Free 2016 Sky Calendar


2016 Calendar Cover

Plan your cosmic year with my free 2016 Sky Calendar.

My Calendar lists all the best sky events for 2016, plus Moon phases, to help you plan your astronomical year.

Coming up we have:

• A fairly close approach of Mars

• A rare transit of Mercury

• A photogenic gathering of Mars, Saturn and Antares

… among many other sky events.

You can download the free PDF at

http://www.amazingsky.com/about-alan.html

Feel free to share the link to this page.

Happy New Year to all!

— Alan, December 29, 2015 / © 2015 Alan Dyer

Heads Up! The Great Evening Conjunction of 2015


June 30 Jupiter & Venus

Look west on June 30 after sunset to see a brilliant “double star” in the dusk.

They’ve been building to this conjunction all month. On Tuesday, June 30 Venus and Jupiter appear at their closest in a stunning pairing in the evening twilight.

That night the two worlds – the two brightest planets in the sky – appear just 20 arc minutes apart.

That’s 1/3rd of a degree and is less than a Moon diameter. That’s so close you’ll be able to fit both planets into a high-magnification telescope field. However, it’s not so close that you won’t still be able to resolve the two worlds with your unaided eyes as separate objects shining in the twilight. In the chart above the circle is a binocular field.

Their proximity is merely an illusion. Venus and Jupiter lie along the same line of sight to us, but in fact are 825 million kilometres apart in space.

If Tuesday looks to be cloudy, good consolation nights are June 29 and July1 – Canada Day! – when Venus and Jupiter will be separated by 40 arc minutes – double their separation on June 30, but still very impressive.

Venus and Jupiter behind old farm water pump windmill, taken March 12, 2012 near home on Glenmore Trail road east of Langdon. Car headlights provide the illumination. Taken with a Canon 5D MkII at ISO 400 and 16-35mm lens at f/4 and 26mm for 20 seconds. A mixture of twilight and light pollution on thin cluds provided the sky colours. Pleiades and Hyades also visible.

The last time we saw Venus and Jupiter close together in the evening sky was in mid-March 2012, when I shot the photo above. But at that time they passed a wide 3 degrees apart. This week they are just a fraction of a degree apart.

They’ll meet again later this year, but in the morning sky, on October 25, when Venus and Jupiter pass one degree from each other.

– Alan, June 28, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – Mercury Rising


May 6 Mercury

The next two weeks are the best in 2015 for sighting Mercury in the evening sky.

Mercury is coming into view in our evening sky, climbing as high as it can get for us in the Northern Hemisphere. This is our best chance for us to sight Mercury as an evening star in 2015.

Spring is always the best time to catch elusive Mercury. The angle of the ecliptic – the path of the planets – swings up highest above the horizon in spring, putting Mercury as high into the evening twilight as it can get. This makes it easier to sight Mercury than at other times of the year when, particularly for observers at northern latitudes, Mercury can be lost in the twilight glow and horizon haze.

When it is at its highest Mercury is surprisingly bright, appearing as a bright star easily visible to the naked eye. However, locating it at first in the twilight usually requires a scan with binoculars.

Mercury will be at its highest on May 6 when it reaches “greatest elongation.” However, it will be almost as good for a week on either side of that date.

So set aside a clear evening during the first two weeks of May to search for the inner planet. (The green line is Mercury’s path relative to the horizon with the green dots marking its position at daily intervals.)

Mercury will be shining above fainter Mars, and well below brilliant Venus, now dominating our evening spring sky. Look north of due west during the hour after sunset.

Mercury & Venus Conjunction Closeup (Jan. 10, 2015)
Mercury and Venus on January 10, 2015 from New Mexico.

This view captures Mercury at its last good evening appearance, back in early January when it appeared close to Venus, then emerging into the evening sky. You can compare their relative brightness.

By coincidence, the emergence of Mercury into our evening sky comes just as it loses its lone visitor from Earth. Since 2011, NASA’s Messenger probe has been orbiting and mapping Mercury.

On April 29, with the probe exhausted of its maneuvering fuel, Messenger is scheduled to end its mission by crashing onto the planet, adding a new crater to Mercury’s barren and volcanic surface.

A global false-color map of the mineral composition of Mercury from Messenger data.
A global false-color map of the mineral composition of Mercury from Messenger data.

This is a recent map of Mercury from Messenger. For more details, see the mission’s website.

– Alan, April 30, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – The Easter Eclipse of the Moon


Total Eclipse of the Hunter's Moon

On the morning of April 4 (for North America) the Moon turns bright red in the third of four lunar eclipses in a row.

We’ve been enjoying a spate of total lunar eclipses over the last year. We had one a year ago on April 15 and again on October 8, 2014. This weekend, we can enjoy the third lunar eclipse in a year.

This Saturday, the Moon undergoes a total eclipse lasting just 4 minutes, making this the shortest total lunar eclipse since the year 1529. Typically, lunar eclipses last 30 to 60 minutes for the total phase, when the Full Moon is completely within Earth’s shadow.

But this eclipse is barely total, with the Moon grazing across the northern edge of the umbral shadow, as this diagram courtesy of SkyNews magazine illustrates. (Click on the image to enlarge it.)

Lunar Eclipse Diagram

• The partial eclipse begins at 4:15 a.m. Mountain Daylight Time on the morning of Saturday, April 4 for North America.

• Totality (when the Moon is reddest and darkest) is from 5:58 to 6:02 a.m. MDT.

• The partial eclipse ends at 7:44 a.m. MDT.

Add one hour for Central time, and subtract one hour for Pacific time.

LE2015Apr04T

This lunar eclipse is best from western North America where totality can be seen. From eastern North America, in the grey zones here, the Moon sets while in the initial partial phase and before totality begins. Those in Australia and New Zealand can also see the eclipse, but late on the night of April 4 into April 5. Europe and Africa miss out.

Total Lunar Eclipse (Dec 10, 2011)

Even from western North America, the Moon will be eclipsed while it is setting into the west, and the sky is brightening with dawn twilight, presenting a view such as in the above photo, which I took in December 2011.

This eclipse occurs over the Easter and Passover weekend – and actually on Easter for some time zones. The last time we had a total lunar eclipse on Easter Sunday was March 23, 1913. The next to occur on Easter won’t be until April 14, 2340.

If you miss this eclipse, you have one more chance this year. On Sunday, September 27, conveniently timed for the evening in North America, we have the last in a “tetrad” series of four total lunar eclipses. After that, we wait until January 31, 2018.

For more details, see the April/May issue of SkyNews magazine.

Clear skies!

– Alan, March 30, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – Moon Meet-ups in March


March 21-24, 2015 Evening Sky

This weekend and early next week look for the Moon passing planets and star clusters in the evening sky.

The waxing Moon returns to the evening sky on Saturday night, March 21, a day and half after it eclipsed the Sun over the North Atlantic and Europe.

On Saturday, March 21 look for the thin crescent Moon very low in the west sitting just a degree (two Moon diameters) left of reddish and dim Mars.

The next night, Sunday, March 22, the Moon, now a wider crescent, shines three degrees (half a binocular field) left of brilliant Venus, for a beautiful close conjunction of the night sky’s two brightest objects. The photo ops abound!

This is one of the best Moon-Venus meet-ups of the current “evening star” apparition of Venus this winter and spring. Next month, for example, the Moon will sit six degrees away from Venus on April 21.

On Monday, March 23, the crescent Moon sits between Venus and its next destination, the bright star Aldebaran.

On Tuesday, March 24, the Moon, still a crescent, shines amid the stars of the Hyades star cluster near Aldebaran in Taurus, for a wonderful binocular scene. The more famous Pleiades star cluster is near by.

On all nights, you’ll see the night side of the Moon dimly illuminated by Earthshine, sunlight reflecting off the Earth and lighting up the dark side of the Moon.

March 24, 2015 CU

Here’s a close-up of the March 24 scene, with the Moon in the V-shaped face of Taurus the bull that is marked by the widely scattered Hyades star cluster.

Please note: This diagram and the main chart above, are for western North America. From eastern North America, the Moon will be 2 to 4 Moon diameters lower in the sky for each of the dates indicated.

Clear skies and enjoy the Moon meet-ups in March!

– Alan, March 19, 2015 / © 2015 Alan Dyer / www.amazingsky.net

Heads Up! – A Picturesque Snow Moonrise


Feb 3 Moon & Jupiter

This Tuesday, Feb. 3, watch the Full “Snow” Moon rise accompanied by the giant planet Jupiter.

Tuesday is Full Moon, the February “Snow Moon” according to some interpretations. Indeed, from most places in North America the Moon will rise over a snow-covered landscape to light the winter night.

This Full Moon is also special because it will pair with bright Jupiter. Both worlds are now at or near “opposition.”

Any Full Moon is always opposite the Sun – that’s why it is fully illuminated by the Sun.

But Jupiter is also near its annual opposition point in its orbit. The official date of opposition is Friday, Feb. 6. On that date Earth passes directly between the Sun and Jupiter – our three worlds lie in a line across the solar system. We are then closest to Jupiter and Jupiter appears opposite the Sun.

Being opposite the Sun, Jupiter rises as the Sun sets. And so will the Full Moon on Tuesday, accompanied by the giant planet now at its brightest for the year.

Look east at sunset. It will be a photogenic sight for the prepared photographer.

But you can also enjoy it with just the unaided eyes or binoculars, as the two worlds will appear about a binocular field apart, 5 degrees.

The double circles on the chart mark the position of the Earth’s shadow, which is always opposite the Sun. You can’t see our shadow out in space – not unless the Full Moon passes through it, which it will on April 4, for a total eclipse of the Moon. More about that in two months.

For now, enjoy the Snow Moon with the Giant Planet.

– Alan, January 31, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – Triple Shadow Dance on Jupiter


Triple Shadow Transit2

Something very special is going to happen on Jupiter this Friday night.

If you have a telescope be sure to train it on Jupiter Friday evening or into Saturday morning for a rare sight. For 24 minutes we will see three of Jupiter’s moons casting their shadows onto Jupiter’s cloud tops at once.

We will not see this sight again until March 20, 2032. 

The shadows of the Jovian moons Io, Europa and Callisto will be on the disk of Jupiter from:

• 1:28 a.m. until 1:52 a.m. EST, after midnight on January 27 for those in eastern North America.

For those in western North America the times are:

• 11:28 p.m. until 11:52 p.m. MST, or 10:28 p.m. to 10:52 p.m. PST, before midnight on January 26.

Callisto’s shadow enters the disk earlier in the evening for North America, at 10:11 p.m. EST. A double shadow transit begins when the small but intense shadow of Io enters the disk at 11:35 p.m. EST. Double shadow transits are fairly common.

The rare sight begins just under two hours later, at 1:28 a.m. EST or 11:28 p.m. MST when Europa’s shadow also enters the disk.

It is short-lived, however. The fast-moving shadow of Io leaves the disk 24 minutes later, at 1:52 a.m. EST, or 11:52 p.m. MST, leaving only the shadows of Callisto and Europa on the disk. (The graphic illustrates the triple transit halfway through the 24-minute-long window.)

You’ll need a telescope to witness this rare dance of shadows. An 80mm refractor or 100mm reflector should suffice. Use high power. The shadows will appear as dark spots of varying size and intensity. Io’s will be darkest, Callisto’s will be largest but less intense. Europa’s shadow will look the smallest.

The disks of Io and Callisto will also be on the disk but will appear as bright dots, making them harder to pick out against the bright cloud bands.

Jupiter is the brightest object in the eastern sky in the late evening. You can’t miss it!

For more details see Sky and Telescope’s webpage.

— Alan, January 21, 2015 / © 2015 Alan Dyer / www.amazingsky.com