In 2005, Spitzer helped astronomers “weigh” some of these early galaxies to determine they are much heavier than expected.
The discovery shed light onto the processes by which the universe took shaped and evolved after the Big Bang.
Spitzer has also played a fundamental role in observing and studying interstellar dust – clouds of cosmic dust released by dying stars.
Often times, the dust will pool into large concentrations, pulled together by gravity, and obscure distant stars and planets from our telescopes.
The dust can even mix and condense to a point where new stars are born.
source: express.co.uk