2012 Astronomy Highlights
Every year Bishop Museum’s Watumull Planetarium provides a calendar of astronomical events specifically for Hawaii’s location and time zone. Most sources that list the times for moon phases, meteor shower peaks, the start of the seasons and other events provide that information in Universal Time (UT), which is ten hours ahead of Hawaiian time. If the moon is full at 4:00 hours UT on August 26, for example, it will be full in Hawai‘i ten hours earlier, or at 6 p.m. on August 25 Hawai‘i Standard Time (HST).
In addition, there are certain celestial events that are specific to Hawai‘i. These include the date of Makahiki (Hawaiian New Year), which is determined by the first visible sliver of a moon after the new moon after the rising of the Pleiades at sunset (which occurs on November 17 each year). This calendar also provides the dates and times for Lāhainā Noon for many locations in the islands. Lāhainā Noon is the term for the two days each year when the sun is exactly overhead. This only occurs in the tropics, and the dates vary depending on latitude.
2012 Astronomical Events
Earth at perihelion (3PM HST, 1 hour UT). Like all planets, the earth’s orbit is not a perfect circle but rather an oval. Earth reaches perihelion, its closest approach to the sun, in early January each year.
Chinese New Year. Chinese New Year occurs two new moons before the first day of spring (which is March 20 this year Universal time). The new moon before the first day of spring occurs on February 21 this year; the new moon before that occurs on January 23; so that marks Chinese New Year. (Note: this new moon occurs on January 22, 2012 in Hawai‘i, but Chinese New Year is set by the day when the moon is new in Beijing, China; which occurs on January 23).
Leap Day. This is a day inserted into the calendar every 4th year to ensure that our earthly calendar remains in line with the seasonal calendar. In a calendar without any leap days, the first day of spring would go from occurring on March 20 to occurring on April 10 in the expanse of a single human lifetime.
The planet Mars is in opposition. Mars’s closest approach to earth at any point in the last two years. The red planet rises at dusk, sets at dawn, and is in the sky all night. Mars shines at minus 1.23 magnitude. Mars’s brightness varies more than any other planet; in March 2012 it will be the 4th brightest dot of light in the sky, outshone by only Venus, Jupiter and the star Sirius.
March 10 - 15
The “conjunction of the year.” Venus and Jupiter shine together in the western sky at dusk. Jupiter shines at minus 2.1 magnitude, Venus at minus 4.4; the two are the brightest dots in the sky. On March 13 the two brightest planets will be only about three degrees apart from each other, or less than the width of two fingers held at arm’s length. Look west from 7:20 p.m. onwards; the planets set around 9:45 p.m..
Daylight Saving Time begins at 2 a.m. for most of North America (not observed in Hawai‘i). As of this day the west coast of the US is three hours ahead of Hawai‘i and the east coast is six hours ahead of Hawai‘i.
Spring begins at 7:15 p.m. Hawai‘i Standard Time (5:15 on March 20, UT). Day and night are equal (12 hours each) all over the world.
Easter Sunday. Easter is the Sunday after the full moon after the first day of spring. The first day of spring occurs on March 20 (UT), March 19 (HST). The full moon occurs on Friday April 6, and Easter on the following Sunday, April 8.
Saturn in opposition; the planet rises at dusk, is high at midnight, sets at dawn.
Partial solar eclipse (visible in Hawai‘i)
A small portion of the sun will be blocked by the moon on the afternoon on May 20, as seen from the Hawaiian Islands. From Honolulu the first contact will occur at 2:03 p.m.. By 3:15 p.m., the time of deepest eclipse, about 1/10th of the sun will be blocked by the moon. The eclipse will end at 4:12 p.m..
In parts of the continental US, this May 20 eclipse will be an annular eclipse. An annular eclipse occurs when the moon is unusually distant from the earth in its orbit around the earth. At times like this, the distant moon is too small to cover the entire disk of the sun. Even when the moon is dead-center in the middle of the solar disk, a ring of sunlight shines around the moon. Such eclipses are called “annular eclipses,” from the Latin word for “ring.” A viewer using safe viewing techniques would see a ring of sunlight surrounding the moon’s disk.
The annular eclipse will pass over the western US in the afternoon of May 20. The annular phase will touch the west coast in northern California near Eureka just after 5 p.m. local time. (While the path to see the annular eclipse is 200 miles wide, that path runs just north of San Francisco, which will see only a deep partial eclipse). In Redding, CA, the annular phase will start at 6:26 p.m. and last for about four minutes. (That’s 3:23 p.m. HST, but we of course won’t see it as an annular eclipse in Hawai‘i). The path of the annular eclipse will proceed through the exact middle of Nevada, and then cross south Utah and Northern Arizona. It will cross the middle of New Mexico; Albuquerque is right in its path.
The annular phase will start at 7:26 p.m. on Albuquerque and last just over four minutes. Elsewhere on the planet, this annular eclipse will be visible in Hong Kong and Tokyo. Those cities are on the other side of the International Date Line, so this eclipse occurs in Asia on May 21. Hong Kong will see the annular phase from 7:05 to 7:10am on May 21. Tokyo will see the annular phase at 7:33 – 7:37 a.m. on the May 21.
Please note that is never safe to view an annular partial eclipse without a proper filter. Annular eclipses can be of particular concern, since so much of the sun’s light is blocked; but even the thin ring of the sun’s disk can do eye damage.
Partial lunar eclipse. Visible from Hawaiian Islands. During a partial lunar eclipse, part of the moon goes into the deep inner shadow of the earth. The moon looks like someone took a bite of out it. In Hawai‘i, stay up late on June 3; right after midnight, around 12:02 a.m.early on June 4 the partial phase will begin. At the peak of the partial eclipse, around 1am, it will look like a about a third of the moon is missing. This partial phase will end at 2:03am.
The west coast of the US and Canada will see the partial phase in its entirely, before the moon sets. The moon will set while in the middle of its partial eclipse phase in the Mountain Time Zone; further east than that, viewers will not see the partial eclipse.
Australia, New Zealand and western Alaska will see all of this partial eclipse as well.
Transit of Venus. Visible in Hawai‘i on June 5. At 12:09 p.m. on June 5, as seen from Honolulu, the small dot of Venus will start to move across the face of the sun. The transit will end in the islands at 6:42 p.m., shortly before sunset. The timings will be the same throughout the islands.
For the parts of earth that are in daylight, this transit starts at roughly the same time all over the planet, allowing for time zones. Thus it will start on the west coast of North America just after 3 p.m. (3:06 p.m. PDT in Los Angeles), and just after 6 p.m. on the east coast (6:03 p.m. EDT in New York, for example).
The transit will be visible from Alaska, New Zealand, eastern Australia and Hawai‘i in its seven-hour entirety. Viewers in the Americas will see the transit at sunset; viewers in Europe, Africa and western Asia will see it just after sunrise on June 6.
Viewers should use a safe viewing technique such as a Mylar filter to view the transit. It is never safe to view the sun directly, except for the very rare moments of a total solar eclipse.
Such transits of Venus occur in pairs, eight years apart. The last transit of Venus, in 2004, was not visible from the islands. The 2012 transit is the last one for 105 years. Transits of Venus have a great deal of historical significant for Polynesia. Captain Cook was drawn to Tahiti on his first voyage to observe the 1769 transit. A transit that was visible from Hawai‘i in 1874 was also the subject of scientific expeditions.
Summer Solstice. Summer for the northern hemisphere begins at 1:09 p.m. Hawai‘i Standard Time (23:09 UT). This is the longest day of the year for the northern hemisphere and the shortest day for the southern hemisphere. In Honolulu, the sun rises at 5:50 a.m. and sets at 7:16 p.m., giving 13 hours and 26 minutes of sun.
Earth at aphelion (most distant point from the sun in our annual orbit around the sun).
6 p.m. on July 4 HST.
Autumnal Equinox. Autumn begins at 4:50am on September 22 Hawai‘i Standard Time (14:50 UT). On the equinox, day and night are equal (12 hours each) all over the planet.
Daylight Saving Time ends at 2 a.m. for most of North America (not observed in Hawai‘i). As of this day, the west coast is two hours ahead of Hawai‘i and the east coast is five hours ahead of Hawai‘i.
Total Solar Eclipse (not visible from Hawai‘i). This is the only total solar eclipse of 2012. The only place it’s visible from land is from the northern territory of Australia. From Cairns, Australia the sun will rise at 5:35 a.m. on November 14; the eclipse will start 10 minutes later it will become total, for two minutes, at 6:39 a.m. local time.
This eclipse is not visible at all from the Hawaiian Islands.
Penumbral lunar eclipse
This would be “visible” from Hawai‘i except for the fact that you see virtually no difference in the moon’s brightness during a penumbral lunar eclipse, when the moon does into the earth’s outer shadow. The peak of the eclipse is early in the morning of November 28, around 4:30 a.m. HST; but again, you’ll probably see nothing different from a regular full moon. The lunar eclipse is penumbral only; in other words there is no place on earth where it appears as a partial or total eclipse.
Makahiki (start of the Hawaiian year). To mark the start of the Makahiki season: 1) wait for the star cluster of the Pleiades to rise at sunset, which occurs every year on November 17; 2) wait for the new moon that follows this sunset rising of the Pleiades, which occurs in 2012 on December 12; 3) wait for the first visible crescent moon that follows this new moon. This year, this slender crescent should be visible in the west at dusk on December 14, thus marking the start of the Makahiki season and of the Hawaiian year.
Jupiter in opposition; rises at dusk, high overhead at midnight, sets at dawn.
Winter solstice; winter starts for the northern hemisphere at 1:12am on December 21 Hawai‘i Standard Time (11:12 UT). This is the shortest day of the year if you are in the northern hemisphere and the longest day of the year for the southern hemisphere. In Honolulu the sun rises at 7:05 a.m. and sets at 5:55 p.m., giving us just under eleven hours of daylight.
For all meteor showers, the viewing will be better after midnight. These repeating annual events are caused as the earth enters into debris left over from a specific comet (or, in the case of the Geminids, an asteroid). As the earth goes around the sun, our planet runs into the same debris at the same time each year. This is why these showers occur at the same time each year. After midnight, the part of the earth that you are on is facing toward the debris that causes the meteor shower. This is why all meteor showers are better after midnight.
Meteor star showers are named for the constellation where the meteors appear to come from. The Lyrid shower in named for Lyra, the harp, for example. (The Quadrantid Shower refers to an old constellation called Quadrans Muralis, which is now part of Bootes). Generally these constellations are rising in the east during the prime post-midnight viewing time for a shower. That said, don’t just look east – scan the entire sky for shooting stars.
To view shooting star showers, just find a dark location (as little city light as possible) and get comfortable (a lawn chair is a good idea).
More meteor information:
Quadrantid Meteor Shower
Peak: Night of January 3-4
This shower peaks early in the morning on January 4 (i.e., stay up late on January 3, and right after midnight look for meteors). Search all the sky, but especially the eastern sky.
Shooting star showers are named after the constellation from which they seem to radiate. While other shooting star showers are named for familiar constellations (Geminids, Perseids, etc), the Quadrantids are named for a constellation you may never have hear of. It is called Quadrans Muralis, or “Mural Quadrant.” A “mural quadrant” is an historical astronomical instrument that consisted of a 90 degree arc made of metal or wood, mounted on a wall. The constellations itself was invented in 1795 and made defunct in 1928, when it was officially made part of Bootes the Herdsman. Bootes is rising in the east about 1:00 a.m. The waning gibbous moon sets at 3 a.m. that night, so viewing should be best in the early hours of the morning on January 4.
Lyrid Meteor Shower
Peak: night of April 21 – 22. That is, stay up late on April 21 and then look for meteors after midnight, very early on April 22. The shower is active from April 16 – 25. While not one of the strongest showers, the Lyrids can produce up to twenty meteors per hour. No interference from the moon this year; the moon is just past new, and not visible at all.
Eta Aquarid Shower
Peak: evenings of May 4-5 and May 5-6. Active from May 4-7. A light shower, 10 meteors or so per hour. This is the only 2012 shower with major interference, since the moon is full. One claim to fame: this shower is caused by debris from Halley’s Comet.
Southern Delta Aquarid Meteor Shower
Peak: nights of July 28-29 and 20-30 Active period: July 18–August 18. Up to 20 meteors per hour. The moon is waxing gibbous and sets around 2:30 a.m. early on July 29 and 3:40am early on 30th. This one should be OK from the Hawaiian Islands but the view will be better from the southern hemisphere.
Perseid Meteor Show
Peak: nights of August 11-12 and of August 12-13. Active from July 23 – August 22. The most famous meteor shower, with up to 80 per hour. The peak nights occur during a waning crescent moon so viewing conditions should be good. The moon does not rise till 1:45 a.m. early on the 12th and 2:40 a.m. on the 13th, and is so slender that it should not cause much interference.
Orionid Meteor Shower
Peak: night of October 20-21. Stay up late on the 20th and into the early hours of October 21. Active period: October 15-25. A good shower, caused by debris from Halley’s Comet. Up to 20-25 meteors per hour. No interference from waxing crescent moon, which is down long before prime shower viewing time
Leonid Meteor Shower
Peak: Nights of November 16-17; possible second spike on night of November 19-20. Stay up late on 17th into the morning of the 18th. Active period is November 13 – 20. The Leonids have an intense peak every 33 years and were responsible for the greatest meteor shower over Hawai‘i in recent times, the 2001 shower. Still, you can still look for up to 10 per hour.
Geminid Meteor Shower
Peak: night of December 13-14 (i.e. stay up late on the 13th). Active period: December 6 – 19. One of the best showers; and we in Hawai‘i often have good weather in December to see it. The moon is new, so viewing conditions are excellent. This meteor shower is a rarity in that it is caused by debris from an asteroid (3200 Phaethon) rather than by comet debris, as is the case for all other meteor showers listed here.
Lāhainā Noon dates for 2012
Every location in the tropics has two days when the sun is exactly overhead. The dates vary depending on one’s latitude.
Note: The zenith (the top of the sky) is a point, and the sun is a disk. The sun will generally cover the zenith on the day before and the day after the listed dates as well. The day chosen for Lāhainā noon is that date when the middle of the sun’s disk covers the zenith.
|May 30 12:35 p.m.||July 11 12:42 p.m.|
|May 27 12:28 p.m.||July 15 12:37 p.m.|
|May 26 12:28 p.m.||July 15 12:37 p.m.|
|May 25 12:24 p.m.||July 16 12:34 p.m.|
|May 25 12:24 p.m.||July 18 12:33 p.m.|
|May 23 12:23 p.m.||July 17 12:32 p.m.|
|May 23 12:22 p.m.||July 17 12:32 p.m.|
|May 23 12:20 p.m.||July 18 12:30 p.m.|
|May 18 12:16 p.m.||July 24 12:26 p.m.|
|May 18 12:20 p.m.||July 23 12:30 p.m.|
|New||First Quarter||Full Moon||Third Quarter|
|Dec 31, 8:15 p.m.||Jan 8, 9:31 p.m.||Jan 16, 11:09 p.m.|
|Jan 22, 9:40 p.m.||Jan 30, 6:10 p.m.||Feb 7, 11:54am||Feb 14, 7:04am|
|Feb 21, 12:35 p.m.||Feb 29, 3:22 p.m.||March 7, 11:40 p.m.||March 14, 3:26 p.m.|
|March 22, 4:38am||March 30, 9:41am||April 6, 9:19am||April 13, 12:50am|
|April 20, 9:19 p.m.||April 28, 11:58 p.m.||May 5, 5:36 p.m.||May 12, 11:47am|
|May 20, 1:48 p.m.||May 28, 10:17am||June 4, 1:12am||June 11, 12:42am|
|June 19, 5:03am||June 26, 5:31 p.m.||July 3, 8:52am||July 10, 3:48 p.m.|
|July 18 6:25 p.m.||July 25, 10:57am||August 1, 5:28 p.m.||August 9, 8:56am|
|August 17, 5:55am||August 24, 3:54am||August 31, 3:59am||Sept 8, 3:16am|
|Sept 15, 4:11 p.m.||Sept 22, 9:41am||Sept 29, 5:19 p.m.||Oct 7, 9:34 p.m.|
|October 15, 2:03am||October 21, 5:33 p.m.||Oct 29, 9:50am||Nov 6, 2:36 p.m.|
|Nov 13, 12:09am||Nov 20, 4:32am||Nov 28, 4:47am||Dec 6, 5:32am|
|Dec 12, 10:42 p.m.||Dec 19, 7:20 p.m.||Dec 29, 12:22am||Jan 4, 5:58 p.m.|
Note: All times are Hawaii Standard Time. To convert to universal time, add ten hours.