By PETER SUR
Tribune-Herald staff writer
The daylit side of the world paused Tuesday to mark an event that won’t be seen again for 105 years.
The transit of Venus across the face of the sun, which started shortly after noon Hawaii time and ended just before sunset, was viewed by webcast, by solar telescope and special viewing goggles around the world. The Aloha State had a rare front-row view of the whole thing, weather permitting.
Viewing parties were held around the world, wherever the sun shone, and on the Big Island — home of an active astronomy community — the mood was no different.
Members of the public took in the sight from Laupahoehoe, Waimea, the Mauna Kea Visitor Information Station, Kailua-Kona, and wherever a broadband Internet connection was available.
Gary Fujihara, the science, education and public outreach director for the University of Hawaii Institute for Astronomy, said that when he drove past the Mauna Kea VIS at 10 a.m., “there were several hundred people there already” and “definitely dozens and dozens of cars in the lower parking lot.”
Fujihara was helping NASA with the Mauna Kea broadcast, set up with an array of solar telescopes near the Infrared Telescope Facility. They showed video feeds from the sun in three different wavelengths for those who weren’t able to get above the clouds.
Anticipation ran high at Hilo’s ‘Imiloa Astronomy Center, where scores of space cases of all ages gathered on the front lawn to witness the start of the transit. The center was buzzing with activity; many people sported special sun-viewing shades and even commemorative T-shirts to mark the event.
The only thing missing was the sun, hidden behind a thick layer of rain clouds. So the people moved indoors, to the Moanahoku Room, to watch the webcast from a portable Mauna Kea telescope projected on a large screen. Again, the anticipation rose.
“What if Venus is not on time today?” one person in the audience was heard asking.
“It might be on Venus time,” answered another.
The transit was supposed to be visible nine seconds after 12:10 p.m. The appointed minute came and went, and the disk of the sun appeared intact. This was the moment known as “first contact,” when the disk of Venus began crossing the disk of the sun.
Finally, something became visible on the lower left of the image. It looked like a dimple, and then over the course of several minutes became more pronounced. The computer operator moved her mouse to indicate that the transit had begun.
Eventually, the black dot had moved entirely into the disk of the sun; this is known as “second contact.” Contacts determine the moments when the transit begins and ends, and were used during historic times in calculating the distance of the Earth from the sun.
The narrators on the webcast called the event “spectacular,” and it was, for those who knew what to expect. The reaction from the crowd upon noticing this event was less so. One woman clapped her hands for a few seconds, and then stopped. Some people went outside to see if they could catch another glimpse of the sun. Others stayed to watch webcam views of the transit from different spots on the globe.
As viewed from Hawaii, someone with the patience to watch the transit over six hours would have seen a black dot emerge from the disk of the sun, make an elongated loop across the sky and exit the sun shortly before sunset.
“It was stunning,” Fujihara said, noting how he could see prominences along the edge of the solar disk. “It was a pretty fine day up there.”
A transit occurs whenever a smaller celestial body appears to pass across the disk of a larger one. Transits of Mercury are uncommon but not rare; the last one took place in 2003 and the next one will be visible in 2016. But because the orbit of Venus orbits is slower and farther from the sun, and inclined with respect to the Earth’s orbit, transits happen in pairs eight years apart separated by gaps of 105 or 121 years. The last transit happened in June 2004. Humans don’t fare well in “Venus time.”
Most of Mauna Kea’s telescopes spent the day shuttered to protect their sensitive optics from the searing light of the nearest star. Only one, the James Clerk Maxwell Telescope, was able to conduct science observations of Venus in the submillimeter wavelengths. Data collected of the Venusian atmosphere’s temperature, wind speed and chemical composition are being combined with simultaneous observations from a probe orbiting Venus.
Because these transits are so rare, they have been used to measure the 93 million miles between the Earth and the sun. Capt. James Cook traveled to Tahiti to observe the transit of 1769 from a place that is known today as Venus Point.
In Honolulu, hundreds of tourists and locals passed through an area of Waikiki Beach where the University of Hawaii set up eight telescopes and two large screens showing webcasts of the transit.
But minutes after Venus crossed into the sun’s path, clouds rolled overhead and blocked the direct view.
“It’s always the challenge of being in Hawaii — are you going to be able to see through the clouds,” said Greg Mansker, 49, of Pearl City, Oahu, as he stood in line at a telescope.
The intermittent clouds didn’t stop people from looking up through filters, but it did drive some to crowd the screens instead.
Jenny Kim, 39, of Honolulu, said she told her 11-year-old son the planet’s crossing would be the only time he’d get to see the transit in person.
“I don’t know what the future will be, so I think this will be good for him,” Kim said as she snapped photos of the webcast with her smartphone.
The Associated Press contributed to this report. Email Peter Sur at psur@hawaiitribune-herald.com.
