Mars mean density 3934
thickness | volume km3 | x Phobos vol | mass @1500 / 1860 / 2900 kg/m3 | equiv sphere D km
1 km | 1,190,000 | 209 | 1.78e+18 / 2.21e+18 / 3.45e+18 | 131
3 km | 3,570,000 | 626 | 5.36e+18 / 6.64e+18 / 1.04e+19 | 190
7 km | 8,330,000 | 1,461 | 1.25e+19 / 1.55e+19 / 2.42e+19 | 252

length of a 'sausage' through the opening (cylinder), km:
1 km layer -> D=32: 1,480; D=47: 686; D=112: 121; D=150: 67
3 km layer -> D=32: 4,439; D=47: 2,058; D=112: 362; D=150: 202
7 km layer -> D=32: 10,358; D=47: 4,801; D=112: 846; D=150: 471

Phobos/Deimos analog: body cross-section = caldera/3.5 .. caldera/2.4 -> for Arsia 112 km: 32-47 km
fluid Roche limit for rho=1500: 11,405 km from centre
fluid Roche limit for rho=1860: 10,616 km from centre
fluid Roche limit for rho=2900: 9,155 km from centre
d=10,290 km rho=1500: tide/self-gravity = 0.19
d=10,290 km rho=2900: tide/self-gravity = 0.10
d=8,000 km rho=1500: tide/self-gravity = 0.40
d=8,000 km rho=2900: tide/self-gravity = 0.21
d=6,000 km rho=1500: tide/self-gravity = 0.95
d=6,000 km rho=2900: tide/self-gravity = 0.49
d=4,500 km rho=1500: tide/self-gravity = 2.24
d=4,500 km rho=2900: tide/self-gravity = 1.16
rho=1500: self-gravity 0.027 m/s2, inertial rounding time ~ 26 min
   eta=1e+04: viscous rounding time ~ 1.05e-06 h
   eta=1e+08: viscous rounding time ~ 0.0105 h
   eta=1e+10: viscous rounding time ~ 1.05 h
   eta=1e+12: viscous rounding time ~ 105 h
rho=2900: self-gravity 0.053 m/s2, inertial rounding time ~ 19 min
   eta=1e+04: viscous rounding time ~ 2.8e-07 h
   eta=1e+08: viscous rounding time ~ 0.0028 h
   eta=1e+10: viscous rounding time ~ 0.28 h
   eta=1e+12: viscous rounding time ~ 28 h
lift energy at 7.9 MJ/kg:
  1 km: 1.75e+25 J
  3 km: 5.25e+25 J
  7 km: 1.22e+26 J
