Phobos and Deimos scaled one in 500 thousand
This model was rendered using MATLAB R2016a on the ICQ model of Phobos made by Robert Gaskell from the images of the Viking 1 orbiter. The model of Deimos was updated using a more detailed model from the NASA Solar System Exploration website, softened and simplified.
The file's names explained: name_1_x_10_y.stl is 1 : x * 10y. So _1_6_10_7 is 1:60000000 or one in 60 million.
The file's names explained: name_1_x_10_y.stl is 1 : x * 10y. So _1_6_10_7 is 1:60000000 or one in 60 million.
M1 Phobos
Phobos is the biggest and closest moon of Mars. It is so close that it takes less than a third of a martian day to make an orbit, so it could be seen twice a day. Its angular speed is faster than the martian spin, so Phobos rises on the west and sets on the east, contrary to the Earth's Moon, that rises on the east and sets on the west. This "faster than the surface" condition makes a similar gravity erosion effect than a retrograde orbit, like Neptune does on Triton, making the Phobos orbit decay constantly over the time. Phobos will eventually get so close to the atmosphere of Mars, that the friction with it will slow the moon making it to fall to the planet surface, probably in 50 million years. It could happen that when Phobos reaches the Roche limit of Mars it breaks up and became a ring around the planet, until this material fall down to the atmosphere.- Type: Satellite.
- Orbit: Mars
- Orbital period: 7 h 39 min 12 s.
- Composition: Silicate rock, carbonaceous material. Rubble pile
- Density: 1.876 g/cm3.
- Dimensions: 27 km × 22 km × 18 km.
- Model scale: 1:2x105 (13cm) 1:5x105 (5cm)
M2 Deimos
Deimos is about a half the size of Phobos. From the martian surface Deimos is seen like a shiny star, while Phobos is about a third of the angular diameter we see the Moon of Earth. Both of the moons of Mars seem to be captured asteroids, probably disrupted by Jupiter's gravity. However, the circularity of their orbit cast doubts on this theory, most of the captured moons have very eccentric and inclined orbits. They could also be accreated from the material ejected after an ancient impact event with a planetesimal, along with many other small moons, that were scattered or fall down into the Mars atmosphere.- Type: Satellite.
- Orbit: Mars
- Orbital period: 30 h 18 min 43 s.
- Composition: Silicate rock, carbonaceous material.
- Density: 1.471 g/cm3.
- Dimensions: 15 km × 12.2 km × 11 km.
- Model scale: 1:2x105 (7cm) 1:5x105 (3cm)
References
- "Gaskell, R.W., Gaskell Phobos Shape Model V1.0. VO1-SA-VISA/VISB-5-PHOBOSSHAPE-V1.0. NASA Planetary Data System, 2011."
- "https://sbn.psi.edu/pds/resource/oshape.html"
- "https://solarsystem.nasa.gov/resources/2434/deimos-3d-model/"
- Surf to STL function for MATLAB










































































































































