Earth has three moons

What is Important?
UPSC perspective:
Prelims :Key Highlights
Mains :Features,Significance & effects

Why in News?

A group of Hungarian scientists have confirmed a long-standing astronomical speculation; the Earth has three natural satellites or moons and not one.
  • The presence of the dust 'moons’ or Kordylewski clouds had been been inferred by researchers since long before
  • But the first glimpse of the clouds was seen only in 1961 by Polish astronomer Kazimierz Kordylewski, after whom the dust clouds were named
  • The new findings note that each Kordylewski cloud is about 15 by 10 degrees wide, or equal to 30 by 20 lunar disks in the night sky
  • They are spread over a space area that is almost nine times the width of Earth -- about 65,000 by 45,000 miles in actual size
  • The dust 'moons' are huge but they are made of tiny dust particles that barely measure one micrometre across
  • When sunlight hits the dust particles, they glow very faintly, much like the zodiacal light we receive from the dust scattered in between planetary orbits
  • Since these satellite dust clouds emit an extremely faint light, they are very difficult to find amidst the star light, sky glow, galactic light and zodiacal light in the sky though they are as close to us as the moon
  • The recent study revealing the existence of the two dust 'moons' used special polarizing filters on cameras to reveal the scattered light coming from the reflection of the individual dust particles in the clouds
Diagram showing the Lagrangian points of the Earth–Moon system. Kordylewski clouds exist in the regions of L4 and L5.

Kordylewski clouds:

The Kordylewski clouds are a very faint phenomenon, comparable to the brightness of the gegenschein. They are very difficult to observe from Earth but may be visible to the unaided eye in an exceptionally dark and clear night sky. Most claimed observations have been made from deserts, at sea, or from mountains.

What is Larger Point?

Lagrange Points are positions in space where the gravitational forces of a two body system like the Sun and the Earth produce enhanced regions of attraction and repulsion. These can be used by spacecraft to reduce fuel consumption needed to remain in position.
There are five special points where a small mass can orbit in a constant pattern with two larger masses. The Lagrange Points are positions where the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them.

Earth has three moons Earth has three moons Reviewed by The Hindu Current Affairs on November 09, 2018 Rating: 5

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