Free Astronomy Magazine May-June 2026

30 MAY-JUNE 2026 ASTRO PUBLISHING T his infographic summarizes the timeline of the Universe's evolu- tion, as hypothesized until a few years ago. The formation of the first stars was dated back to about 400 million years after the Big Bang. Today, thanks to Webb, we know that galaxies were already populating the Universe 280 million years after the Big Bang. To address this, scien- tists are exploring various possibili- ties. These include changes to their theories. [NASA/WMAP Science Team] ization. This is when early stars pro- duced light of high enough energy to break through the dense hydro- gen gas of the early universe and begin travelling through space, even- tually making its way to Webb, and us. Galaxy MoM-z14 provides an- other clue for mapping out the time- line of reionization, work that was not possible until Webb lifted the veil on this era of the universe. have direct information about gal- axies during that time. It turns out we are seeing some of the same fea- tures, like this unusual nitrogen en- richment,” said Naidu. With galaxy MoM-z14 existing only 280 million years after the big bang, there was not enough time for gen- erations of stars to produce such high amounts of nitrogen in the way that astronomers would expect. One theory the researchers note is that the dense environment of the early universe resulted in supermassive stars capable of producing more ni- trogen than any stars observed in the local universe. The galaxy MoM-z14 also shows signs of clearing out the thick, pri- mordial hydrogen fog of the early universe in the space around itself. One of the reasons Webb was origi- nally built was to define the timeline for this “clearing” period of cosmic history, which astronomers call reion- early universe – 100 times more than theoretical studies predicted before the launch of Webb, according to the research team. “There is a growing chasm between theory and observation related to the early universe, which presents compelling questions to be explored going forward,” said Jacob Shen, a postdoctoral researcher at MIT and a member of the research team. One place researchers and theorists can look for answers is the oldest population of stars in the Milky Way galaxy. A small percentage of these stars have shown high amounts of nitrogen, which is also showing up in some of Webb’s observations of early galaxies, including MoM-z14. “We can take a page from archeol- ogy and look at these ancient stars in our own galaxy like fossils from the early universe, except in astron- omy we are lucky enough to have Webb seeing so far that we also !