AAAA Members Observe
Transit of Mercury,
May 7, 2003
Transit of Mercury Photos by Leo Andriao,
Araraquara, Sao Paolo, Brazil
Click on images to enlarge.
I have sent my photos of the Transit of Mercury, taken from
Araraquara, Sao Paolo, Brazil, on the morning of May 7, 2003. The
small dot of the planet Mercury can be seen to the upper left in the
first photo, but is not so clear in the other photos. The large dot
near the center of the sun is a sunspot.
Andriao, Junior, Brazil
It was very exciting to see the Mercury Transit. We projected the
Sun on white plane cloth and paper. The big sun spot in the middle was
also noticeable. Our program was organized at near GIDC Awas, Sector
No. 1 Plot No. 13, consisting of Pomal, Anand Thacker, Navin
Bapat, and Raysinhji Rathod. We also did another thing. We were
asking questions to new comers as to which is Mercury, and most of the
people were pointing to the big sunspot! The photo is attached
herewith. Mercury is the dot at the top of the photo, and the sunspot
is near the center.
Narendra Gor, India
images of the Transit of Mercury
taken through GONG, a division of the National Solar Observatory, you can visit
National Solar Observatory
P.O. Box 62
Sunspot, NM 88349
Transit of Mercury
May 7, 2003
The Transit of Mercury on May 7, 2003, was seen in its entirety across
Asia, Africa and Europe, and at its end at sunrise in easternmost North
America and South America. Most of North America was not able to see
Transits of Mercury can occur only in the months of May and November,
because, to be seen from Earth, it must be near one of the two nodes of
its orbit. Nodes are the points where the planet crosses the plane of
the Earth's orbit. If the time that Mercury crosses one of the node
points coincides with a favorable position of Earth in its own orbit, we
see a transit.
There are approximately 14 Transits of Mercury in a century. This
transit is the first of the 21st Century.
Transits of Mercury
HERE to see AAAA reports and photos from
the Transit of Mercury on November 15, 1999
A Press Release Regarding
The Transit of Mercury from NSO
National Solar Observatory Press Releases
Mercury Transit 2003
IMMEDIATE RELEASE: May 5, 2003
Contact: Dave Dooling
P.O. Box 62
Sunspot, NM 88349
Modern solar telescope network's view of Mercury passage will help
students use web to recall historical era.
A global network of telescopes designed to watch the Sun's atmosphere
pulsate will be pressed into service on May 7 to help students recreate
early measurements of our solar system.
The telescopes will record the transit of Mercury as it crosses in
front of the Sun. Transits once were the most valued of astronomical
events, a rare chance for astronomers to size up the solar system. Today
it is an opportunity to involve science teachers and students in
studying both the Sun and mathematics.
The observations will be made by the National Solar Observatory's
Global Oscillation Network Group (GONG) telescopes located in Australia,
India, and the Canary Islands.
"We were approached by a French colleague, Professor Michele Gerbaldi
of the Institut d'Astrophysique in Paris, Maitre de Conferences at the
University of Paris-Sud, Orsay," explained Dr. Cliff Toner, the GONG
scientist who is spearheading the transit observations. "She wanted to
the work of a French expedition in the late 18th century to measure the
scale of the solar system with modern data of the transit of Venus,
observable next year, the one of Mercury this year being used as
just as it has been the case in the 18th century. It has tremendous
historical value, and it is awesome what those people were able to
Transits occur when Mercury or Venus passes between Earth
and Sun. The timing is complex and depends on the relative motions of
and the other planet. Mercury transits in May at intervals of 13 and 33
years, and in November at intervals of 7, 13 and 33 years. GONG observed
last transit of Mercury on Nov. 15, 1999. Venus is less frequent, only
times in the last four centuries. The last was 1882; the next will be
soon, on June 8, 2004.
In the 17th century, pioneering work by
Jeremiah Horrocks (an English astronomer) and James Gregory (a Scottish
astronomer) demonstrated that the transits could be used to determine
Earth-Sun distance. In 1716 Sir Edmund Halley published "A new Method of
determining the Parallax of the Sun, or his Distance from the Earth" by
using many observational stations spread over the world. But Halley's
expedition to the South Atlantic in 1677 to observe the transit of
came to naught when bad weather in England deprived him of the other
Several nations mounted expeditions in 1761 and 1769
to observe the transits of Venus and produced measures of the Earth-Sun
distance. Using those data, Joseph Jerôme Lalande of France in 1771
calculated the Earth-Sun distance at 153 million km (95 million miles),
3.4 million km (2 million miles) off the correct number, 149,597,871 km
(92,750,680 miles). Today, radar ranging to the planets and tracking of
space probes have relegated transits to reminders of the pioneering days
But GONG's constant watch on the Sun means that we don't
have to mount a special expedition. Three GONG stations will see the
19-minute transit. It starts at 05:12:56 Universal Time (12:13 a.m. EDT)
when Mercury's limb appears to touch the Sun's limb, and ends at
(5:13 a.m. EDT) when Mercury clears the Sun. Teide will see the first
hours (from sunrise), Udaipur, India will see the entire transit, and
Learmonth, Western Australia, will see the last 3-1/2 hours (to sunset).
Learmonth and Teide will overlap each other by almost 2 hours. So while
transit will occur entirely at night for half the world, people anywhere
should be able to see it.
CAUTION: It is exceptionally dangerous to
view the Sun without the right equipment. Blindness or painful,
eye damage will result.
"While we don't expect the size of the
Universe to change as a result of these measurements" said Dr. John Leibacher, the GONG program director in Tucson, AZ, "it is an exciting
spectacle to watch, and it is of important practical use to us in
establishing the precise orientation of the images taken with different
telescopes around the world."
GONG was designed to measure the
pulsations of the visible surface of the Sun's atmosphere as it rings
bell with millions of different harmonic notes. These vibrations are our
only way of probing the Sun's interior, just as earthquakes probe
interior. Six identical GONG stations around the globe monitor the Sun
time: Big Bear Solar Observatory, Big Bear Lake, Calif.; Learmonth Solar
Observatory, Australia; Udaipur Solar Observatory, India; Observatorio
Teide, Canary Islands; Cerro Tololo Interamerican Observatory, Chile;
Mauna Loa Observatory, Hawaii. Thus, the Sun never sets on GONG, making
uniquely suited to catching a transit whenever it may occur.
explained that software has been developed for the GONG network
extract one image every 15 minutes from each site as Mercury crosses the
and post the image in near real-time on the GONG web site. Only 25 or so
images will be posted for this quick-look, stop-motion movie of the
Toner cautioned that the real-time connection with Udaipur is new and
experience some interruptions. The connections with Learmonth and Tiede,
though are working well and the overlap between the two will ensure
Over the next two months, as data tapes arrive
from the GONG sites, the GONG team will prepare an education CD-ROM with
transit images taken every minute for a total of more than 300 images.
"We'll provide the raw data from the white-light images, so the
students can learn what is the triangulation method and how to measure
Earth-Sun distance from planetary transits and be prepared for the
of Venus, next year which is the one allowing a measure of the
unit," Toner explained. Reproducing the timing aspect of the early
experiments may not be possible because each image will have an
time of one minute, too long for making precise contact measurements.
CD-ROM will include instructions on how to use the images and data.
"This is the first time that we have tried something like this, so
everyone here is pretty excited," said Leibacher, "and it's just a
for the transit of Venus next year."
GONG is operated by the
National Solar Observatory under contract to the National Science
For additional information on GONG and the 2003 transit of
http://gong.nso.edu/mercury_transit03. For a larger
the 1999 transit, visit the NOAO Image Gallery. [
Historical and technical information on transits is drawn from the
pages maintained by Fred Espanak of NASA's Goddard Space Flight Center:
paper on determining the Earth-Sun distance is republished at
Dave Dooling and Ruth A. Kneale
Solar Observatory is sponsored and supported by the National Science