English: The transit of Mercury on May 7th, 2003 was visible at three GONG sites. The transit was in progress when the El Tiede instrument began observing, Udaipur saw the entire transit, and Learmonth collected about 3.5 hours of the event before the Sun set. This is an excerpt from the NSO press release, entitled Mercury Transit 2003: GONG Network Records Transit of Mercury; Ready for Venus. GONG's global network of telescopes captured and relayed images of the transit of Mercury across the face of the Sun on May 7th, 2003, providing people worldwide with a safe, front-row view of the event. "The network worked extremely well with clear skies at all three sites, and the data transmission back to Tucson was great!" said Dr. John Leibacher. "We transmitted just one image from each site every 15 minutes, and a few were missed, but it looks like we'll have very close to 100% when the dust has settled." ... Dr. Cliff Toner said, "Success with the Mercury transit sets the stage for next year's Venus transit, which will allow more accurate calculations because Venus is farther than Mercury from the Sun." The data will be used to verify the absolute angular orientation and image scale for these three instruments. It may also be useful in estimating the upper limits of any image distortion. See the September 2003 NOAO Newsletter (currently only available in PDF format), and the GONG transit site.