Postgres geography type is not limited to Earth

Re:Postgres geography type is not limited to Earth by askvictor on Sunday August 20, 2017 @08:36PM (#15061094)

This is awesome. Purely out of interest, how would one go about a similar location database for arbitrary locations in space? PostGIS presumably assumes a spheroid planet; what if I'm tracking objects in interplanetary space? Are there any DB plugins (accessible outside of national space agencies) that can do that?

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Re:Postgres geography type is not limited to Earth by bad_alloc on Sunday August 20, 2017 @08:54PM (#15061157)

> what if I'm tracking objects in interplanetary space?

I guess you'd just want to store the orbital information of that object, as it probably won't stay at a fixed position.

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Re:Postgres geography type is not limited to Earth by askvictor on Sunday August 20, 2017 @09:16PM (#15061256)

Indeed; does that mean such a database would need to run an n-body simulation to determine where one object is compared to another at a given time?

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Re:Postgres geography type is not limited to Earth by Demiurge on Monday August 21, 2017 @02:51AM (#15062459)

That would require arbitrary telemetry and possibly non-deterministic solution, or something like SPICE(https://naif.jpl.nasa.gov/naif/toolkit.html) which is a bit too far outside of 'database' domain.

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Re:Postgres geography type is not limited to Earth by pjc50 on Monday August 21, 2017 @06:12AM (#15063363)

http://tdc-www.harvard.edu/catalogs/sao.html

Sensibly, the star catalog is arranged by apparent position from Earth. There are two kinds of motion that need to be accounted for: the precession of the earth, which affects all coordinates uniformly ( http://www.stargazing.net/kepler/b1950.html ) and "proper motion" of the stars themselves: https://en.wikipedia.org/wiki/Proper_motion

Proper motion is rather slow. Fortunately astronomy can take measurements across the centuries.

"Proper motion was suspected by early astronomers (according to Macrobius, AD 400) but a proof was not provided until 1718 by Edmund Halley, who noticed that Sirius, Arcturus and Aldebaran were over half a degree away from the positions charted by the ancient Greek astronomer Hipparchus roughly 1850 years earlier."

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Re:Postgres geography type is not limited to Earth by b34r on Monday August 21, 2017 @04:13AM (#15062795)

X, y, z

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