Astronomical SIGHTS Coming to a SKY NEAR YOU!
Graphics c/o Starry Night Education

This page updated March 12 and includes events to end of April, 2017.

See the COMING EVENTS page for detailed information.

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

Sky Sights: March and April 2017:

Several planets are visible in the west after sunset in the first months of 2017.
Mars is still a reddish dot above the SW horizon and will continue to be visible until late spring 2017 and Venus is ending its appearance in the SW sky (March) but is replaced for a short time by Mercury which takes over as Evening Star until mid-April or so.

Mars and Venus have been prominent in the W and SW sky all spring long but Venus is quickly dropping towards the Sun. It is lost by the third week in March. But for a short time at the end of March, Mercury takes over as Evening Star in the west and on March 29 and 30, the thin crescent Moon is near first Mercury, then Mars. Both planets will be below the western horizon soon, Mercury disappearing first by mid-April, and then by mid-June, Mars will also be gone. But don't miss Mars near the Pleiades on Apr 21. It passes right through M35 onJun 7 but this will be in bright twilight with Mars very close to the Sun.

Jupiter is a morning planet now and is finally far enough from the Sun to appear in dark sky before dawn. You will see it rising before midnight in February and it reaches opposition in April when it will be in the sky all night long.

Saturn takes a bit longer to clear the eastern horizon but by the start of April, it rises around 2 am DST. By month-end, look for it around midnight. Saturn reaches opposition on June 15 and is in the sky all night long afterwards. It will, once again be the showpiece for summer star parties.

A summary of the entire 2017 year of ASTRONOMY events can be found here:

An astronomical calendar for 2017 (with diagrams of sky sights like those below) is available for download from Alan Dyer's website here: (look at the bottom of the "about Alan" page).

March - April 2017 Sky Events

Mar 1, Wed: Crescent Moon, Mars and Venus in west.
A nice grouping of a 3 day-old crescent Moon with Mars and Venus in the evening sky. Venus is still brilliant (magnitude -4.6) Mars much fainter at magnitude 1.5 and Uranus is a binocular planet at magnitude 5.9. A nice grouping for photos!

Mar 1 moon, Mars Venus

Mar 4, Sat: Aldebaran skims north edge of Moon
A grazing occultation of Aldebaran occurs around 11:14 pm late on March 4. The event lasts several minutes and time of onset depends where in Ontario along the track (see map) you are located. Just south of Kincardine is an ideal place to observe (and BAS members will be viewing from there) but the graze will be visible across N. America. A grazing occultation involves a star skimming the north or south edge of the Moon and disappearing behind mountains and reappearing in valleys. See the limb profile below to get an idea. Note that a small difference in location on the Earth will produce different events. If you are too far north by even a few hundred metres, you could get a miss! Observers south of the track below will get a single disappearance and reappearance or just a regular total occultation. Please read the article: Aldebaran Graze 1983 for a detailed explanation of grazes and the story of a successful past graze.

This graze on Mar 4 is described in detail on the International Occultation Timing Association (IOTA) member Brad Timerson's website:
Aldebaran Mar 4 where he explains the track map and limb profile. An interactive Google map is available here which you can customize for your own location. Note that the most interesting limb profile is for about 0.3 km south of the track.

Aldebaran graze Mar 4:17 track

Graze Profile 692SK5 2017 Mar 5_200mMarkersColor

Mar 19, Sun: Mercury and Venus as Evening Stars!
Venus makes a last stand in the western sky as it drops towards the Sun and is lost in its glare in late March. But there is one last hurrah when Mercury (Venus' replacement as Evening Star) travels far enough eastward from the Sun so that both Mercury and Venus are visible side by side. For a few days around March 19, look above the sunset point after dark and you should be able to see both (diagram below). Mercury climbs a bit higher into the western sky in the first part of April (by then Venus is too close to the Sun) and takes over duties as Evening Star until mid-April when it too drops back down to the horizon and is lost in the Sun's glare. After that both are Morning Stars but not as nicely spaced as they will be on March 19. Don't miss it.

The diagram below is a screen-snap from Starry Night c/o Simulation Curriculum and shows the appearance on March 19 about 8 pm DST.

Ven Merc Mar19

Mar 29 to 31: Moon crescent, Mercury and Mars
Mercury takes over duties as Evening Star in the west at the end of March and a lovely crescent Moon appears near Mercury March 29, then near Mars on March 30 and at the tip of the nose of Taurus on March 31. It will be a nice sight as it gradually increases its phase but earthshine should be prominent until FQ around Apr 4. Mercury does not last long in the sky and both it and Mars will be closing in on the Sun on the next few weeks and will be lost in the glare by the end of April. Have a look at Mercury in a telescope, it should exhibit a crescent phase getting thinner and thinner rather quickly. Mercury viewing will last only a few weeks. Don't miss it.

The diagram below is from Starry Night c/o Simulation Curriculum and shows the crescent Moon on March 29, 30 and 31 about 8:30 pm DST. Sunset is around 7:50 pm DST so there is not much true dark sky before the group itself sets. A flat western horizon is highly recommended. Click on the image to download a copy.

Moon Mar29-31

Apr 1, Sat: Mercury at Greatest Elongation East (19°)
Mercury is an evening star in March and April and reaches its farthest point east of the Sun today. It is located almost straight up from the point where the Sun sets in the West and will be visible for a good hour or more after twilight is gone in evening skies. It is bright at magnitude 0 and should be easy to spot if you have a clear horizon towards the west. Mars and the crescent Moon are in the same part of the sky. Diagram below is for 8 pm when Mercury is still 5° above the horizon.

Mercury is farthest from Sun Apr 1.
Merc GEE Apr 1

Apr 7, Fri: Jupiter at Opposition
The Planet King of the solar system is at opposition on Apr 7 when it opposite the Sun and lined up with the Earth on the same side of the solar system. Planets at opposition then appear at best at local midnight and rise when the Sun sets and set when the Sun rises again in the east. At opposition, the planet is in the night sky from dusk to dawn and appears brightest and largest in our sky. Jupiter will be -2.5 magnitude and 44 arc-sec across. The only planet that gets bigger is Venus when it is closest to Earth, which coincidentally is occurring in February.

Screen shot 2017-02-16 at 9.28.30 AM

Apr 21, Fri: Mars near Pleiades and Aldebaran
Mars is closest to the Pleiades tonight at just under 4°, but it has been nearby (less than 5°) for several days. Aldebaran is to the east of Mars and the Hyades Cluster also adds some background sparkle to the scene. A nice photo opportunity! Look west after sunset for this grouping and note that the dwarf planet Ceres is also nearby shining at magnitude 8.32 -it may be visible in binoculars.

Apr 21 Mars &M45

Apr 28, Fri: Moon joins Mars, Pleiades and Aldebaran
A crescent Moon joins the grouping in the western sky on Apr 27 (2-days old) and Apr 28 (3-days old). Mars is now over 6° from M45 and about 8° from Aldebaran. Mars viewing will be drawing to a close at the end of May as it sinks below the western horizon. Even in March and April it is setting in evening twilight and only visible for an hour or two after sunset.

Moon Mars Aldeb M45 west Apr 28