Page 188 - Innovator's Science-8

planet and is essential for life. You know that Earth’s gravity pulls objects
Science toward its surface. If Earth were significantly smaller (but with the same
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average density), its gravitational pull wouldn’t be strong enough to hold
Testimony
India’s Mangalyaan– the onto atmospheric gases, and they would escape into space. In fact, Mars
Mars Orbiter Mission has an atmosphere that is about 100 times thinner than Earth’s, and
launched by the Indian
Space Research Mercury has virtually none.
Organisa on (ISRO) in On the flip side, if Earth were much larger, its stronger gravity could exert so
2013— marked a
significant milestone in much force that it might cause harm to living organisms possibly even
planetary explora on. making movement difficult or dangerous for humans. Fortunately, Earth’s
Designed to study Mars’s size strikes just the right balance, allowing it to maintain a life-supporting
atmosphere, surface, and
traces of water, it raised atmosphere.
important scien fic
ques ons such as This atmosphere contains oxygen, which is essential for breathing and
whether Mars could ever supports nearly all life forms on Earth. Interestingly, some oxygen in the
have supported life. Using atmosphere transforms into ozone— a
smart, cost-effec ve
technology, Mangalyaan molecule made of three oxygen atoms. The
not only showcased ozone forms a protective layer that shields
India’s capabili es in
space science but also living organisms from the Sun’s harmful
brought the mysteries of ultraviolet (UV) rays, which can damage cells.
the Red Planet closer to
everyday people. Earth’s Magnetic Field Ozone layer
You know that a freely hanging magnet always aligns in a specific direction.
This is because Earth itself acts like a massive magnet. The space around a
magnet where its force can be felt is called a
magnetic field. Scientists believe that Earth’s

magnetic field is generated by the movement of
Science molten iron deep within its core.
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Testimony Our planet is constantly bombarded by tiny, high- S
Earth’s magne c field is energy particles from space. These include N
created deep inside the
planet by the movement cosmicrays from distant parts of the universe and
of molten iron in its outer solar wind particles emitted by the Sun. Many of
core. This slow churning these particles can be harmful they may damage
mo on acts like a giant A freely
dynamo, producing our atmosphere, thin the ozone layer, and allow hanging magnet
electric currents that dangerous UV rays to reach the surface.
generate magne c lines
of force around the Fortunately, Earth’s magnetic field serves as a protective barrier. It deflects
planet. Without this many of these harmful particles helping to preserve our atmosphere and
invisible shield, the solar
wind could strip away our safeguard life on Earth. Together with the planet’s ideal distance fror the
atmosphere – Just as it Sun, its suitable size, and its life-supporting atmosphere, Earth’s magnetic
did on Mars billions of field contributes to making it unique and habitable world.
years ago!

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