UNIVERSE
SURVEY OF THE PLANETS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
must orbit the sun
|
|
|
must be round
|
|
|
must have a clear orbit
|
|
|
must have water
|
Detailed explanation-1: -It says a planet must do three things: It must orbit a star (in our cosmic neighborhood, the Sun). It must be big enough to have enough gravity to force it into a spherical shape. It must be big enough that its gravity cleared away any other objects of a similar size near its orbit around the Sun.
Detailed explanation-2: -Pluto is a dwarf planet in the Kuiper Belt, a donut-shaped region of icy bodies beyond the orbit of Neptune.
Detailed explanation-3: -Sirius is not a planet of the Solar system. It is a star.
Detailed explanation-4: -A special planet: the habitable Earth What makes the Earth habitable? It is the right distance from the Sun, it is protected from harmful solar radiation by its magnetic field, it is kept warm by an insulating atmosphere, and it has the right chemical ingredients for life, including water and carbon.
Detailed explanation-5: -Liquid water is an essential requirement for life on Earth because it functions as a solvent. It is capable of dissolving substances and enabling key chemical reactions in animal, plant and microbial cells. Its chemical and physical properties allow it to dissolve more substances than most other liquids.