The SkyMapper Southern Survey (SMSS, Southern Sky Survey)
is a survey of all the sky south of the equator
by the SkyMappertelescope, including
photometry, astrometry, and digital images.
Filters include U, V, G, R, I and Z
(which are each slightly different than the corresponding filters
in the griz and ugriz systems).
It is more-or-less a southern counterpart
to the original Sloan Digital Sky Survey.
As it continues, fainter objects are added.
Among the discoveries are SM0313
(SMSS J031300.36-670839.3) the oldest
star yet found, based upon its metallicity.
SMSS DR4 was made available February 2024 with
data from 2014 to 2021.