Archive

Archive for the ‘Conjunction’ Category

06/11/2020 – Ephemeris – The Moon passes Mars starting tomorrow morning

June 11, 2020 Comments off

This is Ephemeris for Thursday, June 11th. Today the Sun will be up for 15 hours and 31 minutes, setting at 9:28, and it will rise tomorrow at 5:56. The Moon, 2 days before last quarter, will rise at 2:04 tomorrow morning.

In the morning sky tomorrow and Saturday morning the Moon will be passing Mars. Actually you’ll see a before and after shot of them because the Moon’s passage south of Mars will occur about 6 pm tomorrow evening when we can’t see them. Mars is getting brighter as we, on the Earth approach it. It is also getting larger in telescopes. On Wednesdays on this blog besides showing where the planets are, I show what they might look like in a small telescope. Until this week Mars appeared too small for me to show detail on Mars. However it is now large enough to maybe see a polar cap and some other detail depending on telescope size. Mars will double its apparent size between now and October.

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

Addendum

Moon and Mars animation

Moon and Mars animation for 5 am Friday June 12, 2020 and 4:56 am Saturday June 13th. The Jump between of 23 hours, 56 minutes and 4 seconds is the Earth’s sidereal day, the true period of its rotation in relation to the stars. Note that the few stars visible do not move, but Mars and the Moon do. Created using Stellarium and GIMP.

05/22/2020 – Ephemeris – Venus hangs out with Mercury and the Moon this weekend

May 22, 2020 Comments off

This is Ephemeris for Friday, May 22nd. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:12, and it will rise tomorrow at 6:06. The Moon is new today, and won’t be visible

Low in the northwest shortly after sunset our brilliant evening star Venus may be seen. It’s getting closer to the Sun every evening. This is an illusion because Venus is in the process of passing between the Earth and the Sun, so it’s not getting closer to the Sun, but it is getting closer to us at 29 million miles (46.8 million km) today. Mercury has passed Venus and is now to the left and a bit above Venus as seen at 10 p.m. Both are pretty close to the horizon, so you may have to move to a spot with a low northwestern horizon. Tomorrow night the day old sliver of the Moon will be spotted just below both of them. It should be quite a sight with these two planets and the Moon in the twilight, just after sunset.

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

Addendum

Venus, Mercury, Moon Animation

Venus, Mercury, Moon animation for 10 pm May 22nd, 23rd and 24th, 2020. The Moon is shown 3 times actual size in an attempt to show its phase. Created using Stellarium and GIMP.

04/14/2020 – Ephemeris – The Moon will be hanging out with the morning planets tomorrow

April 14, 2020 Comments off

This is Ephemeris for Tuesday, April 14th. Today the Sun will be up for 13 hours and 28 minutes, setting at 8:27, and it will rise tomorrow at 6:57. The Moon, at last quarter today, will rise at 3:56 tomorrow morning.

Tomorrow morning the Moon will be in the midst of passing the three morning planets, from right to left: Jupiter, Saturn and Mars. Specifically, the last quarter Moon will be below Saturn at 6 a.m. Mars is traveling east rapidly. Its rise times decrease by only two minutes a day compared to the 4 minutes a day for the stars, so it won’t enter the evening sky until October, while Jupiter and Saturn will enter the evening sky in July. A planet is considered to be in the morning sky if it rises after sunset, and in the evening sky if it rises before sunset. Rising in the morning is definitely after sunset. The dividing point is when a superior* planet is at opposition from the Sun when it enters the evening sky, or in conjunction with the Sun when it enters the morning sky.

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

* Superior planets have orbits outside the Earth’s orbit: Mars, Jupiter, Saturn, Uranus and Neptune.

Addendum

Morning planets and Moon

Morning planets and Moon in the south-southeast tomorrow morning at 6 a.m. April 15, 2020. Click on image to enlarge. Created using Stellarium.

03/19/2020 – Ephemeris – Mars will pass Jupiter tomorrow morning

March 19, 2020 Comments off

Ephemeris for Thursday, March 19th. Today the Sun will be up for 12 hours and 7 minutes, setting at 7:54, and it will rise tomorrow at 7:44. The Moon, 3 days past last quarter, will rise at 6:31 tomorrow morning.

Spring will start today, or rather this evening 10 minutes before midnight. But today I’d like to talk about something more immediately visible than the vernal equinox, that is the conjunction of Mars passing Jupiter tomorrow morning. In astronomy a conjunction means that the two planets pass north and south of each other. On Earth we’d say that they had the same longitude. In the sky that would be the same right ascension. The term longitude in the sky is given to measurements along the ecliptic or Sun’s path in the sky, which were more important to ancient astrologers interested more in the motions of the planets, which hung close to the ecliptic. On Earth, measurement of longitude is made from Greenwich Observatory in England, in the sky right ascension is reckoned from the point in the sky where the Sun will be at 11:50 this evening.

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

Addendum

Jupiter and Mars in conjunction near Saturn

The three morning planets in the southeast at 7 a.m. Friday March 20, 2020. Appearing in the southeast means that Mars being south of Jupiter does not mean that it is not directly below Jupiter. See the chart below. Created using Stellarium.

Jupiter and Mars in conjunction near Saturn with equatorial grid

The same chart as above with celestial equatorial coordinates. The lines labeled 19h and 20h near the top are right ascension lines. The lines crossing them are lines of declination which are analogous to latitude on the Earth. Created using Stellarium.

Slightly off topic

Right ascension is measured in hours, minutes and seconds.  Because the Earth revolves within the starry sky in 23 hours, 56 minutes and 4 seconds, special clocks can be made to run fast by that amount.  These are sidereal clocks, and tell sidereal time or star time for one’s location on the Earth, which is the right ascension of the sky or celestial sphere on that’s due south or more properly on the meridian.

Time panel for LookingUp

The time panel from my LookingUp program showing date, time and the sidereal time that corresponds to it for my location.

03/17/2020 – Ephemeris – A planetary traffic jam tomorrow morning

March 17, 2020 2 comments

Ephemeris for St. Patrick’s Day, Tuesday, March 17th. Today the Sun will be up for 12 hours and 1 minute, setting at 7:52, and it will rise tomorrow at 7:48. The Moon, 1 day past last quarter, will rise at 5:12 tomorrow morning.

What I’m going to talk about today is the confluence of the Moon and planets, none of which is green for St. Patrick’s day. The event actually takes place tomorrow morning, which looks like a real planet traffic jam. Of course it just looks like it. The Moon is about 240 thousand miles (390 thousand km) away, Mars is 146 million miles (235 million km), and Jupiter is three and a half times farther away than Mars, and Saturn is twice as far away as Jupiter. These are seen in the southeast, from right to left are Mars, and Jupiter, close together and Saturn a bit farther away. The crescent Moon will pass south of Mars at 4:19 a.m., and Jupiter at 6:18 a.m. The Moon will pass south of Saturn at 8 p.m. tomorrow night while they are below the horizon.  By the time they rise Thursday morning the Moon will be a ways left and below Saturn.

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

Addendum

Mars, Jupiter, Saturn and Moon traffic Jam

Mars, Jupiter, Saturn and Moon traffic Jam as it will appear in the southeast at 7 a.m. March 18, 2020. Created using Stellarium.

 

02/25/2020 – Ephemeris – Mercury at inferior conjunction with the Sun today

February 25, 2020 Comments off

Ephemeris for Fat Tuesday, February 25th. Today the Sun will be up for 10 hours and 56 minutes, setting at 6:24, and it will rise tomorrow at 7:26. The Moon, 2 days past new, will set at 8:27 this evening.

A bit more than two weeks ago Mercury was visible in the evening twilight at its greatest elongation from the Sun, then at 8:37 this evening it will pass between the Earth and the Sun and enter the morning sky. The event is called an inferior conjunction. That’s not a dig on the quality of the event. Indeed an inferior conjunctions are more important and can produce a transit of the planet across the Sun. A rare and formerly important event when we were trying to determine the distance to the Sun. In astronomy an inferior planet is one that orbits the Sun inside the Earth’s orbit. A superior planet orbits the Sun farther than the Earth. It’s not a sign of quality. The best time to spot Mercury in the morning is in August to October, so we’ll miss Mercury this time.

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

Addendum

Mercury at inferior conjunction

Mercury about 7 hours before inferior conjunction February 25, 2020 near local solar noon. The last inferior conjunction of Mercury on November 11, 2019 Mercury passed across the Sun’s disk in a transit. The red ellipse is Mercury’s orbit as seen From the Earth. It’s orbit is tilted about 7 degrees from the Earth’s orbit, so transits are fairly rare events. Created using Stellarium.

12/24/2019 – Ephemeris – Was this the star of Bethlehem?

December 24, 2019 Comments off

Ephemeris for Christmas Eve, Tuesday, December 24th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:06, and it will rise tomorrow at 8:18. The Moon, 2 days before new, will rise at 7:41 tomorrow morning.

Many writers of the 2nd and 3rd centuries AD place Jesus’ birth around 2 BC, which had to be before Herod the Great’s death, which I suggest was in 1 BC marked by to a total lunar eclipse. So the Star of Bethlehem could appear several years later than the triple conjunction of Jupiter and Saturn in 7 BC that’s been popular. In 3 and again in 2 BC there were star-like conjunctions or apparent joinings of the planets Jupiter and Venus against the backdrop of constellation of Leo the Lion. A lion is related to Judah, son of Jacob by a blessing the latter gave his 12 sons in Genesis. The first conjunction occurred in August of 3 BC in the morning sky. In June the next year the two planets got together again, this time in the evening sky, a month or more after Jesus would have been born in the lambing season of spring.

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

Addendum

August 12, 3 BC conjunction

Here is an animation created using Stellarium of Jupiter and Venus, the brighter of the two seeming to coalesce on August 12, 3 BC in the early morning twilight. Created using Stellarium and GIMP.

The second appearance of the "Star"

On June 16th 2 BC, this time in the evening, Venus and Jupiter seem to coalesce as one, at least to the naked eye.  The first few frames contain the Sickle asterism of Leo the lion’s head and mane. Created using Stellarium and GIMP.

I have much more information on this topic in my December 2, 2016 posting: https://bobmoler.wordpress.com/2016/12/02/12022016-ephemeris-my-talk-about-the-star-of-bethlehem-is-tonight/

11/22/2019 – Ephemeris – Jupiter and Venus will appear to cross paths this weekend

November 22, 2019 Comments off

Ephemeris for Friday, November 22nd. Today the Sun will be up for 9 hours and 20 minutes, setting at 5:08, and it will rise tomorrow at 7:49. The Moon, 3 days past last quarter, will rise at 3:55 tomorrow morning.

Tomorrow night the planet Venus will be just below Jupiter low in the southwestern sky not long after sunset. Jupiter is retreating toward the Sun four times faster than Venus is advancing from the Sun. Jupiter will pass in conjunction with the Sun on December 27th and enter the morning sky. Venus after this will pass Saturn on December 11th. It will become Christmas Star this year. Venus will continue moving away from the Sun until March 24th next year. While Venus is hanging around low on the western horizon now, in winter and most of spring it will be high in the western sky after sunset, our Evening Star. Saturn itself will pass into the morning sky January 13th.

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

Addendum

Jupiter-Venus conjunction

Jupiter-Venus conjunction animation for 6 p.m. from Friday thru Monday November 22-25, 2019. Click on image to enlarge. Created using Stellarium and GIMP.

09/03/2019 – Ephemeris – Yesterday and today conjunctions of Mars and Mercury with the Sun

September 3, 2019 Comments off

Ephemeris for Tuesday, September 3rd. Today the Sun will be up for 13 hours and 8 minutes, setting at 8:16, and it will rise tomorrow at 7:08. The Moon, 2 days before first quarter, will set at 10:59 this evening.

Yesterday morning Mars passed in conjunction with the Sun. For astronomers Mars was either just north or south of the Sun. In this case it was north of the Sun, moving from the evening or east side of the Sun to the west or morning side. Later this evening Mercury will pass in superior conjunction with the Sun. Mercury, being an inferior planet, that is one whose orbit is within Earth’s orbit of the Sun can pass between the Earth and the Sun in what we call an inferior conjunction or around the back side of the Sun in superior conjunction. In doing so Mercury is moving from the morning to the evening sky. Today the SOHO satellite will show both planets, the Sun and even Venus in its coronagraph.

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

Addendum

Mars in the C2 coronagraph

Solar and Heliospheric Observatory (SOHO) LASCO C2 Coronagraph image of the solar atmosphere at 8:24 p.m. September 2, 2019. A disk, called an occulting disk covers the bright Sun. The white circle is the size of the Sun’s photosphere. The white dot just about directly above the Sun is Mars, which is slowly heading to the right (west).

Venus and Mercury in the C2 coronagraph

SOHO LASCO C3 Coronagraph image of the solar atmosphere at 8:14 p.m. September 2, 2019. A disk, called an occulting disk covers the bright Sun. The white circle is the size of the Sun’s photosphere. Venus is the bright object to the left. It passed superior conjunction of the Sun back on September 14th. Mercury is just to the upper right of the occulting disk.  Both planets are heading to the left (east).

06-18-2019 – Ephemeris – Mercury and Mars will be seen together tonight

June 18, 2019 Comments off

Ephemeris for Tuesday, June 18th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:56. The Moon, 1 day past full, will rise at 10:49 this evening.

This evening the Planets Mercury and Mars will appear less than a moon-width apart in the evening twilight. Mercury, the brighter of the two, by a factor of 4 times, will be visible first, at about 10:15 p.m. very low in the west-northwest. Mars will be immediately below it by less than the width of the Moon. At that time they will be a bit less than the width of your fist held at arm’s length above the horizon. Binoculars are the best way to spot them. Mercury will continue to move eastward in the sky away from Mars. Until after it reaches its greatest separation from the Sun on the 23rd. It will then head back and pass at a much greater distance below Mars on July 5th. This is the best chance to spot Mercury in the evening sky this year.

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

Addendum

Mercury-Mars Conjunction

Mercury and Mars this evening at 10:30 p.m., June 18, 2019. Created using Stellarium.