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Ways of Looking
Introduction
Explore how various peoples observe the sky and what it means to them. Learn what you can see with your own eyes, and discover some of the constellations that have important meaning for indigenous peoples. Find out how technology has changed the way we study the sky-but not our reasons for doing it.
Looking back in time
When you look at a star, you're actually seeing it as it appeared in the past. It takes sunlight about eight minutes to reach the Earth, so we see the Sun as it was eight minutes ago. Proxima Centauri, the closest star to the Sun, is 4.3 light-years away, so we see it as it was 4.3 years ago. Galaxies are so distant that we see them as they appeared millions, or even billions of years ago.
The spiral galaxy NGC 4603 is 103 million light-years away from us. | ©CFHT.
The Naked Eye
The simplest way of watching the stars is with your own two eyes. Long before telescopes or satellites, when the skies were free of city lights, people studied the stars to help tell time, predict the weather, and understand their place in the universe.
The stars, planets and constellations that we see have special meaning in different cultures. Stories about important life lessons have been passed down for generations, and some are still told today. On a dark, clear night, you can still see the celestial objects that inspired our ancestors-the same ones that give people today a sense of wonder and meaning.
Watching the Skies
Stars spin by the Gemini North Telescope in Mauna Kea, Hawaii. | Gemini North
What you see when you look at the sky depends a lot on where you're standing on the Earth.
If you're in the southern hemisphere, for example, in Australia, then maybe you've seen a
constellation called the
Southern Cross.
If you're in a country in the northern hemisphere, such as Canada, then perhaps you've spotted the
Big Dipper on a cold winter night.
The Milky Way
Under ideal conditions, about 3 000 stars are visible to the naked eye, and if you're far from artificial lights, you can see a hazy band of light that stretches across the sky. What you're looking at is the flat edge of our own galaxy, the Milky Way, seen from the inside out.
Watch a video about the Milky Way.
© Gemini North
Cheepahi Meskanaw (Cree) is translated into English as the Spirit
Road. This is the path marked across the sky by the Milky Way
galaxy when it is turned westward. According to traditional beliefs,
the spirit of a person who dies on Earth ascends into the star world,
then dances along this path to the place of eternal happiness in the
West, beyond the setting Sun. In the Anishinabe language, the Milky Way
is called Binessiwi Mekuna, the Bird's Path. In autumn, when it
points South, the birds follow it. In spring, it turns North and the birds
follow it back again.
The Milky Way is considered a
wolf trail or a
river by different indigenous cultures.
Spinning Sky
As the Earth orbits the Sun, it also spins on its axis, so we spend about half a day facing
the Sun and half facing away from it. The Earth's rotation makes everything in the sky
appear to rise in the east and set in the west. In reality, the Sun and the stars aren't
moving around the Earth. Instead, it's the Earth turning on its axis that creates that
impression.
A time exposure photograph centred on Polaris, the northern pole star, or on Sigma Octantis in the south, shows circles of star trails which are dramatic proof that the Earth spins on its axis. Because these stars are located above the North and South Poles (the Earth's axes of rotation), the other celestial objects appear to revolve around them.
Earth. | © NASA.
The angle at which you see stars rise and set actually depends on where you are on the Earth. For example, if you were standing at the North or South Pole, the stars would never rise or set, they would move in large circles parallel to the horizon. If you were at the equator, all the stars would rise and set vertically. And at in-between latitudes, the stars would rise and set at an angle to the horizon.
Auroras
The northern lights. | © NASA.
The aurora is a ghostly glow in the nighttime sky. In the northern hemisphere, you might see the Aurora Borealis (northern lights), while in the southern hemisphere, you'd see the Aurora Australis (southern lights). Most auroras are blue-green, but sometimes they have shades of red, yellow and violet. They often look like arcs that stretch across the horizon, or like tall billowing curtains.
Auroras happen when particles from the Sun stream across space-this phenomenon is called the solar wind. Some of these particles converge at the Earth's north and south magnetic poles. When they enter the Earth's upper atmosphere, their electrical charges make the air glow like a neon light.
If you live above a mid-northern latitute, or below a mid-southern latitute, you can see auroras almost any night. People closer to the equator have to wait until times of peak solar activity, when the Sun sends more particles towards the Earth. At these times, the auroras move closer to the equator, where people who can't usually see them get a spectacular show.
Cheepayak Nemitowak (Cree) is translated into English as The
Spirts Dancing. This phenomenon is called Wawatay in the Anishinabe
language. In the English language this phenomenon is called the
Northern Lights or Aurora Borealis. According to traditional
Aboriginal beliefs, the Northern Lights are the Spirits dancing as they
proceed westward through the star world to their final destination.
This image taken by the Viking Satellite shows the aurora borealis over the North Pole. | © NRC-HIA.
Seeing in the dark
To see the faintest stars possible you have to spend about 15
minutes in the dark. This is called dark adapting. Doing this makes your eyes more
sensitive to light. But if a bright light suddenly shines in your eyes, you won't be
able to see faint stars for another 15 minutes or so. In big cities,
light pollution makes it hard to see any but the brightest stars.
Sky Objects
The rings of Saturn. | © NASA / JPL.
Depending on where you live, you could see dozens or hundreds of stars if you step outside on a clear night. If your timing is right, you might also see the Moon or up to four of the planets. If you're lucky, you'll spot a shooting star as it burns a path through the atmosphere. Below are just a few of the objects you can see with the naked eye.
Sun and Moon
The Sun. | © NASA / Extreme UV Imaging Consortium.
Because the
Sun is the
closest star to the Earth, it appears large and very bright. But it's never safe to look directly at the Sun, because doing so can damage your eyes.
Viewing the Sun!
Build a solar viewer to safely watch an eclipse of the Sun.
The Moon, our closest neighbor in space, orbits the Earth and is the brightest object in the nighttime sky. Its various phases can be seen at different times of the month; however, when the Moon is full, its glare can obscure your view of many fainter stars and celestial objects.
Because the Sun is critical to life on Earth, it has played an important role in the cultural beliefs of indigenous peoples for centuries. Some Indigenous Australians see the Sun as a giant emu egg!
Read an
Indigenous Australian story about the Sun.
Read the
Anishinabe story "Snaring the Sun".
The Moon is another important player in indigenous stories. Sometimes it is featured alone, as a Moon Man, as in Anishinabe cultures of Central North America. Sometimes the Moon appears with the Sun as part of a larger group of Sky Beings, as in the Blackfoot culture of the North American Plains. Find out about these sky characters.
Read about the
The Sky Beings of the Blackfoot.
Read an
Indigenous Australian story about the moon.
Read an
Anishinabe story about the moon.
Tipiskawi Pisim (Cree) or Tibiki Keesis (Anishinabe) is translated into
English as the Moon.
Planets
Four of the planets are bright enough to see easily with the naked eye:
Venus,
Mars,
Jupiter, and
Saturn.
Mercury and
Uranus are harder to see.
Neptune appears like a small blue dot in binoculars, while
Pluto looks like a very faint star even in large telescopes. Your local newspaper may be able to tell you when the planets are visible in your area, or you can check with a local planetarium or observatory.
Canadian astronaut Chris Hadfield on the outside of the International Space Station, just below the Canadarm2, during a mission in May 2001. | © NASA.
The planet Venus has been the subject of numerous indigenous stories around the world.
Learn about the different ways in which people have incorporated this planet into their
world view.
Read an Indigenous Australian story about the planet Venus.
Read a Blackfoot story
about the planet Venus.
Stars Twinkle, Planets Don't
How can you tell a star from a planet? A simple way is to watch for twinkling. Twinkling happens when atmospheric turbulence distorts starlight. Because stars are far away, they look like points of light. Planets are closer, so they look like tiny disks. Atmospheric turbulence affects points of light more than disks, so stars twinkle and planets don't. This method works most of the time.
Is That a Galaxy I See?
Hold your thumb at arm's length against the night sky. Your thumbnail covers
2 million of the Universe's 100 billion galaxies, but it's hard to see a galaxy with your naked eye. In the northern hemisphere, you can barely see the Andromeda Galaxy in the constellation Andromeda.
Stargazers in the southern hemisphere can pick out the Large and Small Magellanic Clouds. For some Indigenous Australians, these two galaxies are the camps of an old man and woman.
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The Large and Small Magellanic Clouds are the closest galaxies to us. | © William C. Keel, University of Alabama.
Shooting Stars
On any clear night, if you stand outside long enough you're bound to see a shooting star. Shooting stars aren't really stars, they're meteors-tiny bits of dust and rock-plunging through our atmosphere. As meteors fall, friction consumes them in a fiery glow.
When the Earth passes through a comet's tail, hundreds of meteors may streak across the sky. Every August 12 and13, Comet Swift-Tuttle's tail provides a stunning light show-the Perseid meteor shower. The shower appears to flow from the constellation Perseus, which is visible in the northern hemisphere.
Comet Swift-Tuttle is responsible for the Perseid meteor shower. It was last seen in 1992 and won't return again until 2126. | Chris Cook © 1992.
One 50-metre rock, that weighed 3000,000 tonnes and travelled at a speed of 100,000 km per hour, created the Barringer Meteor Crater in Arizona 50,000 years ago. | © US Government public domain. Dr. D. Roddy.
Constellations
The Whirlpool Galaxy, M51, is a spiral galaxy located just off the end of the handle off the Big Dipper. | CFHT.
Long ago, people learned to organize the sky into recognizable patterns. They connected the brightest stars together, imagining the outlines of gods and ancestors. These imaginary outlines are called constellations.
Today there are a total of 88 constellations that cover both the northern and southern
hemispheres. Certain constellations and planets that can be seen with the naked eye are
important to the beliefs of the Blackfoot Anishinabe and Cree of North America, and the
Indigenous Australians. We know they are important because
stories have been told about them for generations. These stories provide traditional
knowledge that reinforces cultural beliefs and serves as a moral, ethical and practical
guide.
The constellations and what they represent to indigenous peoples are in part the inspiration for Star Chant, a major work for chorus and orchestra to a text by the astronomer Fred Watson.
More
The Pleiades
Throughout history, many peoples around the world have considered the Pleiades to be sacred. By observing the position of the Pleiades in the sky, people know when to plant, harvest, and hunt. Many ceremonies take place as the Pleiades crosses the centre of the sky at midnight.
The Pleiades is sometimes called the Seven Sisters, since you can see seven stars with the
naked eye (if you have excellent vision). This constellation looks like a tiny dipper, and is
often mistaken for the Little Dipper.
The Pleiades isn't really a constellation, it's a star cluster in the northwest corner of the constellation called Taurus the Bull. Pleiades is visible during the winter and early spring in the northern hemisphere and from November to February in the southern hemisphere.
Stories about the Pleiades:
The Blackfoot of the North American Plains
Miohpokoiksi - The Six Lost Boys
Indigenous Australians
The Seven Sisters
The Anishinabe of Central North America
The Seven Daughters of the Moon and Sun
Behgonay Geeshik (Anishinabe) or Pakone-Kisik (Cree) is translated
into English as the Hole in the Sky. It is called the Pleiades in English. This is the Hole in
the Sky through which Sky Woman descended to the Earth.
The Big Dipper
The Big Dipper is part of the constellation called the Great Bear. You can see the dipper shape in the top part of the image. | © Centre of the Universe (CU).
The Big Dipper is the brightest part of a constellation called Ursa Major-the Great Bear. By itself, the Big Dipper iscalled an asterism-a group of bright stars that have a familiar shape, but are only part of a larger constellation.
The Big Dipper can be seen from most of the northern hemisphere. The seven dipper stars are easily visible to the naked eye, and they do look a lot like a dipper. Since the Big Dipper is near Polaris-the North Star-it appears to swing around the North Pole throughout the year.
Joane CARDINAL-SCHUBERT, R.C.A.Canadian; First Nations; Blood (1942-)Ursa Above the Earth, 1987 oil pastel, watercolour, pencil on wove paperGlenbow Collection. Purchased with the support of the Canada Council for the Arts Acquisitions Assistance Program / Oeuvre achetée avec l'aide du programme d'aide aux acquisitions du Conseil des Arts du Canada and with the Glenbow Collections Endowment Fund, 20002000.002.001. | Glenbow Museum
Stories about the Big Dipper:
The Blackfoot of the North American Plains
Ihkitsikammiksi (The Seven Brothers)
The Anishinabe of Central North America
The Fisher
The Bear
Ochekatak (Cree) or Odjig Anung (Anishinabe) is translated into
English as the Fisher. There is a book called Murdo's
Story about how the Fisher came to be. It is also called the Big
Dipper or Ursa Major.
The Southern Cross
The Southern Cross. | © Centre of the Universe (CU).
The Southern Cross is also called "Crux" (Latin for cross). Four bright stars form the cross and it's the tiniest constellation in the sky. The Southern Cross is visible only in the southern hemisphere. It contains a beautiful star cluster called the Jewel Box.
An Indigenous Australian story about the Southern Cross:
The Southern Cross
The Star World of the Anishinabe and Cree Peoples
Indigenous peoples' knowledge of astronomy, which assisted in telling
time, direction, and weather, was vital to survival. Below is a list of the
names of some of the planets, stars, and constellations according to the
Cree and Anishinabe people of Manitoba, Canada. These two distinct peoples share a long
history as they have lived near one another for centuries and share territory,
particularly in Ontario, Canada.
Amisk Achak (Cree), or Amik Anung (Anishinabe), is translated into
English as the Beaver stars. This constellation is called Gemini on
star charts.
Anungokwun (Anishinabe) is translated into English as the Star World,
or the Universe.
Beedabun-Anung (Anishinabe,) or Petapun Achak (Cree), is
translated into English as the Coming Dawn Stars. The smaller star
is called Gamma Aquila on star charts. This star rises first. The
second to rise, and larger star, is called Altair on star charts. The
Coming Dawn Stars are the children of the Morning Star. They rise
before her, in the false dawn, and are aligned one above the other so
that they point to where she will appear.
Behgonay Geeshik (Anishinabe), or Pakone-Kisik (Cree), is translated
into English as the Hole in the Sky. It is called the
Pleiades in English. This is the Hole in the Sky through which Sky
Woman descended to the Earth.
Cheepahi Meskanaw (Cree) is translated into English as the Spirit
Road. This is the path marked across the sky by the Milky Way
galaxy when it is turned westward. According to traditional beliefs,
the spirit of a person who dies on Earth ascends into the star world,
then dances along this path to the place of eternal happiness in the
west, beyond the setting Sun. In the Anishinabe language, the Milky Way
is called Binessiwi Mekuna, the Bird's Path. In autumn, when it
points south, the birds follow it. In spring, it turns north and the birds
follow it back again.
Cheepayak Nemitowak (Cree) is translated into English as The
Spirts Dancing. This phenomenon is called Wawatay in the Anishinabe
language. In the English language this phenomenon is called the
Northern Lights or Aurora Borealis. According to traditional
Aboriginal beliefs, the Northern Lights are the Spirits dancing as they
proceed westward through the star world to their final destination.
Chi-Okimah Anung (Anishinabe), or Kisci-Okima-Achak (Cree), is
translated as the Great Chief Star, or King Star, and is called Vega in
English. The King Star controls all the other stars and assigns them
their roles, so that there is nothing on Earth that does not have a
ruling spirit or star in the heavens. The King Star controls the force of
gravity and causes the water to be lifted off the lakes and
rivers. He stores it up and later releases it to cause snowfalls.
Ishpiming (Anishinabe) is translated as the Heavens.
Kisikaw Achak (Cree), or Geezhigo Anung (Anishinabe), the Day
Star, is the planet Venus when seen during the day. Since Kisikaw Achak,
or Geezhigo Anung, is really a planet orbiting the
Sun, its position cannot be fixed on a star map.
Kewatino Achak (Cree), or Keewatin Anung (Anishinabe), is
translated into English as the North Star. The North Star is also
called Polaris.
Maskote Pisike (Cree), or Mushkoday Beezheeke (Anishinabe), is
translated into English as the Buffalo. This is the constellation Perseus. The
buffalo is the guardian of the Shaking Tent ceremony. In the winter,
the Buffalo Star can be easily seen, but in the summer, she is barely
visible because she is on Earth, feeding and helping indigenous
peoples.
Mikinaw (Cree), or Mikinak (Anishinabe), is translated into English as
the Turtle Star. This star is called Capella on star maps. The
turtle is the teacher and interpreter of the Shaking Tent ceremony.
The Atasokans (spirits) speak in their own language, and the turtle
interprets what they are saying to the people.
Matootsan (Cree), or Madodisswun (Anishinabe), is translated into
English as the Sweat Lodge. It is
called Corona Borealis, or the Northern Crown, in English.
Mokwachak (Cree), or Maung Anungonse (Anishinabe), is translated
into English as the Loon. It is called Delphinus on star
charts.
Myeengun Anung (Anishinabe) is translated into English as the Wolf. The
wolf is brother to Nanabush and walks the star
world with him. It is called Canis Major on star charts.
Nanabush Anung (Anishinabe) is the Nanabush.
Nanabush is the elder brother and teacher of the Anishinabe. It is also called
Misabe by some Anishinabe speaking people,
which translates into English as the Giant. In Cree
language, it is called Mistapiw, also translated as the
Giant. This constellation is called Orion in English.
Nakapahanachak (Cree), or Ningabi Anung (Anishinabe), is translated
into English as the Western Star. This is the planet Venus, seen as
the Evening Star. Since the Evening Star is really a planet orbiting the Sun,
its position cannot be fixed on a star map.
Ochekatak (Cree), or Odjig Anung (Anishinabe), is translated into
English as the Fisher. There is a book called Murdo's
Story that tells how the Fisher came to be. The Fisher is called the Big Dipper or Ursa Major in English.
Ochakatakos-iskewew (Cree), or Odjig Anungonse (Anishinabe), is
translated into English as the Little Fisher Stars, or Little Fisher.
In the English language, it is called the Little
Dipper, or Ursa Minor. Kewatino Achak (Cree), or Keewatin Anung
(Anishinabe), the North Star, forms the end of the Little Fisher's tail.
Pisim (Cree), or Keesis (Anishinabe), is translated as the Sun, in
English.
Sawanachak (Cree), or Shawan Anung (Anishinabe), is translated into
English as the Southern Star. This is the planet Jupiter as seen in the
south. Since Sawanachak or Shawan Anung is really a
planet orbiting the Sun, its position cannot be fixed on a
star map.
Tipiskawi Pisim (Cree), or Tibiki Keesis (Anishinabe), is translated into
English as the Moon.
Wapan Achak (Cree), or Wabun Anung (Anishinabe), is translated into
English as the Dawn, or Eastern Star. This is the planet Venus seen
as the Morning Star. Wapan Achak or Wabun Anung
is really a planet orbiting the Sun, so its position
cannot be fixed on a star map.
This information is from The Native Language Program, Grades 7-12, published by Native Education Branch of Manitoba, Canada.
The Death of Night
Artificial light has changed the face of our planet. This image shows the concentrations of artificial light around the globe. | © NASA / Goddard Space Flight Center.
When bright city lights shine into the sky, it's called light pollution. Light pollution
cuts down the number of stars that you can see with the naked eye. Out in the country, far
from city lights, you can see about 3 000 stars, but only about 20 or 30 stars are visible
from the centre of most big cities.
Nick Lomb, Curator of Astronomy at Sydney Observatory, talks about light pollution.
Light pollution makes it hard for astronomers to do their job. Any object astronomers want to
see has to be distinguished from natural light sources such as the aurora borealis, sunlight
reflecting off dust in space, and the Moon. Often they're looking for very faint objects.
Artificial light makes this even harder, and is one of the reasons that telescopes are
often built out in the country or on mountains.
The Sombrero, named after the broad-brimmed Mexican hat it superficially resembles, is probably the most famous galaxy in the sky. The light from this remarkable spiral system is dominated by the billions of old, faint stars that form the vast 'bulge' around its tiny hidden nucleus. Most spirals, including the Milky Way, have clouds of old, faint stars around their nuclei, but in M104 the galaxy's light is dominated by them. | Image and text © 1990-2002, Anglo-Australian Observatory, photograph by David Malin.
The disappearing Milky Way
A fifth of the world's population-more than a billion people-can no longer see the Milky Way.
In Europe, that's half the population; in the USA, 70 per cent. And the problem is growing.
The environment
Light pollution not only stops us from seeing the wonderful universe that we live in, but it
wastes energy and costs about $2 billion worldwide each year. The more energy we waste,
the more we have to produce. This means damming more rivers, building more nuclear power
plants and burning more fossil fuel.
Migrating birds are drawn to floodlit buildings, where they crash and die. Even brief
bursts of bright light can make nocturnal frogs stay still for hours. Lighting has been
blamed for the falling numbers of some moths, fireflies changing their habits, and trees
hanging on to their leaves too long in Autumn.
What do we do?
AATCCD 7. Orion nebula imaged in narrow emission lines ('Taurus'). | © Anglo-Australian Observatory. CCD image by C. Tinney, S. Lee and D. Malin
Australian photographer David Malin discusses light pollution
Some countries are considering laws that enforce better lighting design and technology:
'fully shielded' lighting fixtures that send the light down, not up, and greater use of
low-pressure sodium lamps, whose yellow light astronomers can filter out.
The Italian region of Lombardy has set the standard: the light pollution law it passed in
January 2000 is praised as the best one around. It was the result of a public 'outcry' by
25 000 citizens who signed petitions to demand action against intrusive outdoor lighting.
Models and Maps
When early explorers sailed to foreign shores, they drew maps to chart the size and shape of the lands that they found. We still explore in this way, but on a much larger scale. Although we've charted most of the Earth, we have only started exploring beyond our planet. By mapping the size and shape of our solar system, galaxy and the universe, we're beginning to chart our place in the cosmos.
The Orrery: a model of the solar system
Orrery, c1800-1850. | © Powerhouse Museum.
Orreries show the rates at which the different planets move around the Sun. They are named after Charles Boyle, the fourth Earl of Orrery, as he commissioned one of the earliest of these models.
Orrery, c1850-1860. (86/60) | © Powerhouse Museum.
This information is from the exhibition By the light of the southern stars at Sydney Observatory, part of the Powerhouse Museum.
A starry globe
Celestial globes are a popular way of mapping the positions of the stars. The shape of the globe matches the curved appearance of the sky. Map makers often decorate celestial globes with drawings of the constellations.
Celestial globe, 1791. (H9894) | © Powerhouse Museum.
This information is from the exhibition By the light of the southern stars at Sydney Observatory, part of the Powerhouse Museum.
Waiting for Venus
Transits of Venus - when Venus crosses the Sun's disc as seen from Earth-were important in the 18th and 19th century for determining the scale of our solar system. These transits happen in pairs eight years apart, separated by a century or so.
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Professor Liversidge's Observations' Photo lithograph in 'Observations of the transit of Venus'. H C Russell. | Government Printer, 1892. © Powerhouse Museum Library.
Charting our Galaxy
Using radio telescopes, astronomers are mapping the gas and dust in the Milky Way to learn more about stars, galaxies and our own origins.
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Dust, ionized gas, and cosmic rays in the Cygnus region of the Milky Way. | © Canadian Galactic Plane Survey.
The universe in 3-D
For the really big picture, astronomers are making a 3-dimensional (3-D) map of the galaxies. Already they've charted the positions of 220 000 galaxies-just a fraction of what's out there.
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Transit of Venus
A transit of Venus takes place when the planet crosses the disc of the Sun as seen from Earth.
Such transits occur in pairs eight years apart, separated by a century or so. To astronomers of
the 18th and 19th centuries they were of crucial importance as they provided a method of
determining the distance between the Earth and Sun, and hence the scale of the Solar System.
Cover of H C Russell's 'Observations of the transit of Venus, 9 December 1874'. Photogravure and letterpress on cloth. (523.92 RUS) | Government Printer, 1892. © Powerhouse Museum Library.
Australia has a close connection with this rare astronomical event through Captain James Cook who mapped the continent's east coast on his way back to Britain after observing the transit of 1769 from Tahiti. When the next transit occurred in 1874, Sydney Observatory was in an ideal position to make detailed observations.
'Large Equatorial, Sydney Observatory'. Photograph in HC Russell, 'Observations of the Transit of Venus'. (523.92 RUS) | Government Printer, 1892. © Powerhouse Museum Library.
Henry Chamberlain Russell started preparing for the 1874 transit immediately on becoming Government Astronomer in 1870. He purchased new telescopes and recruited a team of observers. Among them were the Reverend W. Scott, the first Government Astronomer, Philip F Adams, the Surveyor-General, Professor Archibald Liversidge who helped to establish the museum that eventually became the Powerhouse and the instrument maker Angelo Tornaghi. These observers went to a number of observing stations scattered around New South Wales - Sydney Observatory itself, Eden, Goulburn and Woodford in the Blue Mountains - so as to maximise the chance of getting a clear sky at least at one site.
'Waiting for the transit of Venus, Woodford' New South Wales, Australia. Photograph in 'Observations of the transit of Venus'. (523.92 RUS) | Government Printer, 1892. © Powerhouse Museum Library.
On the day of the transit the weather was fine at all locations except at Eden on the south coast. Russell wrote that, 'Never perhaps in the world's history, did morning dawn on so many waiting astronomers as it did on the 9th of December, 1874'. Although atmospheric effects such as shading between the edge of the planet and the Sun made observing difficult, good results were obtained.
After the transit Russell left for England, taking with him the reports and observations of all his observers. These he handed to the Astronomer Royal who was arranging the analysis of all the observations made in the British Empire. Many years later, in 1892, Russell published a beautifully illustrated book with the complete details of all the observations that he and his observers had made.
Nick Lomb, from Observer & observed: a pictorial history of Sydney Observatory and Observatory Hill, Powerhouse Publishing, Sydney, 2001.
Video portrayal of Henry Chamberlain Russell by Australian actor David Baldwin explains Russell's role at Sydney Observatory and his work to document the important event of the Transit of Venus.
Mapping the Milky Way
A possible "galactic chimney" mapped by the International Galactic Plane Survey, a partnership of radio surveys being conducted in Canada, the U.S., Australia, Germany and Sweden. | © Canadian Galactic Plane Survey.
Everyone knows that there are stars and planets in space, but what about in between? Although it might look like a dark void, there is matter between the stars. Astronomers call this matter the interstellar medium, and it's a mixture of gas and tiny dust particles. Out of this material, stars are continually forming-some big, some small and some medium-sized , like our Sun.
A project called the International Galactic Plane Survey (IGPS) is using radio surveys to map the interstellar medium. It started as a Canadian effort to map the section of the Milky Way visible from the Northern Hemisphere. The results were so good that American and Australian partners started a similar project for the southern hemisphere, and eventually they joined forces.
A 3-D Map of the Cosmos
From 1997 to 2001, the Anglo-Australian telescope in eastern Australia carried out what was
then the world's largest survey of galaxies, the 2dF (two-degree field) Galaxy Redshift
Survey. The 2dF survey mapped the 3-D positions in space of more than 220000 galaxies, and
gave us the most detailed map of the Universe to date.
The 2dF instrument captures the light from up to 400 galaxies at a time, using 400 optical
fibres - one for each galaxy to be observed. A robotic arm positions the ends of the fibres,
which have little lenses on them, onto the telescope's 'focal plate', which is where the light
coming into the telescope is focused to. Each fibre is placed so that it catches the light
from one galaxy.The fibres carry the light from each galaxy into one of two spectrographs.
The spectrographs split the light into its component colours. By analyzing these colours,
astronomers can tell how far away a galaxy is.
The 2dF team made some astounding findings. They gathered evidence showing how the universe's
mysterious 'dark matter' is distributed, and how giant
superclusters
of galaxies evolve over time due to gravity. In 2002, they found independent evidence to
support the controversial idea that the universe is accelerating faster and faster, like a
runaway car.
The 2dF survey was an international collaboration of more than 30 scientists from 11
institutions. In Australia, the Anglo-Australian Observatory, the Australian National
University and the University of NSW were involved.
A night assistant at the Anglo-Australian Telescope control console. | © Anglo-Australian Observatory, photograph by David Malin.
Take a tour of the Universe with the 2dF survey
Extending the Senses
Distant objects, like galaxies, are simply too far away for our eyes to see. Many forms of energy, like radio waves, are invisible and silent to us.
With technologies like telescopes and photography, we can see the universe that is hidden from our physical senses. We can see how stars are born, or reveal the rainbow of colours hidden in white light. Technology lets us extend our perception of reality to see our place within the solar system, galaxy and an infinite universe.
Telescopes
Everything with a temperature above absolute zero (-273° Celsius) emits electromagnetic radiation-including you! Generally, the hotter the object, the shorter the wavelengths it emits. Cool interstellar gas emits long infrared rays. The hottest stars emit short ultraviolet and X-rays. Astonomers use different types of telescopes, depending on what wavelength they want to see.
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James Clerk Maxwell Telescope (JCMT) Giant dish collects submillimetre wavelengths JCMT converts extremely weak radio signalsinto new information about our Solar System, interstellar matter, and star birth in distant galaxies. The telescope's 15-metre dish is made of 276 adjustable aluminum panels held in place by a massive support structure. A giant Gore-Tex veil protects the dish from dust, wind and sunlight. | JCMT.
Photographing the Sky
Early astronomers spent long, cold nights at the telescope making observations by hand. In the 1800s, astronomers found a better way-they decided to use a new technology called photography to show the stars in better detail and plot their exact positions.
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By pointing a camera towards the south (or to the north in the northern hemisphere) at night, we can record the paths of stars which never set. The exposure time for this photograph was about 10.5 hours - this kind of exposure is only possible from an extremely dark site, with no light pollution from nearby cities. Copyright Anglo-Australian Observatory, photograph by David Malin. | Image and text © 1979 Anglo-Australian Observatory, photograph by David Malin
A Spectrum of Colours
How do astronomers manage to learn so much about stars and galaxies that are so far away? The answer is found in rainbows. The light from stars can be separated into a spectrum-the rainbow of the light's component colours. By studying this spectrum, astronomers have learned almost everything they know about the universe.
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A prism separates white light into it's component colours. | National Research Council of Canada.
Canadian artist Joseph Drapell has produced an innovative high-end refractor for observing galaxies, nebulae, clusters, double stars, planets or the Moon. For a number of years now Astronomy has played an important role in his painting, inspiring the shapes he develops and the bright colours he uses.
Unbending Starlight
Looking at a star through Earth's atmosphere is like bird-watching from the bottom of a swimming pool. Pockets of hot and cold air in the atmosphere act like prisms and lenses, distorting incoming starlight. This makes a star look twinkly and blurry when viewed in a ground-based telescope. But with a technology called adaptive optics, astronomers can "straighten out" bent starlight.
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Adaptive optics help to correct for the distortion caused by the earths atmosphere.The left side of this image was taken without adaptive optics; on the right, the light has been "corrected" to give a clear image. | National Research Council of Canada.
Telescopes
Until the mid-1950s, visible light was our only source of information about the universe. Visible light is collected by optical telescopes like the kind you might have in your backyard.
But visible light is only a tiny portion of the
electromagnetic spectrum. Astronomers use other kinds of telescopes to detect the invisible parts of the spectrum, such as near-infrared, microwaves, and radio waves. Planets, stars and galaxies all look different when "viewed" in each region of the spectrum.
The ability to detect invisible energy created an information explosion in astronomy. Radio telescopes first pointed us to distant quasars. Gamma ray telescopes revealed immense explosions known as Gamma Ray Bursters (GRBs). X-ray telescopes gave us new information about the Sun, neutron stars and exotic black holes.
Three Views of the Crab Nebula
Optical image of the Crab nebula. | © [Credit CU 33] Public Domain. Palomar Observatory.
X-ray image. | © [copyright] [Credit CU 31] Public Domain. NASA/CXC/SAO.
Radio image. | © [Credit CU 32] Public Domain. VLA/NRAO.
The Crab Nebula is the remnant of a supernova explosion. Optical images show the nebula as it would appear to a human observer. X-ray images show the discarded shell of hot gas. Radio images reveal a magnetic field that draws radiation from electrons in the surrounding gas.
Optical Telescopes
Optical telescopes capture the visible part of the
electromagnetic spectrum. Today, the largest optical telescopes have mirrors eight to 10 metres across. It's not practical to make single optical mirrors any larger than this.
The Canada France Hawaii Telescope sees in both optical and infrared wavelengths. | © Odysseum (formerly Edmonton Space Sciences Center).
Radio Telescopes
Telescopes that gather longer waves, like radio waves, need a wider collecting surface. Radio dishes are often 100 metres or more across. A radio dish must be 10 000 times wider than an optical dish to "see" the same amount of detail.
The 26-metre Radio Telescope dish at the Dominion Radio Astrophysical Observatory in Penticton British Columbia. | National Research Council of Canada.
Space Telescopes
The Hubble Space Telescope orbits 600 Kilometers above Earth. It provides stunning views of the Universe that cannot be made using ground-based telescopes or other satellites. | © NASA.
Earth's atmosphere screens out many kinds of radiation that astronomers need to study.
Space telescopes catch the rays that never reach ground-based telescopes. Untroubled by clouds, light pollution, radio noise and the turbulent atmosphere, space telescopes "see" with astonishing clarity.
A space telescope doesn't quit at sunrise. It can collect radiation from a patch of sky for days and nights on end, producing phenomenally detailed images of very faint objects.
Does this mean that ground-based telescopes are obsolete? Definitely not. They are much cheaper to build and have the advantage of size. With bigger mirrors, they can collect more detailed information. Astronomers often carry out research by combining ground-based and space observations.
The James Webb Space Telescope will replace the Hubble Space Telescope by the end of the decade. This proposed 6-metre space telescope will be stationed more than a million kilometres from earth. | © US Gov public domain. NASA.
Read about some of the world's major telescopes
Photography
With the invention of photography, astronomers were able to study the sky in great detail and soon began to create highly accurate maps of the stars. Both professional and amateur astronomers use photography to capture beautiful images of the cosmos.
Mapping the Stars
In the late 1800s, a project called the Astrographic Catalogue was launched to map the positions of the stars. Twenty observatories around the world took part. Each was assigned a specific zone of the sky, and together they charted the positions of 4.6 million stars. Australia's Sydney Observatory mapped 250 000 stars-so many that it took 76 years to publish the results.
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'The star camera, Sydney, NSW' from H C Russell, 'The Star Camera at the Sydney Observatory', Department of Public Instruction, 1892. (522.6 SYD) | Department of Public Instruction, 1892. © Powerhouse Museum Library.
Pioneer in space photography
Henry Chamberlain Russell was the Government Astronomer at Australia's Sydney Observatory from 1870 to 1905. Russell was an early pioneer in using photography to capture the details of sky objects. Among his many photos were some excellent images ot the Moon.
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'No 2 Sept 2 1891' (The Moon). Henry Chamberlain Russell,1891. Photograph, 24 x 17.5 cm. (95/239/5) | © Powerhouse Museum.
Photographer to the stars
David Malin approaches photography both as a scientific tool and as a medium for artistic self expression. His astronomical images reveal important details about stars and galaxies, and are also beautiful representations of the natural world.
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AAT 69. Reflection nebula around the Trifid nebula. | © Anglo-Australian Observatory, photograph by David Malin.
The Great Star Map
'The Sydney astrographic zones', Department of Lands, NSW, 1895. Lithograph, 32 x 32.5 cm. (P3549-14) | Department of Lands, NSW, 1895. © Powerhouse Museum.
The Astrographic Catalogue project was a great international plan to map the whole sky. When Henry Chamberlain Russell (the Government Astronomer) committed Sydney Observatory to this project in 1887, he unknowingly established its future direction for most of the next century.
By the 1880s photography had become sufficiently advanced that it became possible to take pictures of the sky through telescopes. Russell was invited to a conference in Paris in 1887 to discuss a project to map the whole sky photographically. To do this the sky was divided into zones that were allocated to the 20 or so participating observatories. Each observatory was to use identical telescopes to photograph their zone, measure the coordinates of the stars and publish the results.
Russell ordered a suitable lens from the firm of Grubb-Parsons in England and designed a mounting for the astrographic telescope that was built by Morts Dock Engineering Company in Sydney. Photography for the catalogue began in 1890, initially at Sydney Observatory although later the telescope was moved to a site at Pennant Hills.
Sydney Observatory had been assigned one of the largest of all zones. The 1400 photographs needed to cover the zone with almost a quarter of a million star images on them were only exceeded by one observatory in South Africa. A large number of the required photographs were taken in the first ten years. Some further exposures were taken in the 1920s to fill gaps and to replace some low quality photographs, while some final ones were taken in the 1940s.
The real brake on the project was the measuring of the photographs. Rather than prints, these were glass-plate negatives, each containing hundreds of star images. Cheaper to employ, young women were engaged in the repetitive task of measuring the plates to determine the position of each star image with great accuracy.
Mary Allen and Ethel Wilcox measuring astrographic plates. | From 'Pix', 15 March 1941. © Powerhouse Museum.
Once the measurement was completed, the astronomers had to work out an equation for each plate that allowed star positions to be converted to positions in the sky. All this took an unexpectedly long time; Sydney Observatory did not publish its final results until 1963-76 years after Russell had begun the project!
Nick Lomb, from Observer & observed: a pictorial history of Sydney Observatory and Observatory Hill, Powerhouse Publishing, Sydney, 2001.
Troughton and Simms plate measurer, 1915. (H10139) By the light of the southern stars at Sydney Observatory, part of the Powerhouse Museum. | © Powerhouse Museum.
Henry Chamberlain Russell
Henry Chamberlain Russell was Government Astronomer at Sydney Observatory in Australia from 1870 to 1905. He made some of the first photographs of the southern sky, including that of the enigmatic object Eta Carinae.
This information is from the exhibition By the light of the southern stars at Sydney Observatory, part of the Powerhouse Museum.
'H C Russell in his office'. Charles Bayliss, 1890-1900. Photograph, 17.5 x 22.5 cm. (95/239/23). | Charles Bayliss. Powerhouse Museum, Sydney.
See and hear a portrayal of Henry Chamberlain Russell by the Australian actor David Baldwin.
'Beta Centauri' and 'The Nebula about Eta Argus'
Russell attended the 1887 Paris conference that initiated the Astrographic Catalogue project - a huge international project to photographically map the whole sky with identical telescopes. Russell undertook the photography and measurement of a large area of the southern sky on behalf of Sydney Observatory. This task became the main activity of the Observatory, continuing for almost 80 years until 1963.
'Beta Centauri', Henry Chamberlain Russell, 1890. 'Photographs of the Milky Way and Nebeculae, taken at Sydney Observatory, 1890'. Photograph, 20.5 x 15.5 cm. (96/6/11) | Government Printer, Sydney 1890. Collection: Powerhouse Museum.
'The Nebula about Eta Argus'. Photograph, 21.5 x 16.5 cm. (95/239/6) | Henry Chamberlain Russell, 1890. © Powerhouse Museum.
These photos were taken in 1890-1891 while waiting for the astrographic lens Russell had ordered in 1887. Russell adapted a Dallmeyer portrait lens to the telescope mounting he had designed for the project. He immediately published a book of photos of the Milky Way and several nebula, the luminous patches of light in the night sky composed of gases, dust and stars. These photographs were 'believed to be the first of their kind of the Southern Skies, so much so that in several important respects we must modify the views which have been the outcome of the study of these Star Spaces with ordinary telescopes . The plates which follow were taken on fine nights, with three hours exposure or about that .'.
Photographs of the stars can capture detail which the human eye cannot see, even with the most powerful telescopes. Russell's photos of the Moon were acclaimed when shown at the 1893 Chicago World Exhibition and at the Royal Astronomical Society in London.
1. H C Russell, Photographs of the Milky Way & Nubeculae taken at Sydney Observatory, Government Printer, Sydney, 1890, pp 3-4
Charles Pickett, from Observer & observed: a pictorial history of Sydney Observatory and Observatory Hill, Powerhouse Publishing, Sydney, 2001. [Credit for this page]
A Starry Spectrum
The light from stars looks white to us, but when you pass this light through a prism, you can see a rainbow of colours. These colours represent different wavelengths of light. Red wavelengths are longer than blue ones.
© NASA.
Light also comes in other "colours" that we can't see, and each has its own wavelength. The wavelength tells us what type of energy is being emitted. The longest wavelengths produce radio waves, and the shortest ones produce gamma rays. In between, we find microwaves, infrared radiation, visible light, ultraviolet radiation, and X-rays. All these types of energy together make up the electromagnetic spectrum.
Adventures along the spectrum.
Learn more about light from the Gemini Observatory on Mauna Kea, Hawaii.
Spectra of Stars
Astronomers study the spectra of stars to understand the stars' physical properties. For example, chemicals in a star's atmosphere may absorb some of the star's energy, but dark lines in the coloured spectrum show where energy was absorbed. Every chemical has a unique pattern of lines, so a star's spectrum reveals its chemical make-up.
The elements in a star absorb certain sections of the spectra, or rainbow of a star. Where these black lines appear tell us what the star is made of. | National Research Council of Canada.
Spectroscopy-the analysis of the spectra of stars-is probably the single most important tool that astronomers have. By carefully analyzing spectral lines, astronomers can learn the chemical composition, temperature, magnetic fields and velocities of stars, nebulae and galaxies.
Spectroscopy in Action
An instrument called a spectrograph spreads the light from celestial objects so that it can be studied. The Gemini North telescope in Hawaii uses a sophisticated instrument called the Gemini Multi-Object Spectrograph (GMOS).
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The Gemini North Spectrograph
The Gemini Multi-Object Spectrograph (GMOS) is a sophisticated new instrument on the Gemini North telescope on Mauna Kea, Hawaii. GMOS works by breaking down starlight into its component colours for analysis. From that light, astronomers can learn the chemical composition of stars and galaxies, their mass and how fast they're moving towards us or away from us.
The first image captured by GMOS was the large galaxy NGC 628 in Pisces. It has been called the "perfect spiral galaxy" due to its nearly ideal form. | © Gemini North.
Although GMOS weighs two tons, it is sensitive enough to measure motions as small as one micron (one-millionth of a metre). Astronomers need this level of precision to measure changes in galaxies that are millions, or billions, of light-years away. | Gemini Observatory.
GMOS was developed by the Herzberg Institute of Astrophysics (Canada), the Astronomy Technology Centre (U.K.) and the University of Durham (U.K.)
More about Gemini
Taking the Twinkle out of Starlight
When starlight passes through our atmosphere, it gets distorted by turbulence (the mixing of warm and cold air). This is why stars twinkle when you look at them. Telescopes only magnify this distortion, so stars can end up looking like shimmering blobs instead of pinpoints of light.
With technology called adaptive optics, astronomers can correct this distortion to get a clearer image. Adaptive optics takes a sample of starlight and calculates how it has been distorted by the atmosphere. It then straightens the light with a flexible mirror that changes shape about 1 000 times per second.
Adaptive optics help to correct for the distortion caused by the earths atmosphere.The left side of this image was taken without adaptive optics; on the right, the light has been "corrected" to give a clear image. | National Research Council of Canada.
See how adaptive optics works.
Gemini North Telescope
With a new adaptive optics system on the Gemini North telescope on Mauna Kea, Hawaii, astronomers hope to peek into the heart of stellar nurseries-or watch the birth of galaxies that formed 10 billion years ago. This adaptive optics system, called Altair, was built by Canada's Herzberg Institute of Astrophysics.
Altair uses an integrated computer to calculate the distortion caused by the atmosphere. Tiny mechanical devices mounted behind the flexible mirror make thousands of adjustments per second to sharpen the telescope's focus.
Altair mounted on the Gemini North telescope. | © Gemini North.
More about the Gemini North telescope
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