... Currently, there is very little information on comets which are active beyond the orbit of Jupiter. ... Previous observations conducted by our team with the SAO RAS 6-m telescope showed that some of these comets have extended tails dissimilar to the tails of comets forming at close heliocentric distances. ... We for the first time measured the linear polarization of scattered emission for the two distant comets C/2010 S1 (LINEAR) and C/2010 R1 (LINEAR) at heliocentric distances of 5.9-7.0 au. ...