Space Mission `Finds` Dark Matter Traces

[Hum]

(ANSA) - Rome, April 2 - An Italian-led space mission may

have collected the first concrete evidence of dark matter,

according to scientists.

A highly sensitive detector launched in 2006 to study

cosmic rays has recorded an unexpected abundance of

positrons, the antimatter counterpart of the electron, which

may be left behind when dark matter is destroyed.

``This is a fantastic result,`` said research

coordinator Piergiorgio Picozza of the National Institute of

Nuclear Physics of the breakthrough to be published in

Nature.

``It`s the first real evidence of the possibility of

dark matter, although it`s still necessary to collect further

data``.

Further research will need to exclude other possible

sources of the positrons, such as spinning stars called

pulsars that emit electromagnetic radiation, or cosmic rays

impacting with atoms.

But Picozza said he was ``hopeful`` that other sources

would be ruled out.

Dark matter is the hypothetical, invisible matter

believed by astrophysicists to account for around 23% of the

universe, and whose presence is inferred from gravitational

effects on visible matter.

Visible matter, which makes up the stars and planets,

comprises just 4-5% of the universe, while the remaining 72%

is dark energy, a hypothetical energy form that some

cosmologists say is behind the accelerating rate of the

expansion of the universe.

Picozza and his team used data from the Pamela (Payload

for Antimatter Matter Exploration and Light-nuclei

Astrophysics) satellite, which is a joint initiative between

Italy, Germany, Sweden and Russia.

source