BEYOND PLUTO
All About Space UK|Issue 145
From Planet X to objects frozen in time – what truly lurks outside the Solar System’s chaotic frontier
James Romero
BEYOND PLUTO

Like an archaeological dig into the history of our Solar System.” That’s how New Horizons principal investigator Howard Stern described the spacecraft’s mission to Pluto and the outer Solar System. In recent decades, our ability to peer into the murky edges of the Solar System and map the populations of icy bodies that reside there has not only changed our understanding of the true scale and nature of the Solar System, but has also shone a light on the past, on how the current arrangement of rocky and icy worlds came to be and how interactions with the wider galaxy might shape its future.

Residents of the outer Solar System can be divided into various populations by their current orbits, history of orbital interactions or their compositional makeup. Kuiper Belt objects (KBOs) are the first population encountered as you move beyond the orbit of Neptune at around 30 astronomical units (AU) – one AU is the Earth-Sun distance. This sparsely populated ring extends out to 2,000 AU and includes icy bodies left over from the formation of the Solar System. Larger residents include Pluto, as well as Eris, Makemake and Haumea, which along with many much smaller inhabitants form a large subgroup known as ‘hot’ Kuiper belt objects.

Hot KBOs owe their current positions to an ancient eviction of between 10 and 30 Earth masses worth of small bodies from the Solar System’s inner regions, likely caused by ancient jostling of young gas and ice giants. This violent event is still evident in hot KBOs’ eccentric orbits, often at significant angles from the general plane of the Solar System.

This story is from the {{IssueName}} edition of {{MagazineName}}.

Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.

This story is from the {{IssueName}} edition of {{MagazineName}}.

Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.

MORE STORIES FROM ALL ABOUT SPACE UKView all
MYSTERIES OF THE UNI WHERE ARE ALL THE SPIRAL GALAXIES?
All About Space UK

MYSTERIES OF THE UNI WHERE ARE ALL THE SPIRAL GALAXIES?

There are far fewer spiral galaxies than elliptical ones in the Supergalactic Plane, and scientists are keen to discover why

time-read
7 mins  |
Issue 161
ZOMBIE STARS
All About Space UK

ZOMBIE STARS

+10 OTHER TERRIFYING SPACE OBJECTS

time-read
8 mins  |
Issue 161
HOW TO BEAT LIGHT POLLUTION
All About Space UK

HOW TO BEAT LIGHT POLLUTION

Thought it was impossible to observe the wonders of the night sky from towns and cities? Think again. Follow our tips and tricks on successfully observing through sky glow

time-read
2 mins  |
Issue 161
15 STUNNING STAR CLUSTERS
All About Space UK

15 STUNNING STAR CLUSTERS

These beautiful stellar groupings are spattered across the cosmos

time-read
8 mins  |
Issue 161
Eileen Collins "It was a difficult mission...we were the first to see Mir"
All About Space UK

Eileen Collins "It was a difficult mission...we were the first to see Mir"

Having served as both the first female pilot and first female commander of NASA's Space Shuttle, Collins boosted the involvement of women in space exploration to a whole new level

time-read
9 mins  |
Issue 161
MARS LEAKS FASTER WHEN IT'S CLOSER TO THE SUN
All About Space UK

MARS LEAKS FASTER WHEN IT'S CLOSER TO THE SUN

The Red Planet has lost enough water to space to form a global ocean hundreds of kilometres deep

time-read
2 mins  |
Issue 161
FUTURE TECH KANKOH-MARU
All About Space UK

FUTURE TECH KANKOH-MARU

This ambitious reusable spacecraft will be capable of taking 50 people to and from orbit

time-read
2 mins  |
Issue 161
THE FINAL FRONTIER
All About Space UK

THE FINAL FRONTIER

Beyond the reach of the Sun is a fascinating region of the cosmos that were only just beginning to explore

time-read
8 mins  |
Issue 161
A long-lost moon could explain Mars' weird shape and extreme terrain
All About Space UK

A long-lost moon could explain Mars' weird shape and extreme terrain

A long-lost moon could explain why Mars is so different from the other rocky planets in the Solar System. Today Mars has two tiny moons.

time-read
2 mins  |
Issue 161
A sprinkling of cosmic dust may have helped kick-start life on Earth
All About Space UK

A sprinkling of cosmic dust may have helped kick-start life on Earth

Cosmic dust may have helped kick-start life on Earth. New findings challenge a widely held assumption that this wasn't a plausible explanation.

time-read
3 mins  |
Issue 161