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The Honolulu Advertiser
Posted on: Sunday, December 31, 2006

Planets soon will be popping back up in night sky

By Carolyn Kaichi
Bishop Museum

Use map (below) by holding it over your head so that its northern horizon points toward the northern horizon on the Earth. This illustration represents the sky at about 10 p.m. early in the month, 9 p.m. mid-month and 8 p.m. late in the month.

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Several notable events highlight this coming year, some we can see, some we cannot, and some in between.

Starting with the first category, January brings planets back to the night sky, with Venus rising higher and staying out later, joined by Mercury late in the month. By February, Saturn will also be in the night sky, Jupiter comes back in June and Mars swings by for another close encounter at the end of the year.

Hawai'i gets a nice view of a total lunar eclipse the night of Aug. 27 going into the morning of Aug. 28, so mark your calendars.

And we will have our usual smattering of meteor showers throughout the year. I will keep you apprised, but if you want some information sooner, check our Web site at www.bishop museum.org/planetarium.

Those events we cannot see but are interesting just the same start on Jan. 3, the night of the full moon but also perihelion, Earth's closest point in its orbit around the sun. The fact that perihelion happens during the middle of the northern hemisphere's winter demonstrates that our seasons are determined by the tilt of the planet, not by our proximity to the sun.

Speaking of the sun, we are now at the nadir of the sun's 11-year sunspot cycle.

If you had the opportunity to view the sun through our observatory's solar telescope in the past year, chances are you weren't too impressed. Although there are occasional sunspots and flares (some rather significant, so we shouldn't discount them), the sun has been relatively quiet. As this year progresses, it's impossible to say how active the sun will get, but we are heading for the upswing of the pendulum.

The 11-year cycle of sunspot activity corresponds to the amount of energy emitted from the sun. Scientists are predicting that the next "solar maximum," in 2010-2011, will be an active one, perhaps one of the strongest in the past 400 years.

The implications of major solar activity are considerable and could impact many aspects of our lives. Studying these patterns of the sun is a relatively recent science and a branch of astronomy called solar weather has emerged to understand and predict solar events.

Lastly, events we can either see virtually or partially involve spacecraft and missions through the solar system.

Although we can sometimes see the international space station or the space shuttles as moving lights in the sky, there's much more going on up there than just flying through space. The shuttle is vital to completing the construction of the space station and in servicing the Hubble Space Telescope.

Other space missions include a remote-controlled laboratory scheduled to launch to Mars this spring and milestones in current missions to Mercury, Pluto and Saturn.

QUADRANTID METEORS AND THE FULL MOON

The new year brings the first meteor shower of 2007. Unfortunately, the moon isn't cooperating with the peak date of Jan. 3. This is the night of the full moon, and the moon will be up at sunset and remain big and bright in the sky until sunrise.

Only the most brilliant meteors will be able to be seen, and waiting for those will be tedious for most people. If you're up for the challenge I certainly don't want to discourage you, but be warned that visible meteors will be far and few between.

Watch the full moon this year, especially in the first few months. January's full moon is high in the sky, almost at the zenith. During the winter months, the Earth's northern hemisphere is tilted away from the sun and the sun appears low in the sky. Right now, the full moon is opposite that tilt and comes up as the sun sets, appearing almost straight overhead around midnight. During the summer, the opposite will occur, with the full moons appearing much lower in the evening sky.

When the sun is straight overhead at noon twice a year in Hawai'i, the shadow is cast straight down. An object perpendicular to the ground appears to have no shadow. We call this phenomenon Lahaina Noon. Likewise, when the moon is full and straight overhead, you will notice the shadows cast by the moon's bright light are short or small. I suppose we could dub this effect Lahaina Moon?

THE PLANETS

Mercury: Quick-footed Mercury is speeding back to our evening sky and should be visible by the end of the month under Venus. Both planets are low in the west and set shortly after darkness, but the best time to find Mercury is when it's next to its brighter sister. Early February will also bring more opportunities to find the small planet.

Venus: As long as there are no clouds or buildings in the way, there's no way you can miss brilliant Venus in the western sky. Even before the sky is completely dark, Venus shines through the sunset. It's still low in the west this month and sets by 7:30 to 8 p.m., but watch it climb higher in the sky as the months go by. See if you can spot a tiny sliver of a crescent moon right above Venus on Jan. 20.

Mars: Mars follows Jupiter in the morning sky, rising just ahead of dawn in the east. The Red Planet is slowly making its way toward a December rendezvous with Earth in another "close encounter." Until then, Mars appears small and unassuming in the sky.

Jupiter: Jupiter is up by 5 a.m. in early January and an hour and a half earlier by the end of the month. The largest planet is not difficult to spot, being the second brightest planet after Venus, and since Venus is in the evening sky, they are not in competition. Look for a waning crescent moon next to Jupiter on Jan. 15.

Saturn: In the first half of January, the night sky is devoid of naked-eye planets for a brief period between Venus setting and Saturn rising. But by the end of the month, Saturn will rise around the same time Venus sets as the ringed planet heads toward its February opposition. A fat gibbous moon sits by Saturn on Jan. 5.

MOON PHASES

Full moon: Jan. 3
Third quarter: Jan. 11
New moon: Jan. 18
First quarter: Jan. 25
All dates are Hawai'i Standard Time.

Contact Carolyn Kaichi at hokupaa@bishopmuseum.org or 847-8203.

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