Astronomers have detected a large body which measures 1.3 km (0.8 miles) in length at the very edge of the Solar System. Scientists claim that the mysterious object is a first ever sighting and could be a remaining piece of the early solar system

• Astronomers detected a large body which measures 1.5 miles (2.4km) in length
• Mass on the Kuiper Belt could be a remaining piece of the early solar system
• Team monitored a large number of stars and watched for the shadow of an object to pass in front of one of the stars after analysing the data

Astronomers have detected a 1.5 mile (2.4km) wide rock hovering at the very edge of the solar system. 

Scientists claim that the mysterious object is the first ever sighting of its kind and could be a missing piece in the evolution of the early solar system. 

The large rock may hold key clues to discovering the secrets of how our star system was born.

It is being heralded as a crucial intermediate step towards knowing how small clouds of dust and ice turned into the planets we have today. 

It was found way beyond the outermost planet, Neptune in the Kuiper Belt, a circumstellar disc in the outer Solar System that holds a collection of small celestial icy objects; the most famous of these is the dwarf planet, Pluto.  

The icy bodies found here are believed to be remnants left over from the formation of the Solar System.  

Small bodies like asteroids in the inner Solar System have been altered by solar radiation, collisions, and the gravity of the planets over time.

But objects in the cold, dark Kuiper Belt preserve the pristine conditions of the early Solar System, which is why astronomers study them.  

Kuiper Belt Objects with a radii of one kilometer or more have been thought to exist, but they are too distant, small, and dim for telescopes to observe directly. 

But, the research team at the National Astronomical Observatory of Japan experimented by using a technique known as occultation.

The large mass could hold clues to how the early formation of our solar system and the process that turned small clouds of dust and ice into the planets we have today. Artist's impression

This approach involves monitoring a large number of stars and watching for the shadow of an object to pass in front of one of the stars. 

Led by astronomer Ko Arimatsu, the team placed two 28 cm telescopes on Miyako Island in Okinawa and surveilled approximately 2000 stars for a total of 60 hours.

They found that one star appeared to dim as a 1.6 mile (2.4km) wide object's shadow was thought to have obscured it.

WHAT IS THE KUIPER BELT?

 The Kuiper Belt is one of the largest structures in our solar system - others being the Oort Cloud, the heliosphere and the magnetosphere of Jupiter. 

Scientists are still just beginning to explore and our understanding is still evolving. 

Its overall shape is like a puffed-up disk, or donut. Its inner edge begins at the orbit of Neptune, at about 30 AU from the Sun.

The inner, main region of the Kuiper belt ends to around 50 AU from the Sun. 

Overlapping the outer edge of the main part of the Kuiper Belt is a second region called the scattered disk, which continues outward to nearly 1,000 AU, with some bodies on orbits that go even farther beyond.  

 

 How was the Kuiper Belt created?

Astronomers think the icy objects of the Kuiper Belt are remnants left over from the formation of the solar system. 

Similar to the relationship between the main asteroid belt and Jupiter, it's a region of objects that might have come together to form a planet had Neptune not been there. 

Instead, Neptune's gravity stirred up this region of space so much that the small, icy objects there weren't able to coalesce into a large planet.

The researchers claim that the find indicates that there are more kilometer-sized objects in the Kuiper belt than previously thought. 

This supports models where planetesimals first grow slowly into kilometer sized objects before runaway growth causes them to turn into planets.

Runaway growth is an important stage in planet formation during which large protoplanets form, while most of the initial mass remains in small planetesimals. 

Ko Arimatsu explains, 'This is a real victory for little projects. Our team had less than 0.3 per cent  of the budget of large international projects. 

'We didn't even have enough money to build a second dome to protect our second telescope!'

'Yet we still managed to make a discovery that is impossible for the big projects. Now that we know our system works, we will investigate the Kuiper Belt in more detail.'