Test: Introduction to Earth & Universe- 2 - UPSC MCQ

The Goldilocks Zone refers to the habitable zone. The habitable zone is the area around a star where it is not too hot nor too cold for liquid water to exist on the surface of surrounding planets.

Collision among the dust particles started the process of aggregation and accretion around the bigger particles which became the embryos of the future planets.

With the passage of time these embryos captured more and more matter and thus grew in size to become asteroids which in turn grew in size due to continuous accretion of nearby matter around them and thus they became planets.

Aurora is the name given to the luminous glow in the upper atmosphere of the Earth which is produced by charged particles descending from the planet’s magnetosphere. Some of these particles penetrate the ionosphere and collide with the atoms there.

This results in an excitation of the oxygen and nitrogen molecular electrons. The molecules get back to their original state by emitting photons of light which are the aurorae.

In his theory, Kant did not explain the source of the origin of the primordial matter. He also did not explain the source of energy which caused the random motion of cold matter, which was motionless in the initial stage. The collision among the particles of the primordial matter can never generate rotatory motion in it. So it is an erroneous statement of mechanism. Kant’s assumption was against the law of conservation of angular momentum that the rotatory speed of the nebula increased with the increase of its size.

Effects of Geomagnetic storms

• The ionosphere gets heated and distorted, which makes long-range radio communication difficult.
• Ionospheric expansion can increase satellite drag, and it may become difficult to control their orbits.
• Geomagnetic storms disrupt satellite communication systems like GPS.
• Astronauts and high-altitude pilots would face high radiation levels.
• Electric power grids would see a high increase in voltage that would cause blackouts

Black hole has very high density as a result of which it has very high gravitational force. Therefore no object whether it is particle or radiation, can come out of it.

Comets are comparatively small, flimsy, erratically shaped bodies. They are the leftovers from the solar system formation. Comets are icy balls that form in the outer solar system. The icy surface is entrenched with grit, dust & particles from space.

Several comets have elliptical orbits that cut across the orbits of planets, taking them very close to the sun & then swinging them far away. The far-off comets may take more than 30 million years to complete 1 orbit.

According to the Collision Hypothesis proposed by Harold Jeffreys, there were three stars in the Universe before the origin of the solar system. primitive sun, the ‘companion star’ and the ‘intruding star’ which was moving towards ‘companion star’.