The Dudley Observatory

Skywatch line for Thursday, December 28, 2006
by Ray Bogucki

The three planets that met in a tight grouping on December 10 have dispersed. Mercury has become lost in the Sun's glare as it prepares to pass behind the Sun on January 7. Bright Jupiter continues to rise earlier each day, now clearing the northeast horizon about 5 a.m., almost an hour before the start of morning twilight. Mars also rises earlier each day but at a slower pace than Jupiter. Ancient astronomers were fascinated with the planets, not only because of their constant "travelling" through the starry background, but also because the brightness of a planet varied with time, sometimes dramatically. Currently, reddish colored Mars rises a little before 6 a.m, about 6 degrees to the left of the bright reddish star that marks the heart of Scorpius, the Scorpion. Ancients named the star Antares, which means "Rival of Mars" because of their similar colors. These frosty mornings, if you compare the two side by side, Antares appears almost twice as bright as Mars. But, we are now slowly overtaking Mars and as we get closer, Mars will brighten noticeably. By April, the two bodies will appear equal in brightness and, by next December, when we are nearing our closest approach to Mars, it will appear ten times brighter than Antares.

On the other side of the sky, Venus rises a little higher each night into the western sky after sunset. This brilliant beacon will dominate the early evening sky all through the winter, spring and early summer.

On Wednesday, January 3, three notable events take place. The Moon becomes full, the earth is at perihelion, its closest approach to the Sun in its annual elliptical orbit, and the Quadrantid Meteor Shower reaches its peak activity. it's interesting to note that only a week away from winter solstice, we are now 3 million miles closer to the Sun than we will be at summer solstice, next July.

The curiously named Quadrantid Meteor Shower will peak about 8 p.m. Wednesday evening. Although this is as active a shower as the recent Geminids, the Full Moon will brighten the sky, so that only the brightest meteors will be visible. Try to find a site in the dark shadow of a building or tree so that the bright Moon will not distract and weaken your vision. The name Quadrantids is derived from a constellation named Quadrans, the Quadrant, which was located just east of the handle of the Big Dipper, and now a part of Bootes, the Herdsman. The constellation was eliminated by the International Astronomical Society early in the 20th century, but its name lives on in the name of the meteor shower.

This is Dudley Observatory's Skywatch Line for Friday, December 22, through
Sunday, December 24.
by Alan French

The Moon was new Wednesday, so a pretty crescent Moon will be visible in the
early evening sky. If you look for the Moon about 30 minutes after sunset,
you'll also have a chance to spot Venus, now moving back into the evening
sky.

If you look toward the southwest at 5:00 PM on Friday night, you'll see a
thin crescent Moon ten degrees above the horizon. If you have a good clear
view of the horizon more toward the west, you should see Venus just three
degrees above the horizon and 15 degrees to the lower right of the Moon.
Venus will be in the evening sky for the first half of 2007.

The bright crescent is the part of the sunlit half of the Moon which we can
see from the Earth. The line between the brightly lit crescent and the
darker part of the Moon is known as the terminator. Right now, that is the
line where sunrise is occurring on the Moon. Over the next several nights,
you will notice that this line is creeping slowly to the left across the
face of the Moon, encroaching upon its night side. This lazy march of the
terminator gives each spot on the Moon about 14 days of sunlight and then 14
days of dark.

If you look closely at the night side of the Moon (the area to the left of
the terminator), you will notice that it is faintly illuminated. This
ghostly light is known as Earthshine. The Earth's phases as seen from the
Moon are exactly the opposite of the Moon's phases as we see them. When we
see a full Moon in our sky, astronauts on the Moon would be staring up at a
new Earth. In the same way, while we now have a crescent Moon, the Moon is
experiencing a gibbous, or nearly full, Earth.

The Moon will be higher and farther south each night over the weekend, and
the Earthshine will become a little less obvious each night as the brightly
lit crescent grows and begins to overpower it. In the Moon's sky, the Earth
is also becoming a little less full each night.

Now, the Earth is one week farther along in its orbit and tonight it will begin running into another meteor stream, the debris left by the comet 8P/Tuttle. This comet moves into the inner Solar system and swings around the Sun every 13.5 years, leaving behind a trail of small particles in our orbit. The violent collisions of molecules and atoms in our atmosphere with these particles raise the particles to incandescent heat and produce the Ursid Meteor Shower. The radiant, the point in the sky from which all Ursids appear to originate, is close to the bowl of the Little Dipper. To locate the Little Dipper, face due North and look for Polaris, the second magnitude North Star about halfway between the horizon and the zenith. Starting with Polaris, the end of the handle, follow a string of three stars traveling down and left to a small rectangle of stars that form the bowl of the Dipper. The radiant is close to the bright star called Kochab at the end of the bowl. The bowl of the Little Dipper appears to be pouring into the bowl of the Big Dipper which is climbing upward from the northern horizon toward the East. Because the radiant is well above the horizon all night at this location, we are well-placed to see a maximum number of meteors. In addition, the waxing crescent Moon will set by 6 p.m., so there will be no moonlight to interfere with observing the meteors. However, note that this is a more modest display than the Geminids, so there will probably be fewer Ursids per hour.

This is the Dudley Observatory Skywatch Line for Tuesday, December 19th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

Sunrise today was at 7:21 AM, and it set tonight at 4:23 PM. Sunrise tomorrow is at 7:22 AM, and Sunset tomorrow is at 4:23 PM.

The New Moon is tomorrow, and rises and sets with the Sun. Therefore, it will not be visible in the sky. Look for the Waxing Crescent moon very low in the west after Sunset, Starting around December 21st. On Thursday, it will be near the Planet Venus.

We are also winding down the days of the Fall season, as Winter officially begins on Thursday. After Midnight on Thursday, and into Friday Morning, look for the Ursid Meteor Showers. Appearing to originate from the area around the Little Dipper, this usually dull Meteor Shower, may yield up to 100 “shooting stars” per hour this year.

The very bright planet Venus is beginning to make an appearance low in the west after Sunset. You will need a nice clear horizon, but look next time when skies are clear.

The Planet Saturn, in the constellation of Leo the Lion, rises by 10:00 PM in the northeast, and by that time, the Winter constellations of Orion, Taurus, and the Seven Sisters are high up in the east.

Mercury, Jupiter, and Mars are all together within a few degrees of each other low in the East before Sunrise.

The Suits-Bueche Planetarium at the Schenectady Museum has re-opened and is now running its regular schedule. Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M. The 1:00 program is “The Sky Above Mister Rogers Neighborhood”, a program for young people. At 2 P. M. is “Tis the Season”, and at 3 P. M. is a live narration of the Fall Sky. “Tis the Season” also plays Tuesday through Fridays at 2 PM.

The Sun sets at 4:23 PM, with night falling at 6:06. Dawn breaks at 5:39 AM and ends with sunrise at 7:22.

Venus appears very low in the southwest at sunset, ending the planetary drought. It sets shortly after the Sun, but sets later as the month progresses. In binoculars or telescope Venus appears bright and “full.” As its winter apparition continues, Venus becomes thinner but larger.

The constellation Perseus is high in the East, below “W” shaped Cassiopeia. The variable star Algol marks the end of Perseus’ shorter leg. The star dims every three days. Algol takes several hours to dim and then brighten. If you can, watch Algol brighten from its minimum, which happens at 10:30 PM.

By midnight, Saturn is high in the East, near the constellation Leo. Saturn’s creamy white color cannot be mistaken for a star.

About a half hour before sunrise, Jupiter, Mars, Mercury and the Moon cluster low in the southeast. Unlike the tight group of last week, these planets are strung out. Jupiter is highest and brightest. Mars is four degrees below Jupiter and requires binoculars to be seen. Mercury lies to Mars’ lower left. A very thin Moon hugs the horizon. Both Mercury and the Moon disappear below the horizon in coming days, while Jupiter and Mars rise higher and earlier.

This time of the year was dedicated to Saturn, the Roman God of Harvests. A series of feasts were held during the week of the Winter Solstice – the Saturnalia. Saturn was depicted as a jolly old man. People decorated evergreen trees. Candles were lit everywhere. Houses were decorated with wreaths and Holly. Decorated cookies were baked. People wore red peaked hats, similar to the “Santa hats” of today. Banquets were held both in honor of the harvest and wishing for a prosperous new year. Gifts were exchanged. Donations and benefits were held for he poor. Saturnalia was an official government holiday. The holiday was so popular that Christians moved the feast of Christ’s birth to compete and adopted many of the symbols and traditions of this pagan feast

Clear Skies

Joe Slomka

This is Dudley Observatory's Skywatch Line for Friday, December 15, through
Sunday, December 18.
by Alan French

Dudley Observatory is participating in the Holiday Magic program in downtown
Schenectady on Friday night, from 4 PM until 9 PM. Weather permitting,
telescopes and a display will be set up at the north end of Jay Street, near
the Open Door. If the weather is not good, Dudley will be set up under the
Proctor's marquee. Stop by and say Hi!

Weather permitting the Albany Area Amateur Astronomers will host a public
Star Party this weekend. At a Star Party a variety of telescopes are set up
for your viewing pleasure. During the early part of the Star Party, club
members will have their telescopes pointed at some of the celestial
showpieces. Later on, we take requests, as long as the object is above the
horizon.

The Star Party will be held Friday night in Indian Meadows Park in
Glenville, beginning at 8:00 PM. Indian Meadows Park is off of Droms Road
in East Glenville, and is marked by a large sign. After passing the park
buildings, bear left at the fork in the road, and continue to a gravel
parking lot on your left. The telescopes are set up beyond the gravel
parking lot. Please park in the gravel lot and walk to the telescope area.
If you are bringing a telescope, you may drive to the observing area, but
try to arrive early.

There is no admission charge and all ages are welcome. You are welcome to
stay as long or as briefly as you wish. Keep in mind that the temperature
feels 20 to 30 degrees cooler when you are inactive under the night sky – so
dress appropriately! The Star Party will be canceled if the skies are
mostly cloudy. If in doubt, call 374-8460 after 6:00 PM.

Area residents will have some good views of the International Space Station
as it passes over our area during the coming week. Visit
www.heavens-above.com and enter your location for exact predictions. Also,
check predictions for viewing the shuttle Discovery, listed as STS-116,
after it undocks from the ISS around mid-week. If the timing is right, you
may be able to see the ISS and Discovery quite close together in the sky.

At bedtime last Saturday, an overcast sky promised little hope for seeing the 3-planet grouping Sunday morning. But while checking the sky at 6 a.m. Sunday, I was astonished to discover that the sky was clear with stars showing from horizon to horizon. I quickly dressed and trudged to a nearby field with a clear, albeit somewhat hilly view to the northeast. When I reached the field, it became obvious that the vindictive northeast weather gods were busily at work. Although the rest of the sky was clear, one tiny layer of dark clouds was sitting on the horizon, just where the planets were to appear. Leaning against a tree, I began to scan the edges of the cloud band, but found nothing. A tiny strip of clear sky had opened between the hilltop and the underside of the cloud layer. I scanned methodically, up and down and side to side. As the sky brightened, hope faded ...but wait - in a conveniently placed notch in the distant hill - a spark! It was not man-made because no one lives up there, and not an airplane, because it was not moving or flashing. The almost imperceptible dropping away of the northeastern horizon revealed it to be a star-like object, bright enough to be Jupiter. Then, as anxious as Longfellow's Paul Revere, searching the belfry tower of the Old North Church in Boston, I looked for the second light and there it was, Mercury, shining weakly through the thin cloud layer about one degree above Jupiter. Although I knew that faint Mars was shining just to the right of Jupiter, no amount of will power was able to wish it into visibility in the bright twilight. Nevertheless, it was satisfying to know that I had witnessed this close grouping of planets, not to be repeated in my lifetime.

This is the Dudley Observatory Skywatch Line for Tuesday, December 12th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

Sunrise today was at 7:16 AM, and it set tonight at 4:21 PM. Sunrise tomorrow is at 7:17 AM, and Sunset tomorrow is at 4:21 PM.

The Last Quarter Moon is today, which means that it can be seen very late at night, or during the morning hours. The Moon rose late last night, and is visible until around 12:15 PM, when it sets. Tomorrow, it will rise just after midnight, and will set at 12:30 PM. After today, the Moon will be in a Waning Crescent phase.

Very low to the horizon during this time of year in the evening, is the famous Big Dipper. It is in the northern sky, and appears upright. Using the end stars of the cup, draw a line upwards, and it will point to the North Star, Polaris, on the end of the handle of the Little Dipper. The Little Dipper is “upside down” compared to the Big Dipper. Technically speaking, the Big and Litter Dippers are not constellations, but parts of the constellations known as Ursa Major and Ursa Minor, the Big and Little Bears.

The very bright planet Venus will soon be making an appearance low in the west after Sunset. You will need a nice clear horizon, but look next time when skies are clear.

Mercury, Jupiter, and Mars are all together within a few degrees of each other low in the East before Sunrise.

The Suits-Bueche Planetarium at the Schenectady Museum has re 0pened and is now running its regular schedule. Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M. The 1:00 program is “The Sky Above Mister Rogers Neighborhood”, a program for young people. At 2 P. M. is “Tis the Season”, and at 3 P. M. is a live narration of the Fall Sky. “Tis the Season” also plays Tuesday through Fridays at 2 PM.

The Sun sets at 4:22 PM, with night falling at 6:03 tonight. Dawn breaks at 5:34 AM, and ends with sunrise at 7:16.

As the Sun sets, there are no obvious planets. Once twilight ends, the asteroid 7 Iris can be found in binoculars and telescopes about eleven degrees West of the Pleiades. Iris appears star like. To identify it, note the pattern of objects in that area. The one that moves after a few days is Iris.

Saturn rises about 9:30 PM, but is ideally observed about midnight. Saturn appears as a bright, creamy white object just to the right of the bright star Regulus in Leo. Regulus forms the period in the backward question mark that forms Leo’s head and shoulders. The Last Quarter Moon rises at midnight and accompanies Leo and Saturn for the rest of the night. By first light, this formation is high in the South and perfect for observation. Saturn’s rings are a treat in any telescope.

The most amazing sight takes place about 45 minutes before sunrise. In the East, Jupiter, Mars, Mercury and the star Beta Scorpii form a tight group about two degrees in width. Yesterday, the group was only one degree wide. If you observed starting last Tuesday morning, you would have seen Mercury go from the highest to lowest member in this group. Mercury will disappear by month’s end. Jupiter is brightest and Mars the least bright. This is the tightest planet cluster since 1974. If you can, track this group’s progress over the next week.

Since the Moon is largely absent in evening sky, it is a good time to be alert for the Northern Lights. A very active sunspot is now rotating into view. This area has already created large eruptions, which missed Earth. If a particle cloud is headed to our direction, Aurorae (or Northern Lights) are a possibility. The US maintains space probes midway between Earth and Sun, providing early warning. Most popular astronomy websites rebroadcast those warnings. If Aurorae are likely, you only need to look north periodically and dress warmly. You only need your eyes to enjoy these heavenly delights.

Clear Skies

Joe Slomka

This is Dudley Observatory's Skywatch Line for Friday, December 8, through
Sunday, December 10.
by Alan French

The Sun has been very active recently and some coronal mass ejections –
streams of high energy particles expelled from the Sun – will hit the Earth
with glancing blows in the coming nights. This means there is a chance for
aurora borealis or Northern Lights. Displays often start with a gentle glow
low in the north to northwest. When they become more active, broad curtains
of light will move up from the horizon, often with brighter shafts of light
extending high into the sky. A very active display can fill most of the sky
with flickering light, sometimes in vivid reds and greens. Keep an eye on
the night sky over the weekend in case we are treated to one of these
celestial light shows. They are always fun to see, and a major display is a
real treat.

Weather permitting; sky watchers will have a chance to see a compact trio of
naked eye planets in the morning sky this weekend. They will be closest on
Sunday morning, and we will not see three naked eye planets closer together
until November 25, 2053! Although they will be closest on Sunday morning,
they will be a pretty sight on Saturday and Monday mornings too. Binoculars
will help locate the fainter planet, Mars, and improve the view of the trio.

To see the trio you will need to be where there is a good clear view down to
the east southeastern horizon, unobstructed by trees or buildings, and
you'll need to be out at 6:30 AM. On Saturday morning, Jupiter, the
brightest member of the planetary trio, will be just over three degrees
above the horizon. (If you hold your first three fingers together at arm's
length, they span five degrees across the tips.) Mercury, the second
brightest, is the highest of the three and is almost five degrees above the
horizon. Mars is faintest, and a bit below and right of Mercury. In the
encroaching dawn, binoculars might be helpful in viewing the trio. They
will span less than two degrees on Saturday morning.

The trio will be closest on Sunday morning at 6:30 AM, spanning less than
one degree. Mercury and Jupiter will be closest, separated by less than a
degree with Mercury just above Jupiter. Mars will be a bit lest than a
degree to their right.

By Monday morning, their motions will have moved them farther apart, but
they will still be a nice compact group, spanning less than a degree and a
half. Let's hope clear skies will let us see this tight planetary trio at
least one morning this weekend.

The other three planets appear in the early morning sky as twilight begins. Mercury appears first, rising into the southeastern sky about 6 a.m. It is now descending rapidly back toward the Sun. Following closely behind Mercury are Mars and Jupiter, in that order. Jupiter is climbing faster than Mars and is rapidly overtaking it, while Mercury is descending rapidly toward Mars. It should be fascinating to watch each morning, about 40 minutes before sunrise, as the three planets seem to approach each other in the sky. Binoculars and a clear view of the southeastern horizon are a necessity. On Sunday morning, December 10, the three planets will come together with all three lying within a one-degree circle, about twice the diameter of the full Moon. The whole group rises about 6 a.m., a little more than an hour before sunrise. This is the tightest three-planet grouping to be seen from Earth between the years 1971 and 2029. Seeing them is a challenge but well worth the effort.

Nearer to home, watch next Wednesday night into Thursday morning, December 13-14, for the peak of what may be the best meteor shower of the year. The Geminids occur when the Earth plunges through small particles of debris left in our orbit, not by a comet, but by the asteroid, Phaethon. The radiant, the point from which all Geminids appear to originate, is close to the star Castor in the constellation Gemini and will be well above the horizon all night. The waning crescent Moon does not rise until early morning and will not significantly interfere with viewing. At its best, this shower can produce more than 60 meteors per hour that move slower and last longer than most meteors. Also watch the night before and after the peak. Remember to dress in more warm layers than you think you can possibly need.

The Sun sets tonight at 4:22 PM, with night falling at 6:03 PM. This is the earliest end of evening twilight. Even though the shortest day of the year takes place on December 21, various events reach their earliest at different dates. Tonight it is earliest end of twilight. The earliest sunset takes place on December 7. However, the day’s length continues to contract until the Winter Solstice.

Dawn breaks at 5:29 and ends with sunrise at 7:10 AM.

As the Sun sets, the Full Moon rises. The Full Moon’s glare washes out most dim objects in the sky. The Moon sits on the northern horn of Taurus, the Bull, midway between the stars Aldebaran, the Bull’s Eye, and Alnath, the tip of the northern horn. About the only object to withstand the Moon is the lovely Pleiades star cluster located 11 degrees West of the Moon. The Pleiades are ideal for beginner binocular observing.

Saturn rises before 10 PM and, by midnight, is high enough for good telescope images. Saturn, famous for its ring system, has them tilted only twelve degrees toward us. Astronomers have long known that the rings were made of large icebergs; however, the Cassini space probe has demonstrated amazing complexity to the countless rings that make up the seven rings seen in telescopes. Saturn is also bright enough to withstand the lunar glare. By Dawn, Saturn is high in the southwest and ideally suited for telescopic viewing.

At about 6:45 AM, the southeast horizon suddenly becomes crowded. Tiny Mercury rises first, followed by Mars and Jupiter. All three planets should be seen in binoculars, given a clear horizon. A fourth object, the star Beta Scorpii, is also included in this group. All four fit in a circle about six degrees in diameter, slightly larger than the typical binocular field. If you can, observe this group for the next two weeks. On December 10, the group shrinks to one degree - the closest planetary gathering since 1974! Afterwards, Mercury dives toward the eastern horizon, while Mars and Jupiter continue to climb higher and join Saturn.

This is Dudley Observatory's Skywatch Line for Friday, December 1, through
Sunday, December 3.
by Alan French

The Moon is approaching full, which will occur on
Monday morning, so the night sky will be brightly lit with moonlight this
weekend.

You might think the Moon, which travels eastward against the background
stars, would often pass in front of a bright star. The Moon occupies a very
small area of the celestial sphere, so such events are relatively rare.

On Sunday night, the Moon's eastward path among the stars will take it
through the Pleiades, one of the best known and brightest star clusters in
the sky. From our location, three of the brighter stars in the Pleiades
will pass behind the Moon. Such lunar occultations are fun to watch, but
you need a telescope to see them. Virtually any telescope should do the
trick – from a spotting scope to that telescope you got years ago and have
stored away in the back closet.

While lunar occultations are fun to watch, they are not something you can
easily share with others. The Moon's motion will gradually move it closer
to the star. For a while the star will seem to hover at the edge of the
Moon, and then it will suddenly wink out as the Moon moves in front of it –
proof that stars are so far away they appear as mere points of light, and
that the Moon has no atmosphere. Fortunately, the Moon will occult three of
the bright star in the Pleiades Sunday night, so you can share the sight
with two other people.

The first bright Pleiad to be occulted is Electra, and it will vanish behind
the Moon's limb at 8:13:37 PM. This time is for Schenectady, but it won't
be more than two minutes different for anyone in the immediate capital
district. (Watching a bit too soon is better than being late!) The second
bright Pleiad to fall victim to the advancing Moon is Maia, which will be
whisked from sight at 8:56:27. The last bright Pleiad to be occulted will
be Alcyone. It will be occulted at 9:49:07.

Check the area near the lunar limb carefully for other stars while you
watch. The Pleiades contains many fainter stars, and your telescope may
show some of these. In addition to the brighter cluster members given
above, fainter stars will also be occulted on Sunday night. Can you catch
any of these?

On this final day of November, sunrise is 7:05 am and sunset is 4:23 pm. The waxing gibbous Moon sets at 1:43 am leaving the balance of the wee-hours dark. Rising around 10 pm, Saturn is best placed for telescopic observations when it is highest around 5 am. Find Saturn due south and 61 degrees altitude at that hour. The predawn hours also provide an opportunity for viewing Mercury during is best morning appearance of 2006. You must have good east-southeast horizon however, as it is only 10 degrees above the horizon at 6:30 am. The Moon rises at 1:35 pm Thursday and transits the meridian at 8:10 pm, setting by 2:59 am Friday.

Initial reports of this years Leonid meteor shower on November 18-19, indicate that there was a short duration increase to about 3 to 4 meteors a minute around midnight. This is about what was predicted. Dramatic meteor showers, like the Leonids of 2001 with hundreds of meteors per hour are rare, and are often referred to as meteor storms.

One can also have a meteorite shower. In a meteorite shower, a swarm of meteoroid particles reach Earth’s surface. These events are rarely observed by humans, but when they are it must be spectacular. Of the more recent, an image of the 1947 Sikhote-Alin meteorite is commemorated on a Russian postage stamp. The image shows a large smoke trail over small homes, plunging downward toward the horizon. The Sikhote-Alin mountains are located along the Russian east coast bordering the Sea of Japan, 100 miles north of the city of Vladivostok. The fireball was observed at 10:30 am and was stated as being as large and as bright as the Sun, and casting a separate shadow. Observers close to the terminal location reported the object breaking apart. Sonic booms were reported as far away as Vladivostok. The “shower” spread over an area ½ mile wide by 1mile long. To date, over 23 tons of iron meteorites have been recovered from this location.

More recently meteorite showers have occurred in 1969 in Chihuahua, Mexico, and in Victoria, Australia; and in 1960 in Alberta, Canada, and Wiluna, Australia. These showers were of the more common, but more complex, stony meteorite variety. Experiencing a meteorite shower might be spectacular, but I personally would not want to be too close to the final location.