Work on the ICRF3 comes to an end

Finally, the work on the International Celestial Reference Frame 3 (ICRF3) comes to an end with the paper in A&A published. With the ICRF3, the reference directions on the sky to quasars have been redefined. The noise floor of those directions is at 30 microarcseconds, corresponding to a tennis ball on the Moon as seen from the Earth. Further reading:

 Dec. 15, 2020

 Higher Geodesy