  An analysis is presented for the photometric data on comet C/2013 A1 (Siding
Spring) from observations at a large heliocentric distance (near 4.1 AU). Comet
C/2013 A1 (Siding Spring) displays intense activity despite the relatively
large heliocentric distance. The morphology of the comet's coma is analyzed.
The following parameters are measured: the color indices V-R, the normalized
spectral gradient of the reflectivity of the comet's dust S', and the dust
production rate Af\r{ho}. A numerical simulation is performed for the evolution
of the comet's orbit after a close encounter with Mars. The most probable
values are obtained for the Keplerian orbital elements of the comet over a
hundred-year period. The comet's orbit remains nearly parabolic after passing
the orbits of all the Solar System planets.
