|
Satellites. You're seeing sun reflected off solar panels, as the satellite spin slowly and the height they are at means they're still in sunshine while you are in darkness below.
Some orbits are particularly attractive for specific applications and hence its not unusual to see small gaggles of them. In addition from an engineering perspective there are reasons why they may want more than 1 - redundancy (in case one fails), comms bandwidth (1 may simply not be enough) and coverage of the planet below (antennas may be pointed at different parts of Australia).
In addition Optus for example operates private networks completely separate from its public network, for example the Dept of Defence and railways. These almost certainly use satellites separate from, but flying close to the civilian equivalents.
|