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While it’s not yet June, you may catch two special astronomy events today.
At 12:28 p.m. today in Honolulu, the sun will go exactly overhead, known as “Lahaina Noon.” An upright object such as a flagpole will have no shadow.
Lahaina Noon occurs twice a year and only in the tropics; the sun is never overhead in any other part of the planet.
Your dates for an overhead noon depend on how far north or south you are in the tropics. The farther north you are, the later the first Lahaina Noon day will occur. It will not happen until 12:28 p.m. Monday in Kaneohe, and 12:35 p.m. Thursday in Lihue.
Also tonight, catch the most beautiful gathering of Jupiter,Venus and Mercury in the west: The three planets will form a perfect, tight triangle, visible from about 7:30 to 8 p.m. Jupiter and Mercury are side-by-side, and Venus is below the two other planets.In late May and early June, the three planets make a striking sight in the western sky at dusk. All of these planet gatherings mentioned below happen in the west around dusk, when all three planets are close to the western horizon, so make sure you have a unobstructed view in that direction over the sea, for example. And start looking by 7:15 p.m., since this an early-evening show; the planets set around 8.
In particular, this gathering provides you with an easy way to spot the elusive planet Mercury. You can use the two brightest planets, Venus and Jupiter, to find your way to the dimmer Mercury.
>> By Monday, that trian- gle of planets has already lost the perfect equilateral shape. Venus and Jupiter are now side-by-side, and that little speedster Mercury is now above and to the right of the other two planets.
>> Tuesday: Venus now appears above Jupiter; as of this night, Jupiter becomes the bottom of the three- planet gathering, while it still remains visible.
>> Wednesday through Saturday: Continue to look west around 7:15 p.m. Now the three planets form a line, with Venus in the middle, Jupiter now on the bottom, and Mercury on top. Jupiter is only 6 degrees above the west horizon at 7:45 p.m. and sets about 8:05.
>> Saturday through June 5: While this lineup remains intact, it will get harder to see Jupiter, since it is now close to the western horizon by the time it gets dark. By June 5, Jupiter sets just after twilight, around 7:50 p.m. Af- ter that, we lose Jupiter for the rest of the month.
>> June 6-14: After Jupiter quits the party, Venus and Mercury continue to put on a show in the west at dusk for the next two weeks. Use Venus as your guide; it’s the brightest dot in the sky and about 10 degrees (a palm’s width at arm’s length) above the western horizon at dusk. Once you have found Venus, look above it for Mercury. From June 6-14, Mercury is about 4 degrees above Venus. The two planets emerge from dusk around 7:30 p.m. and set around 8:30., so you have an hour to spot the duo. Look for the crescent moon next to the two plan- ets on June 10.
>> June 15-19: Mercury moves from being to the up- per left of Venus (3 degrees away) on June 15 to being side-by-side with it on June 19. However, as Mercury ap- pears to draw closer each night to Venus, Mercury also fades fast in brightness. By June 19, when it is to the left of Venus, Mercury is no brighter than an average bright star.
>> June 20-30: Mercury is now below Venus and gets fainter by the night. On June 25, Mercury is 5 degrees be- low Venus and sets by 8:25 p.m. By the end of June, Mercury is gone, leaving Ve- nus alone to reign over the western evening sky.
OTHER PLANETS
While Venus, Jupiter and Mercury huddle in the west at dusk, Saturn shines in the east and is overhead most of the night.
Saturn is about 45 degrees up in the east at dusk in early June, is high in the south at 10 p.m. and sets in the west just before 4 a.m. By the end of June the ringed planet is due south at dusk, about two-thirds up in the sky from the south hori- zon, and sets a little before 2 a.m. The planet makes a nice triangle with the bright stars Arcturus and Spica this year. Look for the waxing gibbous moon next to Saturn on June 18-20.
We lost Mars in early February, so its been gone for months from our sky. The red planet creeps its way into the predawn sky at the end of June. The red planet rises in the east at 4:30 a.m. and is only visible for a few moments before dawn breaks.
JUNE SKY MAP
June provides the last chance each year to see the Southern Cross, officially called Crux, from the Hawai- ian islands. At the start of the month, Crux is due south at dusk, and sets by 11 p.m. By the end of June, Crux is already heading for the western horizon at dusk, and sets by 9 p.m. Our star map, good for 11 p.m. at the start of June and 9 p.m. at the end, shows the Cross as it sets.
Also in the south, look for Scorpius rising high. To its left, Sagittarius the archer has returned to our sky.
In the north, look for the Big and Little Dippers, with Draco winding its away between the two.
In the west, the classic spring constellation of Leo the Lion heads for the horizon while Altair-Deneb-Vega, the Summer Triangle, rises in the east.
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Mike Shanahan is director of Education, Exhibits and Planetarium. For more information, go to www.bishopmuseum.org/planetarium/planetarium.html.
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