APOD 2.5 The Magnificent Tail of Comet McNaught

In 2007, Comet McNaught became the brightest comet to streak across the sky in the last 40 years and the second brightest since 1935. The comet was visible in the Southern Hemisphere. In the Northern Hemisphere, the tail of the comet was visible right after sunset. The tail was measured to be about 35 degrees in length at its peak. This image, taken by the discoverer of the comet, was captured in Australia in 2007 after sunset and the comet reached an apparent magnitude of -6. For comparison, Venus' maximum brightness is at an apparent magnitude of -4.6 and the full moon has an apparent magnitude of -12.6. The head of the comet was extremely bright and was even visible to some observers in cities in the Southern Hemisphere. The Ulysses spacecraft, which was designed to study the sun, encountered the tail of Comet McNaught.