Neptune scaled one in 250 million

This model was made using the contrast enhanced mosaics made by Bjorn Jonsson from the data of the Voyager 2 probe. The "relief" of the model is actually the albedo (brightness) level. White clouds are high altitude clouds, and the greats storms are darker vortex of clouds, so we can assume the albedo is proportional to the level of the clouds and the these models represent that. However it must be consider that the wind speeds of the atmosphere change with the latitudes, so the configuration of the atmosphere changes drastically over the time. The rings are actually thinner than the represented model. The height of the ring is 1mm for the more solid disk; 0.6mm for the wider thinner disk; and 0.3mm for the voids between the rings.
The file's names explained: name_1_x_10_y.stl is 1 : x * 10^y. So _1_6_10_7 is 1:600000000 or one in 60 million.

Neptune

Neptune is the farthest known planet in the Solar System, and the fourth in diameter, four times Earth's. It is slightly heavier and denser than Uranus. These two planets are labeled as "ice gigants". The atmosphere is rich in water ammonia and methane, together with hydrogen and helium gases. The mantle has no a discrete interface with the atmosphere, and consist mainly in a ocean of superionic water, a mix of hydrogen and oxygen ions. Deeper in the mantle, methane decomposes and condense into diamonds, falling like rain into a ocean of liquid carbon. Neptune has a big captured moon, Triton, which may be a former TNO (Trans Neptunian Object). Many TNO's orbits (mainly scattered disk objects, like Eris, and resonants, like Pluto) are greatly influenced by the gravity effect of Neptune. The other moons of Neptune may be rubble piles from the capture process of Triton. Scattering and collisions prevented the formation of medium sized moons. Among the other moons of Neptune are Proteus, Nereid and Larissa. It also has a tiny ring system that it would be difficult to see even close to it, with arcs within the disks with denser areas.

• Type: Planet. Ice giant.
• Orbit: Sun.
• Orbital period: 164.8 yr.
• Composition: Hydrogen, helium atmosphere; water amonia and methane mantle, rocky core.
• Density: 1.638 g/cm³.
• Dimensions: 49528 km × 48682 km
• Model scale: 1:2.5x10⁸ (20cm) 1:5x10⁸ (10cm) 1:1x10⁹ (5cm)

References

• Source of the images
• Surf to STL function for MATLAB

Other astronomical objects

Object	Scale [1:x] K = 103 (thousand) M = 106 (million) G = 109 (billion)	Image
Inner Solar System
Mercury	20M, 60M, 120M
Venus	60M, 120M, 250M
Earth	60M, 120M, 250M
Luna	10M, 20M, 60M
Mars	20M, 60M, 120M
Phobos and Deimos	200K, 500K
Artificial
Salyut 7	40, 48, 80, 160
Near Earth Asteroids
Moshup and Squannit	8K, 20K, 40K
Ra-Shalom	20K, 40K
Castalia	8K, 20K, 40K
Bacchus	8K, 20K
Bennu	3K, 8K
Ryugu	3K, 8K, 20K
Geographos	40K, 80K
Phaethon	40K, 80K
Itokawa	3K, 8K
Eros	80K, 200K, 500K
Nereus	3K, 8K
Mithra	20K, 40K
Golevka	8K
Toutatis	40K, 80K
Main Asteroid Belt
Gaspra	200K
Annefrank	40K, 80K
Braille	20K, 40K
Vesta	2M, 4M, 10M
Šteins	40K, 80K, 200K
Iris	2M, 4M
Hebe	1M, 2M, 4M
Lutetia	500K, 1M, 2M
Julia	1M, 2M, 4M
Mathilde	500K, 1M
Juno	2M, 4M
Ceres	4M, 10M
Pallas	4M, 10M
Kleopatra	2M, 4M
Ida	500K, 1M
Psyche	2M, 4M
Interamnia	2M, 4M
Hygiea	2M, 4M, 10M
Antiope	1M, 2M
Jovian System
Jupiter	500M, 1G
Amalthea	2M, 4M
Thebe	1M, 2M
Io	20M, 60M
Europa	20M, 60M
Ganymede	60M, 120M
Callisto	60M, 120M
Saturn System
Saturn	500M, 1G
Pan, Daphnis and Atlas	80K, 200K, 500K, 1M
Prometheus and Pandora	1M, 2M
Janus and Epimetheus	2M, 4M
Mimas	2M, 4M, 10M
Methone, Anthe and Pallene	40K, 80K
Enceladus	4M, 10M
Tethys	4M, 10M, 20M
Telesto and Calypso	200K, 500K
Dione	4M, 10M, 20M
Helene	500K, 1M
Rhea	10M, 20M
Titan	60M, 120M
Hyperion	2M, 4M
Iapetus	10M, 20M
Phoebe	1M, 2M, 4M
Uranian System
Uranus	250M, 500M, 1G
Puck	1M, 2M, 4M
Miranda	4M, 10M
Ariel	10M, 20M
Umbriel	10M, 20M
Titania	10M, 20M
Oberon	10M, 20M
Neptunian System
Neptune	250M, 500M, 1G
Larissa	2M, 4M
Proteus	2M, 4M, 10M
Triton	20M
Comets
Tempel 1	40K, 80K, 200K
Wild 2	40K, 80K
Churyumov-Gerasimenko	20K, 40K, 80K
Hartley 2	20K, 40K, 80K
Borrelly	40K, 80K, 200K
Halley	80K, 200K
Centaurs and TNOs
Hidalgo	500K, 1M
Chariklo	2M, 4M
Pluto and Charon	10M, 20M
Styx, Nix, Kerberos and Hydra	500K, 1M
Haumea, Namaka and Hiʻiaka	10M, 20M
Arrokoth	200K, 500K, 1M
Largest TNOs and their moons	10M, 20M
Extrasolar
Exoplanets	120M, 250M, 500M
Nearest white dwarfs	120M, 250M
HD 189733 b	1G
Pulsars	200K, 500K
Cygnus X-1 accretion disk	10M, 20M
Sky maps
Heliosphere	7.5*1013, 1.5*1014
Constellations	-
CMBR	2*1028
Ancient
Earth (540 Mya to 20 Mya)	60M, 120M, 250M
Luna (4 Gya)	20M, 60M
Speculative
Planet Nine	250M, 500M
Cube planet	60M, 120M, 250M
Science Fiction
Ghroth	4M, 10M
Arda	60M, 120M
B612	10, 20, 32, 40
Mesklin	500M, 1G
Arrakis	60M, 120M
Borg cube	8K, 20K, 40K
Pern	60M, 120M
Europa Monolith	200K, 500K
Leonora Christine	500, 600, 1K, 3K
Rama	80K, 200K, 500K
Death Star	500K, 1M, 2M
Starkiller Base	2M, 4M, 10M
Nirn, Secunda and Masser	20M, 60M, 120M
Independence Day mothership	2M, 4M, 10M
Arrival heptapod spaceship	1K, 3K, 8K
Gaijin flowership	3K
Halo Array	4M, 10M, 20M, 60M
Gem Homeworld	120M, 250M, 500M
The Skeld	40, 80, 160, 350, 500
Misc
Mars (1962 reconstruction)	60M, 120M
Flat Earth	250M
Expanding Earth	60M, 120M
Spaceship of Ezekiel	80, 160