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URLs  for images and movies showing the transit


Venus Transit Certificate

Participate in the NASA / Astronomical League Venus Transit certificate program. Visit the Astronomical League website for instructions.

To register for the program, visit http://sunearthday.nasa.gov  and select "For Amateur Astronomers," and then select registration at the top of the screen.

For questions about the program, contact Lou Mayo at NASA.

Measuring the Parallactic Shift of Venus

PDF Files
by Nirupama Raghavan

Part 1. Parallactic Shift of Venus: Concepts


Parallax refers to the apparent shifting of an object when viewed from different angles. Learn two simple methods to measure Venus's parallactic shift. Learn how a large number of amateur astronomers will use this method on June 8,2004 for measuring the parallactic shift.

Part 2. Observations on Transit Day


For observers who are likely to have access to a telescope of at least 60 mm diametre on an alt-azimuth tripod/mount and will use it in eye piece projection mode without a drive. They will be noting the positions and the corresponding times manually, during the transit.

Get Adobe Acrobat 3.02

NASA Photo - Venus

Named after the ancient Roman goddess of beauty and love, to the naked eye, planet Venus is the brightest of the planets in our sky. This is partly due to its size and partly due to its high albedo or reflecting power. It was once called Hesperus, when it was the morning star and Phosphorus, as an evening star.

Venus, with its diameter of 12,104 kilometers, is almost a twin of Earth. Though it's almost the size of the earth, it's not the same as earth. It's a rocky sphere blanketed by dense yellowish clouds. The yellowish color is due to presence of sulfuric acid.

For a naked eye, Venus can be very bright, at times almost as bright as the moon. It's easily noticeable in the evening or morning sky at such times. Sometimes, if you are sure of its exact position; you can even see Venus in broad daylight. Several amateur astronomers have taken photographs of Venus in broad daylight. Venus also has its phases like the moon and Mercury. During it's crescent phase, you will notice a faint glow on the darned region. This is called Ashen Light. 

Manoj Pai, Ahmedabad, Gujurat, India

NASA Photo - Venus

Transit of Venus - June 8, 2004

For the first time in more than 100 years, astronomers on Planet Earth will be able to view a Transit of Venus. On June 8, 2004, Venus will appear to travel across the face of the sun. While this exciting and rare astronomical event can be see by observers in most of the world, the only North American astronomers who will be able to view this transit will be those located in the North East United States and Eastern Canada.

The last Transit of Venus occurred in 1882. Since transits of Venus occur in pairs, your next chance to see Venus cross the face of the Sun will be in 2012. If you do not catch it now or in eight years, you will have to wait until 2117, another 105 years, for your next opportunity!

What is a Transit?

NASA Graphic Tranist of Venus - June 8, 2004
NASA Photo Transit of Venus

A transit is essentially an eclipse of the sun by another planet. During a solar eclipse, the moon moves between the Earth and the Sun, blocking out our view. This happens because the moon, as it moves between Earth and the Sun,  has an apparent size almost exactly equal to the angular size of the Sun as seen from Earth.

Transits, however, occur when either Venus or Mercury move in their orbit exactly between Earth and the Sun. But because these two planets are significantly smaller than the apparent size of the Sun, we only see a small dot moving across the face of the Sun.

Transits can only be caused by the two planets Venus and Mercury. That is because these two planets are "inferior" to Earth, i.e., they orbit the Sun INSIDE the orbit of the Earth. On the other hand, planets like Mars and Jupiter lie OUTSIDE of the orbit of Earth, and are thus "superior" planets. (The opportunity does exist for observers one one of these superior planets to observe a Transit of Earth!)

Transits of Mercury occur approximately 13 times per century. This is due to the fact that Mercury orbits the Sun at a very close distance, and the orbits of Earth and Mercury intersect quite often.

Venus, on the other hand, has a much longer orbit, and its orbit is inclined 3.4 degrees to that of Earth. That means Venus and Earth do not orbit the Sun in exactly the same plane, and that the orbit of Venus is at an angle to the orbit of Earth. Thus, the opportunities for Earth and Venus to line up properly are much less frequent than for Mercury.

NASA Map shows where you can view the Transit of Venus
Click on image for enlarged view

2004 June 8 Venus Transit  Contact Times

05:13:29 UT  
II 05:32:55 UT  
Mid 08:19:44 UT

04:19:44 EDT

III 11:06:33 UT 07:06:33 EDT
IV 11:25:59 UT 07:25:59 EDT

For US observers on the east coast, the Transit of Venus will already be in progress as the sun rises at about 4:45 am EDT, and the transit event will be almost over. Venus will be visible as a black dot on the solar surface.

always use a safe solar filter to view the Sun
even when the Sun is low in the sky.

Transits of Venus: 1601 - 2200

Transits of Venus occur in 8 year pairs, separated by about 105 years. This is due to the relationship of the orbits of Earth and Venus. Venus transits currently occur at intervals of 8, 105.5, 8, and 121.5 years. Only six transits of Venus have occurred since the invention of the telescope.


Universal Time Separation
1631 Dec. 7 5:19 939"
1639 Dec. 4 18:26 524"
1761 Jun. 6 5:19 570"
1769 Jun. 3 22:25 609"
1874 Dec. 9 4:07 830"
1882 Dec. 6 17:06 637"
2004 Jun. 8 8:20 627"
2012 Jun. 6 1:28 553"
2117 Dec. 11 2:48 724"
2125 Dec. 8 16:01 733"

The Next Transit of Venus - 2012 June 06

Click on image for enlarged view

If you miss the Transit of Venus this year, you get another chance 8 years from now, on June 6, 2012. Unlike this year's transit, observers in most of the continental US will be able to view at least part of this next transit without leaving home.

 The global visibility of the 2012 transit of Venus is illustrated with the NASA world map above. The entire transit (all four contacts) is visible from northwestern North America, Hawaii, the western Pacific, northern Asia, Japan, Korea, eastern China, Philippines, eastern Australia, and New Zealand. The Sun sets while the transit is still in progress from most of North America, the Caribbean, and northwest South America. Similarly, the transit is already in progress at sunrise for observers in central Asia, the Middle East, Europe, and eastern Africa,. No portion of the transit will be visible from Portugal or southern Spain, western Africa, and the southeastern 2/3 of South America.

Transit Links

There's a whale of information about the Transit of Venus at the following links. You might also want to register for your free copy of the Venus Transit kit from the NASA site.

Clear skies

Manoj Pai,
Ahmedabad, India

Venus transit maps & local events/view software

Venus Transit Map by Daniel Fallas - June 8, 2004

Daniel Falla and John Brooks have updated and expanded their maps of the June 8th Venus transit for the USA & Canada; Europe; and Asia; you can find them on John Brook's Web site at

Especially, look at the "USA map", Asia In and Out, and Europe In and Out.

And Adri Gerritsen of the Dutch Occultation Association (DOA) has produced and made available on the Web (at top of the DOA Web site) free software to calculate the local circumstances of the June 8th Venus transit from any location that you specify; it also includes an animated view of the transit at 1 hour, 1 min., or 1 second intervals.  See his message copied below.

From: "Adri Gerritsen"
To: "Eberhard Bredner"
"David Dunham"
Subject: Venus transit
Date: Sat, 29 May 2004 10:27:41 +0200

Dear all,

Just one week left to the BIG event: the Venus transit of June 8th.

For this special occasion, I developed a freeware program that can be downloaded from the homepage of the Dutch Occultation Association:

Besides the local circumstances, it also deals with (real-time) animations.

Spread the news!

Clear skies,
Adri Gerritsen
Dutch Occultation Association.

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