Penticton, BC: Canadian and French astronomers are set to embark
together on a massive exploration of the universe using a unique new
instrument. The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS)
will be the largest observing project in Canada over the next five
years. Its goals are to determine the properties of the dark energy
that is driving the acceleration of the universe, to precisely the
measure the amount of dark matter, and to study the dark chunks of rock
and ice leftover from the formation of the solar system.

The CFHTLS will run for approximately 500 nights over the next five
years at the 3.6 metre (142 inch) Canada France Hawaii Telescope (CFHT)
on Mauna Kea, Hawaii. This is the first time a large telescope has been
so dedicated to a single project. The CFHTLS will take over 2000
pictures with the newly built MegaCam, the world’s largest astronomical
camera. MegaCam is capable of taking a one square degree picture of
the sky at a time (for comparison, the Moon takes up only 1/4 of a
square degree).

The CFHTLS three related observational components. The first of these
is the UltraDeep Survey, which will help astronomers choose among the
possible candidates for “dark energy”. Dark energy is a mysterious
repulsive force that was proposed to explain the apparent acceleration
of the universe. This acceleration was discovered in 1998 by studying
images of approximately 80 supernovae. The UltraDeep Survey will find
about 2000 new supernovae, some as distant as 10 billion light years (a
redshift of z = 1.4). This will be the largest sample of supernovae
from any ground-based telescope.

The second component, known as the Deep Survey, will allow astronomers to
create maps of “dark matter”. Dark matter is an unknown substance that
makes up over 90% of the gravitating mass in the universe. Dark matter
cannot be seen directly, but its gravitational field will bend light that
travels through it, in a process known as “gravitational lensing”. The
Deep Survey pictures will contain approximately 2 000 000 galaxies. The
galaxies will be analyzed to determine how their light has been bent by
the dark matter. The dark matter maps created from the Deep Survey data
will be the largest ever made.

The third component, the UltraWide Survey, will find 1000 or more Kuiper
Belt Objects (KBOs). KBOs are chunks of rock and ice that orbit our sun
out beyond Neptune, the leftovers from the disk that formed our solar
system. The UltraWide Survey will find the biggest of the KBOs, some of
which may be even larger than the “planet” Pluto. Studying these objects
will help astronomers understand how our planets formed, which in turn
will help them understand the formation of planets orbiting other stars.
The UltraWide Survey will be the first comprehensive survey of the KBOs.

The CFHTLS is a joint project of the Canadian and French astronomical
communities. Any of the hundreds of astronomers in Canada and France
are able to register to become part of the project. All project
members will have equal and simultaneous access to the data for any
scientific purpose they choose. This way of managing telescope time
and data handling is unique for such a large project.

The CFHT is operated by the National Research Council of Canada, le Centre
National de Recherche Scientifique in France, and the University of
Hawaii. The CFHTLS is supported by the Centre National de la Recherche
Scientifique and the Institut National des Sciences de l’Univers in
France, the Canada France Hawaii Telescope, and the National Research
Council and the Natural Sciences and Engineering Research Council in

For more information, please contact:

Prof. Ray Carlberg

Department of Astronomy and Astrophysics

University of Toronto

Phone: (416) 978-2198


Dr. David Schade

Group Leader, Canadian Astronomy Data Centre

Herzberg Institute of Astrophysics

National Research Council

Phone: (250) 363-6904


Margaret Milne

CFHTLS Canadian Media Contact

Phone: (250) 721-7747