Type: Prelims Only

Why in the News?

• Scientists long believed that volcanic activity on the moon ceased about a billion years ago.
  • However, a study based on China’s Chang’e-5 mission samples has questioned this belief with evidence suggesting the moon had active volcanoes as recently as 120 million years ago.

What are the Beads on the Moon?

• Lunar glass beads are small, spherical or egg-shaped glass particles found on the moon’s surface.
• These beads are formed in two main ways:

• • Volcanic Activity: During volcanic eruptions, molten lava fragments are thrown into the air, where they cool rapidly and form glass beads.
  • Impact Events: When asteroids or meteorites hit the moon’s surface, the intense pressure and heat melt the surface material. The molten material cools quickly, forming glass beads as it lands back on the surface.

• These beads are important because they:

• • Provide clues about the moon’s geological history.
  • Help scientists determine the age of volcanic eruptions.
  • Offer insights into the formation of the moon’s surface and its volcanic and impact events.

Key characteristics of Lunar Glass Beads

• Composition: These beads are primarily made of silicon, magnesium, and iron, with trace amounts of other elements such as potassium, titanium, and uranium.
• Volcanic vs. Impact Beads: Volcanic glass beads tend to be more uniform, while impact beads may show fractures or deformations caused by high-energy impacts. Volcanic beads often contain more volatile elements like sulphur, which are released during eruptions.

Why in the News?

Starlink satellites, operated by Elon Musk’s SpaceX, are causing issues for astronomers by disrupting both optical and radio astronomy due to unintended electromagnetic radiation (UEMR).

What is a Starlink Satellite?

• Starlink satellites are part of a network created by Elon Musk’s SpaceX to provide high-speed internet to remote areas around the world.
• The network, known as a satellite constellation, currently includes more than 6,300 satellites orbiting Earth at around 550 km altitude.
• These satellites aim to offer internet connectivity to places that would otherwise lack access, especially in rural or underserved regions.

What Starlink does to Space Communications?

• Starlink satellites are designed to improve global internet access, especially in hard-to-reach places, by transmitting signals from space.
• However, these satellites also emit unintended electromagnetic radiation (UEMR), which causes radio noise that disrupts radio astronomy observations.
• The situation may worsen as more satellites are launched — some estimates suggest 100,000 satellites could be orbiting Earth by 2030.
• There are currently no regulations controlling how much radio pollution these satellites can emit, making it harder for astronomers to mitigate the impact on their work.