Context:
Recently, a study by Physics Research Laboratory (PRL) Ahmedabad points to a familiar source of zodiacal dust mystery in Mars’ 2 moons.
Zodiacal Light:
- A faint, diffuse glow of sunlight scattered by interplanetary dust particles that are present in the solar system.
- When observed from earth, light is faintly visible but it glows on completely dark nights.
- Light is present across the entire path of the ecliptic, which is the path along which the Sun moves in the sky over the course of a year.
Zodiacal Dust:
- Zodiacal dust refers to the small or fine particles of dust that moves around the solar system.
- These particles scatter the lights from the sunlight creating zodiacal light.
- These particles are scattered throughout the space between the planets, forming a relatively thin cloud known as the zodiacal cloud or zodiacal dust cloud.
- The dust is most concentrated along the ecliptic plane, which is the plane of the Earth’s orbit around the Sun.
Meteorites:
- They are solid objects originating from space that survive their passage through the Earth’s atmosphere and reach the Earth’s surface.
- They are remnants of asteroids, comets, or other celestial bodies that have not completely burned up during their entry into the Earth’s atmosphere.
Micrometeorites:
- Very small dust particles
- Weigh no more than 1/10000th of a gram
- Can move really fast, and when they do they can pack a punch
- Fall into Earth – they burn up and disintegrate in the atmosphere.
- Fall into Mar’s Moon – Since Deimos and Phobos don’t have atmospheres, most micrometeorites slam into their surfaces and kick up small clouds of dust.
Deimos and Phobos: 2 moons of mars
Phobos:
- Phobos is the bigger Deimos.
- Drifts closer to Mars at a rate of 6 feet per century.
- Cannot trap heat due to lack of atmosphere.
- Does not have spherical shape due to low gravity of Mars
- During day time temperature will be around -4 degree C but during night it drops to lower than -112 degree C.
- Reason for temperature difference – the surface of Phobos is covered with fine dust that lacks the ability to hold heat
- Expects to crash into the planet or break up into a ring around it known as dust ring.
- Contains a 10-km-wide crater – Stickney crater – as wide as the entire moon
Deimos:
- Does not have spherical shape due to low gravity of mars.
- Actual surface is buried under almost 100 metres of dust.
- Smoother appearance caused by the partial filling of some of its craters.
Source: The Hindu
Previous Year Question
Consider the following phenomena:
1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.
Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?
[UPSC Civil Services Exam – 2018 Prelims]
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d)
