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
by Nirupama Raghavan
1. Parallactic Shift of Venus: Concepts
GET PDF 1
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
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.
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
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
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
What is a Transit?
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
Click on image for enlarged view
2004 June 8 Venus Transit Contact Times
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
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.
|1631 Dec. 7
|1639 Dec. 4
|1761 Jun. 6
|1769 Jun. 3
|1874 Dec. 9
|1882 Dec. 6
|2004 Jun. 8
|2012 Jun. 6
|2117 Dec. 11
|2125 Dec. 8
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.
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
Venus transit maps & local
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
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"
Subject: Venus transit
Date: Sat, 29 May 2004 10:27:41 +0200
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)
Spread the news!
Dutch Occultation Association.