GOLDILOCKS ZONE OF HABITABILITY
- February 28, 2021
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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GOLDILOCKS ZONE OF HABITABILITY
Subject: Science & tech
Context: One thing that astronomers search for in exoplanets, in the so-called Goldilocks zone of habitability, is the existence of liquid water and an atmosphere like that on Earth.
Concept:
- In this context it is believed by many that Mars once had such an atmosphere. The mechanism as to why it lost its atmosphere has remained in doubt.
- Scientists from Indian Institution for Science Education and Research (IISER) Kolkata suggest that it was the planet’s intrinsic magnetic dynamo which, by shielding its atmosphere from the sun’s solar wind, protected its atmosphere.
- When the magnetic dynamo switched off, the atmosphere slowly was eroded by the solar wind and eventually vanished, leaving the thin remnant we see today.
Goldilocks Zone
- A habitable zone, also called the “Goldilocks zone”, is the area around a star where it is not too hot and not too cold for liquid water to exist on the surface of surrounding planets.
- Our Earth is in the Sun’s Goldilocks zone. If Earth were where the dwarf planet Pluto is, all its water would freeze; on the other hand, if Earth were where Mercury is, all its water would boil off.
- Life on Earth started in water, and water is a necessary ingredient for life as we know it.
- So, when scientists search for the possibility of alien life, any rocky exoplanet in the habitable zone of its star is an exciting find.
Does it mean a Planet in the Goldilocks Zone Bound to Have Liquid Water?
- No, not necessarily.
- If we look into our own planetary system, both Venus and Mars are also in the Goldilocks zone. But, water is nowhere to be seen on these planets.
- On Venus, a catastrophic greenhouse effect is in play that is heating up the planet and presumably evaporated all the water it held.
- On Mars, lack of an atmosphere and a magnetic field is bombarded by the solar particles which have evaporated the water present on it.
- Thus, being present in a goldilocks zone does not guarantee the availability of water on a planet.
- But make them potential targets for astronomers to explore and determine the presence of water through various other methods.