UK astronomers say they have unlocked one of the Universe's oldest secrets - the origin of cosmic dust.
Cardiff University and Royal Observatory Edinburgh scientists found that some stars throw out huge quantities of this dust when they explode.
The dust comes together to form planets
These explosions could be responsible for the Universe's first ever solid particles, they say in the journal Nature.
The scientists used the James Clerk Maxwell Telescope in Hawaii to make their discovery.
Astronomers had thought space dust was mostly made in the winds from cool, giant stars in the late stages of their lives.
Researchers used the Scuba instrument on the James Clerk Maxwell Telescope to hunt for dust in the remains of a star called Cassiopeia A, which is 11,000 light-years distant and exploded 320 years ago as viewed from Earth.
Until recently, astronomers had only been able to detect warm dust.
"This is because it operates at longer sub-millimetre wavelengths than the infra-red instruments used previously," said Dr Steve Eales, an astrophysicist at Cardiff.
"With Scuba we can see dust which is very cold."
The dust found indicated stars might have been responsible for the earliest particles in the Universe, the team said.
The James Clerk Maxwell Telescope was used in the work
Project leader Loretta Dunne added: "The origin of cosmic dust is, in fact, the basic question of the origin of our planet and others.
"Effectively, we live on a very large collection of cosmic dust grains and yet, until now, we have not been sure where cosmic dust is made."
Cosmic dust consists of tiny particles of solid material floating around in the space between the stars, but unlike house dust, it more closely resembles cigarette smoke and blocks out half of the light given off by stars and galaxies.
Dr Dunne added: "Dust has been swept under the cosmic carpet. For years, astronomers have treated it as a nuisance because of the way it hides the light from the stars.
"Now studies have shown that there is dust right at the edge of the Universe in the earliest stars and galaxies; we realise that we are ignorant of even its basic origin."