Notices by Prof. Sam Lawler (sundogplanets@mastodon.social), page 2

The blizzard is going to start with a few hours of "freezing rain mixed with snow." It just keeps getting better and better! Going to try to get a lot done outside before it gets terrible... (edited to add a screenshot of the gross mess that's coming)

Oh yeah it's a blizzard. Almost every road in the entire southern half of Saskatchewan (larger than most European countries, as we learned from a post earlier!) is blue for "travel not recommended" or red for "closed".

And there are some true superheroes out there working right now: snowplow drivers, utility workers, tow truck drivers, emergency workers... lots of helpers!

131 catalogued objects reentered, 41 were Starlinks. (Still a bit more than 1 Starlink per day reentering on average). Not many reentries were observed, no new debris reported on the ground. We had a bit of discussion about whether or not this is observation bias (northern hemisphere winter so it's cloudier, and people aren't outside as much, maybe?)

With more than 600 new objects in orbit in just over a month, the CRASH Clock is not going to go down anytime soon. https://outerspaceinstitute.ca/crashclock/

A single Falcon 9 rideshare launch had 115 satellites in it, several of which were tugs that will deploy additional satellites. So, 126 sats deployed from that one launch. On the one hand, great, because rocket launches pollute a lot. On the other hand, holy crap that's a lot of satellites at once.

42 rocket bodies in orbit from all these launches (rocket bodies are often bus-sized or larger, so this is scary). 23 were promptly deorbited, 19 left for uncontrolled reentry later.

One of my million meetings yesterday was the space debris subcommittee of the AAS Committee on the Protection of Astronomy and the Space Environment (yeah, it's a long name). But the very very best part of that meeting is always getting the orbital traffic report from Jonathan McDowell @planet4589.bsky.social

He has been writing Jonathan's Space Report for decades with details on what has launched and reentered and what is happening in orbit around Earth. https://planet4589.org/space/jsr/jsr.html

Relatedly, one of the Chinese-launched satellites had a 200 meter close approach with a Starlink satellite 2 days after deployment https://www.space.com/space-exploration/satellites/spacecraft-from-chinese-launch-nearly-slammed-into-starlink-satellite-spacex-says

China (and every single other entity launching satellites) really really really has to share their orbital data with everyone else.

Jonathan's traffic report for yesterday included the 35 days since our previous subcommittee meeting. A few highlights:

There were 42 launches in the last 35 days, 16 of which were Starlink.

There were 617 new objects catalogued in orbit, 455 of them Starlinks (all V2 "mini", which are like 800kg, scares me that they consider that "mini"). The next largest batch addition after Starlink was 32 of China's Guowang megaconstellation.

Today I have nearly continuous Zoom meetings from 9am-5pm, and my job during every single one of those meetings is to effectively yell/complain/inform about Starlink or Reflect Orbital. Achievement unlocked, I guess.

Reposting for those not bridged to BlueSky, and to add alt-text, because this is important!

Jonathan McDowell @planet4589.bsky.social posted this morning: "The number of active satellites in orbit has now passed the 14000 mark according to my estimates"

8pm interview about the CRASH Clock. It is completely chaos in my home office, and I'm wearing a well-worn farm hoodie, and that's just how this is going to be! Might be a camera-off interview...

I'll end with the last paragraph of the paper:

"In addition to the dangerously high collision risks calculated here, we are already experiencing disruption of astronomy, pollution in the upper atmosphere from increasingly frequent satellite ablation, and increased ground casualty risks. By these safety and pollution metrics, it is clear we have already placed substantial stress on LEO, and changes to our approach are required immediately."

Official Weather Canada windchill here is -43 right now, if it goes below -45 they cancel the busses and I have to go pick up my kids from school, where they will probably have to wait outside until I get there... (Kind of a ridiculous rule, but ok whatever. These are pretty ridiculous conditions.)

First below -40 windchill morning. Yuck.

@ai6yr We now have quantified exactly how dangerous Starlink is for collision risk (ok it's not just Starlink, but it's really mostly Starlink that's driving this extremely dangerous situation)

@ai6yr 😭 😭 😭 https://arxiv.org/pdf/2512.09643

@ai6yr Yeah, could be shorter though! I posted a long explainer thread this morning: https://mastodon.social/@sundogplanets/115698651300339937

It's very very bad.

We set up a CRASH Clock website here: https://outerspaceinstitute.ca/crashclock/

Note that this is a probabilistic calculation. A catastrophic collision could happen sooner than 2.8 days of no maneuvers. In our (extremely computationally expensive) collision simulation, just by random chance we actually got the first collision just 3 hours in.

We are currently well inside the Caution Zone. The probability of collisions happening if no avoidance maneuvers occur is >10% in any 24 hour period.

The CRASH Clock uses the current density in altitude bins (averaged over eccentric orbits) of satellites, rocket bodies, and tracked debris, assuming typical cross sections for each type and orbital speeds. This calculation tells us how long to a collision if all orbital maneuvers were to suddenly stop.

The CRASH Clock is currently* at 2.8 days.

In 2018 it was 121 days.

*This is actually for June 2025 because that's when we ran it. Will update soon!

One of the scariest parts of this project was learning more about Starlink's orbital operations. I had always assumed they had some kind of clever configuration of the satellites in the orbital shell that minimized conjunctions, and we would see the number of conjunctions grow over time. But no! It's just random! There's no magic here, it's just avoiding collisions by moving a Starlink satellite every 2 minutes. This is bad.

"In the short term, a major collision is more
akin to the Exxon Valdez oil spill disaster than a Hollywood-style immediate end of operations in orbit. Indeed, satellite operations could continue after a major collision, but would have different operating parameters, including a higher risk of collision damage."

This is why I did a poll here about name recognition for Exxon Valdez a few months ago! (You young'uns go read about it because many of you don't know)