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.

Moon meets Uranus next / Oddball comet update

Wow! What a fine photo from last night's conjunction. Venus, Mars and waxing crescent Moon over sculpture "Calling The Power" by Larry Bechtel at Vic Thomas Park. Credit: Terry Aldhizer

Wow! What a fine photo from last night’s conjunction. Venus, Mars and the waxing crescent Moon over the sculpture “Calling The Power” by Larry Bechtel at Vic Thomas Park in Roanoke, Virginia. Credit: Terry Aldhizer

Close-up of the moon, Venus, Mars gathering last night. The earthshine on the moon is amazing! Credit: Terry Aldhizer

Close-up of the moon, Venus, Mars gathering last night. The earthshine on the moon is amazing! Credit: Terry Aldhizer

We were  hopelessly cloudy for last night’s conjunction. You were luckier I hope. Don’t forget, tonight’s thicker crescent passes very close to the planet Uranus, occulting it from the far northeastern U.S. and southeastern Canada. Venus and Mars will also be in conjunction today and a smidge closer that they were yesterday evening.

Wide view of Uranus and the moon on tonight (Feb. 21)  as seen from the Midwest about an hour and a quarter after sunset. Source: Stellarium

For the Central Time Zone, Uranus will lie 0.5° west of the moon in twilight, 1° away the Mountain States and 1.5° for the West Coast. What a great opportunity to spot the 7th planet in binoculars. Not only that, but a simple time exposure with a tripod-mounted camera will easily show it. Wait till late twilight and try a range of exposures starting around 5 seconds at ISO 800 with the lens wide open to f/2.8 or 3.5.

Uranus in early twilight (left) just before its dramatic disappearance behind the earth-lit edge of the moon tonight 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

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 will take a second or two to disappear behind the moon’s edge.

SOHO-8275 comet about 7 east of the Sun this morning at 9:06 a.m. (CST) this morning. Credit: NASA/ESA

SOHO-2875 comet about 7 east of the Sun this morning at 9:06 a.m. (CST) this morning. Credit: NASA/ESA

The little comet we discussed yesterday continues trekking away from the Sun after its searing encounter two days ago. SOHO-2875 still shows a short tail and hangs in there around magnitude +3.5. It reached the edge of the field of view of the Solar and Heliospheric Observatory’s C3 wide-field coronagraph this morning headed east-northeast.

Since the field of view of the coronagraph is 15°, the comet’s presently about 7° east of the Sun, too close to spot yet in twilight. Give it 4-5 more days and someone may see it in a telescope in evening twilight. As soon as an orbit becomes available I’ll put together a chart to help you find it.

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.

Moon perambulates with Uranus tonight

The half-moon creeps up on the planet Uranus this evening. The two will be near each other all night in the constellation Pisces, but closest – less than one-third of a moon diameter apart – just before midnight (CST). The views are what you’ll see in a pair of binoculars. The 4th magnitude star Delta Piscium is at top in the field. Source: Stellarium

Sunlight. Moonlight. Starlight. I saw all three for the first time in weeks yesterday. Filled with photons, I feel lighter today, less burdened. Ready to float off the floor.

Seattle, two time zones west of the Midwest, will see the two closest around 9:30 p.m. local time. Source: Stellarium

There’s a nice event you’ll want to see tonight if only because it’s so effortless. The half-moon will pass very close to the planet Uranus for skywatchers across North America this Sunday evening Dec. 28th.

Pop the rubber lens caps off those binoculars and point them at the moon. If you look a short distance to the left you’ll notice a star-like object. That’s the planet!

You can do this anytime it’s dark, but the later you look the better because the moon moves eastward and closer to the planet as the hours tick by. Early in the evening, the two will be separated by a couple degrees, but around 11:30 p.m. CST (9:30 p.m. PST) when the moon reclines in the western sky, the planet will dangle like an solitary diamond less than a third of a lunar diameter away. When closest to the Moon, Uranus may prove tricky to see in its glare. If you hide the Moon behind a chimney, roofline or power pole, you’ll find it easier to see the planet.

Binocular view from the desert city of Tucson around 10:45 p.m. local time tonight. The moon’s farther north of the planet compared to the view from Seattle because the 1,500 miles between the two cities is enough to shift the moon’s position against the background stars. Source: Stellarium

The farther north you live, the closer the twain will be. Skywatchers in Japan, the northeastern portion of Russia, northern Canada and Alaska will see the moon completely hide Uranus for a time.

The farther west you are, the higher the moon will be when they conjoin. West Coast states see the pair highest when they’re closest.

The radically different character of each world can best be appreciated in a telescope. Pump the magnification up to 150x and slide both planet and moon into the same field of view. Uranus, a pale blue dot, wears a permanent cover of methane-laced clouds where temperatures hover around -350°F (-212°C).

Though the moon will be lower in the sky at closest approach, observers in the eastern U.S. and Canada will still see planet and moon just 1/2 degree apart before moonset. Source: Stellarium

The fantastically large-appearing moon in contrast has precious little atmosphere and its sunny terrain bakes at 250°F (121°C). And just look at those craters! First-quarter phase is one of the best times for moon viewing because the terminator or shadow-line that divides lunar day from night slices right across the middle of the lunar landscape.

Shadows cast by mountain peaks and crater rims are longest and most dramatic around this time because we look squarely down upon them. At crescent and gibbous phases, the terminator is off to one side and craters and their shadows appear scrunched and foreshortened.

The day-night line or terminator cuts across a magnificent landscape rich with craters and mountain ranges emerging from the lunar night. Several prominent lunar “seas” or maria and prominent craters are shown. Credit: Christian Legrand and Patrick Chevalley / Virtual Moon Atlas

Enjoy the view and consider the depth of space your view encompasses. Uranus is 1.85 billion miles from Earth today — 7,700 times farther away than the half moon.

We interrupt this program with a special weather bulletin from Uranus

Infrared images of Uranus obtained on Aug. 6, 2014, with the 10-meter Keck telescope. The white spot is an extremely large storm that was brighter than any feature ever recorded on the planet in the 2.2-micron (infrared) band. The cloud rotating into view at the lower-right limb grew into the large storm that was seen by amateur astronomers at visible wavelengths. Credit: Imke de Pater (UC Berkeley) and Keck Observatory images

We’ve had a few good blows this fall but none compare to what’s underway on the solar system’s seventh planet. Storm clouds have billowed up on Uranus over the past several months, so big and bright that even amateur astronomers have photographed them.

“The weather on Uranus is incredibly active,” said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley, and leader of the team that first noticed the activity when observing the planet with the 10-meter (393.7-inch) Keck telescope in Hawaii.

Animation showing the movement of the bright spot as Uranus rotated over a two-hour period on Oct. 4, 2014. The infrared images were taken at the Pic du Midi telescope in the French Pyrénées. Courtesy of Marc Delcroix and F. Colas (S2P)

How big is this bad boy? Observing at a variety of wavelengths, the Hubble Space Telescope tracked multiple storm fronts extending over a distance of more than 5,760 miles (9,000 km) and clouds at a variety of altitudes. That’s nearly a fifth of the planet’s 31,518 mile-diameter!

Uranus, four times the size of Earth and nearly twice as far from the Sun as Saturn, is a bitter cold planet rich with water, methane and ammonia ice in its interior swaddled in an atmosphere of hydrogen and helium with just enough methane to give it a blue tint.

Uranus photographed in September 2010 when few features were visible. Outside of a bright polar region, the planet usually appears bland in even large amateur telescopes. Credit: Damian Peach

Through a telescope, Uranus is normally a featureless dot that few amateurs astronomers bother to photograph. But once news of the storm got out, French amateur Marc Delcroix used the 39-inch (1-m) Pic du Midi telescope to give it a try. He nailed it on the second night out:

“I was so happy to confirm myself these first amateur images on this bright storm on Uranus, feeling I was living a very special moment for planetary amateur astronomy.” said Delcroix, who works for an auto-parts supplier in Toulouse, France. Anthony Wesley of Australia also succeeded in photographing the storm on September 19th and October 2nd with his 16-inch reflecting telescope. I’ve not heard whether anyone has actually seen it. Perhaps it might be possible with a large amateur scope, the right filter and a darn good night.

images of Uranus on Sept. 19 and Oct. 2, 2014 showing the dramatic appearance of a bright storm on a planet that normally displays only a diffuse bright polar region. Credit: Anthony Wesley, Murrumbateman, Australia

Bright clouds seen by amateurs and pros alike are probably caused by gases such as methane rising in the atmosphere and condensing into highly reflective clouds of methane ice.

De Pater and team detected eight large storms in all in Uranus’s northern hemisphere when observing the planet with the Keck Observatory on Aug. 5 and 6. Interestingly, the extremely bright storm in the Keck photos is not the one seen by the amateurs, which is much deeper in the atmosphere, below the uppermost cloud layer of methane ice crystals. Clearly, this Uranian hurricane rages at multiple levels in the planet’s atmosphere.

Because Uranus has no internal source of heat, its atmospheric activity was thought to be driven solely by sunlight, which is now weak in the northern hemisphere. Had it occurred during during Uranus’ every-42-year-equinox in 2007, when the Sun shined directly over the equator, no one would have been surprised, but what could cook up a meteorological megastorm with little input from the Sun is anyone’s guess.

“The colors and morphology of this cloud complex suggests that the storm may be tied to a vortex in the deeper atmosphere similar to two large cloud complexes seen during the equinox,” said Larry Sromovsky, de Pater’s colleague and planetary scientist at the University of Wisconsin-Madison. So the storm may have deeper roots. Yet Uranus is the coldest planet in the solar system, even colder than Neptune, which radiates 2.6 times the energy it receives from the Sun into space. Uranus hardly leaks at all.

Cutaway showing the structure of the planet Uranus. Wikipedia

Maybe the storm is a dust devil writ large, where warmer and denser air from the lower atmosphere suddenly rises through cooler, low-pressure air higher up and begins to rotate when conditions are just right.

“These unexpected observations remind us keenly of how little we understand about atmospheric dynamics in outer planet atmospheres,” wrote De Pater and team in their report. Still, it’s nice to know the team’s willing to put up with years of bland to wring a new discovery now and then.

Poor Uranus – we won’t forget you, I promise

Uranus and Earth compared. Uranus has an atmosphere of hydrogen and helium with clouds of ammonia and methane. It’s the methane that gives the planet its characteristic aqua color. Although little more than a dot in the sky, the planet’s 4 times larger than Earth. Credit: NASA

Poor Uranus. So dim it barely gets noticed. A lost soul. But every year at opposition, it’s nice to give the 7th planet its due. Uranus will be closest to the Earth on Tuesday October 7 at “just” 1.8 billion miles (2.9 billion km) or 19 times the Earth’s distance from the sun.

Understandably, the naked eye planets get most of our attention. They’re brighter, closer and bigger. We can follow them without optical aid, and when viewed through a telescope, there’s usually cool stuff to see. Mars wows with polar caps and dust storms, Jupiter shows his stripes, Venus and Mercury’s phases look like miniature versions of the moon and Saturn spins a hula-hoop.

Shoot a line from Beta Pegasi (upper right) through Gamma Pegasi and continue about one fist to the lower left to Delta Piscium. Uranus is 3 degrees south-southeast of Delta to the left of a similarly bright star. Use the binocular map below for further help. Click map for a larger version. Source: Chris Mariott’s SkyMap

Uranus at magnitude +5.7 can be seen with the naked eye just like the others if you know exactly where to look. This season it tracks slowly across the middle of Pisces the Fish below the bright fall asterism, the Square of Pegasus. Finding and following this tiny blue orb will be easier than usual thanks to a lucky alignment.

Here’s the scene in a pair of 7×35 or 7×50 binoculars. The numbers next to stars are magnitudes. Uranus, at magnitude 5.7, will slowly glide south of a similarly bright star now through December, giving skywatchers lots of time to spot and track the planet. Source: Chris Marriott’s SkyMap

Draw a line from Beta Pegasi, the upper right star in the Square, diagonally to Gamma Pegasi and continue in that direction until you bump into Delta Piscium. Uranus lies about 3º to its south in the same binocular field of view. To pinpoint the planet, use the binocular map. Right now, the planet lies about a degree to the east of a 5.7 magnitude star, its twin in brightness. Using this star as a reference, you’ll easily see Uranus’ slow westward crawl over the next three months.

With a diameter of 31,518 miles (50,724 km) Uranus is the third largest planet in the solar system after Jupiter and Saturn. Being so far away it takes 84 years to revolve once around the sun, 4 years longer than the average life expectancy of a U.S. citizen. One of my goals in life is to celebrate one complete Uranian year. Maybe even a little more.

Uranus has 27 moons in all. These are its five largest which range from 980 miles (Titania) to 293 miles (Miranda) in diameter. They’re composed of roughly half water ice and half rock. Credit: NASA

Uranus has 27 moons named after characters from the works of William Shakespeare and Alexander Pope and 13 known rings, the first of which was discovered only in 1977. NASA’s Voyager 2 spacecraft visited the planet in January 1986 and discovered 10 new moons and two new rings. A day on Uranus lasts just 17 hours 14 minutes. But the planet’s oddest trait is that it rotates on its side.

Only after 84 years would a hypothetical Uranian citizen be able to celebrate their 1st birthday. Uranus rotates on its side unlike the other planets with each of its four seasons lasting 21 years. It will be fall in the planet’s northern hemisphere until the 2028 winter solstice. Credit: Nature of the Universe with additions by Bob King

All the other planets have tilted axes but they rotate right side-up generally perpendicular to the plane of the solar system. Not wayward Uranus. With an axis tilted at 98º, it rotates on its side like a bowling ball! This makes for curious seasons. Since Uranus takes 84 years to orbit the sun, each of the planet’s poles gets 42 years of continuous sunlight during the summer season followed by 42 years of winter darkness.

The sun seen from the equator of one of Uranus’ moons during the northern “summer years”. It would circle the north celestial pole every 17-plus hours. Credit: Kurdistan Planetarium

Seen from Uranus (its cloudtops at least – below that it’s permanently overcast), as northern spring progresses toward summer, you’d see the sun the move in ever tighter circles toward the planet’s north celestial pole. On the solstice, the sun would be just 8º from the celestial pole and circle it once every Uranian day (17-plus hours). Then the sun would spiral out from the pole over the next 21 years until it finally set, not to return to view for another 42 years. Bizarre.

Astronomers think that long ago Uranus was struck by an Earth-sized planet at an angle that effectively tipped it over on its side like a well-placed football tackle.

Any telescope magnifying 100x or higher will show the planet as a tiny pale blue disk. Because Uranus’ atmosphere is almost featureless, higher powers and larger telescopes reveal little more on the planet. Not so the moons. Four or five are visible in 10-inch and larger scopes with Titania and Oberon the easiest. Were it not for the glare of the planet, an 8-inch would suffice. If you’d like to give the moons a try, Sky and Telescope has a very nice Javascript utility Moons of Uranus to pinpoint them at any time.

Uranus will be a snap to see in binoculars just east of the totally eclipsed moon for much of the central U.S. Wednesday morning October 8. It will be even closer (just below the moon) for observers in the western states. This simulated binocular shows the pair around 5:30 a.m. CDT. Source: Stellarium

The best time to view Uranus is without a bright moon nearby. Since the moon is now near full, you’ll want to wait a few nights to make your first observation. But Wednesday morning’s total eclipse offers an exceptional opportunity.

Because the moon’s light will be quenched during total eclipse, you’ll be able to spot Uranus with ease in binoculars about a degree to the left or east of the moon.

Anticipating Wednesday’s awesome lunar eclipse

Watch for a ruddy moon in Pisces the Fish during the total lunar eclipse which happens Wednesday morning October 8th. The moon’s color can range from dark brown to coppery red depending on the transparency of the Earth’s atmosphere as described below. This map shows the view at the start of total eclipse as seen from the Midwest. Source: Stellarium

If you missed last April’s total lunar eclipse because of weather or commitments, you’ve got a second chance Wednesday morning October 8th. This is the final total lunar eclipse of 2014 and the second of four in a series called a tetrad – four consecutive total eclipses occurring at approximately six month intervals this year and next.

On Wednesday morning October 8, the moon will slide into Earth’s shadow and we’ll be treated to a total lunar eclipse. The outer shadow or penumbra only lightly shades the moon; for most of us the eclipse begins when the moon touches the inner, darker shadow called the umbra. Times are shown for each stage of the eclipse. Add one hour for EDT, subtract one hour for MDT and two hours for PDT. Credit: NASA / F. Espenak with additions by Bob King

“The most unique thing about the 2014-2015 tetrad is that all of them are visible for all or parts of the USA,” says longtime NASA eclipse expert Fred Espenak.

This eclipse happens during the early morning hours, so North American skywatchers will need to remember to set their alarm clocks. In the Midwest, partial eclipse begins at 4:15 a.m., when the moon’s eastern limb eases into Earth’s umbral shadow.

World map showing where the eclipse will be visible. Most of North America and much of Asia and Australia will see the event. Those living in the western half of the U.S. will see the eclipse from beginning to end. Farther east, the partially eclipsed moon sets at sunrise. Credit: NASA / F. Espenak

Earth’s shadow is composed of two nested components – the inner umbra, where the Earth completely blocks the sun from view, and an outer penumbra, where the planet only partially blocks the sun. Because the penumbra is a mix of shadow and sunlight, it’s nowhere near as dark as the umbra.

Animation showing the moon’s passage through the penumbra and umbra during the upcoming total eclipse. Credit: Tom Ruen

A lunar eclipse is divided into stages beginning with the moon’s entry into the penumbra. Most of us won’t notice any shading on the moon until it’s well inside the outer shadow about a half hour before partial eclipse begins. Look for a subtle darkening along its eastern edge.

During a lunar eclipse, the sun, Earth and moon are neatly lined up in space. For a few hours, the orbiting moon passes through Earth’s shadow and we experience a lunar eclipse. Credit: Starry Night

Because the Earth is a solid object, it casts a shadow in sunlight just like you and I. A lunar eclipse occurs when the sun, Earth and moon are precisely lined up in a row at the time of full moon, and the moon moves into Earth’s shadow.

Although the moon’s doing all the moving, it looks like the shadow is encroaching on the moon, slowly devouring it nibble by nibble. When the moon’s about half covered you’ll notice that the shadowed half is deep red or orange.

Artist view of Earth totally eclipsing the sun as viewed from the moon. Low angled sunlight filtered by our atmosphere is reddened in exactly the same way a setting sun is reddened. That red light bathes the moon’s surface which reflects a bit of it back toward Earth, giving us a red moon during totality.

Sunlight filtered and bent by Earth’s atmosphere spills into the umbral shadow and colors the moon a coppery red, burnt orange or rust. You can picture why this happens by pretending you’re standing on the moon looking back at Earth during total eclipse.

From your new perspective, the Earth passes in front of the sun, ringed by a glowing, red-orange atmosphere. Our atmosphere bends or refracts the light from all the sunrises and sunsets around the planet’s circumference into the umbra, adding color to the moon.

Depending on the amount of suspended particles called aerosols in Earth’s atmosphere at the time, the moon’s disk can glow a bright copper orange to deep brown-black. The more particles and haze, the greater the light absorption and darker the moon.

For the East Coast, totality begins during bright twilight with the moon low in the western sky. Skywatchers in the central U.S. will see all of totality and most of the final partial phases before moonset. If you live in the western U.S. you’ll get to watch the whole shebang in a dark sky.

Mid-eclipse is when the moon is deepest in Earth’s shadow. Since the top or northern end of the moon is closer to the shadow’s edge, it should appear noticeably lighter than the bottom half, which lies closer to the center.

The moon in mid-eclipse during the last total eclipse on April 14-15, 2014. You’ll notice a lot of variation of light and color across the disk. Credit: Bob King

After mid-eclipse, the moon slowly exits the Earth’s shadow and performs the whole show in reverse, transitioning back to partial eclipse and finally exiting the penumbra.

Besides the pleasure of seeing moon change color like a quickie version of fall, watch for the sky to darken as totality approaches. Eclipses begin with the sky flooded in bright moonlight nearly barren of stars. During totality, all the stars come back in a most breathtaking way. Be sure to sweep your gaze east to enjoy great views of the winter constellations including Orion.

A rare treat greets anyone with a pair of binoculars during next Wednesday morning’s total eclipse. The planet Uranus will sit a little more than one moon diameter to its southeast during totality. This view shows the scene from the U.S. Upper Midwest at 5;30 a.m. Source: Stellarium

By good fortune, the eclipsed moon will lie only about 1/2° west of the planet Uranus which should be easy to spot in binoculars during the hour of totality. Speaking of which, binoculars are a great way to enjoy the eclipsed moon. Somehow they give it a more three-dimensional look. Colors are richer and you’ll see the lunar disk suspended among the stars, a rare sight.

For your latest forecast, click HERE. I’ll have more information for you early next week including links for watching the eclipse on the web and photo tips. Stay tuned!

Struggled to find Uranus? Let the moon take you there tonight

Once you’re done chuckling, we’ll move on. Ahem!

The waning gibbous moon will near the planet Uranus tonight September 10, 2014. From northeastern U.S. it will be covered by the moon. These views show moon and planet from Syracuse (eastern U.S.) and the Midwest at the times shown. Source: Stellarium

If you’ve ever had trouble finding the remote planet Uranus, Luna can help you tonight. The waning gibbous moon will occult or cover up the planet for observers in northeastern North America, Greenland, Iceland and northern Scandinavia around 8 p.m. Eastern Daylight Time this evening.

If you have a small telescope, you’ll be able to watch the bright eastern (left) edge of the moon slowly approach and then hide the planet. Unlike a point-like star, which winks out in a split second when covered by the moon’s edge, Uranus shows a small disk and will fade more gradually over several seconds.

Observers in the wedge-shaped zone that spans the Northeastern U.S., Canada and other northern countries will see the moon cover Uranus. Those living in the U.S. and Canada will spy the planet very close to the moon’s west rim. Credit: USNO

But let’s say like me you live outside the occultation zone. What will we see? From the Midwest, Uranus will be just less than 1° to the west (right) of the moon as it comes up in the eastern sky in late twilight. Over the hours, it will appear to move gradually drift to the west away from the moon as the moon moves eastward in its orbit.

The farther west you live, the farther Uranus will be from the moon’s western edge. But not too far. Even from the California Coast, Uranus strays only about 2° (four moon diameters) to the right of the moon.

The planet may even be easier to see in binoculars from points west because it will be further from the lunar glare. No matter what, it’ll be easy to find the planet, which shines around 6th magnitude.

The view from the U.S. West Coast around 10 o’clock local time tonight. Source: Stellarium

Remember, you’ll need 50 mm binoculars, or better, a small telescope, to view the planet near the moon. Telescope users are encouraged to crank up the magnification and see Uranus’ diminutive disk next the moon, which appears gigantic in comparison. In reality, the 7th planet is nearly 15 times as large.

Uranus only a degree east of the totally eclipsed moon seen from the Midwest on October 8, 2014. Stellarium

Get ready for an even better shot at seeing Uranus. On the morning of October 8th, the full moon will be in total eclipse and the planet will lie very close due east. With no glary moonlight and everyone focused on the eclipse, more people will probably see Uranus at one time than perhaps any time in history.