Is Google building a 3D map?

OK, maybe its not, but I think somebody is.

For the last couple of nights, around 11PM (NZDST), while sloshing in my spa pool, I have spotted 3 satellites flying in exactly the same formation in a circumpolar orbit.

Two of them side by side in the lead, I would guess about 10 miles apart and a third following about 40 miles behind (I may be out by a factor of 10 given the other variables) in an isoceles triangle. Seeing them all in the same formation on two different nights argues for deliberate, to maintain that relationship for more than a few seconds they have to be in exactly the same orbit and exactly parallel tracks.

Any ideas?

Comments

[RobiNZ]

You're not paranoid, they are out to get you!

Would there be enough resolution from satellite data? Presume land contours but they could buy that for NZ to within a few metres. I thought higher detail stuff was still flown closer to the ground, or driven?

[nomad496]

You might be seeing the ESA Cluster group of satellites. They are a synchronized set of four satellites investigating the magnetosphere surrounding the earth. There is also a pair of NASA satellites, I forget the mission name, investigating gravitational variations in the Earth. I have seen the NASA ones here in Oregon, USA.

[Earl Mardle]

Thanks Steve, I didn't even know there were synchronised low-orbit jobs about. This cluster is definitely three and in a triangle both times. Is it possible one of them has dropped out?

I'll Google them and see if I can find out some more.

[Earl Mardle]

Got it, the four are in a tetrahedron which means one will be outside the plane. Separations vary from 100 to 1,000km.

What I can't get my head around is how you could synchronise the 4th satellite which must be in a different orbit from the other three. The higher the altitude the longer the period so synching with the other three must be a computational nightmare.