Olympiad Test Level 1: Earth and Universe- 1 - Class 4 MCQ

Planets with no natural satellites:
- Mercury: Mercury is the closest planet to the Sun and it does not have any natural satellites.
- Venus: Venus, the second planet from the Sun, also does not have any natural satellites.
Planets with natural satellites:
- Mars: Mars has two natural satellites, Phobos and Deimos.
- Uranus: Uranus has 27 known natural satellites, including Titania, Oberon, Umbriel, Ariel, and Miranda.
- Jupiter: Jupiter, the largest planet in our solar system, has a total of 79 known natural satellites, including Ganymede, Callisto, Io, and Europa.
Explanation:
The correct answer is B: Mercury and Venus. They are the only two planets among the given options that do not have any natural satellites. Both Mercury and Venus are inner planets, closer to the Sun, and their gravitational pull is not strong enough to capture and retain natural satellites. On the other hand, Uranus and Jupiter have multiple natural satellites, and Mars has two.

The sky appears blue because of the scattering of sunlight by the gas molecules present in our atmosphere. If there was no sun, the sky would appear black because no scattering of light will take place.

In 1543, Nicolaus Copernicus detailed his radical theory of the Universe in which the Earth, along with the other planets, rotated around the Sun.

Jupiter is the biggest planet of the Solar System. It is nearly 11 times the size of the Earth.

The movement of Earth on its own axis from west to east direction is known as rotation.

Jupiter is the planet which rotates the fastest. It takes only 10 hours to complete one rotation.

Venus rotates the slowest with a single revolution equal to 243 Earth days.

There are eight planets in our solar system. These are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

These are divided into two categories: Inner Planets and Outer Planets

Inner Planets - These planets are very close to the Sun. They are made up of rocks. Mercury, Venus, Earth, and Mars are called Inner Planets.

Outer Planets - These are very far from the Sun. These are huge planets made up of gases and liquids. Jupiter, Saturn, Uranus, and Neptune are outer planets

As in given options Mars, Mercury and Venus are Inner Planets and Uranus is Outer Planet.

Mars is the fourth planet from the sun in our solar system in terms of distance from the sun.

A celestial object is a naturally occurring unit in Universe. Stars, Planets, Natural Satellites, Comets, Asteroids, etc. are examples of celestial bodies.