Viewing the Transit of Venus on Mauna Kea

Everyone is gearing up for the Transit of Venus. Starting at just after noon on June 5th, Venus will cross the face of the Sun. This will be our last chance to see such an event in our lifetimes, as a result, many skywatchers are making an extra effort to see this transit. This includes a number of folks who are traveling to Hawai’i this June, just to be here for the transit.

Transit of Venus
The June 2004 Transit of Venus, image credit Jan Herold
The Office of Mauna Kea Management and and Mauna Kea Support Services are making an extraordinary effort for the transit. An interesting exercise, protecting the mountain, ensuring everyone is safe, and allowing reasonable access to the summit. This is a challenge under normal circumstances. Throw in the possibility of a much larger crowd and it could be a real problem. Thus, the following extra measures will be in place…

  • The summit access road will be closed to public vehicular traffic at the Visitor Information Station.
  • Access to the summit will be provided via free shuttle service between the Visitor Information Station (VIS) and Mauna Kea summit.
  • Parking at the Visitor Information Station (VIS) is limited. Additional parking will be provided, however If parking spaces fill up, vehicles will be held below the VIS until parking becomes available.
  • Mauna Kea Rangers and Hawaii County Police Officers will be present to assist with parking and public safety.

There will be solar telescopes stationed at the MKVIS, at the summit, and at a number of other locations around the island. With many options to choose from, you do not need to go to the summit to get at least some view of this event.

The diehards, those wanting to see the entire transit, will probably go to Mauna Kea. I really do not know what sort of crowd to expect on the mountain. While it could be substantial, I really expect a more modest showing than some folks are predicting. In any case it will be a fun event.

Myself? I will be on the summit. I will be running the Keck live webcast of the event using one of my telescopes. From a vantage point behind the Keck 1 telescope we should be in position to witness the entire event from start to finish.

Transit of Venus Timing

Transit of Venus
The June 2004 Transit of Venus, image credit Jan Herold
For reference I am posting precise transit timing for the June 5th Transit of Venus. The data is taken from Fred Espenak’s wonderful NASA Eclipse Website. I just extracted the cities that are of most interest to my Hawaiian readers. For the full list of US cities you can go here.

As you might notice, the times change by a mere two seconds between Kona and Honolulu. These times will be pretty close for the entire island chain. That last number is the Sun’s altitude, the angle above the horizon. Note that this is near 90° for Hawai’i, nearly straight up for the start of the event. Final contact will occur with an altitude of about 5°, just above the horizon near sunset.

Location Name External Sun
Ingress Alt

h m s °
Internal Sun
Ingress Alt

h m s °
Greatest Sun
Transit Alt

h m s °
Internal Sun
Egress Alt

h m s °
External Sun
Egress Alt

h m s °
Anchorage, AK 14:06:30 51 14:24:04 51 17:26:53 38 20:30:46 16 20:48:32 14
Honolulu, HI 12:10:07 85 12:27:46 89 15:26:20 49 18:26:38 9 18:44:38 5
Kona, HI 12:10:09 86 12:27:48 87 15:26:16 47 18:26:33 7 18:44:33 3
Los Angeles, CA 15:06:26 58 15:24:02 55 18:25:33 18 — – — –
Phoenix, AZ 15:06:03 54 15:23:40 50 18:25:32 13 — – — –
Portland, OR 15:06:05 57 15:23:40 54 18:25:53 23 — – — –
San Francisco, CA 15:06:29 61 15:24:04 57 18:25:39 22 — – — –
Seattle, WA 15:05:58 56 15:23:32 53 18:25:57 23 — – — –

All times are local time. Keep in mind that this event occurs on June 5th for viewers in the US and Hawai’i. Some sources show June 6th for a date, and so it will be for viewers on the other side of the date line in Australia, Japan and China.

Viewing the Transit of Venus on Hawaii

There is only one more chance in our lifetimes to see a Transit of Venus. If you are curious about this event, where do you go to see it?

Transit of Venus
The June 2004 Transit of Venus, image credit Jan Herold
Hawai’i is well placed to see the entire event. The transit starts just after noon, with the sun high in the sky. As the transit ends just before sunset, a clear western horizon will be required to witness final contact. For the true astronomical diehards, the summit of Mauna Kea will be the destination. With a clear view, above the clouds, the entire event will be visible.

For those folks who just want a nice view of the event, and do not necessarily need to watch for the entire seven hours, there are a number of easier options. To accommodate the public, there will be solar telescopes setup and manned by volunteers at a number of locations around the island…

  • Mauna Kea Visitor Information Station (MKVIS) A portion of the VIS parking lot will be converted into a viewing station. Telescopes with solar filters will be available. A NASA-sponsored live web cast of the Transit will be displayed inside the VIS and in the presentation room. Parking space at the VIS is limited. If parking fills, vehicles will be held below the VIS until parking becomes available. You may want to consider some of the other sites listed below.
  • ʻImiloa Astronomy Center of Hawaii, Hilo ʻImiloa will display the NASA webcast of the Transit. Leading up to the day of Transit, ʻImiloa will also be running a special planetarium show titled “When Venus Transits the Sun.”
  • W. M. Keck Headquarters, Waimea Livestream from the summit at headquarters in Waimea. Headquarters will be open until 6 p.m. Solar telescopes will be available. Free solar cards for viewing the Transit directly will be provided, while supplies last.
  • Canada France Hawaii Telescope (CFHT), Waimea Solar telescopes and a sunspotter will be available for the public. A raffle for a copy of “Hokuloa: The 1874 Transit of Venus Expedition to Hawaii” by Michael Chauvin will also be held.
  • Puʻu Koholā Heiau National Historic Site, Kawaihae From Noon till 4:30pm. Special glasses will be available, and a live webcast from the summit of Mauna Kea in the Visitor Center theater. As well, park rangers will give special presentations about the historical significance of this event throughout the day.
  • Natural Energy Lab in Kailua-Kona Mahalo to the Natural Energy Lab for sponsoring this event!
  • Keaʻau In the lot across from the Fire Station, Mahalo to W. H. Shipman Ltd for sponsoring this event!

Venus Transit

This is your last chance this lifetime to witness a Venus transit! On June 5th the Earth, Venus and the Sun will line up correctly so that earthbound observers will see Venus cross the disk of the Sun.

Mercury Transit
Mercury transiting the face of the Sun, 6 Nov 2006
Venus transits are relatively rare events, that occur in pairs1, with the paired events separated by eight years. Each pair is separated from the next pair in a predictable pattern, alternating 105.5 or 120.5 year gaps. The first transit of the current pair was in June 2004, with the 2012 event completing the pair. The next pair of events will begin in December 2117. Given the century long separation between events Venus transits have only occurred seven times since the invention of the telescope (1631, 1639, 1761, 1769, 1874, 1882 and 2004)2.

To witness this event you only need to be on the daylight side of our planet when it occurs. The 2012 event favors the Pacific, Australia, Japan and eastern Asia.

For Hawai’i the event will begin at about 12:10pm with the Sun high in the sky, mid-point will be about 3:26pm and will end about 6:44pm, just before sunset. These times are only approximate, exact times will depend on the observer’s location and can vary by several minutes across the islands.

As always the single best source on the web (or anywhere) for eclipse and transit information is Fred Espenak’s eclipse website at NASA. Stop by whenever you have a question on upcoming events as well as viewing and photography tips.

Keck Observatory will be making an extra effort for this transit as Mauna Kea is perfectly positioned to observe the event. We will be webcasting the transit from a small telescope located at the summit. The webcast can be seen on your computer, or come over to our headquaters in Waimea to see the webcast and a live view in a solar telescope if the weather cooperates. there will be extra staff on hand to answer your questions.

Stay tuned to DarkerView for further details as the transit draws near.

1) Transit of Venus, Wikipedia Article, retrieved 8 Feb 2009

2) 2004 and 2012 Transits of Venus, Fred Espenak, NASA/GSFC, NASA Eclipse Website, retrieved 8 Feb 2009

Venus Transit in the Press

Public awareness of a unique astronomical event, the Transit of Venus, is appearing. While avid sky-watchers have been anticipating this event for years, the general public is mostly unaware of the event.

This seems to be changing… A number of articles have appeared in the mainstream press this last week, from MSNBC to Fox News, providing information about the transit.

Yes, it is the same article on all of the sites, all apparently picked up from the Space.com site. There is some lesson here on the nature of corporate news today. In any case it is nice to see an astronomical event getting coverage. Any opportunity to get more astronomy onto the public stage is to be taken advantage of.

A transit is a less spectacular event, not exactly a total solar eclipse. It is quite interesting from an astronomical and historical standpoint. There are other articles, the transit is getting more press as the date approaches. In the run up to June 5th it will be interesting to see just what the public response to this event will be.

Venus and the Pleiades

Over the next few days, the planet Venus will transit the Pleiades star cluster. Tonight sees the planet about two degrees from the cluster center, tomorrow the planet will have closed to just over a degree from Merope. April 2nd and 3rd will see the planet essentially among the primary stars of the cluster. On the 2nd the planet will be only 25′ from Merope, on the 3rd it will be 14′ from Atlas.

At -4.4 magnitude the planet will be far brighter than the brightest stars of the cluster which are 3rd and 4th magnitude. Still, it should be an interesting sight to see the brilliant Venus surrounded by a cluster of stars.

The Moon, Venus and Jupiter

While Jupiter and Venus are now drawing apart after their rendezvous a few days ago one more pretty dance will liven the evening sky. With the two only 10° apart a crescent Moon will slide between them. The 11% illuminated Moon will make a nice match for the two brilliant planets, creating a lovely trio in the evening sky.

Tomorrow night the Moon will have moved to the other side of Venus, still quite close at about 4° separation, creating another pretty view.

Venus Transit on Mauna Kea

A Venus Transit is a truly rare event. Transits occur in pairs eight years apart, with the next pair not occurring for another 120 years. The first event of the current pair occurred in 2004. Thus the next event will happen in June 2012. Considering the century long period between events, this is the last chance to witness a Venus transit during our lifetimes.

The 2012 event will be visible from the west coast of North America to Japan, China, Australia and Central Asia. For those wanting to observe the entire event from start to finish the choices narrow quite a bit. You have the choice of the Central Pacific, Japan, as well as Eastern China and Eastern Australia. This, of course, includes here in the Hawaiian Islands.

Many sky-watchers from North America will see only one choice if they wish to observe the event… the Big Island. The only place easily accessible by air, featuring excellent visitor accommodation, and an observing site that sits above the clouds that could so easily interfere with carefully laid plans. For the serious observer there is one obvious choice… Mauna Kea.

We saw the first signs of this well over a year ago. The tour companies that specialize in astronomy related travel, the folks that feature solar eclipse tours and similar events, began scouting Mauna Kea as a destination. Then the ads appeared, in Sky & Telescope magazine, Astronomy magazine, etc., “See the transit from Mauna Kea!” We had fair warning that this event was not going to pass peacefully.

2012 Venus Transit Visibility
Visibility chart for the 2012 Venus transit, image credit: Fred Espenak/NASA

Some folks seem to think the crowd will be huge, a thousand people or more. I am not so certain, this does not have the general appeal of a total solar eclipse. The transit is something that will be of interest to amateur astronomers and some interested segments of the public. I personally expect hundreds of people coming to Mauna Kea to view the transit, not thousands.

However many folks do ascend the mountain for this event, we have begun putting plans in place to handle it. Various groups have met to do a bit of planning. Most significantly, those in charge of managing the mountain, The Office of Mauna Kea Management, are putting a few measures in place. As usual, expect to stop at the Mauna Kea Visitor Information Station on the day of the transit. But this day there will be a few differences…

  • All available MKSS staff will be on duty. All of the Mauna Kea rangers and visitor station staff will be helping make sure assistance is available to visitors when traveling to the high altitude environment of the summit.
  • Access to the mountain will be controlled for the day, a gate at the VIS allowing access for official vehicles only.
  • A free shuttle will run from the VIS to the summit. The Mauna Kea tour companies providing the vehicles and drivers.
  • Solar telescopes and video monitors will be set up at the VIS to allow safe viewing. Staff will be available to answer questions and assists with the equipment.
  • Several other locations on the island will be setup for viewing the transit with solar telescopes and staff. Expect these to include ‘Imiloa, Keck HQ in Waimea, and some possible other locations.

All of these plans are somewhat preliminary, details may change as the date approaches and final arrangements are made. I will attempt to post what I know here on Darker View.

Myself? I plan to observe the event from the summit. Set up behind Keck with a solar telescope to photograph the transit. We plan to set up a live feed of the transit for use by other sites, and available to viewers across the internet.

Venus and Jupiter

A reminder that tonight will see the two brightest planets in our sky just 3° apart. The two have been close for several days now, the closest approach will be this evening. The bright pairing will be visible as soon as the sky begins to darken, setting around 21:46HST. Venus will be the brighter of the pair at -4.3 magnitude, compared to Jupiter at -2.1 magnitude.