A few weeks after its historic Pluto flyby, NASA's New Horizons spacecraft continues to uncover new findings about the farthest dwarf planet in the solar system.

In its latest update on Pluto, NASA said the data collected by its space probe revealed two new important discoveries: that the dwarf planet has hazy skies and flowing "glaciers" of nitrogen ice on its surface.

"Pluto has a very complicated story to tell; Pluto has a very interesting history, and there is a lot of work we need to do to understand this very complicated place," New Horizons principal investigator Alan Stern said.

The NASA spacecraft detected layers upon layers of haze stretching some 100 miles into Pluto's atmosphere—five times further than models predicted.

These layers of haze are also believed to be the reason why the dwarf planet appears to have a reddish colour in photos taken by New Horizons.

New Horizons co-investigator Michael Summers from the George Mason University said the hazy skies may not be visible if you're standing on Pluto's surface looking up.

The hazy skies were quite prominent in a silhouette of Pluto's night side captured by New Horizons after the flyby.

"This is the image that almost brought tears to the eyes of the atmospheric science team," Summers said.

He further explained that layers of haze were formed when methane gas is broken apart by the sun's ultraviolet light.

Images captured by the New Horizons spacecraft also showed wavy patterns on Pluto's surface made of nitrogen ice that resemble the flowing ice of glaciers on Earth when viewed by satellites from outer space.

With temperature on Pluto's surface at a freezing minus 380 degrees Fahrenheit (minus 229 degrees Celsius), why would ice water move? New Horizons co-investigator Bill McKinnon said this could indicate that there could still be some warmth under Pluto's surface.