Test: Earth & Its Natural Satellites - Class 5 MCQ

The ozone layer, which is made up of ozone (O₃), is the primary component of the Earth's atmosphere that protects us from harmful ultraviolet rays emitted by the sun.
It absorbs most of the sun's harmful radiation, preventing it from reaching the Earth's surface.

The crust is the outermost layer of the Earth and is composed mainly of solid rock.
It is where all the continents and oceans are located, making it the layer where we live.

The thickness of the Earth's crust varies significantly: it can be about 5 kilometers thick beneath the ocean floor and up to 70 kilometers thick under the continents.
This variation is due to the geological processes that shape the Earth's surface.

The outer core of the Earth is primarily composed of liquid iron and nickel, while the inner core is a solid ball mainly made of iron.
This composition plays a crucial role in generating the Earth's magnetic field.

The gravitational pull of the Moon causes ocean tides by pulling water towards it, resulting in high and low tides.
The Sun also influences tides, but the Moon has a more significant effect.

A lunar eclipse occurs when the Earth is positioned directly between the Sun and the Moon, casting a shadow on the Moon.
This can result in a total or partial lunar eclipse depending on the alignment of the three celestial bodies.

Apollo 11 was the first spacecraft to land on the Moon on July 21, 1969, carrying astronauts Neil Armstrong, Edwin Aldrin, and Michael Collins.
This historic mission marked a significant achievement in human space exploration.

The Moon takes about 30 days to complete one orbit around the Earth.
This period includes the different phases of the Moon that we observe from Earth.

Spring tides occur when the Earth, Moon, and Sun are aligned, resulting in higher high tides and lower low tides.
This alignment typically happens during the full moon and new moon phases.

Sputnik 1 was the first artificial satellite launched by the Soviet Union on October 4, 1957.
This event marked the beginning of the space age and the start of satellite technology.

Weather satellites are primarily used to forecast the weather and provide early warnings for storms and cyclones.
They capture images and data about atmospheric conditions from space.

The innermost layer of the Earth is called the inner core, which is primarily solid and composed mostly of iron.
This layer is extremely hot and under immense pressure.

Craters on the Moon are primarily formed by the impact of meteoroids striking its surface.
These impacts create depressions and can vary in size from small to large.

The Sun is primarily composed of hydrogen, which undergoes nuclear fusion in its core to produce helium and release energy.
This process is what powers the Sun and provides light and heat to our solar system.

Artificial satellites are man-made objects designed to orbit around the Earth for various purposes, such as communication, weather forecasting, and scientific research.
This capability allows them to gather data from a unique perspective.

A solar eclipse occurs when the Moon is positioned directly between the Sun and the Earth, blocking sunlight from reaching the Earth's surface.
This can create a total or partial eclipse depending on the alignment and distance of the Moon.

Chandrayaan-1 was India's first spacecraft to reach the Moon, launched on October 22, 2008.
This mission was significant for its role in studying the Moon's surface and contributing to lunar science.

The dark areas on the Moon's surface are known as maria (singular: mare), which are large, flat plains formed by ancient volcanic eruptions.
These areas contrast with the lighter highlands of the Moon's surface.

The Moon takes approximately the same amount of time to rotate on its axis as it does to revolve around the Earth, which is about 27.3 days.
This synchronous rotation is why we always see the same side of the Moon from Earth.