Observations of the Solar F-Corona from Space

The observations of the solar F-corona from space are reviewed emphasizing 25 years continuous monitoring achieved by LASCO-C2 and C3 coronagraphs. Our work includes images obtained Clementine cameras, STEREO/SECCHI/HI-1A PSP/WISPR heliospheric imagers. characteristic radiance profiles along equatorial polar directions follow power laws in 5{\deg}-50{\deg} range elongation, with constant exponents -2.33 -2.55. Both connect extremely well to corresponding standard zodiacal light. LASCO profile exhibits a shoulder implying 17% decrease within 10Rsun that may be explained disappearance organic materials 0.3 AU. detected for first time secular variation F-corona, an increase at rate 0.46% per year integrated LASCO-C3 FoV. This is likely observational evidence role collisions inner cloud. A composite C2 produced reference map 2 30Rsun and, combining ground-based measurements, extended 1 6 Rsun. plane symmetry cloud strongly warped, its inclination increasing towards planes planets ultimately equator. In contrast, longitude ascending node found equal 87.6{\deg}. did not detect any small-scale structures such as putative rings occasionally reported during eclipses. outer border depletion zone where interplanetary dust particles start affected sublimation appears constrained 19Rsun. extends down 5Rsun, thus defining boundary dust-free most refractory materials, moderately absorbing silicates, disappear.