James Webb Telescope

 

Today December 25th an Ariane Rocket would shoot into space in French Guiana up into the rarefied atmosphere 1.5 million KM from earth 3 times distance to moon to reach the L2 or Lagrange point 2 in order to place the JAMES WEBB TELESCOPE prescisely at that point .

There are three Lagrange points in our orbit around sun .

The reason for James Webb telescope  a follow up of internationally known Hubble Telescope is not replacement but improvement .

James Hubb is bigger and smarter than Hubble .

While Hubble is more closer to earth it detects visible light rays and some infra red signals while James webb only detects infrared signals which cannot be seen by naked eye .

The reason is older stars in galaxies emanate and can be studied by their infra red signals as these signals are weaker than light waves hence are from the earliest galaxies .

Otherwise these signals cannot be recieved in say a Hubble as its more in visible wave length 

Definitely not from a telescope on earth as the atmosphere is like an opaque shield but the James webb so far out in the orbit can catch infra red rays from the begginobg of time when the earliest galaxies wele formed 96 million years back 

Just think light @ speed of 160000 km per second travelling 96 million years caught by a telescope up in orbit sent from earth by humans now isnt that mind boggling .

Of course astronomers have a better scale of some 23 zeros 

One light year is distance travelled by light in one year @ 160000 km per second which is approximately 6 trillion miles

Which is average distance between sun and earth .

James webb was an administrator in NASA and was involved in APPOLO 11 project ,the telescope is named aftrr him .

It was initially planned in 1996 and is ajoint collabration of NASA ,European and Canadian space agencies .

It weighs around 6000 kg though smaller than Hubble its 18 hexagonal Gold plated Berrylium mirrors is 6.5 mts or 21 feet is larger than Hubbles mirror of 2.5 mts .

Its kept folded in launch ,and once placed in orbit unfurled in steps it takes more than 6 months to be deployed .

It has a tennis court sized sun shield as its position nearer to sun can destroy its delicate parts by heat  and it has to be at a temp of - 379 degree celsius which is why its at the L2 point where its always under earths and moons shadow where they are like an umbrella to the telescope .

If not the heat emitted infrared rays would be absorbed from sun  instead of from a distant galaxy .

It would take 6 months for the Ariane rocket to be placed in orbit .

Hubble is at 550 km from earth while James Webb at 400000 km so it would be impossible to make any repairs in Webb as in Hubble .