Most people will be familiar with snow on Earth, but it seems there may be blizzards in space too.

Astronomers have seen a mixture of ice, water and snow in the disk of dust and gas surround a young star.

But while on Earth snow can mean a day of sledging and chaos on the roads, in space it may be a fundamental part of the formation of planets.

When stars are young, they are often surrounded by a disk of dust and gas that stretches for billions of miles, from which planets can be born. Part of this, where water turns from gas into ice, is called the water snow line. This is an artist's impression of the water snow line around the young star V883 Orionis

SNOW IN SPACE The bizarre idea of snow orbiting in space is fundamental to planet formation. The presence of water ice regulates the efficiency of the coagulation of dust grains - the first step in planet formation. Within the snow line, where water is vapourised, smaller, rocky planets like our own are believed to form. Outside the water snow line, the presence of water ice allows the rapid formation of cosmic snowballs, which eventually go on to form massive gaseous planets such as Jupiter. Advertisement

When stars are young, they are often surrounded by a disk of dust and gas that stretches for billions of miles, from which planets can be born.

Because of the heat from the star, any water too close to the star itself would be gas, but after a certain distance the water transitions from gas straight to solid ice, because of the low pressure.

Where the transition takes place is called the 'water snow line' and the new research is the first time one has been caught on camera.

It is in the water snow line that water is vapourised, and small rocky planets like our own are believed to form.

Outside the water snow line, the presence of water ice allows cosmic snowballs to form, which eventually go on to form massive gaseous planets such as Jupiter.

Normally the disk surrounding young stars, or the 'protoplanetary disk' is not large enough for this water snow line to be resolved using telescopes.

But researchers came across an unusual star called V883 Orionis, which they found has a protoplanetary disk that stretches out to 40 times the distance between Earth and the sun, otherwise known as 40 astronomical units (au).

This illustration shows how the outburst of the young star V883 Orionis has displaced the water snowline much further out from the star, and rendered it detectable with Alma

Image of the planet-forming disc around the young star V883 Orionis obtained by Alma, shown left, with the orbits of the planet Neptune and Pluto in our solar system shown for scale, right. The dark ring midway through the disc is the water snowline, where the temperature and pressure dip low enough for water ice to form

When stars are young, they are often surrounded by a disk of dust and gas that stretches for billions of miles, from which planets can be born. Normally the disk surrounding young stars, or the 'protoplanetary disk' (artist's impression pictured) is not large enough for the water snow line to be resolved using telescopes

THE WATER SNOW LINE When stars are young, they are often surrounded by a disk of dust and gas that stretches for billions of miles, from which planets can be born. Because of the heat from the star, any water too close to the star itself would be gas, but after a certain distance away the water transitions from gas straight to solid ice, because of the low pressure. Where the transition takes place is called the 'water snow line'. Advertisement

This is 3.7 billion miles (6 billion km), which is roughly the distance between our sun and Pluto.

The stretching of the disk was caused by a dramatic increase in the star's brightness, the group said.

The star, which is in the Orion constellation, is faint so can only be seen with a telescope.

Because the disk was so large, the researchers could see the water snow line.

The sudden brightening that V883 Orionis experienced is an example of what occurs when large amounts of material from the disc surrounding a young star fall onto its surface.

V883 Orionis is only 30 per cent more massive than the sun, but the outburst it is experiencing makes it 400 times brighter, and much hotter.

The team, led by researchers from the Universidad Diego Portales in Santiago, Chile, used the Attacama Large Millimetere Array (Alma) telescope in Chile to study the star.

'The ALMA observations came as a surprise to us,' said lead author Professor Lucas Cieza.

'Our observations were designed to look for disc fragmentation leading to planet formation. We saw none of that; instead, we found what looks like a ring at 40 au.'