Telescopes

Close your eyes.

Create a picture in your mind of a telescope.

Think about: What does a telescope look like?

Did you picture a structure like this?

Compare size of the structure to the People. It is huge!

From Gemini North, astronomers watch the Universe with amazing power and precision.

This telescope stands eight stories tall, weighs 300 tons and operates with nanometre precision.

A Canadian company builds the structures for this and other telescopes around the world

Likely you pictured something like this...

Telescopes like this are used by many amateur astronomers for enjoyment, research and public education.

Telescopes come in all shapes and sizes, from a little plastic tube you buy at a toy store for $2, to the Hubble Space Telescope, which weighs several tons.

Definition

• Telescope: a device to collect light (or other radiation) and bring it to a focus, where it can be studied with camera, spectrographs or other instruments.

Invention of the Telescope• The breakthrough for astronomy came

with the invention of the telescope. An Italian named Galileo Galilei was the first to construct an astronomical telescope in 1610 and use it to look at the night sky.

• His small handheld telescope did not provide sharp images and had a magnification of only 20 times (similar to modern binoculars), but what Galileo saw was unlike anything anyone had ever seen before.

• Over the first few months of observations Galileo had discovered more about the solar system and the universe than anyone had previously achieved.

What Could Galileo see?• To the naked eye Venus appeared

as any other star in the night sky but using his telescope Galileo could see that Venus appeared to have phases, similar to the Moon.

• These signified that the Earth was not the center of the solar system, the sun was.

What Could Galileo see?

• Numerous craters and mountains on the Moon

• Rings around Saturn• Four of Jupiter’s moons.• Spots on the Sun

Telescopes Today...

• With larger telescopes came a higher image resolution and greater light gathering power, giving astronomers clearer images and allowing them to probe deeper into the universe.

• There are telescopes that collect radio waves, infrared and other forms of radiation.

Giant Telescopes

• Today, two of the world’s largest telescopes are the Keck I and II telescopes in Hawaii. They are constructed of 36 individual mirrors measuring 1.8 metres across, giving the telescope a mirror with an effective diameter of 10 metres.

Hubble Space Telescope• The atmosphere limits the capabilities of Earth-

based telescopes• HST went into orbit on the Space Shuttle in 1990• The HST cost more than every major observatory

on the Earth combined• The Hubble Space Telescope has produced some

of the most amazing images of our universe, and has given astronomers valuable information about everything from the solar system and the birth and death of stars to the beginnings of the universe.

The Hubble Space Telescope

What has Hubble shown us?

Hubble's camera takes a deep look at two merging galaxies.

Chaotic activity atop a pillar of gas and dust, where stars and planets are forming.

The smallest dots on this image are distant galaxies whose light has taken billions of years to reach us

Six of Saturn’s moons shown in orbit.

Canadian Astronomy• The Dominion Radio

Astrophysical Observatory (DRAO) in Penticton, B.C. boasts an array of seven radio telescopes and also has a 26 metre radio telescope.

Dunlap Observatory

• The David Dunlap Observatory in Richmond Hill, Ontario, houses the largest telescope in Canada.

• The Royal Astronomical Society of Canada, Toronto Centre, operates the 74-inch reflecting telescope and is providing public education and outreach programs at the DDO.

• Interested in stargazing? Perhaps a visit to the Dunlap Observatory could be your next family outing!

• Public events are held most Saturday nights from early summer through the fall months.

• www.theddo.ca

Canadian Astronomy

Did you know that... • At one time, Canada had two of the three largest telescopes

in the world!• When the Dominion Astrophysical Observatory opened in

1918, its telescope (usually said to be a 72" (mirror diameter) telescope but actually a 73" telescope) was briefly the largest in the world, until the 100" telescope on Mount Wilson opened a few months later. When the David Dunlap Observatory (U of T) opened in 1935, its 74" telescope was #2, and the DAO telescope was #3.

Canadian Astronomy• Our country has also

contributed to many international projects, often in collaboration with the United States. One observatory heavily used by professional Canadian astronomers is the Canada-France-Hawaii Telescope in Hawaii.

• The CFHT is a 3.6 metre state of the art telescope used for valuable research by astronomers.

Canadian Astronomy• Canadians have contributed to

the construction of two new telescopes one is located in the Chilean Andes (Gemini South), the other in Hawaii (Gemini North)

• These telescopes are among the most technically advanced in the world, and their 8 metre mirrors provide Canadian astronomers with the best available tools to conduct their research.

Gemini Telescope

Thirty Meter Telescope

Thirty Meter Telescope• a team of scientists and

engineers is busily designing what eventually will become the most powerful telescope on Earth. When completed in 2018, the Thirty Meter Telescope (TMT) will enable astronomers to study objects in our own solar system, our Milky Way and its neighbouring galaxies, and forming galaxies at the very edge of the observable Universe, near the beginning of time.

• It will be about 15 times larger than the current largest telescope and have capabilities that surpass the Hubble Space Telescope.

Canadian Astronomy

• TMT is a partnership between Canada and some California Universities

• This would mean that Canadian astronomers would have guaranteed access to it. That'sthe way it presently works with the twin Gemini 8m telescopes and the Canada-France-Hawaii 4m telescope. Canada gets acertain fraction of the time. The benefit, of course, is that our astronomers get access to the best facilities in the world.

• Check out the following video to learn more fascinating things about the Thirty Meter Telescope:

http://www.tmt.org/gallery/video/tmt-overview