> dig where-is-the-iss.dedyn.io NAPTR
; <<>> DiG 9.10.6 <<>> where-is-the-iss.dedyn.io NAPTR
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31786
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;where-is-the-iss.dedyn.io. IN NAPTR
;; ANSWER SECTION:
where-is-the-iss.dedyn.io. 3600 IN NAPTR 100 100 "u" "E2U+voice:tel" "!^.*$!tel:+12814830123!" .
;; Query time: 84 msec
;; SERVER: 100.100.100.100#53(100.100.100.100)
;; WHEN: Sun Jul 06 10:53:39 EDT 2025
;; MSG SIZE rcvd: 111If you know of a DNS update which allows for per-minute updates for free, I'll happily move to it.
Why not setup your own name server?
Serving DNS yourself is such an incredibly small bandwidth impact - most of the packets are in the 10's to 100's of bytes - and authoritative DNS servers do not do a lot of processing, just send back RR's from zones which are read at boot time, or updated in an in-memory database.
But I would love to read your blog post about setting one up and what you learned.
I'm not being snarky. I've never set up something like that and I'm sure lots of people would be happy to ready about it.
https://youtu.be/AJ2Q12vYojY https://youtu.be/GoPWuJR6Npc
and i host https://dnsroleplay.club which lets you answer real people’s dns requests, there should be links to the github for how it’s done
People like me have been recommending not running public proxy DNS servers for the entirety of the 21st century thus far, and the world has taken some notice, although more work is required, world!
* https://jdebp.uk/FGA/proxy-server-ip-addresses.html
In any case, ANY queries do not work nearly as well for amplification attacks as they used to. Many people have read RFC 8482. I, for example, changed all of the DNS servers in djbwares to respond to ANY queries per RFC 8482 back in March 2019.
The task at hand in this discussion only involves running a content DNS server, serving LOC records from some file/database or other.
Brilliant. :-D
Oh, and accuracy is shit anyway (altitude is rounded to 10m)
Does Cloudflare not allow this?
I'm going to take a walk now...
dig iss.sky +short @dns.toys
Unfortunately LOC DNS records top out at ~42 million meters (42,000 km altitude) and JWST is 38x further out (~1.5 million km away). So you can’t represent its location with a LOC altitude field. Maybe Hubble?
It would be like asking for the GPS coordinates of the moon. NASA did test receiving weak GPS signals on the moon with LRO in 2023. It wouldn’t be useful for navigation though (not yet unless someone has like a way to do reverse GPS on the moon but not sure how that would work)
Reason this works for the ISS is because of the subsatellite point. It can receive GPS signals regardless of altitude above the Earth’s surface.
Also TLEs apply to the ISS because it’s earth orbiting.
TLEs are designed for satellites in Earth orbit, where they define position and velocity using orbital elements interpreted by models like SGP4.
No problem at all, just give the location where the moon is at the Zenith and use the distance as the altitude.
> Reason this works for the ISS is because of the subsatellite point. It can receive GPS signals regardless of altitude above the Earth’s surface.
No, wether the object can actually receive GPS signals is completely irrelevant to wether its location can be described in the GPS coordinate system.
You could describe the location of the Sun in GPS coordinates too, the altitude value would just be very large.
I was referring to finding your position on the moon using Earth referenced GPS signals.
No, you can describe any point in the universe using GPS coordinates. You just lose some resolution the further away from earth you are because it's basically spherical coordinates (like polar coordinates but for 3D). And the system isn't inertial but earth-fixed, of course, so you would have to give the coordinates together with a time.
And if you're describing the location of the moon and the sun, you would probably pick their center of gravity.
- Earth isn’t a universal reference
- GPS uses WGS84
- GPS is bound to the Earth’s surface and center
- It’s Geodetic
- There's no universal “equator” or “prime meridian” beyond Earth
- Space uses inertial frames or celestial coordinate systems (right ascension and declination, or galactic coordinates)
They are meaningless for things not near Earth because they’re tied to Earth's shape, rotation, and gravity field
And yes, you can transform between GPS coordinates and GCRS (or ECI/ECEF), depending on what you’re trying to do. The key distinction I’m making is about contextual meaning and application. GPS (WGS-84) coordinates are geodetic.
Once you're transforming positions millions of kilometers away (eg. L2, the Moon, or Mars) into lat/lon/alt, you're applying a system optimized for geodesy to a domain where the altitude is arbitrary, and "longitude" rotates with Earth.
If you’re saying it physically isn’t possible, then you’re basically saying the universe has some topological structure that cannot be projected onto the surface of a sphere. Which now that I’m thinking about it, is probably the case because of black holes? Lol maybe if the object is “in” a black hole then the coordinate actually is completely meaningless, but any other object would have some amount, even if low, of “meaning”
GPS coordinates are geodetic, tied to the WGS-84 ellipsoid and Earth’s rotating reference frame. They were designed for terrestrial navigation and near-Earth orbit, not for interplanetary space. Once you're dealing with the Moon, the Sun, or Lagrange points, you're so far outside the system's intended domain that projecting lat/lon/alt onto those locations introduces more confusion than clarity.
You're also right to point out that it's not physically impossible to describe a faraway object in that coordinate system.
There is just no practicable utility.
NASA and others use inertial frames, barycentric coordinates, and RA/Dec for a reason.
Also, love the black hole tangent - that’s where coordinate systems get seriously weird :-)
I doubt very much that the position of the ISS in the article is being sent from the ISS at real time. It's more likely calculated using NORAD / Celestrak orbital elements plus orbital calculations.
I remember having a Windows desktop app to show the satellites locations, I'd have to download those text files to keep the information accurate. For the information beyond the snapshot, the app has to calculate distance and trajectory to estimate "If NORAD said it was here at this point in time, and heading that way with that speed, then right now it should be around here.". A bit like "If a train left Chicago 5 hours ago going 60 mph, where is it now?".
Nowadays it's all online of course: https://in-the-sky.org/satmap_worldmap.php .
Yes, this is how the referenced site knows the approximate position of the ISS via TLEs. TLEs are updated regularly for space objects
That has been a very long running experiment [1]:
> University of Warwick, January 1996
Then run a program that listens to UDP/53 and TCP/53. Have it respond with a DNS packet that's only dynamic in the LOC record and message ID. Not fully compliant with the DNS spec, but good enough for this use case.
You could cache API response to combat rate limiting.
Chapter 5.1 (Suggested Uses) has at least some vague suggestions:
> Some uses for the LOC RR have already been suggested, including the
> USENET backbone flow maps, a "visual traceroute" application showing
> the geographical path of an IP packet, and network management
> applications that could use LOC RRs to generate a map of hosts and
> routers being managed.
There's no reason this couldn't be a human-readable string like "42 Wallaby Way, Sidney".
I overall like the DNS, it is a global database with eventual consistency. Possible to store transient data. Usually not blocked by firewalls just by the sheer innocent nature. (Although gets intercepted quite a lot...)
It's still a fun little project, but definitely feeling a little disappointed in comparison to what the title felt like it suggested to me...