Astronomer watches Starlink satellites sinking to build a 'planetary barometer'

wwhh about 4 hours ago 16 commentsRead Article on theregister.com

FR version is available. Content is displayed in original English for accuracy.

⚡ Community Insights

Discussion Sentiment

45% Positive

Analyzed from 629 words in the discussion.

Discussion (16 Comments)Read Original on HackerNews

BlackRabbit1•about 3 hours ago

That's cool.

Reminds me that scientists can use GPS to track earthquakes indirectly as it is interacting with the ionosphere: https://link.springer.com/article/10.1186/s40623-025-02211-y

pclowes•about 2 hours ago

Any solid citations for "and has pushed Low Earth Orbit to the brink of the Kessler Syndrome."?

I would be honestly intrigued but wary of just the usual Elon bad/good so all things he does bad/good narratives.

If we are on the brink of Kessler Syndrome in LEO I would expect market pricing to reflect that.

smallerize•about 2 hours ago

https://arstechnica.com/space/2026/09/there-are-now-17000-sa... "It does indeed start to look pretty dicey by mid-century."

The report itself https://www.esa.int/Space_Safety/Space_Debris/ESA_Space_Envi...

About pricing: https://www.satellitetoday.com/launch/2026/09/17/the-era-of-...

brandonagr2•about 2 hours ago

If the report is predicting 100 years in the future, are we really "to the brink" now? Not to mention the decay time of these LEO is in months, hardly a kessler syndrome scenario.

smallerize•about 1 hour ago

The report says we will be in trouble in 10-20 years, not 100. Look under "collisions causing collisions". Debris from previous collisions increases the risk of future collisions.

embedding-shape•about 1 hour ago

> If we are on the brink of Kessler Syndrome in LEO I would expect market pricing to reflect that.

Wouldn't the market pricing only reflect this after that fact? Up until it happens and no one knows any better, business will continue as usual because otherwise numbers don't go up. Like any past financial crisis, things look fine until they don't.

ck2•about 1 hour ago

almost positive Kessler LEO will be triggered by Russia taking out a cluster by the end of the decade

* https://satellitemap.space

* https://platform.leolabs.space/visualization

dzhiurgis•about 1 hour ago

Same. Somehow first 50% of mass to orbit was woke science and next 50% is fascist oppression.

ortusdux•about 3 hours ago

Link to article: https://www.spaceweather.com/starlink/starlink_drag_explaine...

autoexec•about 2 hours ago

> "The megaconstellation interferes with astronomy, pollutes the atmosphere with metallic re-entry debris, and has pushed Low Earth Orbit to the brink of the Kessler Syndrome... On the other hand, it makes a terrific barometer.”

I'm not sure we're coming out ahead on that one, but leave it to a guy who can detect things light-years away to be able to find a silver lining

sandworm101•about 3 hours ago

The author seems to treat the atmosphere as a, well, sphere. It isnt. It is not of equal depth at all areas. As starlink (and every other sat) only travels in part of the atmosphere each day they cannot measure the entire atmosphere. So you measure a thousand starlinks to get an average. Ok, but a significant bulge on one side of the planet will slow all sats, giving the false impression of a homegenous trend. So you have to track very specific sats in very specific survey orbits... but also update that list as the orbital shell rotates around the earth. It is a very complex problem.

schiffern•about 3 hours ago

Unfortunately the data doesn't have the required time or space resolution. The drag term is averaged over many orbits, and you can't even use perigee/apogee drift to localize it since the atmosphere rotates so it gets averaged over all longitudes.

You can do some rudimentary localization by latitude, however, by comparing satellites in different inclinations. You also get data by altitude, of course.

sandworm101•about 3 hours ago

What you want is realtime accelerometer records from satellites in flight, exposing their drag factors over specific parts of the planet. The only tricky variable would be their orientation, but that is certainly recorded too.

Something like this: https://en.wikipedia.org/wiki/GOCE

schiffern•about 2 hours ago

Based on losing "a few meters of altitude per day," if we assume 5 meter/day at 500 km that's 3 nano-gee. Sensitive piezoresistive accelerometers seem to run in the single digit micro-gee range.[0]

Easier to look at the altitude loss and infer the acceleration indirectly. With access to the raw higher time-resolution altitude data, mapping should be possible.

SpaceX has in the past gone above and beyond to expose TLE data for scientists and astronomers[1], so it's possible that people inside SpaceX would be open to collaborating on such a project.

[0] https://www.pcb.com/sensors-for-test-measurement/acceleromet...

[1] https://youtu.be/MNc5yCYth5E?t=1719

crtified•about 3 hours ago

I suspect the author understands the concept of a spheroid, though they don't mention the term as such.

There is a fair bit of statistical rigour described in the original article at : https://www.spaceweather.com/starlink/starlink_drag_explaine...

jjk166•about 1 hour ago

> Ok, but a significant bulge on one side of the planet will slow all sats, giving the false impression of a homegenous trend.

A bulge would not homogenously slow all satellites, each one would be slowed by a different amount depending on its particular path through the bulge. Those that pass through more of the bulge will be slowed to a greater extent than those passing briefly through. Satellites in different orbits tell you where the bulge is, satellites in the same orbit tell you how the bulge is moving.