(Students for the Exploration and Development of Space) Homepage on Mercury
USGS Web Site with Images of Mercury
Upcoming Transits of Mercury
Planets Page (SEDS)
All about Mercury: planet, element, etc.
Mercury page at JPL
Mercury page at NASA Goddard Space Flight Center
Seeing Mercury: elongations
Transit of Mercury, 15 November 1999
TRACE Observations of the 15 November 1999 Mercury Transit
Schneider, Pasachoff, Golub paper about the 1999 transit
Transit of Mercury Movie
This transit is a warmup for the June 8, 2004, transit of Venus. It
will be the first transit of Venus since 1882. Images of that transit
of Venus appear in the text. See
See also http://www.transitofvenus.org.
May 7, 2003, transit of Mercury:
A TRACE combination image, composited from over 5 hours of
observations in an extreme ultraviolet-wavelength:
A TRACE movie in an extreme-ultraviolet wavelength:
A TRACE movie in white light, with vignetting limiting the view to a
small region of the Sun by defining a circular lower edge to the field
A ground-based image by Philippe Jacquot of Annecy, France
A movie from the Global Oscillation Network Group (GONG):
A composite image from the Udaipur, India, GONG site, carefully
co-registered so that the overall Sun stayed steady. The solar
rotation blurred out the sunspots:
A ground-based composite white-light image by D. Dierick:
European Southern Observatory
A solar mini-eclipse! On May 7, 2003, Mercury, the innermost planet in the solar system, willpass in front of the Sun and produce a solar eclipse. But this event will hardly be noticed. Mercury's small disk will indeed barely be bigger than the point of a pencil. Even the smallest sunspots on the solar surface are as big as the Earth and measure 10,000 km or more in diameter, while Mercury's equatorial diameter is only 4878 km.
Bathed in intense sunlight, this small, hot planet moves around the Sun in an elliptical orbit at a mean distance of only 58 million km, much closer to the Sun than other inner planet, Venus (108 million km) and the Earth (150 million km).
The disk of Mercury is very small and will be very difficult to see. A powerful telescope is needed to observe this event and to show clearly how Mercury moves across the solar disk. The disk of Mercury is indeed only 13 arcseconds across (while the solar disk measures about 1800 arcseconds). This corresponds to the size of a 1 EURO coin located at the top of the Eiffel Tower as seen from the ground. Therefore, Mercury will only block 1/20,000th of the Sun's light.
In order for a Mercury transit to happen, the planet must be located directly between the Earth and the Sun and also near one of the two points in its orbit where Mercury's orbital plane intersects that of the Earth. We then face the dark side of Mercury - the hemisphere that is not illuminated by the Sun - and see it as a small dark spot moving across the bright solar disk.
There are about 13 Mercury transits each century and they follow in time intervals of approximately 13, 7, 10 and 3 years. The most recent one took place in November 1999 and the next will be on May 7, 2003 and November 8, 2006.
The next Mercury transit happens on May 7. It lasts from about 7:13 hrs CEST (Central European Summer Time) until 12:32 hrs CEST (5:13 to 10:32 UT) and the contour of the small planet as it moves across the solar disk can be seen from all places where the Sun is above the horizon and the sky is clear. The best observing conditions are from Europe, Africa and Asia.
Observations can only be made by means of telescopes which project the solar image onto a white screen.
Public observatories, planetaria and other educational institutions will arrange special events on this occasion. News about such arrangements will appear in the local press.
Full information and many weblinks to other educational sites are
available via the special website at:
On this site, extensive background information about Mercury and the Sun can be found and, in particular, useful sheets for school students and teachers in many languages. Live images from professional telescopes (depending on the weather at the observing sites) will be available on the special webpage:
and it will also be possible to ask questions in "real-time" to astronomers via this page.
The entire transit of Mercury will be visible in Europe. Many people are especially interested in this transit of Mercury, the first since 1999, as a precursor to the June 8, 2004, transit of Venus, which will be the first transit of Venus since 1882.
Weather, seeing, and computer networks permitting, we will display quasi real time images (updated every few minutes) at http://www.solarphysics.kva.se/Mercurytransit7May2003. Later the same day, we will make a movie available at the same site.European Space Agency release for the transit of Mercury
Johns Hopkins University APL Press Release, March 29, 2002
The first mission to orbit the planet Mercury took a big step toward its scheduled March 2004 launch when NASA's MESSENGER project received approval to start building its spacecraft and scientific instruments.
MESSENGER - which stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging - passed a thorough four-day critical design review last week, during which a project advisory panel and NASA assessment team examined every detail of the mission and spacecraft design.
"The review was very successful," says Max R. Peterson, MESSENGER project manager at the Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Md. "Both panels confirmed that our designs are sound and meet the mission's science and engineering requirements. We're ready to move to the next stage."
MESSENGER team members are building flight hardware now and will begin integrating parts on the spacecraft this November, Peterson says. After launch and a five-year journey through the inner solar system, MESSENGER will orbit Mercury for one Earth year, providing the first images of the entire planet and collecting information on the composition and structure of Mercury's crust, its geologic history, the nature of its thin atmosphere and active magnetosphere, and the makeup of its core and polar materials. While cruising to Mercury the spacecraft will fly past the planet twice - in 2007 and 2008 - snapping pictures and gathering data critical to planning the orbit study that begins in April 2009.
A key MESSENGER design element deals with the intense heat at Mercury. The sun is up to 11 times brighter than we see on Earth and surface temperatures can reach 450 degrees Celsius (about 840 degrees Fahrenheit), but MESSENGER's instruments will operate at room temperature behind a sunshield made of heat-resistant Nextel fabric. The spacecraft will also pass only briefly over the hottest parts of the surface, limiting exposure to reflected heat.
"The project is well on its way," says Dr. Sean C. Solomon, MESSENGER principal investigator from the Carnegie Institution of Washington (D.C). "Exploring the many mysteries of Mercury will help us to understand all of the terrestrial planets, including Earth. The team is eagerly looking forward to assembling and launching the spacecraft and to the first new data from the innermost planet."
In July 1999, NASA selected MESSENGER as the seventh mission in its innovative Discovery Program of lower-cost, highly focused space science investigations. APL manages the $286 million project for NASA's Office of Space Science and will build and operate the MESSENGER spacecraft.
MESSENGER Mission Web Site: http://messenger.jhuapl.edu NASA Discovery Program Web Site: http://discovery.nasa.gov
Mark Robinson has some reprocessed images of Mercury available on his web site .