees Celsius, much hotter than the surface of the sun.
- It extends millions of kilometers into space and is most easily seen during a total solar eclipse when it forms a beautiful halo around the sun.

Importance of the Corona:
- Studying the corona is important for understanding solar phenomena such as solar winds, solar flares, and coronal mass ejections.
- The corona plays a crucial role in the sun's magnetic field and influences space weather around the Earth.

Observing the Corona:
- Scientists use specialized instruments like coronagraphs to observe the corona without the need for a total solar eclipse.
- Space missions like NASA's Solar and Heliospheric Observatory (SOHO) provide valuable data on the corona's behavior and dynamics.
In conclusion, the corona is a fascinating and important part of the sun's atmosphere, and studying it helps us better understand the sun and its impact on our solar system.

Artificial Satellite:
An artificial satellite is a human-made spacecraft that orbits around the Earth. These satellites are launched into space to perform various functions such as communication, weather forecasting, navigation, Earth observation, and scientific research.

Key Points:
- Artificial satellites are different from natural satellites, which are celestial bodies like the moon that orbit around the Earth.
- They are designed and built by humans to serve specific purposes based on the type of satellite.
- Artificial satellites can be placed in different orbits depending on their intended function, such as low Earth orbit (LEO), geostationary orbit (GEO), or polar orbit.
- They are equipped with various instruments and technology to carry out their tasks, such as cameras, sensors, antennas, and communication systems.
- Artificial satellites play a crucial role in modern society by enabling global communication, weather monitoring, GPS navigation, disaster management, and scientific research.
In conclusion, artificial satellites are essential tools that provide a wide range of benefits to humanity by enabling us to gather information, communicate, and navigate efficiently on a global scale.

Use of Remote Sensing Satellites:
Remote sensing satellites have various uses, but one of the primary purposes is to take photographs of the earth. Let's delve into the details of how these satellites are utilized for this purpose.
Monitoring Earth's Surface:
- Remote sensing satellites are equipped with sensors that capture images of the Earth's surface.
- These images provide valuable information about land cover, vegetation, urban development, and more.
- Scientists and researchers use these images to monitor changes in the environment over time.
Weather Forecasting:
- Remote sensing satellites also play a crucial role in forecasting the weather.
- By capturing images of clouds, storm systems, and other weather patterns, these satellites help meteorologists predict weather conditions accurately.
- This information is vital for issuing warnings and ensuring public safety.
Disaster Management:
- Remote sensing satellites are instrumental in disaster management efforts.
- They provide real-time images of areas affected by natural disasters, such as hurricanes, wildfires, and earthquakes.
- These images help authorities assess the extent of damage and plan rescue and relief operations effectively.
Environmental Monitoring:
- Remote sensing satellites contribute to environmental monitoring and conservation efforts.
- By capturing images of forests, oceans, and other ecosystems, these satellites help track changes in biodiversity and detect environmental degradation.
- This information is essential for implementing sustainable resource management strategies.
Conclusion:
In conclusion, while remote sensing satellites have various applications, including studying outer space and transmitting communication signals, their primary use is to take photographs of the Earth. These images serve multiple purposes, from monitoring the environment to forecasting weather and managing disasters effectively.

Importance of Weather Satellites:
Weather satellites play a crucial role in forecasting the weather accurately and providing valuable information to meteorologists. Below are some key points explaining the importance of weather satellites:

1. Forecasting Weather:
Weather satellites help in monitoring weather patterns, such as hurricanes, storms, and other severe weather conditions. They provide real-time images of the Earth's atmosphere, enabling meteorologists to track weather systems and predict their movement.

2. Early Warning Systems:
By continuously monitoring the Earth's atmosphere, weather satellites can detect and track developing weather systems, allowing for early warnings to be issued for potential hazards like severe storms, tornadoes, and floods.

3. Climate Research:
Weather satellites also play a crucial role in climate research by providing data on long-term weather patterns, changes in the Earth's climate, and the impact of human activities on the environment.

4. Agricultural Planning:
Farmers and agricultural experts use weather satellite data to monitor crop conditions, predict weather patterns, and plan agricultural activities such as planting, irrigation, and harvesting.

5. Aviation and Maritime Safety:
Weather satellites provide critical information to pilots, ship captains, and air traffic controllers to ensure the safety of aviation and maritime operations. They help in planning flight routes, avoiding severe weather conditions, and ensuring smooth operations.
In conclusion, weather satellites are essential tools for monitoring and forecasting the weather, providing valuable data for various sectors like agriculture, transportation, and disaster management. Their role in ensuring public safety and supporting scientific research makes them indispensable in today's world.

The Thickness of the Earth's Crust
The Earth's crust is the outermost layer of the Earth and plays a crucial role in supporting life on our planet. It is divided into two types: continental crust and oceanic crust.

Thickness of the Crust
The average thickness of the Earth's crust varies depending on whether it is continental or oceanic. The continental crust is thicker than the oceanic crust.

Option B: 70 km
The correct answer to the question is option B, which states that the thickness of the Earth's crust is 70 km. This measurement is an average value and can vary in different regions of the Earth.

Continental vs. Oceanic Crust
- Continental crust is thicker, ranging from 30 to 50 km beneath the continents.
- Oceanic crust is thinner, averaging around 5 to 10 km beneath the ocean basins.

Importance of Crust Thickness
The thickness of the Earth's crust is important for understanding the geology of the planet, including tectonic plate movements, volcanic activity, and the formation of mountains. Scientists study the crust to learn more about the Earth's history and the processes that shape its surface.

Full Moon:
The full moon is the moon phase where the entire side facing us gets sunlight, and we can see the entire moon. This happens when the moon is directly opposite the sun in the sky, with Earth in between.

Explanation:
- During a full moon, the sun's light shines directly onto the entire side of the moon that faces us, making it appear fully illuminated.
- This is the best time to view the moon as it is bright and easy to see in the night sky.
- The full moon rises at sunset, reaches its highest point in the sky around midnight, and sets at sunrise.

Characteristics of a Full Moon:
- The moon appears as a complete circle in the sky.
- It is the brightest phase of the moon.
- Full moons occur every 29.5 days.
In conclusion, the full moon is a beautiful and fascinating sight in the night sky. It is a time when the entire side of the moon facing us is illuminated by the sun, creating a stunning celestial display.

Understanding the Moon's Phases
The appearance of the Moon changing shape every day is primarily due to its orbit around the Earth. This phenomenon is known as the lunar phases.
Why Does the Moon Change Shape?
- The Moon does not produce its own light; instead, it reflects sunlight.
- As the Moon orbits the Earth, different portions of its surface are illuminated by the Sun.
The Moon's Orbit
- The Moon takes approximately 29.5 days to complete one orbit around the Earth.
- As it moves, we see varying parts of the illuminated side, leading to different phases.
The Phases of the Moon
- New Moon: The Moon is positioned between the Earth and the Sun, making it invisible.
- Waxing Crescent: A small sliver of the Moon becomes visible as it starts to move away from the Sun's direct line.
- First Quarter: Half of the Moon is illuminated.
- Waxing Gibbous: More than half the Moon is visible as it approaches a full moon.
- Full Moon: The entire face of the Moon is illuminated.
- Waning Gibbous: The light starts to decrease after the full moon.
- Last Quarter: Again, half of the Moon is illuminated but on the opposite side.
- Waning Crescent: Only a small sliver is visible before returning to a new moon.
Conclusion
The changing shapes of the Moon, or its phases, result from its revolution around the Earth. As the Moon orbits, we see varying amounts of its illuminated surface, creating the beautiful cycle of lunar phases we observe in the night sky.