Astronomers have lost thousands of comets. A University of
Melbourne physicist thinks they may still be there, just invisible
and some of them potentially on a collision course with Earth.

Dr Robert Foot suggests that many of the missing comets could be
made of an exotic material called ‘mirror matter’, a new type of
invisible matter that a small group of physicists believe could
be the elusive ‘dark matter’. Dark matter is considered the
cosmic scaffolding that makes up most of the universe, but
nobody can identify it.

"If mirror matter exists, then there should exist also mirror
stars, mirror planets, even mirror life. Over the last few years
almost every astrophysical and experimental prediction of the
theory has actually been observed by observations and
experiments," says Foot.

"Most tantalysing of all, is evidence that our planet is
frequently bombarded by asteroids made of mirror matter, causing
puzzling events such as the devastating Siberian explosion in
1908 and similar, but smaller recent events in Jordan and
Spain," he says.

Foot has outlined his theories and those of other mirror matter
proponents in a new book, Shadowlands-quest for mirror matter
in the Universe.

The theory of mirror matter has been around for decades. The case
of the missing comets has baffled scientists for nearly as long.
Yet, if Foot is right, the two mysteries may have a common and
potentially cataclysmic answer.

Astronomers have found that most comets disappear after their
first pass through our solar system. The consensus is that they
either disintegrate or ‘turn off’, having lost their volatile
gases and ice that form their glowing head and tail. They
become, in effect, chunks of rock similar to asteroids.

But some US scientists recently did some modelling and number
crunching to determine the fate of the missing comets. They came
to the striking conclusion that the number of dormant comets or
asteroids being discovered is far too low to accommodate the
predicted number — about 100 times too low. So where did they

Dr Foot says there is a good case for these missing comets to
be made of mirror matter. He points to some freaky and, so far,
inexplicable events to make his case.

Tunguska, Siberia was the site of a blast with the explosive
power of 1000 atomic bombs that flattened 2100 square kilometres
of forest in 1908. Scientists have blamed an asteroid, but
remarkably they have found no crater, no evidence of meteorite
fragments and no significant chemical traces.

In Jordan, April 2001, 100 witnesses on their way to a funeral
watched a ball of light streak across the sky at low altitude,
break into two, and then slam into a hill about one kilometre
away. Again, local astronomers found neither a crater nor
evidence of a meteorite; just a patch of scorched earth and
burnt trees.

"These events cannot be explained in terms of a space-body
made of ordinary matter. If the Jordan space-body was made of
ordinary matter it should have lit up a large part of the
Middle East. This was not observed," says Foot.

So what is mirror matter and how does it affect us?

Nearly 50 years ago physicists discovered that the way particles
interact was not symmetrical. Instead, they are predominantly
left-handed. This was contrary to the strongly held belief that
all fundamental interactions were mirror symmetric. That is,
for every left hand interaction there was a right hand
interaction to balance it out.

This is where mirror matter makes its entrance. Mirror matter is
the predicted right hand or mirror image of ordinary matter. For
each of the known basic particles, such as the electron, proton
and photon, there is a distinct mirror partner. Where the
ordinary particles favour the left hand, the mirror particles
favour the right hand.

It is thought that ordinary particles, for example, photons
(light particles), cannot interact or couple with mirror
particles directly. Because we are made of ordinary matter we
are unable to see mirror photons and therefore the world of
mirror matter remains invisible to us.

Theory predicts, however that mirror particles have a mass. This
means one force that does act on both is gravity, which means we
should be able to detect this effect. It is one fact that takes
mirror matter out of the realms of science fiction and into
reality. Another is the possibility of new forces connecting
ordinary and mirror matter.

A recent experiment suggests one such force could exist. The
force measured was a small electromagnetic coupling between
mirror and ordinary particles. Two groups, including the world’s
largest physics research centre, CERN, are about to begin highly
sensitive experiments to try and confirm the existence of this

Foot has calculated this force, should it exist, is sufficient
to allow interactions between ordinary particles and those of
a mirror asteroid entering the Earth’s atmosphere.

These interactions could allow heat to build up within the
mirror body, causing it to explode. It would also make the
mirror body visible. If the events of Tunguska and Jordan are
the results of mirror space-bodies, then tonnes of mirror
matter might lie hidden just below the surface of these sites,
waiting to be found. Nobody has looked," says Foot

"As for the missing comets, they could simply be mirror comets
with embedded ordinary matter. Once they have passed the sun,
their ordinary volatile components progressively burn off
leaving an invisible mirror matter core. This would explain
why so many simply fade away," he says.

Dr Foot’s website on mirror matter can be found at
It contains links to further information and his new book.

[NOTE: Images supporting this release are available at ]