EGS - zs8 - 1 was born 670 million years after the Big Bang , during the period of reionization .
It 's 15 percent the size of the Milky Way .
EGS - zs8 - 1 was born 670 million years after the Big Bang , during the period of reionization , and it 's 15 percent the size of the Milky Way .