Dr. Ragbir Bhathal received a signal from the direction of Gliese 581 - but has heard nothing since
astronomer picked up a mysterious pulse of light coming from the
direction of the newly discovered Earth-like planet almost two years
ago, it has emerged.
Dr Ragbir Bhathal, a scientist at the
University of Western Sydney, picked up the odd signal in December 2008,
long before it was announced that the star Gliese 581 has habitable
planets in orbit around it.
A member of the Australian chapter of
SETI, the organisation that looks for communication from distant
planets, Dr Bhathal had been sweeping the skies when he discovered a
'suspicious' signal from an area of the galaxy that holds the
newly-discovered Gliese 581g.
The remarkable coincidence adds another
layer of mystery to the announcement last night that scientists had
discovered another planet in the system: Gliese 581g - the most
Earth-like planet ever found.
Dr Bhathal's discovery had come just
months before astronomers announced that they had found a similar,
slightly less habitable planet around the same star 20 light years away.
This planet was called Gliese 581e.
When asked about his discovery
at the time Dr Bhathal admitted he had been really excited about what he
had possibly stumbled across.
He said: 'Whenever there’s a clear
night, I go up to the observatory and do a run on some of the celestial
objects. Looking at one of these objects, we found this signal.
you know, I got really excited with it. So next I had to analyse it. We
have special software to analyse these signals, because when you look
at celestial objects through the equipment we have, you also pick up a
lot of noise.'
He went on: 'We found this very sharp signal, sort of a
laser lookalike thing which is the sort of thing we’re looking for - a
very sharp spike. And that is what we found. So that was the excitement
about the whole thing.'
For months after his discovery Dr Bhathal
scanned the skies for a second signal to see whether it was just a
glitch in his instrumentation but his search came to nothing.
discovery of Earth-like planets around Gliese 581 - both 581e and 581d,
which was in the habitable zone - has also caught the public
Documentary-maker RDF and social-networking site Bebo
used a radio telescope in Ukraine to send a powerful focused beam of
information - 500 messages from the public in the form of radiowaves -
to Gliese 581.
And the Australian science minister at the time
organised 20,000 users of Twitter to send messages towards the distant
solar system in the wake of the discoveries.
artist's conception shows the inner four planets of the Gliese 581
system and their host star, a red dwarf star only 20 light years away
from Earth. The four tiny planets in the background are the planets that
have already been discovered. The closer, blue and green planet is
581G, the most Earth-like planet ever discovered
And Dr Steven
Vogt who led the study at the University of California, Santa Cruz,
today said that he was '100 per cent sure ' that there was life on the
The planet lies in the star's 'Goldilocks zone' - the
region in space where conditions are neither too hot or too cold for
liquid water to form oceans, lakes and rivers.
The planet also
appears to have an atmosphere, a gravity like our own and could well be
capable of life. Researchers say the findings suggest the universe is
teeming with world like our own.
'If these are rare, we shouldn't have found one so quickly and so nearby,'
number of systems with potentially habitable planets is probably on the
order of 10 or 20 per cent, and when you multiply that by the hundreds
of billions of stars in the Milky Way, that's a large number. There
could be tens of billions of these systems in our galaxy.'
GLIESE 581g FACT FILE
Diameter - 1.2 to 1.4 times that of the Earth
Mass - 3.1 and 4.3 times that of the Earth
Average surface temperature - between -24F and 10F (-31C and -12C)
Distance from the Earth - 20 light years or 118,000,000,000,000 miles
Time needed to travel to Gliese 581g in a rocket travelling one tenth the speed of light, or 19,000 miles per second - 200 years
One of six planets to orbit the star Gliese 581
Length of year - 37 Earth days
Gravity - similar or slightly higher than Earth
Distance from its sun - around six million miles
The planet orbits a red dwarf which is 50 times cooler and a third the size of our Sun
Composition - rocky with liquid water and atmosphere.
told Discovery News: 'Personally, given the ubiquity and propensity of
life to flourish wherever it can, I would say that the chances for life
on this planet are 100 percent. I have almost no doubt about it'.
planet is so far away, spaceships travelling close to the speed of
light would take 20 years to make the journey. If a rocket was one day
able to travel at a tenth of the speed of light, it would take 200 years
to make the journey.
Planets orbiting distant stars are too small to
be seen by telescopes. Instead, astronomers look for tell-tale
gravitational wobbles in the stars that show a planet is in orbit.
The findings come from 11 years of observations at the W. M. Keck Observatory in Hawaii.
planet orbits a small red star called Gliese 581 in the constellation
of Libra. The planet, named Glieseg, is 118,000,000,000,000 miles away -
so far away that light from its start takes 20 years to reach the
It takes just 37 days to orbit its sun which means its seasons
last for just a few days. One side of the planet always faces its star
and basks in perpetual daylight, while the other is in perpetual
The most suitable place for life or future human colonists
would be in the 'grey' zone - the band between darkness and light that
circles the planet.
'Any emerging life forms would have a wide range
of stable climates to choose from and to evolve around, depending on
their longitude,' said Dr Vogt who reports the find in the Astrophysical
If Gliese 581g has a rocky composition similar to the
Earth's, its diameter would be about 1.2 to 1.4 times that of the Earth.
It's gravity is likely to be similar - allowing a human astronaut to
walk on the surface upright without difficulty.
doesn't have days and nights. Wherever you are on this planet, the sun
is in the same position all the time. You have very stable zones where
the ecosystem stays the same temperature... basically forever,' Vogt
581, the brightest object in this Nasa image from 2007, is only 20
light years from Earth and is one of our nearest neighbours
life can evolve, it's going to have billions and billions of years to
adapt to the surface. Given the ubiquity of water, it seems probable
that this thing actually has liquid water. On the surface of the Earth,
everywhere you have liquid water you have life,' Vogt added.
have now found six planets in orbit around Gliese 581 - the most
discovered in a planetary system other than our own solar system.
Like the solar system, the planets orbiting Gliese 581 have mostly circular orbits.
of its detected planets have previously been proposed as habitable
planets. However they lie at the extremes of the Goldilocks Zone - one
on the hot side, the other on the cold side.
Gliese 581g, in contrast, lies right in the middle.
star has not been given a proper name. It appears in a catalogue of
stars compiled by the German astronomer William Gliese where it has been
given the reference number 581.
Astronomers name planets found orbiting stars with a letter.
The previous five planets found around Gliese 581 were named b to f, making the latest discovery Gliese 581g.
star is a red giant - a massive star near the end of its life. It is
too dim to see in the night sky from Earth without a telescope.
Astronomers have found nearly 500 exoplanets - or planets outside our own solar system.
However, almost all are too big, made of gas instead of rock, too hot or too cold for life as we know it.
orbits of planets in the Gliese 581 system are compared to those of our
own solar system. The Gliese 581 star has about 30% the mass of our
sun, and the outermost planet is closer to its star than we are to the
sun. The 4th planet, G, is a planet that could sustain life.