system
Given the following post, respond as if you're commenting on Reddit:
human
Parade of low-earth-orbit satellites?

About an hour after sunset, my son and I just saw about 30 lights moving across the sky that looked exactly like LEO satellites (we’ve watched the ISS pass over before, so we know what to look for).  These were not airplanes. 

What was notable was the sheer number — about 30 in groups of 3-5 over about 12 minutes — but even more so, *they were all traveling in the exact same line about 40 degrees above the northwestern horizon here at 37 degrees north latitude, in the same direction (~ ENE) at the same speed.*

What gives?
gpt
You've most likely seen the Starlink satellites being deployed by SpaceX. Their goal is to deploy a large set of satellites (up to 12,000) to provide broadband internet access around the world.

These satellites are being deployed in batches by the SpaceX Falcon 9 rocket. The Falcon 9 carries the satellites into a low orbit, after which the satellites boost themselves into their final orbital spot.

In the period following deployment, all satellites in a batch will be close together in a line, but as time passes the line will start to break up and the satellites become dimmer as they spread out and boost to higher orbits.

You and your son likely saw the batch that was launched 10 days ago, already separated into multiple groups. If you observe the satellites shortly after launch, you can see them in one single parade line. The next launch is scheduled 3 days from now (weather permitting), so consider doing some stargazing next week to see if you can spot the satellite parade before it breaks up.