Astronomical SIGHTS in a SKY NEAR YOU!

Graphics c/o Starry Night Education

This page updated Nov 24, 2018.

See the HOME page or COMING EVENTS for daily listings.

VIS. COMETS page has more details and finder charts for currently visible comets.

The Planets for December 2018:

Venus reappears as Morning Star in November. Mercury follows Venus shortly thereafter and Jupiter does the same by mid-November as well.

Both of the gas giants,
Uranus and Neptune are well up in the south by dark and continue to be good viewing this winter. Both are past their respective oppositions.

Saturn is still visible in the SW but quickly gets to close too the Sun for good viewing. Only Mars is well up by dark and even though it is past maximum size and is shrinking quickly in diameter, you will notice it becoming more gibbous. Some surface details are still showing through.

Dwarf planet, Pluto is in Sagittarius right between Mars and Saturn and visible only in moonless sky and with larger telescopes. it is low in the SW and getting more difficult to see in clear steady air. Finder charts are found on our CHARTS/FORMS page.

December 2018 Sky Sights

Dec 1, 2018 Week before New Moon -Look for Comet Wirtanen
The week before and after new Moon (Dec 7) is a good time to try for Comet Wirtanen in a dark sky free of interference from moonlight. Wirtanen rises by the time it is dark and stands on the meridian around midnight well before the Moon rises. On Dec 1, Comet 46P will be in Eridanus below Cetus above the southern horizon and it is visible until the Moon comes up in the wee hours of the morning. The Moon is absent on Dec 7 and in the second week of Dec, sets before the comet gets into dark sky . By Dec 14 or so, a gibbous Moon is present not far from 46P and for dark skies, you need to wait for it to set. After that, a bright Moon drowns out the comet until after Christmas Day when the comet rises ahead of the last quarter Moon. Then another period of dark sky ensues for another two weeks into the beginning of January 2019. Check WEBLOG for more about Wirtanen.

Wirtanen Dec 13-17
Comet Wirtanen passes between the Pleiades and Hyades Dec 15 and 16 -a nice photo opportunity

Dec 7, 2018 Mars Really Close to Neptune

Mars (mag 0.07) and Neptune (7.89) get very close on Dec 7 and are visible until after midnight separated by less than 1/4 degree of arc. At sunset (5:43 pm EST) Mars is 33° high and the separation is 12 min. When Mars sets at 12:52 am Dec 8 the separation doubles to 23 min. The diagram below shows a typical 25 mm eyepiece FoV in an 8-inch dobsonian. Nearby stars are 81 Aquarii (mag 6.2) and 82 Aquarii (mag 6.1 upper left). Only Mars will be brighter than these two and Neptune is almost two magnitudes fainter. When Mars and Neptune were closest (2 min separation) at 10 am, Dec 7, they were below our horizon, -the closest approach of any two planets in recent times. Planets occulting planets are rare, -the most recent occurred on Jan 3, 1818 and the next will happen on Nov 22, 2065. Note also that Neptune has returned to the constellation in which it was found (Sep 23, 1846 by John Galle) having completed one Neptunian year of 164.8 Earth years. Actually it crossed into Aquarius early in 2010.

Typical view in 25 mm eyepiece of Mars and Neptune on Dec 7 just before the pair sets around midnight in the west. Separation then is about 23 minutes of arc.

Dec 8, 2018 Crescent Moon Near Saturn
Saturn is quickly disappearing in the west, but Dec 8 offers an opportunity to spot it near a nice thin crescent Moon. The view should be very pretty in twilight above the western horizon with the 1.5 day old Moon about 4 degrees to the right of the ringed planet. It may be the last chance to see Saturn for some time.

Screen Shot 2018-10-31 at 9.32.05 PM

Dec 13/14, 2018 Gemini Meteor Shower (120/h. Moon 41%)
If it wasn’t for cold weather, this meteor shower would be the one to observe. Yes, the Perseids this year occurred during NM so you couldn’t beat them but those August meteors had a smaller hourly rate (90/h) than the Geminids at 120/h. Note that these numbers are called Zenithal Hourly Rates because they are under ideal condition: no clouds, radiant at zenith and no Moonlight. There is a fat crescent Moon (41%) just one day or so before FQ so it interferes for a time on Thursday night Dec 13. But by midnight, the Moon sets and from then on into the morning hours of Friday Dec 14, the sky should be moon free. Cloud free is another story. Technically, the peak of the shower happens around 7 am on Dec 14 (RASC Obs. Hnbk), so prime observing time is Friday night Dec 13/Sat morning Dec 14. The radiant of the shower is near Castor will be highest (76°) 2 am Dec 14, so the ideal time to observe will be the morning of Dec 14. More info about this shower will be available soon on the WEBLOG. All the info you could want and then some (analysis of the 2017 Geminids) is available here:
Meteor News Geminids

Sky &Telescope chart shows the radiant of the Geminids on the morning of Fri Dec 14, 2018

Dec 21, 2018 Mercury 0.8° N of Jupiter
Mercury and Jupiter follow Venus into the morning sky and are closest together this morning with a separation of less than a degree. Venus is well up in the SE and is 2.5 hours farther along the ecliptic when Mercury and Jupiter clear the horizon, only a hour ahead of sunrise. Mercury was farthest east of the Sun Dec 15 and is hurrying back towards Sol when it passes Jupiter who is going the other way, away from the Sun. Eventually Jupiter and Venus meet as well (mid Jan 2019). Today is also the winter solstice and the Sun starts climbing in elevation in our sky, having reached a mere 21°58min above the southern horizon for Owen Sound.

Jupiter Merc Vwnus Dec 21

A summary of the entire 2019 year of ASTRONOMY events can be found here:
coming soon
An astronomical calendar for 2018 (with diagrams of sky sights like those above) will be available soon for download from Alan Dyer's website here: (look at the bottom of the "about Alan" page). Or here: Amazing Sky Calendar 2019