  Several models have predicted that stars could form inside galactic outflows
and that this would be a new major mode of galaxy evolution. Observations of
galactic outflows have revealed that they host large amounts of dense and
clumpy molecular gas, which provide conditions suitable for star formation. We
have investigated the properties of the outflows in a large sample of galaxies
by exploiting the integral field spectroscopic data of the large MaNGA-SDSS4
galaxy survey. We find that star formation occurs inside at least half of the
galactic outflows in our sample. We also show that even if star formation is
prominent inside many other galactic outflows, this may have not been revealed
as the diagnostics are easily dominated by the presence of even faint AGN and
shocks. If very massive outflows typical of distant galaxies and quasars follow
the same scaling relations observed locally, then the star formation inside
high-z outflows can be up to several 100 Msun/yr and could contribute
substantially to the early formation of the spheroidal component of galaxies.
Star formation in outflows can also potentially contribute to establishing the
scaling relations between black holes and their host spheroids. Moreover,
supernovae exploding on large orbits can chemically enrich in-situ and heat the
circumgalactic and intergalactic medium. Finally, young stars ejected on large
orbits may also contribute to the reionization of the Universe.
