I would like to know which object in the Universe (star, galaxy, quasar) is moving at the greatest velocity Please Register or Log in to view the hidden image! I DO NOT mean the relative velocity towards our planet/galaxy because in this sense the fastest object would be the one with the greatest Z (now UDFj-39546284 and UDFy-38135539 with the highest value of Z=~10.3), since the universe in expanding these objects are flying so quickly DUE TO this expansion and not due to other reason. Here is example how the space is expanding in geometric sense: Please Register or Log in to view the hidden image! The space is expanding, and the CMBR is “expanding” together with it. As far as I remember the relative speed of local/our galaxies’ cluster relative to CMBR (and hence relative to expanding space, am I right?) is approximately 700 km/sec, this probably can be considered as “real” speed. So, which object in Universe has got the maximal “real” speed relative to CMBR? Is this question explored? Please Register or Log in to view the hidden image!