NASA telescope's 1st cosmic view goes deep
- NASA has unveiled images from the James Webb Space Telescope, the largest and most powerful orbital observatory ever launched.
The Image
- NASA released a deep field photo of a distant galaxy cluster, SMACS 0723.
- Significance: Revealed most detailed glimpse of early universe recorded to date.
- Collection also included fresh images of another galaxy cluster known as Stephan’s Quintet, first discovered in 1877.
James Webb Space Telescope
- A joint NASA–ESA–CSA space telescope planned to succeed Hubble Space Telescope as NASA’s flagship astrophysics mission
- Most powerful space telescope ever built.
Significance
- It will enable investigations in fields of astronomy and cosmology.
- Help understand events such as formation of first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets.
Dark Ages
- Universe started with Big Bang event 13.8 billion years ago, which left it in ultra-hot, ultra-dense state.
- It began expanding and cooling after Big Bang.
- Around 400,000 years after Big Bang, universe was 10 million light-years across and temperature cooled to 5,500 F (3,000 C).
- Throughout this time, space was filled with soup of high-energy particles, radiation, hydrogen and helium.
- There was no structure.
- As expanding universe became bigger and colder, soup thinned and everything faded to black.
- This was start of Dark Ages of the universe.
How will JWST study this?
- By studying first light
- Dark Ages ended when gravity formed stars and galaxies that emitted the first light.
- Astronomers aim to study this but detecting first light is challenging.
- First objects were small
- Due to constant expansion of universe, they’re very distant.
- Earliest stars were surrounded by left over gas from their formation.
- It acted like fog that absorbed most of the light.
- It took several hundred million years for radiation to blast away the fog.
- This early light is very faint by the time it gets to Earth.