by Richard Rosenberg
As we enter a new year, we can look forward to the interplay of celestial objects creating interesting, occasionally exciting displays for us. Some of these events, like eclipses, meteor showers and conjunctions, take place every year, though differing in detail. Others, like a transit of Mercury across the face of the Sun, are rarer. Then we have the unpredictable ones, like comets. Here’s this year’s menu.
There will be a TOTAL ECLIPSE OF THE SUN on March 29th. As usual, we‘ll have to travel a good distance to see it live. The Earth‘s shadow will fall on Africa, Turkey and Central Asia. If interested, better make reservations quickly.
Two weeks earlier, on March 14th, we have a PENUMBRAL ECLIPSE OF THE MOON whose latter stages can be seen from New York. Unfortunately, this is not a very dramatic event — during a penumbral eclipse, only a slight darkening of part of the Moon can be detected.
Later in the year on September 7th, a PARTIAL ECLIPSE OF THE MOON occurs which is not visible here. Then on September 22nd an ANNULAR ECLIPSE OF THE SUN can be seen from northern South America and the Atlantic Ocean, with a partial eclipse visible from a larger area but not including New York. The difference between an annular and total solar eclipse is that the Moon is too small (because it’s relatively far from Earth) to cover all of the Sun, so a ring of light surrounds the Moon. A dramatic event to be sure, but not comparable to a total eclipse.
2006 is a good year for METEOR SHOWERS, as an unusually large number of the reliable ones occur during the dark of the Moon. These include:
Jan 3 — Quadrantids
Apr 22 — Lyrids
May 6 — Eta Aquarids
Oct 21 — Orionids
Nov 17 — Leonids
Dec 22 — Ursids
OCCULTATIONS BY THE MOON
The Moon doesn’t just cover the Sun in a solar eclipse; sometimes it blocks other objects from our view. These could be called eclipses, but the usual terminology for such an event is an occultation. This year we will be treated to a SERIES OF OCCULTATIONS OF THE PLEIADES, a bright star cluster in Taurus. The view is best with a binocular or wide-field telescope. Occultations occur on the following dates and times:
Jan 9 (evening)
Apr 1 (early evening)
Apr 28 (morning) — a narrow miss, but still interesting
Jul 20 (3 AM)
Oct 9 (11 PM)
Dec 3 (9 PM)
The Moon also occults the bright star SPICA in Virgo several times this year, but most of these events are not visible from New York. An exception is February 17th, when the Moon will rise around 10:30 PM having already occulted Spica. Wait a half hour and Spica will appear. On May 10th a near repeat occurs but with Spica reappearing at 7:40 PM while the Sun is still up a telescope will be required. On December 10th there’s a close call — see below under conjunctions.
I should mention the Moon will also occult another bright star, ANTARES in Scorpius several times in 2006. However these occultations will be visible only in the Southern Hemisphere.
CONJUNCTIONS OF PLANETS
Like the Moon, the movements of the planets result in interesting configurations. When a planet passes another object (another planet, a bright star, star cluster, galaxy, etc.), the event is called a conjunction. Several such events this year are in or near the BEEHIVE CLUSTER, a bright star cluster in Cancer visible in binoculars from New York City. At the end of January, Saturn brushes the cluster’s outskirts (closest on February 2nd). Having reversed its course, Saturn moves back through the center of the cluster the first week of June. At the same time Mars is making a beeline for the Beehive and on the 15th the Red Planet plows through. Only two days later Mars overtakes Saturn (they will be only ½° apart, the size of the Moon). Binoculars or a wide-field telescope will put both planets and the cluster in the same field of view!
There’s also a spectacular grouping of three planets in early December. On the 10th and 11th, MARS, JUPITER AND MERCURY GATHER IN THE MORNING SKY. All three planets fit in a 1° circle on the morning of the 10th, with Mercury and Jupiter only 20’ (arc minutes) apart, each less than 1° from Mars. Mars will be the faintest of the trio — binoculars will probably be needed to see it in the morning twilight. While all this is going on, on the same night of the Moon sweeps by Saturn, just missing it.
A few other conjunctions are listed in the table below. These will probably require a telescope since they are close to the Sun,
TRANSIT OF MERCURY
On November 8th, the planet Mercury reaches inferior conjunction with the Sun, passing directly between Earth and our star. Since Mercury’s orbit does not lie exactly in the same plane as Earth’s orbit, Mercury usually passes invisibly above or below the Sun. But this time we see a TRANSIT OF MERCURY — the planet crosses in front of the Sun’s disk, appearing as a black dot. In New York City the transit will begin at 2:12 PM as Mercury begins to cross the face of the Sun. At 4:40 PM Mercury will be at greatest transit, the halfway point. A few minutes later Mercury and the Sun will set, so the transit will end prematurely for us. (Those on the West Coast can see the entire event.) Be sure to use a reliable solar filter when looking at the Sun! The next transit of Mercury will be in 2016.
A GREAT COMET?
Last and possibly least, but also possibly the year’s highlight, we have COMET SCHWASSMANN-WACHMANN 3. This periodic comet was discovered in 1930 and revolves around the Sun every 5.5 years. Its perihelion (closest point to the Sun) is near Earth’s orbit, so if the timing is right Earth can get quite close to this usually-faint object. Such is the case this year.
But in 1995 while over 1 AU* from Earth the comet underwent a series of outbursts, resulting in a dramatic increase in brightness. In December multiple nuclei were found within the comet’s coma — the comet had split apart. On the next return in 2001, though even farther from Earth, three fragments of the comet were seen.
The comet’s perihelion this year is on June 7. Shortly before, on May 13, the Earth will pass only 0.0735 AU (less than 7 million miles) from the comet. How many, if any, of the fragments will still exist, and how bright will they be? Or will we have a meteor storm instead, as was the case after Biela’s Comet fragmented? Or will we see nothing? Time will tell.
Two other comets may become bright enough to see in binoculars. Check the table below for Comet C/2005 E2 McNaught and C/2004 B1 LINEAR.
2006 EVENTS BY DATE
|January 3 (AM hours)||Quadrantid Meteor Shower|
|January 9 (evening)||Moon occults stars in the Pleiades|
|Late Jan – Early Feb||Comet C/2005 E2 McNaught visible in binoculars?|
|February 2||Saturn passes the edge of the Beehive Cluster|
|February 14 (evening)||Mercury ½° north of Uranus (telescope required). This morning at 10:30 AM they were only 0.02° (1′) apart.|
|February 17 (evening)||Moon rises while occulting Spica|
|March 29||Total solar eclipse in Africa, Turkey, Russia|
|April 1 (early evening)||Moon occults the Pleiades|
|April 22||Lyrid meteor shower|
|April 28 (morning)||Moon narrowly misses the Pleiades|
|Late April – Early May||Comet C/2004 B1 LINEAR visible in binoculars?|
|May (all month)||Comet 73P/Schwassmann-Wachmann 3 naked eye?|
|May 6||Eta Aquarid meteor shower|
|May 10||Spica reappears after being occulted by the Moon (telescope)|
|June 1 – 8||Saturn passes near the center of the Beehive Cluster|
|June 15||Mars passes through the center of the Beehive Cluster|
|June 17||Mars 0.56° from Saturn near Beehive Cluster|
|July 20 (3 AM)||Moon occults several stars in the Pleiades|
|August 21||Saturn 1° from Mercury (binoculars)|
|August 27||Saturn 0.6° from Venus (but only 16° from the Sun)|
|September 22||Annular eclipse of Sun in northern South America|
|October 9 (11 PM)||Moon occults Pleiades|
|October 21||Orionid meteor shower|
|November 8||Mercury transits the Sun|
|November 17||Leonid meteor shower|
|December 3 (9 PM)||Full Moon occults Pleiades|
|December 10||Moon just misses occulting Saturn|
|December 10 – 11
10, 1 AM (EST)
10, 9 AM
10, 2 PM
11, 10 AM
|Mercury, Mars and Venus together in morning sky
Mercury 0.97° from Mars
Three planets fit in a circle of diameter 1.01°
Mercury 0.13° from Jupiter
Mars 0.79° from Jupiter
|December 22||Ursid meteor shower|