James Webb captures galaxies as mature as the Milky Way – 02/22/2023 – Science

Observations made by NASA’s James Webb Space Telescope are changing understanding of the early universe, indicating the presence of large, mature, but remarkably compact, star-studded galaxies much earlier than scientists thought possible.

Astronomers said the data obtained by the telescope reveal what appear to be six large galaxies as mature as our Milky Way existing about 540 to 770 million years after the Big Bang explosion that started the universe 13.8 billion years ago. years. The universe was approximately 3% of its current age at the time.

These galaxies, one of which appears to have a mass rivaling our own Milky Way but 30 times more densely packed, appear to differ in fundamental ways from those that populate the universe today.

“Oh, they are radically different, truly bizarre creatures,” said astrophysicist Ivo Labbe of Swinburne University of Technology in Australia, lead author of the study published in the journal Nature.

“If the Milky Way were a regular, medium-sized adult, say, about 1.75 meters tall and 70 kilograms in weight, these galaxies would be one-year-old babies weighing the same but less than three centimeters in length. height. The early universe is a freak show.”

Webb launched in 2021 and started collecting data last year. The findings were based on the first set of data released by NASA in July last year from Webb, a telescope with infrared detection instruments capable of detecting light from stars and older galaxies.