Data sent back by the New Horizons spacecraft, which flew by Pluto last year, is now giving us lots of new insights into the (dwarf) planet and its moons.
This is how Pluto and its moons orbit each other.
That's Pluto in the middle and its largest moon Charon closest in, followed by Styx, Nix, Kerberos, and Hydra. You can see how Charon is big enough to actually pull Pluto about, meaning they both orbit a spot outside of Pluto.
As for the smaller, irregularly-shaped moons, we now know that Nix and Hydra are about 40km wide, and Styx and Kerberos are about 10km wide. All four of Pluto's small moons have highly reflective surfaces, suggesting they have water ice on their surfaces.
H.A. Weaver et al. / Science
There’s not much dust around the dwarf planet.
There are only six grains of dust per cubic mile of space around Pluto and its moons, according to data sent back from an instrument on board the New Horizon's spacecraft. That means that any left over planetary dust and debris from when the dwarf planet formed has all been swept up one way or another over the intervening years.
Scientists also saw that the solar wind (illustrated in the image above) – the flow of of protons and electrons continuously streaming from the sun at about 400 kilometres per second – is deflected around Pluto because of the dwarf planet's atmosphere.
Bagenal et al. / Science
It’s atmosphere is colder and more compact than we thought.
Before New Horizons, we knew Pluto had an atmosphere but we didn't know all that much about it.
(Above is a picture of New Horizons incase you'd forgotten when it looked like).
There’s a haze all over the planet that goes all the way up to high altitudes.
You might recognise this photo as one of the first that came out shortly after the New Horizon's spacecraft passed by Pluto. Well, now scientists have done some science on it, and they've found that the haze that apparently surrounds Pluto has got lots of thin layers. It also has a bluish colour, which means it's probably made up of lots of very small particles.
Gladstone et al. / Science