The aging Hubble Space Telescope looks back into deep time, billions of years ago, before our sun was even born.

At the very limits of Hubble's viewing abilities lies a cluster of spiraling, disk-shaped galaxies, collectively called SPT0615. NASA posted an image of these ancient structures, one of which was born over 13 billion years ago, relatively soon after the Big Bang likely created the universe. Light left these faraway galaxies long ago, but Hubble can sleuth out this ancient luminosity.

"The light from distant objects travels to us from so far away that it takes an immensely long time to reach us, meaning that it carries information from the past — information about the time at which it was emitted," NASA wrote.

Galaxy cluster SPT0615. Image: ESA / Hubble NASA / I. Karachentsev et al., F. High et al.

Viewing these galaxy clusters is an eerie look at events that transpired long ago. But it's something the space agency's astronomers do every day.

"Just as ancient paintings can tell us about the period of history in which they were painted, so too can ancient galaxies tell us about the era of the universe in which they existed," NASA wrote.