Pleiades passage / Aurora night 3?

Venus nearly overwhelms the Seven Sisters or Pleiades star cluster yesterday evening around 9 p.m. in the western sky. Watch for the two to be nearly as close together tonight. Credit: Bob King

Venus nearly overwhelms the Seven Sisters or Pleiades star cluster yesterday evening around 9 p.m. in the western sky. Watch for the two to be nearly as close together tonight. Credit: Bob King

You couldn’t help noticing Venus and the Pleiades last night glimmering in the west at dusk. Tonight they’ll be nearly as close. If you have a small telescope, take a closer look and see if you can discern the planet’s small, not-quite-round disk.

Venus passes through phases just like the moon and has surprised more than a few first time viewers who thought that’s what they were looking at. A moon in miniature but shiny white and without a bump or crater to mare its smooth and perfect “skin”. Unlike the moon, Venus is 100% cloaked in clouds. From its surface you wouldn’t see a single star not just for a week or two but for as long as you’d live. If there were ever a nightmare planet for amateur astronomy, this is it.

As Venus revolves around the Sun interior to Earth's orbit, we see it go through phases depending on its position in relation to the Sun.  Credit: Wikipedia

As Venus revolves around the Sun interior to Earth’s orbit, we see it go through phases depending on its position in relation to the Sun. Credit: Wikipedia

Venus orbits the Sun inside of Earth’s orbit — the reason we see lunar-like phases — with a period of 225 days. That makes a Venusian year only 0.6 times as long as an Earth year. For those who love birthdays then, Venus offers nearly twice as many as our plodding planet.

Through April, Venus appears as small waxing gibbous moon through a telescope, but as it catches up to Earth, it will gradually slim down to a half-moon and finally a crescent. Because it’s approaching our planet, its apparent size will also increase. By crescent phase, Venus’ shape is easily visible in little more than 10x binoculars.

While Venus is 106 million miles (170 million km) from us today, that’s peanuts compared to its neighbor, the Pleiades, which beckons from a distance of 444 light years or 2.66 quadrillion miles.

The aurora at 3:27 a.m. this morning April 10 from Midway Township near Duluth, Minn. Moonlight lit the foreground. Credit: Matthew Moses

The aurora at 3:27 a.m. this morning April 11 from Midway Township near Duluth, Minn. Moonlight lit the foreground. Credit: Matthew Moses

I can vouch that the northern lights remained active all the way into twilight this morning. Even with the last quarter moon shining, a rayless hump of aurora glowed brightly in the lower half of the northern sky until finally quenched by dawn. Chances for seeing northern lights drop off this evening, but there may still be some action. Once again, watch for a glow in the north as soon as the sky gets dark.

Last night, a low auroral arc minded its own business for a very long time before surging into activity. I stood out on a dirt road somewhere north and watched the slow, slow process unfold to the sound of a single saw-whet owl’s relentless peeping.

More auroras forecast / Venus snuggles up to the Pleiades

Time lapse of the aurora from Spirit Lake, Idaho April 9-10 by Donny Mott. Things get interesting about halfway through.

Yes – auroras made a sweep of the sky overnight and were visible as far south as Colorado. Unfortunately they weren’t particularly bright in part because of moonlight. But through the camera lens, the rays and arcs shone as a kaleidoscope of red, green and purple.

 Paul Zizka took this beautifully composed aurora portait last night from Athabasca Glacier, Jasper National Park, Alberta, Canada. "when the sky filled with aurora Im pretty sure I started screaming like a little girl. The aurora showed a wide array of colours and shapes over the Canadian Rockies and lasted several hours. Dream come true." Credit: Paul Zizka

Paul Zizka took this fantastic aurora portrait last night from Athabasca Glacier, Jasper National Park, Alberta, Canada. “When the sky filled with aurora, I’m pretty sure I started screaming like a little girl. The aurora showed a wide array of colors and shapes over the Canadian Rockies and lasted several hours. Dream come true.” Credit: Paul Zizka

It appears that activity kicked in a little later than expected – mostly after midnight – but raged till dawn. Expect a continued chance for northern lights tonight especially before midnight.

Venus passes closest to the Seven Sisters star cluster a.k.a. the Pleiades tonight and tomorrow. Created with Stellarium

Venus passes closest to the Seven Sisters star cluster a.k.a. the Pleiades tonight and tomorrow. This view shows the sky facing west around 8:45 p.m. local time in late dusk this evening. Created with Stellarium

There’s more than one cool thing happening in this evening’s sky. Look west at late dusk and fix your gaze on the brilliant planet Venus. When you do, you’ll notice some fuzzy stars only 2.5° away — the Pleiades!

The brightest planet passes closest to the sky’s most awesome star cluster this evening and next. What a contrast they make. Venus so shockingly luminous set against the delicate twinkle of the cluster stars. I encourage you to use your binoculars to appreciate them together under a little bit of magnification. It’s not often that both neatly fit in the same field of view.

You’ll also discover that the Seven Sisters, an alternate name for the Pleiades, is something of a misnomer. With 7x or 10x magnification their number increases dramatically. I dare you to count them. For more about the event and the curious 8-year-cycles of Venus-Pleiades visits, click HERE.

Dawn near Ceres – approach images, videos and animations

Today or tomorrow we should be seeing a new set of higher resolution photos of the dwarf planet Ceres taken by NASA’s Dawn spacecraft today. Check back later and hopefully we’ll have some fresh views of crescent Ceres.

See the starry stepping stones of spring

Like stepping stones across the twilit sky, Sirius, Orion's Belt, the Hyades and Pleiades star clusters (and Venus too!)  follow one another across the western sky during at nightfall in April. Credit: Bob King

Sirius, Orion’s Belt, the Hyades and Pleiades star clusters (and Venus too!) splay across the western sky at nightfall in April. Photo taken April 4, 2015 around 8:45 p.m. local time. Credit: Bob King

They may all officially belong to the winter sky, but Sirius, Orion’s Belt, the Hyades and Pleiades tilt over in the most appealing way every April. With Venus joining the scene, you can star hop from one to the next the way you might use stepping stones to cross a stream. Take a look in the west during evening twilight, and you’ll see what I mean.

Each “stone” is distinctive in its own right — Sirius (the brightest star in the sky); Orion’s Belt (a stand-out star pattern visible across the globe); the Hyades (bright star cluster and the closest one to Earth at just 153 light years); the Pleiades (the famed Seven Sisters star cluster shaped like a dipper) and Venus, brightest planet in the sky.

Two fists held at arm’s length separate Sirius from Orion’s Belt and Orion’s Belt from the Hyades. You can squeeze one fist between the Hyades and Pleiades and the Pleiades and Venus. There’s a rhythm or spacing to the pattern pleasing to the eye.

Watch for Venus and the Seven Sisters to draw closer and closer this week. From April 10-12 (Friday-Sunday), they’ll be just 2.5° apart and a wonderful sight together in binoculars.

There’s also a hidden pattern among the five objects relating to their distances. At 8.6 light years, Sirius is the 5th closest star system beyond the Sun. Orion’s Belt stars all lie much farther – between 800 and 1,000 light years away. With the Hyades, our gaze returns to the “neighborhood” 153 light years from Earth, recedes again to 444 light years with the Pleiades and returns to our own front yard with Venus, a mere 110 million miles from home.

Near-far-near-far-near. E-I-E-I-O! Anyone for a round of Old MacDonald Had a Farm?

Typhoon Maysak strengthened into a super typhoon on March 31, reaching Category 5 hurricane status on the Saffir-Simpson Wind Scale. ESA Astronaut Samantha Cristoforetti captured this image while flying over the weather system on board the International Space Station. Credit: NASA

Typhoon Maysak strengthened into a super typhoon on March 31, reaching Category 5 hurricane status. ESA Astronaut Samantha Cristoforetti captured this image while flying over the weather system on board the International Space Station. Credit: NASA

While you’re out enjoying spring’s many rhythms, watch for the International Space Station (ISS). It’s making passes again over the U.S. and other countries during convenient evening viewing hours through late April. When brightest, the space station bests the planet Jupiter as it travels steadily (and unblinkingly) from west to east across the sky.

You can get viewing times and more information at Heavens Above (click on the ISS link), key in your zip code at Spaceweather’s Satellite Flybys page, have NASA alert you via e-mail or text message or download an app for your phone.

For the Duluth, northern Minnesota and northern Wisconsin region, here are a few viewing times:

* Tonight April 5 from 8:40-45 p.m. you’ll see the ISS track across the southern sky
* Monday April 6 from 9:22-27 p.m. a brilliant high pass straight across the top of the sky
* Tuesday April 7 from 8:29-35 p.m. high in the south. Another brilliant pass.

Largest recorded explosion on moon excavates 60-ft. crater

Simulation of the flash of impact on March 17, 2013 when a boulder-sized meteorite excavated a 59-foot-wide crater in the moon's Mare Imbrium. Credit: NASA

Simulation of the flash of impact on March 17, 2013 when a boulder-sized meteorite excavated a 59-foot-wide crater in the moon’s Mare Imbrium. Credit: NASA

Two years ago March 17 an object the size of a small boulder hit the surface of the moon in Mare Imbrium and exploded in a flash of light nearly 10 times as bright as anything ever recorded before. Mare Imbrium is a lunar “sea” that forms the left eye in the Man in the Moon face we see at full moon.

NASA video of the meteorite impact that created a new moon crater

The impact and explosion were recorded with a video camera at NASA’s Marshall Space Flight Center. Based on the brightness of the flash, scientists determined a space rock about a foot wide struck the lunar surface, big enough to hollow out a substantial crater. After pinpointing the impact’s coordinates, the information was relayed to NASA’s Lunar Reconnaissance Orbiter (LRO) team, which then directed the probe to take pictures of the area in hopes of finding a fresh impact scar.

Illustration of the pattern of rays the LRO team discovered which led them to the new crater. Credit: NASA

Illustration of the pattern of rays the LRO team discovered which led them to the new crater. Credit: NASA

Nothing was found at first because the low resolution video images didn’t allow for precision targeting. So the team broadened their search to adjacent swaths of terrain. After several attempts, they noticed something unusual – streaks that looked like faint rays. Could it be part of a classic blast pattern left by impact debris showering down on the moon’s surface?

The new moon crater carved out by a meteorite strike last March 17 measures about 62 feet across. A faint blast pattern surrounds it. Credit: NASA

The new moon crater carved out by a meteorite strike last March 17 measures about 62 feet across. A faint blast pattern extends outward from its rim. Credit: NASA

They did the logical thing and traced the rays back to their convergence point. When the LRO was directed to photograph the new coordinates, immediately a fresh, new crater at the center of that pattern was revealed in photographs sent back to Earth.

This image pairing shows a lunar impact crater created on March 17, 2013. The two images are from the LROC instrument aboard NASA's Lunar Reconnaissance Orbiter. The left image is from Feb. 12, 2012, and the right image is from July 28, 2013. The new crater is about 59 feet wide. Click and drag the slider bar to swipe between the two images. Image Credit: NASA/Goddard Space Flight Center/Arizona State University

This paired photos taken by the LRO show a lunar impact crater created on March 17, 2013. The left image is from Feb. 12, 2012, and the right image from July 28, 2013. The new crater is about 62 feet wide. Credit: NASA/Goddard Space Flight Center/Arizona State University

The crater itself is small, measuring 61.7 feet (18.8 meters) in diameter, but its influence large; debris excavated by the sudden release of energy flew for hundreds of meters. More than 200 related changes, including surface material swept away and smaller secondary impacts, were spotted up to 19 miles (30 km) away. Before and after photos clearly show that less than a year prior, no crater was there.

Watch for the thin crescent moon to join brilliant Venus at dusk in the western sky this evening. Created with Stellarium

Watch for the thin crescent moon to join brilliant Venus at dusk in the western sky this evening. Created with Stellarium

Hundreds of changes have been recorded by the Lunar Reconnaissance Orbiter during its four years at the moon by comparing old and new images called “temporal pairs”. More than 25 new impacts have been discovered this way.

While we’re on the topic, the crescent moon will pass just 3° south or left of Venus this evening in the western sky at dusk. They should make for an attention-grabbing scene. Be sure to look up!

Uranus preps for tomorrow’s hand off to Mars

Like a baton in a relay race, Uranus has been passed on from one bright planetary body to the next in a series of close conjunctions. Credit: Steve Kuchera

Like a baton in a relay race, Uranus has been passed on from one bright planetary body to the next in a series of close conjunctions. Credit: Steve Kuchera

In a relay race, a baton is passed from one teammate to another during each leg of the race. Uranus can relate. It was picked up by the moon on Feb. 21, handed off to Venus on March 4th and tomorrow night will be handed off again to Mars. Before the planet crosses the finish line at solar conjunction, here’s one last opportunity to see it in binoculars in the evening sky.

Tonight the passed-along planet will lie just 1/2° or one full moon diameter to Mars’ upper left. Though just about any pair of binoculars, Uranus will look exactly like a star. Tomorrow night the two planets will be closest, separated by about 1/3° with Uranus directly below or south of the Red Planet. Thereafter they part, both hurrying in the Sun’s direction.

Uranus will be close to Mars tonight and even closer tomorrow evening March 11. Use binoculars to find it. Created with Stellarium

Uranus will be close to Mars tonight and even closer tomorrow evening March 11. Use binoculars to find it. Created with Stellarium

Venus, brilliant gem of dusk, stands high in the west as the sky darkens after sunset. Mars is considerably dimmer and shines not quite a fist to its lower right. Be sure you’re in a spot with nice open view to the west. To see Uranus, start at Venus and drop down to Mars. Point your binoculars at Mars and use the maps to help you spot it.

Because Mars sets early, I suggest you start looking about an hour after sunset. Take your time and stay out till nightfall, so you can also use those opera glasses to look at Comet Lovejoy, now passing very near the star Ruchbah in the familiar W of Cassiopeia high in the northwestern sky. Here’s a map to help you find it.

It’s double duo week: Moon-Jupiter and Venus-Uranus

The nearly full moon is in conjunction with Jupiter tonight. Their minimum separation of 5 happens around 10 p.m. (CST). Source: Stellarium

The nearly full moon is in conjunction with Jupiter tonight. Their minimum separation of 5° happens around 10 p.m. (CST). Source: Stellarium

I looked until around 11 p.m. last night but moonlight diluted any aurora that may have out. But the predicted storm did hit between about 2 a.m. and dawn this morning. While some readers might think I stay up all night, I really did sleep through this aurora. I know at least a few of you saw it. Tonight, there’s a chance for more minor storming.

There’s also an even better chance you’ll be struck by two very bright objects in the eastern sky at nightfall: a plump gibbous moon and the jolly giant planet Jupiter. They’ll be in conjunction tonight just ahead of Leo’s brightest star Regulus. Pairings like these make for great company and contemplation while walking the dog at night.

Venus and Uranus will be very close together on March 4th, an ideal time to find the fainter planet in binoculars. Source: Stellarium

Venus and Uranus will be very close together on March 4th, an ideal time to find the fainter planet in binoculars. Source: Stellarium

A planet-to-planet pairing occurs on Wednesday evening the 4th when Venus and Uranus will be just 1/3° apart. Like last month’s close graze with the crescent moon, this will provide yet another easy opportunity to see a planet that is too dim for most to see with the naked eye. Just point your binoculars at brilliant Venus in late twilight in the western sky and look for a tiny speck of light immediately below it.

I love how planets can appear so close and yet be so far from one another. Venus is a quick jaunt at 128 million miles from Earth compared to Uranus’ 1.9 billion miles, nearly 15 times farther away.

The stars in the constellation of Orion all look like they are at the same distance. Turn the constellation through 90 degrees and you can see the stars are actually at different distances. Two of the Belt stars plus the two bottom stars in the constellation are far from the sun but relatively near one another in space. Betelgeuse is much closer to us. Credit: ESA

The stars of Orion might be easily dismissed as all being at the same distance from us. That’s how they appear on the 2-D “surface” of the sky. Butturn the constellation through 90 degrees (look at it from the side) and you can see the true distances of each star. Notice that Betelgeuse is much closer to us than the Belt stars. Credit: ESA

When we see conjunctions and appreciate the real distances between objects in the sky, it’s helpful to remember the same applies to the constellations. We see familiar rectangular outline of Orion and the neat arrangement of his three belt stars by lucky chance. Looking back toward Orion’s stars from a different direction in space (a couple hundred light years beyond the solar system) Orion would be unrecognizable.

Planetary traffic jam lookback / Speedy comet update

To capture the planet Uranus (at lower right) I had to overexpose the bright, sunlight lunar crescent. Naturally, this made the earth-lit portion stand out very clearly. Credit: Bob King

To capture the planet Uranus (at lower right) I had to overexpose the bright, sunlight lunar crescent. Naturally, this made the earth-lit portion stand out very clearly. Credit: Bob King

Wow, we had quite a weekend. The moon visited every evening sky planet while Venus and Mars squeezed together for their closest approach of the year. We’ve already looked at the “triple play” conjunction that occurred Friday. I thought it would be fun to look at the other alignments that have made the past few nights so memorable.

The moon (top) along with Venus and Mars Saturday evening Feb. 21, 2015. Credit: Guy Sander

The moon (top) along with Venus and Mars Saturday evening Feb. 21, 2015 from near Duluth, Minn. Credit: Guy Sander

Here, Guy has enlarged portions of the image to better see all three planets involved. Credit: Guy Sander

Here, Guy has enlarged portions of the image to better see all three planets involved. Credit: Guy Sander

Venus and Mars were still close Sunday night Feb. 22, but they will part in the coming days as Venus moves up and Mars slides closer to the Sun. Credit: Bob King

Venus and Mars were still close Sunday night Feb. 22, but they will part in the coming days as Venus moves up and away from the Sun while Mars slides closer. Credit: Bob King

As for that fast-moving comet discovered last week and en route to the evening sky, Karl Battams, an astrophysicist and computational scientist based at the Naval Research Laboratory (NRL) in Washington DC, is right now at his computer measuring positions of the comet from photos made with the orbiting Solar and Heliospheric Observatory (SOHO).

Comet SOHO-2875 survived its close passage of the Sun and may make an appearance in the evening sky soon. This photo montage was made using the coronagraph (Sun-blocking device) on SOHO. Click to watch a movie of the comet. Credit: NASA/ESA

Comet SOHO-2875 survived its close passage of the Sun and may make an appearance in the evening sky soon. This photo montage was made using the coronagraph (Sun-blocking device) on SOHO. Click to watch a movie of the comet. Credit: NASA/ESA

Once enough positions are known, he’ll send the data off to the Minor Planet Center where a preliminary orbit will be determined. With that information I can make a nice map showing us where to look for it. Stay tuned.

Spectacular fireball over Pittsburgh / Juvenile moon alert


Pittsburgh fireball February 17

A fireball meteor at least as bright as the full moon flared over the Pittsburgh region around 4:50 a.m. Eastern time Tuesday morning. The object, detected by three NASA meteor cameras, was moving at a speed of 45,000 miles per hour. Based on its brightness, NASA’s Meteoroid Environment Office estimated the object at 2 feet across with a weight of 500 pounds. Something like a very heavy TV falling out of the sky.

“I’ve seen many meteor showers and this wasn’t anything like that. Instead of crossing the upper atmosphere, this feel almost directly down and brighter than any thing I’ve ever seen of this nature,” reported John D. of Elyria, Ohio. “It looked so big that my son and I expected to hear or see an impact.”

Based on data from pictures taken by multiple cameras, an orbit for the Pittsburgh fireball could be made. Originating in the asteroid belt between Mars and Jupiter, it came a long way to get to PA.Copyright David L. Clark, prepared by NASA MEO

Based on pictures taken by multiple cameras, NASA scientists determined an orbit for the Pittsburgh fireball. Originating in the asteroid belt between Mars and Jupiter, it came a long way to get to PA. Copyright David L. Clark, prepared by NASA MEO

“The entire landscape was lit up like daytime. Startling experience. I was very fortunate to be looking out window at the time.” So wrote Robert M. of Clarion, Penn. in his report to the American Meteor Society’s fireball reporting website.

Map showing reported sightings of the fireball. To date, 125 reports have been received. Credit: AMS

Map showing reported sightings of the fireball. To date, 125 reports have been received. Credit: AMS

NASA’s cameras first spotted the meteor at an altitude of 60 miles northwest of Pittsburgh and last saw it 13 miles above Kittanning, northeast of Pittsburgh. Around 13 miles altitude, the meteoroid entered its “dark flight” phase, when the air slowed it down enough to drop in free fall.

When we see a meteor, we don’t actually see the object itself but rather a brilliant “tube” of ionized air caused by the rock’s incredibly speedy passage through the atmosphere. Once a meteoroid loses sufficient speed, it no longer has the energy to ionize or make the air glow around it and falls in dark flight.

Earth seen from the perspective of the meteoroid moments before it entered our atmosphere to become a fireball. Click to see the movie. Credit:

Earth seen from the perspective of the meteoroid moments before it entered our atmosphere to become a fireball. Click to see the movie. Credit: Copyright David L. Clark, prepared by NASA MEO

Some people heard sonic booms during the fall, a good sign that the meteoroid (what you call a meteorite before it hits the ground) fragmented and dropped pieces on the ground east of Kittanning. According to Bill Cooke of the Meteoroid Office, seismographs in the region recorded the pressure wave created by the meteoroid’s flight.

Like most meteors and meteorites, this one’s a visitor from the main asteroid belt located between Mars and Jupiter. If pieces did survive the atmosphere’s ferocity, may I be the first to welcome them to their new home.

Watch for a 1-day-old super-thin crescent moon below the duo of Venus and Mars tonight. This map shows the sky about 35 minutes after sundown. Source: Stellarium

Watch for a 1-day-old super-thin crescent moon below the duo of Venus and Mars tonight. This map shows the sky about 35 minutes after sundown. Source: Stellarium

On another note, I wanted to remind moon lovers that a very young, very thin 1-day-old moon will be visible during early twilight in the western sky this evening starting about 25 minutes after sundown.

The moon’s about about one fist held at arm’s length below the pair of Mars and Venus. Tonight’s act is a warm-up for tomorrow night’s very close gathering of the moon with the two planets. For more information on that event, click HERE.

Tracking down February’s mystery supermoon – where is it?

This week’s new moon will be unusually close to Earth. Think of it as a ghostly supermoon. As is true for any new moon, it will be too close to the Sun in the daytime sky to see. This illustration shows the moon’s appearance and location if our eyes could somehow make it out through all the daylight. Source: Stellarium

Here comes the supermoon! But wait, doesn’t that only happen around full moon? Well, not always. Every month the moon swings around Earth in its elliptical (oval) orbit. On one side of the ellipse, it’s closest to Earth and on the opposite side, farthest. When it’s at its closest point, called perigee, at the time of full moon, we call it a supermoon.

During the closest supermoons, our satellite can appear up to 30% brighter and 14% larger. Whether anyone can actually see the difference is open to debate simply because there’s no normal-distance moon nearby with which to make a comparison.

No one pays attention to first quarter or crescent supermoons even though the moon can be closest to us at those phases, too. Thanks to incessant media coverage, only full supermoons get coverage. We like full moons for all sorts of reasons. When an extra close one’s in the offing, as happens on Sept. 27 this year, that’s just one more reason to like them.

The moon’s orbit around Earth is an ellipse with the Earth off-center at one the ellipse’s foci. During its 27-day-long orbit, the moon passes through perigee (closest) and apogee (farthest) points. This week’s new moon will be the second closest perigee of the year after the Sept. 27 full moon. Illustration not to scale. Credit: Bob King

Lest crescents and quarters get short shrift I’m here to hawk this month’s supermoon. Full disclosure. Since it occurs during new moon phase on Feb. 18 you won’t see it. No one sees a new moon except when it happens to be eclipsing the Sun. But northern hemisphere skywatchers can spot the moon two days before new and just one day after new this month, and it’ll be nearly as super as on the18th.

Tomorrow morning Feb. 16 the planet Mercury will lie about 9.5° (about one fist held at arm’s length) to the lower left of the thin crescent two days before new moon phase. This map shows the sky facing southeast about 40 minutes before sunrise. Source: Stellarium

What’s more, if you have a good view of the southeast horizon, tomorrow morning’s skinny crescent will lie near the planet Mercury low in the southeastern sky 40 minutes before sunrise. Be sure to carry along a pair of binoculars as Mercury is near “last quarter” phase and not nearly as bright as it can be.

The moon’s average distance is 240,000 miles, but tomorrow morning at 6 a.m. (CST) it will lie just 226,549 miles from Earth. At 1 a.m. Feb. 18 – the time of the invisible supermoon –  it will be 4,723 miles closer. The following day the moon slides out a bit to 222,092 miles en route to a striking double conjunction with Mars and Venus on Friday the 20th.

Even though we won’t see February’s supermoon, our planet will sense the difference. The additional gravitational force exerted by the close moon will make for unusually high tides. High tides occur when the Sun, moon and Earth are all in a line as they during both new moon phase and at full moon.

The moon, still very close to perigee, pops up in the western sky at dusk on Thurs. Feb. 19 well below Venus and Mars, now in close embrace. This map shows the sky about 35-45 minutes after sunset facing west. Source: Stellarium

So tomorrow morning you can catch the moon near Mercury at dawn, and on Thursday the 19th you’ll have the chance to enjoy the delicate grin of a one-day-old crescent in the west at dusk. Finally, on Friday, don’t miss the close conjunction of the moon with Mars and Venus.

Our satellite has a busy schedule this week!

 

A triple-scoop conjunction with a cherry on top!

Venus and Mars (at right) are drawing closer every night. This photo was taken at dusk Thursday Feb. 12 an hour and 15 minutes after sunset. On Feb. 20-21 they’ll be just half a degree apart or 8 times closer. The moon joins the pair on the 20th. Details: 35mm lens, f/3.5, ISO 800, 12 second exposure. Credit: Bob King

Get ready. One week from tonight fate has arranged a celestial spectacle. That night (Feb. 20) a two-day-old crescent moon will “triple up” with the planets Venus and Mars after sundown.

The entire bunch will fit within a circle 1.5° wide or just three times the diameter of the full moon. Like a glittering pendant around your sweetheart’s neck the trio will dangle above the western horizon in the afterglow of sunset. This is a not-to-miss event and one that should be fairly easy to photograph.

Moon, Mars and Venus around 6:45 p.m. (CST) on Feb. 20 in the western sky. Be sure to look for the darkly-lit part of the moon illuminated by sunlight reflecting off Earth called earthshine. It’s a beautiful sight in binoculars. Source: Stellarium

Look toward the west in the direction of the setting Sun; the best viewing time will be 45 to 90 minutes after sunset. With plenty of light to work with, taking a picture of the scene shouldn’t be too difficult. Attach your camera to a tripod and use the information in the photo caption as a place to start. Try to keep your exposure times to 20 seconds or less. Any longer and the planets will stretch into short trails instead of compact dots due to Earth’s rotation.

When you look at the LCD screen on the back of your camera, don’t be surprised if the crescent moon is completely filled out. Time exposures in semi-darkness necessarily overexpose the bright sunlit crescent. The rest of the moon is illuminated by dimmer earthshine, sunlight reflected from the Earth to the moon and back.

From the East Coast, the moon will lie a little farther to the right of Venus and Mars than depicted in the map; from the West Coast, it sits above the pair. Conjunction with Venus occurs around 5 p.m. (CST) and with Mars an hour later.

Venus and Mars will be close conjunction the following night (Feb. 21) only 0.5° or one moon diameter apart. If the weather doesn’t cooperate on the 21st, don’t sweat it – the two planets will be close from the 19th through the 22nd. You’ll easily tell the two apart. Venus is SO much brighter than Mars (about a hundred times) and the lunar crescent brighter yet. This promises to be one of the best moon-planet gatherings of the year.

Uranus in early twilight (left) just before its dramatic disappearance behind the earth-lit edge of the moon on Feb. 21 as seen from Portland, Maine. 36 minutes later Uranus emerges at the bright crescent’s edge. Both disappearance and reappearance occur in a dark enough sky to see in a small telescope. Source: Stellarium

Here’s a wider view of Uranus and the moon on Feb. 21 as seen from the Midwest about an hour and a quarter after sunset. Source: Stellarium

Ah, but the moon won’t be quite finished with its magic. There’s still the cherry on top. The very same night – Feb. 21 – the crescent covers up or occults the planet Uranus for skywatchers in northeastern U.S. and southeastern Canada during twilight. For the Central Time Zone Uranus will lie 0.5° west of the moon, 1° from the Mountain States and 1.5° for the West Coast. Amazing stuff – yet another opportunity to easily spot planet #7 in binoculars.

Map showing where the occultation of Uranus by the moon will be visible. Between the white lines, it’ll be visible in a dark sky. Blue is twilight and the red dotted line is daytime. Uranus is too faint to see in the daytime sky. Click the map to get a list of disappearance and reappearance times for a variety of cities. Credit: IOTA/Occult

Most of the time the moon occults stars along its path since there are a lot more of those than planets. Because they’re so remote, stars are little more than points of light; as the moon moves over them they disappear with surprisingly suddenness. Since Uranus displays a real, measurable disk it takes a second or two to disappear behind the moon’s edge. This should be a very fun occultation for those lucky skywatchers living out East. Maybe it will help take their minds off the unrelenting snow.