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Archive for December, 2015

12/31/2015 – Ephemeris – Next year’s big astronomical event

December 31, 2015 Comments off

Ephemeris for New Years Eve, Thursday, December 31st.  The Sun will rise at 8:20.  It’ll be up for 8 hours and 51 minutes, setting at 5:11.   The Moon, 2 days before last quarter, will rise at 11:56 this evening.

The big astronomical event of 2016 will be the passage of the planet Mercury across the face of the Sun on May 9th.  This type of event is called a transit.  Back in 2012 we saw the transit of Venus, an extremely rare event that won’t be repeated for over 100 years.  Transits of Mercury are not so rare.  The next will be in three years.  It also will not be as impressive as a transit of Venus because Mercury is a tiny planet and looks smaller than a small sunspot on the Sun.  It cannot be seen without a solar filtered telescope.  The actual Transit will last about 7 ½ hours.  Should it be clear for all or part of that time members of the Grand Traverse Astronomical Society will be at two locations to show the event.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Path of Mercury across the face of the Sun

Path of Mercury across the face of the Sun from east to west. Credit IOTA/Occult4

Transit of Mercury visibility map. Click on the Image to view a higher resolution pdf. Credit; Astronomical Almanac Online/USNO

Transit of Mercury visibility map. Click on the Image to view a higher resolution pdf. Credit; Astronomical Almanac Online/USNO

       TRANSIT OF MERCURY GEOCENTRIC PHASES
                                              Position
                                   UT          Angle 
                               d  h  m   s        °
Ingress, exterior contact  May 9 11 12 17.6     83.2
Ingress, interior contact      9 11 15 29.5     83.5
Least angular distance         9 14 57 25.3    153.8
Egress, interior contact       9 18 39 12.8    224.1
Egress, exterior contact       9 18 42 24.8    224.4

Least angular distance from the center of the Sun: 5' 18".5
Position angle:  Contact point measured counterclockwise from the north
   point on the face of the Sun.
UT = Universal time A.K.A. Greenwich Mean Time (GMT or Zulu).  
   Subtract 4 hours to obtain Eastern Daylight Time (EDT) for
   most of Michigan.  In short the transit will span from
   7:12 a.m. to 2:42 p.m.

Above time-table is from Astronomical phenomena for 2016  Credit:  USNO/UKHO

12/30/2015 – Ephemeris – Last look at the bright planets for this year

December 30, 2015 Comments off

Ephemeris for Wednesday, December 30th.  The Sun will rise at 8:19.  It’ll be up for 8 hours and 50 minutes, setting at 5:10.   The Moon, 3 days before last quarter, will rise at 10:58 this evening.

Let’s check out the whereabouts of the bright naked eye planets.  Mercury moved to its greatest separation from the Sun Monday night.  It will be visible very low in the southwest before it sets at 6:42 p.m. in the west-southwest.  In the morning sky there are four bright planets.  Jupiter will be the first to rise, actually at 11:23 p.m., in the east.  Tomorrow it will be just left of the Moon.  Mars will rise next at 2:27 a.m. also in the east.  It’s left of the bright star Spica.  Venus will rise at 5:11 a.m. in the east-southeast.  Saturn will rise at 6:10 a.m. in the east-southeast.  Comet Catalina is a binocular object just below the bright star Arcturus, which is pointed to by the arc of the handle of the Big Dipper.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury

Mercury at 6 p.m., 50 minutes after sunset, December 30, 2015. It may be visible as early as 5:30. Binoculars will help. Created using Stellarium.

Morning planets

The morning planets, Jupiter, Mars, Venus and Saturn, plus Comet Catalina at 7 a.m. December 31, 2015. Created using Stellarium.

Jupiter and the Moon

Jupiter and the Moon tomorrow morning December 31, 2015 at 7 a.m. Created using Stellarium.

Telescopic Jupiter

Telescopic view of Jupiter at 7 a.m. December 31, 2015. Created using Stellarium.

Telescopic Venus

Telescopic view of Venus at 7 a.m. December 31, 2015. Created using Stellarium.

Telescopic Saturn

Telescopic view of Saturn at 7 a.m. December 31, 2015. The satellites would be pretty much invisible except for Titan with Saturn low in the sky in twilight. Created using Stellarium.

The three planet telescopic views are shown to the same scale, that is seen with the same magnification.

Comet Catalina Track

Comet Catalina’s path for the next week. Note the magnitudes for the comet are about 1 magnitude too bright. It will take binoculars or a small telescope to spot the comet which will not show a tail visually. Created using Cartes du Ciel (Sky Charts)..

The planets at sunrise and sunset

This is a chart showing the sunrise and sunset skies for December 30, 2015 showing the location of the planets, the Moon and Comet Catalina at that time. Created using my LookingUp program.

Several of the images above are shown smaller than actual size.  Image expansion lately hasn’t worked.  If you are using Firefox, right-click on the image, and then click on View Image.

12/29/2015 – Ephemeris – Some space triumphs of 2015

December 29, 2015 Comments off

Ephemeris for Tuesday, December 29th.  The Sun will rise at 8:19.  It’ll be up for 8 hours and 50 minutes, setting at 5:10.   The Moon, half way from full to last quarter, will rise at 9:58 this evening.

This past year had several important events.  Perhaps the biggest was the flyby of Pluto and its moons July 14th By the New Horizons spacecraft.  The transmission of data and images will continue for most of 2016, but what has been revealed has been spectacular if puzzling.  In other space news Blue Origin landed their New Shepard rocket vertically after sending it straight up 60 miles.  In June the SpaceX Falcon 9 blew up while attempting to send its 7th resupply Dragon capsule to the International Space Station.  Eight days ago The Falcon 9 returned to flight orbiting 11 satellites for Orbocomm, and flew the booster from over 100 miles up and 100 miles out over the Atlantic to land upright on its designated landing pad back at the cape.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Pluto

Enhanced color portrait of Pluto by the New Horizons spacecraft. Credit: NASA/JHUAPL/SwRI.

Shepard landing

Blue Origin New Shepard rocket, with landing legs expended about to land. Credit: Blue Origin.

Falcon 9

First stage of the SpaceX Falcon 9 descending on its center rocket engine to the center of the main landing pad at Cape Canaveral. Credit: SpaceX.

These weren’t the only highlights of 2015.  Having only 45 seconds to devote to the story, I picked the three most important events.  I consider the reuseability of rockets to be the Holy Grail of reducing the cost to access to space.  The Space Shuttle was a partial, but ultimately failed solution.  SpaceX had the most difficult task in refurbishment and reuse because the first stage had to endure a supersonic reentry, though it didn’t need a heat shield.  We’ll have to see if the cost of recycling rocket boosters is cheaper than building one from scratch.

12/28/2015 – Ephemeris – Mercury is at its greatest penetration into the evening tonight

December 28, 2015 Comments off

Ephemeris for Monday, December 28th.  The Sun will rise at 8:19.  It’ll be up for 8 hours and 49 minutes, setting at 5:09.   The Moon, 3 days past full, will rise at 8:57 this evening.

Later this evening the tiny planet Mercury will appear at its greatest separation from the Sun.  This is a little early to be viewing Mercury in the evening.  Generally the best time to be able to view Mercury, when it’s east of the Sun, in the evening is from late winter into spring.  Mercury’s event is called its greatest eastern elongation from the Sun.  The sky may be dark enough in the west to start looking for Mercury 20 minutes after sunset.  That’s about 5:30 when Mercury will be 9 degrees above the true horizon and due southwest.  For the next half hour Mercury will drop to 5 degrees altitude, but the skies will be darker.  Mercury will set at 6:38, and you will lose it before that.  Mercury has always been a difficult planet to view from the Earth.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury

Mercury at greatest eastern elongation (19.7 degrees) from the Sun. 6 p.m. December 28, 2015. Created using Stellarium.

12/25/2015 – Ephemeris – This year’s Christmas Stars

December 25, 2015 Comments off

Merry Christmas.  This is Bob Moler with Ephemeris for Christmas Day, Friday, December 25th.  The Sun will rise at 8:18.  It’ll be up for 8 hours and 48 minutes, setting at 5:07.   The Moon, at full today, will rise at 5:53 this evening.

It’s Christmas morning, and if it’s clear the full Moon will low in the west.   Venus the brilliant Morning Star will be low in the southeast,  Jupiter, second only to Venus in brightness will appear half way up to the zenith in the south.  Venus or perhaps Jupiter, take your pick can be this year’s Christmas Star.  The bright stars in the evening sky tonight are those of winter, that have looked down on us in their familiar patterns for millennia.  The bright planets and stars, or even a brilliant supernova, or the one at the top of our Christmas tree, cannot be, according to those astronomers who accept the Star of Bethlehem as a real phenomenon, as what the star was.  The leading contenders for the Star have always involved two planets.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Morning Planets

The morning planets, Jupiter, Mars, Venus and Saturn, plus Comet Catalina at 7 a.m. . Created using Stellarium.

Winter stars of Christmas night

The bright stars of Christmas Night and the full Moon. Created using Stellarium.

 

12/24/2015 – Ephemeris – Jupiter and Venus the “Star” of Bethlehem?

December 24, 2015 Comments off

Ephemeris for Christmas Eve, Thursday, December 24th.  The Sun will rise at 8:18.  It’ll be up for 8 hours and 48 minutes, setting at 5:06.   The Moon, 1 day before full, will set at 8:02 tomorrow morning.

Last year August and earlier this year in June we had a near repeat of two very close conjunctions of Jupiter and Venus that occurred in 3 and 2 BC.  These two conjunctions spaced by a month more than the human gestation period and seen against the constellation of Leo the lion, symbol of Judah could have brought the Magi, who were Persian astrologer-priests to Jerusalem, capital of Judea.  The events could have signified the them the birth of a king of Judea.  It was the interpretation of the scriptures by the scribes that actually sent them to Bethlehem.  This version of the Star of Bethlehem seems to be the one that’s being accepted more and more by those who believe the Star has a physical reality.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Jupiter and Venus Conjunctions August 2014 and June 2015

Jupiter and Venus

Watch Jupiter and Venus approach each other and separate. From August 15 to August 19, 2018. Created using Stellarium and GIMP.

 

Jupiter-Venus animation

Jupiter-Venus approach animation June 11 to July 1, 2015 at 10:30 p.m. Created using Stellarium and GIMP. Click on image to enlarge.

Jupiter and Venus Conjunctions August 3 BC and June 2 BC

Jupiter-Venus conjunction of August 3, 3 BC.

Animation of the Jupiter-Venus conjunction of August 3, 3 BC. in the morning twilight. Created using Stellarium.

June of 2 BC just after sunset Jupiter and Venus again cross paths.

June of 2 BC just after sunset Jupiter and Venus again cross paths. Created using Stellarium.

 

 

 

12/23/2015 – Ephemeris – Only Mercury is making a stand in the evening sky

December 23, 2015 Comments off

Ephemeris for Wednesday, December 23rd.  The Sun will rise at 8:17.  It’ll be up for 8 hours and 48 minutes, setting at 5:05.   The Moon, 2 days before full, will set at 7:04 tomorrow morning.

Let’s check out the whereabouts of the bright naked eye planets.  Mercury is becoming marginally visible very low in the southwest before it sets at 6:24 p.m. in the west-southwest.  In the morning sky there are four bright planets.  Jupiter will be the first to rise, actually at 11:49 p.m., in the east.  Mars will rise next at 2:33 a.m. also in the east, Venus will rise at 5 a.m. in the east-southeast.  Even as Venus and Jupiter separate Mars still lies almost halfway between the two.  Don’t confuse Mars with the star Spica which is brighter and below right of it.  Saturn will rise at 6:30 a.m. in the east-southeast.  Comet Catalina is a binocular object about three widths of a fist held at arm’s length directly above Venus at 6 a.m.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mercury

Mercury at 6 p.m., 55 minutes after sunset, December 23, 2015. It may be visible as early as 5:30. Binoculars will help. Created using Stellarium.

Morning Planets

The morning planets, Jupiter, Mars, Venus and Saturn, plus Comet Catalina at 7 a.m. December 24, 2015. Created using Stellarium.

Telescopic Jupiter

Telescopic view of Jupiter at 7 a.m. December 24, 2015. Note Europa is in transit of Jupiter at that time and would pretty much be invisible. Created using Stellarium.

Telescopic Venus

Telescopic view of Venus at 7 a.m. December 24, 2015. Created using Stellarium.

Telescopic Saturn

Telescopic view of Saturn at 7 a.m. December 24, 2015. The satellites would be pretty much invisible in the twilight. Created using Stellarium.

Note that the planets shown as they would be seen in telescopes at the same magnification.

The planets at sunrise and sunset

This is a chart showing the sunrise and sunset skies for December 23, 2015 showing the location of the planets and the Moon at that time. Created using my LookingUp program.

A note on enlarging the pictures:  Apparently WordPress is not able to enlarge pictures by clicking on them.  However if you are using Firefox and you right-click on an image, select View Image to show the image up to full size.

12/22/2015 – Ephemeris – Welcome to winter, or summer if you’re down under

December 22, 2015 Comments off

Ephemeris for Tuesday, December 22nd.  The Sun will rise at 8:17.  It’ll be up for 8 hours and 48 minutes, setting at 5:05.   The Moon, 3 days before full, will set at 5:59 tomorrow morning.

Today is the first full day of winter.  For folks south of the equator this is the first full day of summer.  The Earth reached a point in its orbit where its north pole is tipped its furthest away from the Sun, and is in shadow in the middle of it’s six month night.   We do see the Sun, though less than 9 hours of daylight, and to boot the Sun only rises 22 degrees above the horizon giving us the least amount of energy of any day of the year.  Why did the ancients celebrate this time of year?  That’s because the Sun had slowed and stopped its drift southward and was beginning to come back higher in the sky.  They still had to go through the worst of winter, but the Sun was coming back.  Spring and summer would eventually return!

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Solstices

Comparing the sun’s path at the summer and winter solstices. This is a stereographic representation of the whole sky which distorts the sky and magnifies the size of the sun’s path near the horizon.

The above chart shows the diurnal path of the Sun at the winter and summer solstices for Traverse City, MI near 45º north latitude.  Peak Sun altitude at noon at the winter solstice is 22º, while it’s 69º at the summer solstice.

 

 

12/21/2015 – Ephemeris – Except for 12 minutes today is the last day of autumn.

December 21, 2015 Comments off

Ephemeris for Monday, December 21st.  The Sun will rise at 8:16.  It’ll be up for 8 hours and 48 minutes, setting at 5:04.   The Moon, 3 days past first quarter, will set at 4:50 tomorrow morning.

Here we are at the mostly last day of autumn.  The last 12 minutes will be the start of winter.   The winter solstice will occur at 11:48 this evening, here in the Eastern Standard Time Zone.  Next year winter will start 18 hours earlier.  The reason is that next year is a leap year and the addition of an extra day will push all the solstices and equinoxes back by about 18 hours.  Why only 18 hours?  18 hours is three-quarters of a day, and by this time next year we will have used up a quarter of that adjustment already.  The Earth takes approximately 365 and a quarter days to orbit the Sun, so a day is added every 4th year, except century years not divisible by 400.  I’ll discuss more about the implications of the solstice tomorrow.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Earth near December solstice

Not quite the solstice, this is the Earth on December 16th, 2015 taken by the EPIC camera on the DISCOVR spacecraft at the Sun-Earth L1 point, some 1.5 million miles (1 million km) from the Earth.  Credit:  NOAA.

 

12/18/2015 – Ephemeris – The Moon at first quarter tonight

December 18, 2015 Comments off

Ephemeris for Friday, December 18th.  The Sun will rise at 8:15.  It’ll be up for 8 hours and 48 minutes, setting at 5:03.   The Moon, at first quarter today, will set at 1:17 tomorrow morning.

By the time we see the moon tonight it will be at least 8 hours since the Moon passed the first quarter point and it’s terminator or sunrise line will appear slightly bowed.   This time, since I can only point out a few features at a time, I’d like to point out three craters on the upper, north portion of the moon.  They may be too small for binoculars, but fine for small telescopes.  They make a nearly right triangle in Mare Imbrium, the Sea of Showers near the terminator.  The largest is Archimedes, named for the 3rd century BC Greek mathematician, and inventor.  The northern crater is Aristillus, named after a 3rd century BC astronomer, The other crater is Autolycus, named for a 4th century BC Greek astronomer.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

First quarter Moon.

The first quarter Moon on December 18 at 9 p.m. EST. Highlighted are the trio of craters of which Archimedes is the largest. Created using Virtual Moon Atlas.

Other features visible are the crater Plato, the Alpine Valley, the crater Alphonsus, which I’ve covered in the past.  Search on them for their location and more information.