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

Triple Shadow Transit on Jupiter


Jupiter put on quite a show last night, with transits galore on its cloud tops.

Not since Comet Shoemaker-Levy 9 hit Jupiter in 1994 have I witnessed such amazing and dramatic sights on Jupiter.

Last night, January 23, was the night of the triple shadow transits on Jupiter, with Io, Europa and Callisto all casting their shadows onto the Jovian cloud tops at one, but just for 24 minutes.

In addition, the disk of Callisto and Io were also superimposed on the disk, though only Callisto’s disk was obvious. With it, for a time I could see Jupiter dotted with 4 dark spots.

I make no claims that the video shows amazing detail. I shot it with the biggest telescope I have at my disposal here in New Mexico, a short-focus 92mm refractor. Such an event really needed a large reflector with lots of focal length to do it justice and magnify Jupiter enough to see the details well.

However, I shot the video clips to serve as my personal souvenir of the event. I hope the video and my commentary convey some of the excitement of the night, in seeing an event we will not see repeated until 2032.

– Alan, January, 24, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – Watch a Monster Asteroid Miss Us!


2004 BL86 by M44

On Monday, January 26 North American stargazers have a ringside seat for the near miss of a monster asteroid.

On Monday night an asteroid known as 2004 BL86 will pass just 1.2 million kilometres from Earth, a close approach that brings it to within three times the distance to the Moon. Many small asteroids have made the news of late that have approached much closer than this.

The difference with 2004 BL86 is that this hurtling interplanetary rock is 1/2 kilometre across. That’s big for a near-Earth asteroid. If one this size were to hit Earth it would create a city- or region-devastating catastrophe of epic proportions.

No bigger asteroid is known to be coming this close to us until the year 2027 when 1999 AN10 comes as close as the Moon.

On Monday night 2004 BL86 will be moving so fast (about 2 degrees an hour) that, through a telescope, you should be able to see it move in real time, appearing as a dim star gliding against the background stars.

The best time to watch will be between 10 and 11 p.m. Mountain Time (or midnight to 1 a.m. Eastern) when the asteroid will be buzzing past the Beehive star cluster, aka Messier 44. It will be high in the east and any star chart, planetarium software or GoTo telescope will show you where to find the Beehive cluster in Cancer. From a dark site, the Beehive appears as a fuzzy glow in Cancer between Gemini and Leo.

Locate the Beehive in a low-power, wide-field eyepiece. The asteroid will be moving up (north) past the cluster on the east side of the cluster. The diagram provides a normal view matching the naked-eye orientation of the sky, with north up and east to the left.

In a Newtonian telescope the field will appear upside down – the asteroid will appear to the right of the cluster moving down. In a refractor or Cassegrain telescope with a star diagonal the field will appear mirror-reversed, with the asteroid again on the right side of the cluster, but moving up.

The asteroid will appear at ninth magnitude, the brightness of some of the moderate brightness stars plotted. Using any telescope 80mm or larger in aperture, picking out a ninth mag star should be easy, even in city skies and with the waxing Moon up, as long as you have clear skies. Just be sure to use your lowest power.

Happy asteroid hunting! Just remember to duck!

For more info and finder charts, see Sky and Telescope’s page.

– Alan, January 23, 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

Heads Up! Sight the Thin Moon by Mercury & Venus


Jan 21 Planets

On Wednesday, January 21 look low in the southwest for a conjunction of the Moon and inner planets.

Mercury is ending its brief evening appearance and proximity to Venus. But this week you can still spot it a binocular field or so below Venus as it descends back toward the Sun.

On Wednesday, January 21, look low in the southwest to sight the thin waxing crescent Moon sitting near Venus and Mercury, forming a wide triangle of inner rocky worlds.

The other rocky planet in the inner solar system, Mars, shines higher up in the evening twilight as a moderate brightness reddish star. The next night, January 22, the waxing Moon will sit beside Mars in a wide conjunction.

Catch the Moon-Mercury-Venus trio early, as they will set an hour or so after local sunset.

Clear skies!

– Alan, January 19, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Finding Lovejoy in the Stars


Comet Lovejoy near Pleiades

The coming week is the best time to sight Comet Lovejoy as it sails through Taurus.

Here’s a finder chart for locating Comet Lovejoy (C/2014 Q2) over the next week as it climbs higher in our southern sky. It is well-placed high in the south as it gets dark each evening.

Unfortunately, it doesn’t pass near any really bright stars to serve as a convenient jumping off point for finding the comet. Look west (right) of the stars of Taurus the bull and the bright star Aldebaran by 2 to 3 binocular fields. In a dark sky, look for a fuzzy star in your binoculars. Once you find it with optics, if your sky is dark enough, you should be able to see it naked eye, but only just. In the city, forget it!

On the nights of January 17 to 19 Comet Lovejoy will be just over a binocular field to the right (west) of the distinctive Pleiades star cluster, marked here as M45, for Messier 45.

Comet Lovejoy in Taurus (Jan 10, 2015)

Here’s the comet as it appeared on Saturday night, January 10, with it west of the V-shaped Hyades star cluster marking the head of Taurus and well below the Pleiades at top.

Comet Lovejoy's Long Ion Tail

This is a closer view, with a telephoto lens, of the comet from Sunday night, January 11, showing how its faint blue ion tail stretches back several degrees. However, only the long exposures used here pick up the full extent of the tail. Visually, even through binoculars, just a hint of a tail is visible extending to the left away from the large fuzzy coma, or head of the comet.

Comet Lovejoy Thru the Telescope (Jan 11, 2015)

This is a closer view of the coma and ion tail, shot through a telescope on Sunday night, January 11. It shows some of the fine structure in the ion tail that is changing hourly and nightly, shaped in part by gusts of solar wind.

The comet is now at at its brightest, while the evening sky is now dark and moonless. So head to a dark sky site, keep warm, and look up to enjoy our winter comet, coming to us from Australia where it was discovered by Terry Lovejoy.

Chart courtesy Starry Night™/Simulation Curriculum.

– Alan, January 11, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Sight the Inner Planet Pairing


Mercury & Venus Jan 9

The two inner planets, Mercury and Venus, meet up in the dusk sky this weekend.


While I usually devote my blog to showcasing my photos of celestial events and wonders, a New Year’s resolution for me was to expand my blog to include alerts to what’s coming up in the sky. Here’s the first entry for 2015.


This weekend and for the following week (January 9 to 18) look southwest to see brilliant Venus accompanied in a close conjunction by elusive Mercury.

Look low in the southwest between 5 and 6 pm local time.

Venus is brilliant and hard to miss. Yes, that’s Venus not an aircraft!

But Mercury is fainter and is best seen at first in binoculars, as a dimmer star near Venus. Once you sight it, it’ll be easy to see naked eye, as long as your evening sky is clear.

Mercury passes less than a degree from Venus this weekend (the circle shows a typical 7° binocular field).

Here are the two planets as they appeared last Sunday night, when they were farther apart.

Mercury & Venus in Twilight (Jan 4, 2015)

After Sunday, Mercury continues to climb higher, separating from Venus, as it moves along the green orbital path shown here. Mercury reaches its highest angle away from the Sun on Wednesday, January 14 – what we call “greatest elongation.”

It then drops back toward the Sun and horizon. We won’t be able to see Mercury well again in the west until early May,

Happy planet hunting!

P.S. Visit my webpage to download a PDF of a free 2015 Sky Calendar.

— Alan, January 8, 2015 / © 2015 Alan Dyer / amazingsky.com