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Let's Learn About Neptune!

Neptune is the furthest planet from the Sun, more than 30 times further away than the Earth.

The Great Dark Spot!

This photograph of Neptune was made from two images taken by the space probe Voyager 2. You can see the Great Dark Spot, accompanied by bright, white clouds. Below the Great Dark Spot is a bright feature that scientists have called “Scooter” because it whizzes round the planet at crazy speeds. Farther south is “Dark Spot 2,” which has a bright core.

Image Credit: NASA/JPL

space iguda small

Iguda’s Neptune Fact File

*FUN FACT* Neptune was discovered in 1846 by Johann Gottfried Galle.

Position from the sun

8th planet

Diameter

50,600 km

Distance from The Sun

4,500,000,000 km

Day length

16.1 hours

Year Length

164 years

Number of moons

14

Surface temperature

-230 °C

Surface gravity

11.2 m/s²

Atmosphere

Hydrogen, helium, methane

Neptunes Largest Moon!

Tanno and Iguda visited Neptune’s largest moon, Triton. It’s 2,700 kilometres across, so about 22% smaller than Earth’s moon. Triton has the coldest surface anywhere in the Solar System. Like Earth, it has a mostly nitrogen atmosphere, and that’s really unusual. Saturn’s moon Titan is the only other place in the solar system with a mostly nitrogen atmosphere.

This picture shows the view of Neptune on Triton’s horizon. Because of their orbits, Neptune won’t rise but will appear to roll along the horizon from left to right.

Or is it a Melon?

When Voyager 2 flew past in 1989, it found geysers blowing darker material up onto the surface making dark streaks.

The pinkish deposits form a big south polar cap, probably made of methane ice. A bluish-green band goes all the way around Triton near its equator. This may be new nitrogen frost deposits. The greenish areas includes what is called the ‘cantaloupe terrain’ or ‘melon skin surface’. Astronomers aren’t sure what causes these, but it could be more piles of material from the geyser plumes.

Do you think Triton looks like a Melon?

YOUR MISSION, SHOULD YOU CHOOSE TO ACCEPT IT …

YOUR MISSION, SHOULD YOU CHOOSE TO ACCEPT IT …

YOUR MISSION, SHOULD YOU CHOOSE TO ACCEPT IT …

YOUR MISSION, SHOULD YOU CHOOSE TO ACCEPT IT …

By reaching Neptune, Tanno and Iguda got to the furthest planet from our Sun!

You can make (or maybe just mark out) a scale model of the solar system to give you an idea of how crazy big it is!

Your Task

There are two possible models you could make: the sizes of the planets, or the distance to the planets.

There are two possible models you could make: the sizes of the planets, or the distance to the planets.

Planet

Distance* (cm)

Mercury 6
Venus 11
Earth 15
Mars 23
Jupiter 78
Saturn 143
Uranus 278
Neptune 450

*from the sun

These numbers will let you set out a solar system so the planets are all the correct distances from the Sun, at a scale of 10 million kilometres in space to one centimetre on your model.

For the next model, the sizes of the planets, you could draw out circles and colour them in, or maybe you could find objects at home that are about the right size.

Planet

Size (mm)

Mercury 4.6
Venus 12
Earth 13
Mars 6.3
Jupiter 130
Saturn 110
Uranus 45
Neptune 46

These numbers will let you set out a solar system so the planets are all the correct sizes compared to each other, at a scale of 1000 kilometres in space to one millimetre on your model.

Don’t try building both models in one – at the scale in the second table, your Mercury will need to be 58 metres from your Sun! Or, at the scale of the second table, your Mercury will need to be smaller than the size of a red blood cell!

Check Out NASA's Interactive Solar System!

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– MISSION END –

– MISSION END –

– MISSION END –

Your Journey So Far …

Tanno and Iguda have explored these places up to now. You can go back and visit again by clicking below.

The Moon

Venus

Mercury

The Sun

Mars

Asteroids

Jupiter

Saturn

Uranus

Neptune

Great to see you here, thank you for the visit! See you next time …

Tanno & Iguda