Skywatch June 2004

Skywatch can be heard  by calling 518-382-7584, and is posted daily on our calendar.

The scripts are written by members of the Albany Area Amateur Astronomers and read by the staff of the Dudley Observatory. All scripts are copyright and may not be reproduced without permission of the writer and the Dudley Observatory.

Skywatch line for Wed., June 16, 2004 Written by Ray Bogucki

   With the excitement of the rare solar transit of our nearest inner planetary neighbor Venus past, we might take a look at activities on our nearest outer planetary neighbor Mars.  Since their separate arrivals at the end of last year, the two rovers, Spirit and Opportunity, located on opposite sides of Mars, have been busy travelling on the surface, examining rocks with diverse instruments and sending back high-resolution images of their surroundings.  Opportunity is currently examining a crater named Endurance from the rim of the crater, while the control team decides whether it would be safe to send the rover down into the stadium-sized impact crater to search for especially ancient rocks.
  Its twin rover, Spirit, has logged over 2 kilometers on its odometer.  It is currently studying the environment at the foot of a set of highlands named the Columbia Hills.  Both rovers are in good working condition and should continue their activities for several more months.  High overhead, the European Space Agency's Mars Express Orbiter, has sent back exquisitely detailed images of areas showing unmistakable evidence of previous water flow on the Martian surface.
  Meanwhile, the Cassini-Huygens spacecraft, launched on Oct. 15, 1997 is closing in on its major target, Saturn.  In December, 2000, Cassini sped past Jupiter and took some of the most detailed pictures ever made of the giant planet.  Last Friday, Cassini passed just 1300 miles from Saturn's small moon, Phoebe, 137 miles in diameter and orbiting 8 million miles from Saturn.  Phoebe's heavily cratered surface is dark in color, possibly from endless drifting down of red organic particles from a 120 mile thick cloud of smog that surrounds the moon.  Closer to the surface, clouds of methane droplets sometimes cause liquid methane rain to fall.  In some places, the rain has washed away the dark deposits, exposing bright areas that appear to be water-ice.  The brightest feature on Phoebe, called Xanadu, may be an entire mountain range of ice.
  In two weeks, on June 30, Cassini will be placed in orbit around Saturn, the first man-made object to orbit the Ringed Planet.  Then, next Christmas Day, Cassini will release the Huygens lander on to the surface of Saturn's moon Titan, the largest moon in the Solar System.  With events like these happening, reality has become more fantastic than science fiction.

Skywatch Line for Friday, June 18, through Sunday, June 20, 2004 written by Alan French

Summer officially begins on Sunday, June 20, at 8:57 PM.  The beginning of summer, or the summer solstice, is when the Sun reaches its northernmost position in the sky.  Right now, we have our longest days and shortest nights, much to the dismay of amateur astronomers.

The Moon is now past New and is moving back into the evening sky.  If you have a superb view of the north-northwestern horizon, and are blessed with clear skies down to the horizon, you have a chance to glimpse a very young Moon and a very slender crescent on Friday night.  Binocular will aid your search and increase your chances of spotting the beautiful thin crescent.  The Sun sets at 8:37 PM on Friday evening, and you'll want to look for the Moon around 9:20 PM. 

Just above the west-northwestern horizon, you should spot three stars in a row, roughly parallel to the horizon.  If you make a fist and hold it at arms length, the distance across the knuckles is 10 degrees.  At 9:20 PM, this trio of star will be 10 degrees above the horizon.  The leftmost star is actually the planet Mars, and the pair to the right of Mars are Pollux and Castor, the brightest stars in the constellation Gemini, the Twins.

If you look below Pollux and Castor, just above the horizon, you should find a thin crescent Moon, and, to the Moon's left, a star.  This star is actually the planet Saturn.  If the duo is not visible with the naked eye, try binoculars.

By Saturday night the Moon's eastward motion among the stars will have moved it higher, and it will be easier to spot.  Look for it about 10 PM just below and left of Pollux. 

On Sunday night, the pretty crescent Moon will be even higher, and should be very easy to spot in the west-northwest around 9:45 PM.  As you look at the Moon, you should see a pretty, thin crescent, but you should also see the rest of the Moon glowing with a faint light.  This is Earthshine, sunlight reflected from our Earth to the Moon.  If you were standing on the Moon, you would see a nearly full Earth shining brightly in your sky.

Weather permitting; there will be a constellation program at George Landis Arboretum starting at 10 PM on Friday evening.  An indoor program will be held if skies are cloudy.

This is the Dudley Observatory Skywatch Line for Tuesday, June 22nd, 2004, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

    The sun will set tonight in the west northwest at 8:38.  It will rise in the east northeast on Wednesday at 5:18 and set in the west northwest at 8:38.  The Moon is currently in a Waxing Crescent phase, rising about 10:45 tomorrow morning, and setting at around Midnight.  Tomorrow, Wednesday, look for the Moon near the planet Jupiter, in the north west sky after darkness.

    After a Spring Sky full of planets, planet viewing is now at a minimum.

Very low in the west you can locate the Red Planet, Mars.  But after

darkness, it is too low to be seen without great difficulty.   It is next to

the bright stars known as Castor and Pollux; the Gemini Twins.  Jupiter, is very bright, and is high up in the west by 10 PM.  It is located in the constellation of Leo the Lion.

    Jupiter is good to view even in a small telescope of around 40 power.

At that low magnification, any number of the 4 Galilean Moons can be seen, and if the air is clear, the North and South Equatorial cloud Bands and the Great Red Spot are visible.

    Also during the Spring, look for the Big Dipper high overhead towards the north.  Using the two stars on the end of the cup, draw an imaginary line away from the top of the cup, and it will point you to the North Star known as Polaris.

    In the northeast, the famous Summer Triangle is getting higher up in the sky each night.  It is marked by the three bright stars of Vega, Deneb, and Altair.  They are the brightest stars in the constellations of Lyra the Harp, Cygnus the Swan, and Aquila the Eagle.

    Public Programs at the Suits –Buech Planetarium at the Schenectady Museum are on Saturdays and Sundays at 1, 2, and 3 P. M.  The 1:00 program is star tours for young people, a live narration of the seasonal skies.  At

2 P. M. is The Voyager Encounters, narrated by actor Patrick Stewart, and at

3 P. M. is NASA star tours, which consists of a live narration of the seasonal sky, and a short NASA video. Updates from the Cassini Spacecraft on its way to Saturn will also be presented.  There will be NO planetarium programs on Sunday, June 27th.

Skywatch line for Wed. June 23, 2004 Written by Ray Bogucki

  Only two weeks after the bright planet Venus sailed in transit across the face of the Sun, it has raced far enough eastward to be seen in the early morning.  Check the eastern horizon about 4:30 a.m., an hour before sunrise.  Morning twilight will be well advanced, so binoculars will be a useful aid.  Venus is very close to the bright star Aldebaran, the eye of Taurus the Bull.  It will remain close to Aldebaran until mid July by which time they will both be rising 2 1/2 hours before the Sun.
  In the evening sky, the Moon is close to Jupiter tonight.  The Moon is approaching the first quarter phase, and, for the next few days, presents optimum views of craters and mountains along the terminator, the edge of sunlight where the Sun is rising and casting deep shadows, easily visible in small telescopes.
  Both of the comets, NEAT and LINEAR, are still visible in the early evening sky.  Comet NEAT is now close to the bowl of the Big Dipper, approaching from the direction of Castor and Pollux in Gemini, while Comet LINEAR is low in the west below the planet Jupiter in the faint constellation Sextans.  Each of these summer visitors is at a distance of about 130 million miles and both are receding rapidly.
  Meanwhile, the ringed comet Saturn is approaching superior conjunction with the Sun and is disappearing into the Sun's glare.  It will not be easily visible again until it climbs into the early morning sky ahead of the Sun at the end of July.  While our view of Saturn is now lost for a while, it continues to become more spectacular to the Cassini-Huygens space probe, now within a few million miles of Saturn and approaching rapidly.  In one week, retrorockets will fire to slow down the spacecraft so it can be captured by Saturn's gravity and fall into orbit around the gas giant.  NASA plans to receive data from Cassini for the next four years while it makes 74 orbits around the planet.

Skywatch for Friday, June 25, through Sunday, June 27, 2004 written by Alan French

Members of the Albany Amateur Astronomers hold monthly Star Parties where guests can view celestial sights through a variety of telescopes.  Because many of the deep sky objects – nebulae and galaxies especially – are faint, these gatherings are usually held on moonless nights.  This weekend the amateur astronomers are doing something a bit different – they are having two "Sun/Moon Party."

Starting at 5:00 PM on Saturday and Sunday, the group will use special solar telescopes to provide safe views of the Sun.  (No telescope should be used to view the Sun unless it has a filter designed specifically for solar viewing attached to the front of the telescope where the light enters the instrument.)  One of these special safe solar telescopes will provide views of sunspots.  The other, a very special hydrogen-alpha telescope, will provide views of solar prominences.

As darkness falls, other telescopes will be aimed toward the Moon, providing detailed views of craters and mountains.  The Moon is a fabulous sight through any telescope.  Right now, the line between light and darkness on the Moon, known as the terminator, is the sunrise line.  Here detail stands out in bold relief.  Often mountains and crater rims just into the darkness catch the light of the rising Sun and become brilliant points of light on the dark side of the terminator.  If you own a telescope, this would be a great weekend to take it out and explore the Moon.

The Sun/Moon Party on Saturday will be held at the George Landis Arboretum in Esperance beginning at 5:00 PM.  If you enter Esperance traveling west on Route 20, watch for the arboretum sign on your right, immediately after crossing the bridge over the Schoharie River.  After taking the right, follow the signs to the arboretum.  Continue up the hill past the main parking area and farmhouse, and turn right into the Meeting House drive as you reach the top of the hill.

Sunday's Sun/Moon Party is in Indian Meadows Park in Glenville, also beginning at 5:00 PM.  Indian Meadows Park is off of Droms Road in East Glenville, and is marked by a large sign.

Very early risers on Sunday morning can see the International Space Station pass almost directly overhead.  It will appear out of the Earth's shadow just before 4:04 AM above the west-southwestern horizon.  It will be highest at 4:06 AM when it will be almost directly overhead and moving toward the northeast.  Simply look for a bright star moving to the northeast.  The ISS will vanish below the northeastern horizon at 4:09 AM.

This is the Dudley Observatory Skywatch Line for Tuesday, June 29th, 2004, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

    The sun will set tonight in the west northwest at 8:38.  It will rise in the east northeast on Wednesday at 5:21 and set in the west northwest at 8:38.  Now that we are past the first day of Summer and the longest days of the year, we are currently losing about 1 minute a day of daylight.  Although this is not much, all of those minutes will add up over a month’s time.  The Moon is currently in a Waxing Gibbous phase, rising at about 6:00 PM tonight, and setting at about 3:00 AM.  The Moon will be Full on Friday July second, and is known as the Full Buck Moon.  

    Planet viewing is now at a minimum. Very, very low in the west you can locate the Red Planet, Mars.  But after darkness, it is too low to be seen without great difficulty.   It is next to the bright stars known as Castor and Pollux; the Gemini Twins.  Jupiter, is very bright, and is high up in the west by 10 PM.  It is located in the constellation of Leo the Lion.

    Jupiter is good to view even in a small telescope of around 40 power.  At that low magnification, any number of the 4 Galilean Moons can be seen, and if the air is clear, the North and South Equatorial cloud Bands and the Great Red Spot are visible.

    Also during the Spring, look for the Big Dipper high overhead towards the north.  Using the two stars on the end of the cup, draw an imaginary line away from the top of the cup, and it will point you to the North Star known as Polaris.

    In the northeast, the famous Summer Triangle is getting higher up in the sky each night.  It is marked by the three bright stars of Vega, Deneb, and Altair.  They are the brightest stars in the constellations of Lyra the Harp, Cygnus the Swan, and Aquila the Eagle.

    Public Programs at the Suits –Buech Planetarium at the Schenectady Museum are on Saturdays and Sundays at 1, 2, and 3 P. M.  The 1:00 program is star tours for young people, a live narration of the seasonal skies.  At 2 P. M. is The Voyager Encounters, narrated by actor Patrick Stewart, and at 3 P. M. is NASA star tours, which consists of a live narration of the seasonal sky, and a short NASA video. Updates from the Cassini Spacecraft on its way to Saturn will also be presented.

Skywatch line for Wed. June 30, 2004 Written by Ray Bogucki

  A sharp-eyed reader caught the mischaracterization of Saturn as a "ringed comet" in last Wednesday's Skywatch line.  Having just finished a discussion of the comets NEAT and LINEAR, this writer inadvertently used the word "comet" instead of "planet".  Regardless of such minor Earthbound errors, astronomy-minded people around the world will be hoping that no calculation errors or instrument failures will mar the historic events scheduled to occur tonight at the ringed planet Saturn.  Launched from Cape Canaveral on October 15, 1997, the spacecraft Cassini-Huygens, after traveling 2.2 billion miles, finally reaches its target, Saturn, tonight.  Easily visible in backyard telescopes, Saturn's three brightest rings, designated A, B and C from the outside in, are composed of countless particles ranging in size from a grain of sand to the size of a small beach cottage, with typical particles the size of a softball.  Most of the particles in the rings are composed of ordinary water ice.  While extending tens of thousands of miles in the ring plane, the rings are exceedingly thin, perhaps, at most, a couple of hundred feet thick. When Saturn tilts its ring plane directly towards Earth, the rings disappear from view.
  Beyond the A-ring, there is a large gap followed by a much more extensive but tenuous ring labeled "E", composed of microscopic dust particles.  At 10:11 p.m. tonight, Cassini will fly through this gap, traveling about 17,000 miles per hour.  Immediately after crossing the ring plane, the spacecraft will turn so that its main rocket engine points forward.  At 10:36 p.m., the rockets will be fired for 96 minutes to slow the velocity down to 1,400 miles per hour, at which time the spacecraft will have entered into a highly elliptical orbit around Saturn.  During the orbital insertion burn, Cassini will reach its closest approach to Saturn of the entire mission, as it skims just 12,400 miles above the cloud tops, providing an unparalleled opportunity for close-up images of the planet and rings.  It is interesting to note that no last-minute adjustments can be made because it takes almost an hour and a half for telemetry signals to reach us from across the almost one billion miles of space and, of course, another hour and a half for our return signals to get back to the spacecraft.  After passing back through the same ring gap on the other side of the planet at 1:58 a.m., Cassini will begin 19 hours of data playback. By 9 a.m. tomorrow, the first close-up images of Saturn and its ring, taken during the orbital insertion, should be retrieved from the recorders.  Check the website  nasa.gov  for details.

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