Thirty-five years ago, our Cosmic Background Explorer, or COBE, was launched! The satellite was a crucial stepping stone in understanding the cosmic microwave background — the afterglow of the earliest moments of our universe.

Launched from what’s now Vandenberg Space Force Base on Nov. 18, 1989, COBE carried three instruments to space to measure microwave and infrared light across the whole sky. COBE’s observations helped us learn how our universe started and evolved.

COBE discovered that the oldest light in the universe contained tiny temperature variations (red indicates hotter regions, blue colder). These were the seeds for the gravitational formation of structures of galaxies seen in the universe today.

S James Webb Space Telescope: + There are still many questions we want to answer about the early universe, and our missions continue to study it and refine our understanding.

With billions of stars in the Milky Way, some nomenclature standardization is necessary.

By Phil Plait edited by Lee Billings.

New studies led by researchers at the University of Central Florida offer for the first time a clearer picture of how the outer solar system formed and evolved based on analyses of trans-Neptunian objects (TNOs) and centaurs.

The findings, published today in Nature Astronomy, reveal the distribution of ices in the early solar system and how TNOs evolve when they travel inward into the region of the giant planets between Jupiter and Saturn, becoming centaurs.

TNOs are small bodies, or “planetesimals,” orbiting the sun beyond Pluto. They never accreted into planets, and serve as pristine time capsules, preserving crucial evidence of the molecular processes and planetary migrations that shaped the solar system billions of years ago. These solar system objects are like icy asteroids and have orbits comparable to or larger than Neptune’s orbit.