The galaxy cluster appears hotter and more mature than it should for its young age, challenging what we think we know about how these cities of galaxies form.
One of the critical aspects of exoplanet habitability is the long-term stability of the stars they orbit. Some stars are extremely massive and blast through their hydrogen fuel in only a few million years. Rigel, the blue supergiant in Orion, is an example of one of these. It will shine for only about 10 million years. That's not much time for life to arise on planets.

