Sarkari Naukri

08 December 2021 Current Affairs:Comet A1 Leonard, discovered in January 2021, will pass near the earth on 18 December 2021. 

Highlights:

• Comet A1 Leonard is a long-period comet. It was the first comet discovered in 2021 by GJ Leonard in January 2021.
• The comet will cross near the earth on 18 December 2021 as it reaches naked-eye visibility in December 2021, and It will make its closest approach to the sun in January 2022. A1 Leonard has a retrograde orbit.
• The long-period comets have eccentric orbits, as the period’s range is more significant than 200 years. 
• It is generally from thousands to even millions of years. On the flip side, the short-period comets are those whose orbital period is less than 200 years. 
• Their orbits exceed the outer planets, and short-period comets are believed to have originated from Centaurs.
• Retrograde orbit is the rotational motion of the celestial object in a direction contrary to the primary rotation. 
• The prograde orbit is the object’s motion in the same direction as its primary.