48 ||MAY/JUNE 2017
Mysterious Radio Bursts
from Outer Space
The search for extraterrestrial intelligence has looked for many
different signs of alien life, from radio broadcasts to laser flashes,
without success. However, new speculative research suggests
that the mysterious phenomena called “fast radio bursts” could
be evidence of advanced alien technology. A big call? You bet!
Specifically, they say these FRBs might be leakage from
planet-sized transmitters powering interstellar probes in distant
galaxies. Pretty much like a solar sail I guess. Either way, FRBs
present one of modern astronomy’s greatest mysteries.
Manisha Caleb, a PhD candidate at the Australian National
University, Swinburne University of Technology and the ARC
Centre of Excellence for All-sky Astrophysics (CAASTRO)
has now confirmed that these signals really do exist, having
worked with Swinburne and University of Sydney colleagues to
detect three FRBs with the Molonglo radio telescope 40 km
from Canberra.
Discovered almost 10 years ago at CSIRO’s Parkes radio
telescope, FRBs are millisecond-duration intense pulses of radio
light that appear to be coming from vast distances. They are
about a billion times more luminous than anything we have
ever seen in our own Milky Way galaxy.So, what or who in the universe is transmitting short bursts
of radio energy across the cosmos, seemingly in our direction?
One potential answer to the mystery is that they weren’t really
coming from outer space, but were some form of local inter-
ference tricking astronomers into searching for new theories of
their radio energy. “Conventional single dish radio telescopes
have difficulty establishing that transmissions originate beyond
the Earth’s atmosphere,” says Swinburne’s Dr Chris Flynn.
The Molonglo telescope has a huge collecting area of 18,000 m^2
and a large field of view, which makes it excellent for hunting
for FRBs. Caleb’s project was to develop software to sift through
the 1000 TB of data produced each day. Her work paid off with
the three new FRB discoveries.Public Search for Ninth Planet
NASA is inviting the public to help search for possible undiscovered
worlds in the outer reaches of our solar system and in neighbouring
interstellar space. A new website called Backyard Worlds: Planet 9
(http://backyardworlds.org) lets everyone participate in the search by
viewing images captured by NASA’s Wide-field Infrared Survey
Explorer (WISE) mission.
WISE scanned the entire sky between 2010 and 2011, producing
the most comprehensive survey at mid-infrared wavelengths currently
available. In 2013 it was given a new mission assisting NASA’s efforts
to identify potentially hazardous near-Earth objects, which are
asteroids and comets on orbits that bring them into the vicinity of the
Earth’s orbit.
The new website uses the data to search for unknown objects in
and beyond our own solar system. In 2016, astronomers at Caltech in
California believed an as-yet undetected “Planet Nine” could be so
bright it would show up in WISE data. Planet Nine would likely be two
to four times the Earth’s diameter, and ten times its mass, orbiting the
Sun every 15,000 Earth years, or about 800 times the distance
between Earth and the Sun.
The search also may discover more distant objects like brown
dwarfs, sometimes called failed stars, in nearby interstellar space. By
using Backyard Worlds: Planet 9 , the public can help astronomers
discover more of these strange rogue worlds by using their own
computer. If you find it you may have naming rights!Backyard Worlds: Planet 9 relies on human eyes because we easily
recognise the important moving objects while ignoring the artefacts.
It’s a 21st century version of the technique astronomer Clyde
Tombaugh used to find Pluto in 1930.
On the website, people around the world can work their way
through millions of “flipbooks” – brief animations showing how small
patches of the sky changed over several years. Moving objects
flagged by participants will be prioritised by the science team for
follow-up observations by professional astronomers.
Backyard Worlds: Planet 9 has the potential to unlock once-in-a-
century discoveries, and it’s exciting to think they could be spotted
first by a citizen scientist. The tantalising thing is it may be found by a
reader of this magazine – someone like you!David Reneke is an astronomy lecturer and teacher, a feature writer for major Australian newspapers and magazines, and a science correspondent for ABC and commercial radio.
Subscribe to David’s free Astro-Space newsletter at http://www.davidreneke.comAn artist’s illustration of a light sail powered by a radio beam,
which would create fast radio bursts similar to those found
recently at cosmological distances. Credit: M. Weiss/CfAOUT OF THiS WOrLD David reneke
Artists’ impression of NASA’s WISE orbiting observatory
looking for traces of life out there. Credit: NASA