Webcasts best bet to see Venus display
By Jan TenBruggencate
Advertiser Science Writer
For the first time since 1882, the planet Venus will cross the face of the sun next month. While the event begins at sunset June 7 in Hawai'i and for the most part won't be directly viewable, the Internet will provide access that has never before been available.
Among the Web sites providing view of the transit, weather permitting, are:
Bishop Museum education director Mike Shanahan said it's possible that people on the west side of Kaua'i could catch a few minutes of the start of the transit before the sun sets. To prevent eye damage, the sun should be viewed only with appropriate lenses, such as No. 14 welder's glass or special solar filters.
See it online
Bishop Museum will provide a live webcast of the event from 7 to 11 p.m. June 7 at its Atherton Halau, along with special programs at its planetarium. The admission fee is $4 for adults and $3 for children, or free for museum association members.
The so-called Transit of Venus is one of the most famous events in planetary astronomy. Today, it is important to people primarily because it occurs so rarely, but it was used 250 years ago to establish the size of the solar system, said Dave Jewitt, planetary astronomer with the University of Hawai'i's Institute for Astronomy.
"It was used originally to set the scale of the solar system," he said. Astronomers viewed the transit from different points on Earth and measured its time of initiation and its end. That allowed them to calculate the distance from Earth to the sun, a distance known as the astronomical unit.
Transits of Venus occur in pairs eight years apart, with the next one coming in 2012. That one will be visible from Hawai'i.
The sets of pairs occur more than a century apart. The last pair was in 1874 and 1882, and the next is in 2117 and 2125.
When the moon crosses the face of the sun, it can cause a total eclipse of the sun's light. However, Venus is so much farther away that it will cover only 1/30th the diameter of the sun.
Capt. James Cook's first voyage into the South Pacific was to view the Transit of Venus in 1769, which that year was not visible from Europe. He set up his viewing station at a coastal spot east of Papeete in Tahiti, which is still called Pointe Venus.
Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808) 245-3074.
