Venus is making a rare move this week – so rare that it won’t happen again until 2117.
In an event known as the “Transit of Venus”, the solar system’s second planet will glide from west-to-east across the face of the sun. To viewers on Earth, the planet will appear like a small black dot in motion across the upper half of the solar disk. The six hour, 40-min. passage will start Tuesday shortly after 6 p.m. Eastern U.S. time; if the skies are clear, people in eastern Australia, New Zealand, Hawaii, and eastern Asia will get the best view of the transit, reports the Los Angeles Times. But a large portion of South America, western Africa, and western Spain and Portugal will miss out on the transit, according to Joe Rao, an instructor at New York City’s Hayden Planetarium and writer for MSNBC.com.
Venus’s trek across the sun is one of the rarest astronomical events and scientists predict that it won’t happen again for the next 105 years. Only six transits of Venus are known to have been observed since the advent of astronomical instruments, with the earliest known passage dating back to 1639, according to Rao.
Sky watchers who plan to view Venus’s passage are advised to never look directly into the sun and to wear special viewing glasses like solar eclipse glasses. Other viewing options include telescopes with special filters and pinhole projects. Earthlings who want to view Venus from the comfort of their desks and sofas can check out the special coverage of Venus’s move on SPACE.com.