Solar System

Sun, planets & moons (size to scale, distances not)

## Planets

Planets of the Solar System to scale

The **Solar System** is the gravitationally bound system of the SunW and all objects that orbit it.

## Planets & moons

### Notes

In our timeline, Pluto lost its planetary status in 2006. It is unknown if Pluto is still considered the 9th planet in the *For All Mankind* timeline.

## Inner Solar System

The inner Solar System is the home of the four rocky planets Mercury, Venus, Earth, and Mars, as well as the main asteroid belt. It spans a region up to about 3.5 astronomical units (AU) from the Sun.

Only two of the four inner planets, Earth and Mars, have moons. The other two, Mercury and Venus, are the only planets in the system without a moon. However, the moons of Mars, Phobos and Deimos, are only two tiny rocks irregular in shape and have diameters of approximately 22.2 and 12.6 km, respectively. Earth is the only planet in the inner system with a moon massive enough to form a nearly spherical shape.

### Asteroid belt

The asteroid beltW, also main asteroid belt or main belt, is a region between the orbits of Mars and Jupiter, spanning an area of approximately 2 to 3.4 AU from the Sun. It contains about 800,000 known and numerous more unknown object of all sizes. The average distance between objects is about one million kilometers.
The darf planet CeresW is by far the biggest object with a diameter of about 950 km. The next three large objects are VestaW, PallasW, and HygieaW, which all have mean diameters less than 550 km. These 4 objects contain about 60% of the total mass of the whole asteroid belt. Despite the large number of objects, the total mass of the asteroid belt is quite small and is estimated to be around 3% that of the Moon.

#### Exploration

Several probes have been sent to various asteroids. In March 1995, NASA's Mariner 32 probe was in transit to the asteroid belt, while its sister probe Mariner 33 was on its way back to return collected samples.

In 2003, the *Ranger 1* spacecraft was sent to the asteroid XF Kronos in a joint mission between the M-7 Mars Alliance and Helios Aerospace with the goal of transporting it back to Martian orbit with the aim of exploiting its resources. During this endeavour, Grigory Kuznetsov became the first man to land on an asteroid. Subsequently, XF Kronos was de-spun and a system of cables was wrapped around it to support it for retrieval. However, due to wobbling in the asteroid, the harness was damaged, leading to the death of Grigori and Helios space worker Tom Parker. The mission was scrubbed as a result, and the asteroid was cut loose.

## Outer Solar System

The outer system is the region of the so called giant planets. Distances between planet's orbits become a lot larger here than in the inner system.

At a distance of 5 to 5.4 AU, the gas giant **Jupiter** is orbiting the Sun. It is the largest and most massive planet in the system. Jupiter's mass is more than 2.5 times the mass of all other planets combined. Jupiter has four of the system's largest moons, with GanymedeW being larger than the planet Mercury. Within its orbit around the Sun, two large clusters of Trojan asteroidsW orbit at the L4 and L5 Lagrange pointsW. In 2003, the Thomas Paine Space Telescope picked up images of the Trojan asteroid 2003LC, which was believd to have decayed from a Jovian trojan orbit. The asteroid was redirected to the inner Solar System, and after an analysis of its moon, it was believed to have an estimate of 70,000 metric tons of IridiumW, valued at $20 trillion. Because of this, 2003LC was nicknamed the Goldilocks asteroid.

At 9-10 AU from the Sun, **Saturn** is the second most massive planet in the system, famous for its ring system. Saturn has way over 100 known moons, the biggest being Titan, the second largest moon of the Solar System and like Ganymede larger than Mercury.

About twice as far away from the Sun is **Uranus**, orbiting it at a distance between 18 and 20 AU. It is one of the two ice giants and the planet with the third-largest diameter and fourth-largest mass in the system. Like the other giant planets, Uranus has a ring system, orbiting natural satellites and a magnetosphere.

Another 10 AU farther out lies the orbit of **Neptune**, the third-most-massive and fourth-largest planet in the Solar System by diameter, and the densest giant planet. 30 astronomical units from the Sun, it takes Neptune about 165 years for one revolution.

### Exploration

Some of NASA's Voyager and Pioneer probes have visited the outer planets. In March 1995, Pioneer 23 is in Neptune's orbit on a photo OPS mission,  while Voyager-5 is performing UV spectro operations in the trans-Neptunian region on its outer planets survey mission.

## Trans-Neptunian region

Beyond the orbit of Neptune lies the Kuiper beltW, the system's second asteroid belt beside the main belt. It is the home of Pluto and several other dwarf planets, and extends between 30 and 50 AU from the Sun. Most parts of that region are still largely unexplored. Most comets are thought to originate in the Kuiper belt or even farther out in the Oort cloudW.

## Distances

Distances between planets to scale

Distances between Earth & Moon to scale.

Yellow line shows differences in distance over a rotational period. Green line below Earth represents distance of Earth's centre from the system barycentre.

## Behind the scenes

1. ↑ **Mariner**
The Mariner programW was a NASA program to explore other planets. 10 robotic interplanetary probes were designed and built by JPLW between 1962 and late 1973, visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations. Mariner 1 failed at launch in July 1962, followed by Mariner 2 in August, which made the first Venus flyby with data returned. The last spacecraft of the program launched in November 1973, performing the first ever flyby of Mercury.
In the *For All Mankind* timeline, the program appears to be still active by 1995 with the last known missions being Mariner 32 + 33, exploring the asteroid belt between Mars and Jupiter.
2. ↑ **Pioneer**
Pioneer 23 in *For All Mankind* appears to be a JPL mission in Neptune's orbit.
In reality, the Pioneer programW were two series of lunar and planetary space probes, the first running from 1958 to 1960, and the second from 1965 to 1992. The best known missions are *Pioneer 10W* and *Pioneer 11W*, which were the first human-built objects to achieve escape velocity from the Solar System. Both vehicles carry a gold-anodized aluminum Pioneer plaqueW with a message from mankind, in the event that either spacecraft is ever found by intelligent lifeforms from other planetary systems.
3. ↑ **Voyager**
The Voyager programW in reality consists of two interstellar probes, *Voyager 1W* and *Voyager 2W*. They were both launched in 1977 and took advantage of a favorable alignment of the planets Jupiter, Saturn, Uranus, and Neptune, to fly near them while collecting data. As of 2023, both probes are still in operation past the outer boundary of the heliosphere in interstellar space.
In *For All Mankind*, the program seems to be running more than two probes, with *Voyager-5* operating beyond Neptune's orbit in March 1995.

## See also

* Space missions
* Mercury
* Venus
* Earth   →   Moon
* Mars
* Jupiter
* Neptune

## External links

* Solar System on Wikipedia
* Asteroid belt on Wikipedia

## References

1. ↑ Season 3, Episode 6: "New Eden" (Mission status board @ 44:25) → Screenshot
2. ↑ *For All Mankind* TV Series - Season 4, Episode 1: "Glasnost"
3. ↑ Season 3, Episode 7: "Bring It Down" (Mission status board @ 43:00) → Screenshot
4. ↑ Season 3, Episode 6: "New Eden" (Mission status board @ 44:50) → Screenshot