Cosmic Dawn: Unveiling the Universe’s Earliest Light
- vidyarthee2021
- Jun 14
- 2 min read
Scientists have detected a 13-billion-year-old microwave signal from the Cosmic Dawn, using the Cosmology Large Angular Scale Surveyor (CLASS) telescope in Chile's Atacama Desert. This breakthrough sheds light on the earliest phase of the universe's evolution.
What is Cosmic Dawn?
Definition: The Cosmic Dawn refers to the period between 50 million and 1 billion years after the Big Bang.
Significance: This epoch marks the formation of the first stars, black holes, and galaxies, initiating the reionization of the universe.
New Discovery: CLASS detected ancient microwave signals that provide evidence of early stellar activity and its effect on the universe’s structure.
About CLASS Telescope
Located in the Atacama Desert, Chile – ideal for clear, dry atmospheric conditions.
Designed to observe the cosmic microwave background (CMB) at large angular scales.
Helps trace polarization patterns caused by reionization and gravitational waves.
UPSC Relevance
GS Paper 3: Science and Technology – Space Technology, Astrophysics.
Useful for Prelims (CMB, Atacama Desert, Cosmic Dawn).
Relevant to GS Paper 1 (World History) when discussing the universe’s timeline and human understanding of the cosmos.
Prelims Practice Question (UPSC CSE Type)
Q. The term 'Cosmic Dawn' is often mentioned in news. It refers to:
A. The exact moment of the Big Bang.
B. The period when planets formed in the solar system.
C. The time when the first stars and galaxies formed in the early universe.
D. The epoch when the Milky Way formed its first habitable zone.
✅ Answer: C. The time when the first stars and galaxies formed in the early universe.
Explanation: Cosmic Dawn refers to the era between 50 million to 1 billion years after the Big Bang when first stars, black holes, and galaxies emerged and started influencing the cosmic environment.
Mains Practice Question (GS Paper 3)
How do recent discoveries from the Cosmic Dawn period enhance our understanding of the origin and evolution of the universe? Highlight the role of advanced telescopes like CLASS in this context.
Comments