Canadian astronomers find new moons of Jupiter

Discovery boosts number of Jupiter’s known satellites to
a record 61

They were small and hard to find, but with the help of some
new telescopic equipment and cameras, UBC professor Brett
Gladman, UBC postdoctoral researcher Lynne Allen, and Dr.
J.J. Kavelaars of the National Research Council of Canada
have discovered nine previously unknown moons of Jupiter.
So far this year, 21 new Jupiter moons have been identified.

The discovery of the distant satellites, announced today
at the annual meeting of the Canadian Astronomical Society,
boosts the number of known moons on Jupiter to 61 — more
moons than any other planet in the solar system.

"The discovery of these small satellites is going to
help us understand how Jupiter and the other giant planets
formed," said Gladman, a Canada Research Chair in Planetary

The new satellites were a challenge to detect because most
are only about 1-5 kilometers in size. The feeble amounts
of light they reflect back to earth must compete against the
glare of brilliant Jupiter. Their small size and distance
from the Sun prevent the satellites from shining any brighter
than 24th magnitude, about 100 million times fainter than
can be seen with the unaided eye. To locate these new moons,
Gladman’s team used the new Megaprime mosaic of CCD cameras
at the 3.6m Canada-France-Hawaii telescope on Mauna Kea, Hawaii.

The mosaic camera enabled the team to take three images of
the entire sky around Jupiter. They used computer algorithms
to search the images for the faint points of light moving
across the sky as moons should.

Because moons can sometimes appear in front of distant stars
or lost in the light scattered from the planet, to find them
requires painstakingly repeating the search several times.
The team undertook the task between February and April 2003.

International members of the jovian search team include Cornell
University astronomers Phil Nicholson, Joseph A. Burns, and
Valerio Carruba, Jean-Marc Petit of the Observatoire de Besancon,
and Brian Marsden and Matthew Holman of the Harvard-Smithsonian
Center for Astrophysics.

For more information on the discovery visit Prof. Gladman’s
Web site at

To arrange an interview with Prof. Gladman or other members
of the discovery team, contact Michelle Cook, UBC Public Affairs
Office at 604.822.2048.