Why is it in news?

NASA scientists have spotted the farthest known galaxy in the universe, a primitive cluster of stars just 500 million years old.

Details

• An intensive survey deep into the universe by NASA’s Hubble and Spitzer space telescopes has yielded the image of the galaxy named SPT0615-JD, stretched and amplified by a phenomenon called gravitational lensing.
• Though a few other primitive galaxies have been seen at this early epoch, they have essentially all looked like red dots given their small size and tremendous distances. However, in this case, the gravitational field of a massive foreground galaxy cluster not only amplified the light from the background galaxy but also smeared the image of it into an arc. No other candidate galaxy has been found at such a great distance that also gives us the spatial information that this arc image does.
• By analysing the effects of gravitational lensing on the image of this galaxy, its actual size and shape can be determined.
• First predicted by Albert Einstein a century ago, the warping of space by the gravity of a massive foreground object can brighten and distort the images of far more distant background objects. Astronomers use this “zoom lens” effect to go hunting for amplified images of distant galaxies that otherwise would not be visible with today’s telescopes.

Source

Livemint