Archive

Archive for the ‘Conjunction’ Category

01/11/2018 – Ephemeris – This morning the Moon passes Jupiter and Mars

January 11, 2018 1 comment

Jan 11. This is Bob Moler with Ephemeris for Thursday, January 11th. The Sun will rise at 8:18. It’ll be up for 9 hours and 5 minutes, setting at 5:23. The Moon, 3 days past last quarter, will rise at 4:19 tomorrow morning.

This morning the thin crescent Moon will be poised over Jupiter and Mars in the east southeast at 7 a.m. It will make a pretty sight for the eye and camera. I follow many amateur astronomers on Twitter with clearer skies than ours who take many great pictures of planetary conjunctions, the Moon and other wonders of the heavens.

There is space mission orbiting Jupiter right now. It doesn’t make great discoveries that shake up the astronomical world enough to make the national news. The Juno mission skims close and then away from Jupiter in order to ferret out its internal structure. It does contain a camera for the public that reveals the spectacular cloud formations of Jupiter’s polar cloudscapes.

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

Addendum

The Moon, Jupiter and Mars

The Moon with Jupiter and Mars this morning January 11, 2018 at 7 a.m. Created using Stellarium.

Jupiter's clouds

Some of Jupiter’s clouds photographed by NASA’s Juno spacecraft.

Ride along with Juno on its 6th close encounter (perijove 6) with Jupiter.  Jove is another Roman name for Jupiter, by Jove!

Jupiter: Juno Perijove 06 from Seán Doran on Vimeo.

Advertisements

01/04/2018 – Ephemeris – Mars will pass Jupiter in the morning sky this weekend

January 4, 2018 1 comment

Ephemeris for Thursday, January 4th. The Sun will rise at 8:20. It’ll be up for 8 hours and 55 minutes, setting at 5:15. The Moon, 3 days past full, will rise at 8:44 this evening.

We have, weather permitting, been watching Mars and Jupiter getting closer together day by day in the morning sky. Their paths will cross Saturday evening as Mars slips under Jupiter. However at that time they will be below our horizon. So Saturday morning the 6th Mars will be just to the lower right of the brighter Jupiter by a bit less than he diameter of the Moon and Sunday morning the 7th Mars will be left and below Jupiter by about the same amount. After that they will continue to separate. Jupiter will stay in the constellation of Libra and enter the evening sky in early May. The Earth will catch up to Mars at the end of July. Then it will be closer to the Earth than any time since 2003. It will come as close as 35.8 million miles (57.9 million km) from the Earth.

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

Addendum

Conjunction of Jupiter and Mars

An animation of the Mars-Jupiter conjunction from January 4th thru 7th at 7 a.m.. The two named stars seen Zubenelgenubi and Zubeneschamali, stars in the constellation Libra, meaning south claw and north claw respectively. Claws of Scorpius, the constellation rising to the east. Created using Stellarium and GIMP.

Planets finder

Morning planets at 7 a.m. January 6th, 2018.  Mars and Jupiter labels are superimposed. Created with Stellarium.

 

12/25/2017 – Ephemeris – The 3 and 2 BC “Star of Bethlehem” conjunctions were repeated 3 and 2 years ago

December 25, 2017 1 comment

Merry Christmas. This is Ephemeris for Christmas Day, Monday, December 25th. The Sun will rise at 8:18. It’ll be up for 8 hours and 49 minutes, setting at 5:07. The Moon, 1 day before first quarter, will set at 12:28 tomorrow morning.

August three years ago and June two years ago 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 had a physical reality.

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

Addendum

I dredged these up from the Ephemeris archives

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

June 16, 2 BC just after sunset Jupiter and Venus again cross paths, at one point too close to be separated with the naked eye. Created using Stellarium.

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.

A link to the 2015 posting is here.  I didn’t realize until later that this was a near repeat of the 3 ans 2 BC conjunctions.  Here’s a link to my posting of the August conjunction.

 

12/22/2017 – Ephemeris – The joining of a god and goddess, a second possibility of the Star of Bethlehem

December 22, 2017 1 comment

Ephemeris for Friday, December 22nd. The Sun will rise at 8:16. It’ll be up for 8 hours and 48 minutes, setting at 5:05. The Moon, half way from new to first quarter, will set at 9:21 this evening.

On Tuesday I talked about what I said was one of two possible physical explanations for the Star of Bethlehem. Here is the second. On August 13th of 3 BC Jupiter and Venus briefly merged in the pre-dawn skies against the constellation of Leo the lion. A month later Jupiter was in conjunction with Regulus the bright star in Leo, the little king star. Then 9 months later, after sunset on June 16th of 2 BC the two planets again joined as one in Leo. The king of the planets twice mating with Venus as Ishtar, the Babylonian goddess of fertility, against the constellation of the lion signifying Judah in Genesis? One might find meaning in all that, especially the Magi, who were Zoroastrian astrologer-priests from Persia.

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

Addendum

Jupiter-Venus conjunction of August 3, 3 BC.

Animation of the Jupiter-Venus conjunction of August 13, 3 BC. in the morning twilight. Created using Stellarium.

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

June 16, 2 BC just after sunset Jupiter and Venus again cross paths, at one point too close to be separated with the naked eye. Created using Stellarium.

 

12/19/2017 – Ephemeris – Were celestial events in 7 BC interpreted as the Star of Bethlehem?

December 19, 2017 1 comment

Ephemeris for Tuesday, December 19th. The Sun will rise at 8:15. It’ll be up for 8 hours and 49 minutes, setting at 5:04. The Moon, 1 day past new, will set at 6:34 this evening.

This year we have no bright evening Christmas star. But what about the one described in the Bible, in the gospel of Luke? We will look today at the first of two events that may have been recorded as the Star of Bethlehem. In 7 BC there was a rare event over 6 months when three times the planet Jupiter passed Saturn against the stars of the constellation Pisces. Could the Persian astrologer priests called Magi, have read into the event enough significance to start the journey to Jerusalem in search of the new born King of the Jews? It was the scribe’s readings that then sent them to Bethlehem. It is thought that Pisces was associated with the Hebrews, Jupiter with the Messiah or world ruler, and Saturn with the peoples of Palestine.

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

Addendum

Triple conjunction

The Jupiter-Saturn triple conjunction of 7 BC. Click on the image to enlarge. Created using Cartes du Ciel.

The animation above shows the planets at 5 day intervals in 7 and a bit in 6 BC.  The normal or posigrade motion is toward the east or left.  When an outer planet approaches its opposition from the Sun, it seems to slow and reverse direction and head westward for a time, which is retrograde motion.  After a time it reverses and heads back eastward again.  That’s why the planets seem to see-saw back and forth.  Jupiter passes Saturn every 20 years.  The next time will be in 2020.  On my Wednesday planet charts Jupiter is seen sneaking up on Saturn week by week.  In order to have three conjunctions instead of one, the planets need to be near opposition from the Sun when they pass.  The last time that happened was in 1980, but it wasn’t against Pisces.  Triple conjunctions against a particular zodiacal constellation are much rarer.

The dates for key events in the animation above are:

  • First Conjunction May 29, 7 BC
  • Planets are Stationary July 6, and begin retrograde motion
  • Second Conjunction October 11
  • Planets are Stationary November 1 and resume posigrade motion
  • Third Conjunction on December 8
  • Mars joins February 26, 6 BC

Retrograde motion was difficult to explain when one thinks that the Earth is the center of the Universe and stationary, while the planets supposedly orbited in perfect uniform circular motion around it.  It’s easy when the Earth is a moving planet like the rest.  When an outer (superior) planet is at opposition from the Sun.  The Earth is between the Sun and planet and moving faster.  So we’re passing the outer planet.  When you are in a car passing another, the car being passed seems to move backward with respect to your car.  Since the planets orbits are like a race track, we get to lap the outer planets at regular intervals.

12/14/2017 – Ephemeris – The Moon wanders over to Jupiter this morning

December 14, 2017 1 comment

Dec 14. This is Bob Moler with Ephemeris for Thursday, December 14th. The Sun will rise at 8:11. It’ll be up for 8 hours and 50 minutes, setting at 5:02. The Moon, half way from last quarter to new, will rise at 5:26 tomorrow morning.

This morning the planet Jupiter will appear right below the crescent Moon. Jupiter is hard to miss, even without the Moon to point it out. It is with the rare exception of Mars when being its closest to the Earth the second brightest of the planets, after Venus. Speaking of Mars, which is to the upper right of Jupiter and has a reddish hue, if you’re going to send anything to Mars, next spring is the time to do it. Flight times to Mars are 6 to 7 months. The midpoint of the flight is when Mars is closest to the Earth, which next year is July 31st. NASA’s Insight Lander, grounded in 2016 due to an instrument failure has to wait 26 months for the next launch opportunity in May of next year.

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

Addendum

The Moon, Jupiter, Mars

The Moon, Jupiter and Mars this morning, December 14, 2017. Earth shine should be visible as shown, though not as prominent. Created using Stellarium.

Hohmann orbit to Mars

A Hohmann lowest energy transfer orbit to Mars. This diagram is for the Mars Exploration Rovers Spirit and Opportunity launched in 2003, arrived in 2004. Solid planets, Spirit launch and arrival. Ghost planets, Opportunity launch and arrival. Credit NASA/JPL.

What’s a Hohmann transfer orbit?  NASA explains.

11/20/2017 – Ephemeris – The Moon is near Saturn tonight and the approaching signs of winter

November 20, 2017 1 comment

Ephemeris for Monday, November 20th. The Sun will rise at 7:46. It’ll be up for 9 hours and 23 minutes, setting at 5:09. The Moon, 2 days past new, will set at 7:04 this evening.

Tonight the two day old Moon will appear near Saturn. The ringed planet will appear to the left and a bit below the thin crescent Moon before they set about an hour later. The approaching winter season and the resumption of standard time have dropped sunset to 5:09 in the Interlochen/Traverse City area. Our sunset will drop another 11 minutes before slowly recovering 19 days from now. Two to three hours later another sign of the approaching winter season will appear, as the constellation of the giant hunter Orion rises in the east. He is resplendent with his nearly vertical belt of three stars rising, framed to the left and right by the bright stars reddish Betelgeuse and bluish Rigel. He will dominate our evening skies until April.

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

Addendum

Saturn and the Moon

The Moon and Saturn at 6 p.m. November 20, 2017. Created using Stellarium.

Orion rising

Finder chart for the rising Orion at 9 p.m., November 30, 2017. Created using Stellarium and GIMP.