ESA experts calculated there was a 1 in 1,000 chance of a collision between the two satellites occurring, as reported by Forbes. That’s a slim chance, but it was enough for the ESA to decide to intervene.

“We informed SpaceX, who replied and said that they do not plan to take action,” Holger Krag, head of the Space Debris Office at ESA, told Forbes. The SpaceX satellites should have automated collision avoidance systems, but this system was not used and it’s not clear why.

Instead, ESA’s Aeolus satellite fired its thrusters to move away from the area, half an orbit before the potential collision would have occurred. In the future, the ESA plans to automate the process of satellite collision avoidance using AI. For now though, the engineers there perform the adjustments manually.

“It is very rare to perform collision avoidance maneuvers with active satellites,” the ESA said on Twitter. “The vast majority of ESA avoidance maneuvers are the result of dead satellites or fragments from previous collisions.”

For what it’s worth, the ESA satellite occupied this particular region of space nine months before the Starlink satellite arrived. However, there are no laws about space traffic and what regions satellites can occupy. This incident highlights the need for an organized international approach to space traffic.

This is not the first controversy involving the Starlink project. Previously, astronomers complained that the launching of the satellites caused problems for telescopes. The satellites’ solar panels made them extra reflective and bright in the sky, though this was lessened once they were oriented correctly.

SpaceX also lost control of three of its Starlink satellites during the first month after launch. While these few satellites likely burned up in the atmosphere, the failure rate raised concerns about future expansions of the project. If SpaceX does launch its planned 12,000 satellites for the Starlink project, the number of lost satellites could cause problems with space debris.

Astronomers previously believed that the galaxy was made of two separate sets of stars, but exactly how or when they came together was a mystery. Using the Gaia space telescope, these researchers were able to take more precise measurements of the position, brightness and distance of roughly one million stars. They also looked at the density of “metals,” or elements without hydrogen or helium, that the stars contain. The researchers determined that both sets of stars are about the same age but that one was set into “chaotic motion,” evidence of a galaxy collision.

The researchers believe Gaia-Enceladus collided with the young Milky Way about 10 billion years ago, and over the course of millions of years, the Milky Way consumed the dwarf galaxy. The researchers also determined that the collision contributed to a four-billion-year stretch of star formation, and gas from that activity settled to form the “thin disk” that runs through the center of the Milky Way. They believe the remnants of Gaia-Enceladus eventually formed the halo of the present-day Milky Way.

According to the researchers, this information provides “unprecedented detail” about the early stages of our cosmic history. Of course, it’s not the first time we’ve heard of one galaxy consuming another. In fact, our galactic neighbor Andromeda cannibalized a nearby galaxy some two billion years ago, and it’s on track to collide with the Milky Way in the very distant future.