Earth and Mars, space pals forever

This single shot of Earth and Mars together was taken on May 24, 2014 with NASA’s Lunar Reconnaissance Orbiter spacecraft as it orbited the moon. Click to see full, hi-res photo. Credit: NASA/GSFC/Arizona State University

Yesterday we watched the total lunar eclipse from Mercury. Today, NASA’s Lunar Reconnaissance Orbiter (LRO) expands our gaze to encompass both Earth and Mars together in space.

LRO’s viewing post was none other than the moon located 240,000 miles from Earth. On May 24th, instead of staring down at the lunar surface, NASA engineers sent commands to the spacecraft to point its Narrow Angle Camera toward Earth. On that date the two worlds were in conjunction from LRO’s perspective.


Mars and Earth from lunar orbit

Mars was about 70 million miles away (112.5 million km) away at the time or 300 times farther away from the Moon than the Earth. That’s why it’s only a tiny dot in the sky.

Moon-facing hemisphere of Mars on May 8, 2014 seen from lunar orbit. Instruments on LRO sometimes use stars and planets for calibration or other special observations. During one of these off-Moon observations, LROC imaged Mars. The planet is so small in LRO’s camera it could only make out the two larger features shown above. Credit: NASA/GSFC/Arizona State University

I know a commercial photographer who takes pictures of babies when they’re asleep. She has to invest a lot time into each of her photos, much of it spent waiting for the children to fall asleep! Likewise the LRO team. To make sure they got the timing and exposure right, the team practiced on Mars weeks in advance.

Seeing the two planets in the same frame seems to shrink the distance between them and tempt us to shove off from home on an exploratory visit.

The LRO folks put it this way:

“The juxtaposition of Earth and Mars seen from the Moon is a poignant reminder that the Moon would make a convenient waypoint for explorers bound for the fourth planet and beyond! In the near-future, the Moon could serve as a test-bed for construction and resource utilization technologies. Longer-range plans may include the Moon as a resource depot or base of operations for interplanetary activities.”

Ever seen a lunar eclipse from Mercury? Me neither … till now


Wednesday’s lunar eclipse photographed by NASA’s MESSENGER spacecraft at Mercury

As millions of us awoke at dawn and trundled outside to watch the total lunar eclipse this week another set of eyes was keeping tabs from afar. 66 million miles away, NASA’s MESSENGER spacecraft turned its camera toward Earth to capture several images of the moon disappearing into our planet’s shadow. Laced together, they make for a brief but fascinating glimpse of planetary bodies in motion.

Two of the still images showing Earth and moon before and during Wednesday morning’s total eclipse. Credit: NASA

The animation was constructed from 31 images taken two minutes apart from 5:18 to 6:18 a.m. EDT. The images start just before the Moon entered the umbra, the darkest part of the Earth’s shadow.

“From Mercury, the Earth and Moon normally appear as if they were two very bright stars,” noted Hari Nair, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory, in Laurel, Md. “During a lunar eclipse, the Moon seems to disappear during its passage through the Earth’s shadow, as shown in the movie.”

MESSENGER photographed Earth and moon on May 6, 2010 from 114 million miles (183 million km) away. Credit: NASA

Because the moon is so much darker than Earth its brightness has been increased 25 times to show its disappearance more clearly. I’ve included another picture of the Earth and moon against the starry backdrop of deep space also photographed by MESSENGER. Sure puts things in perspective. While not as breathtaking as photos of Earth taken by the Apollo astronauts, seeing our tiny home floating in the void effectively communicates how improbable our existence is. Thank goodness life got a grip and kept it. After 3.5 billion years of evolution the double helix has proven itself a force with which to be reckoned.

The 133-mile-wide double ringed crater Vivaldi captured at sunrise. The low sun highlights valleys and chains of secondary impact craters radiating away from it. Credit: NASA

MESSENGER has been in orbit around Mercury since March 2011 studying the chemical composition of the surface, measuring planet’s magnetic field, mapping polar ices and of course taking pictures. Enjoy a few recent ones.

Hollows on the floor of an unnamed crater on Mercury. Hollows may be areas “eaten away” by the ceaseless bombardment of particles in the solar wind. Or they may form when heat from volcanic activity melts away softer rocks. No one knows for sure. Credit: NASA

Moon and illusion in the Hyades tonight

The waning gibbous moon moves across the Hyades star cluster tonight October 11. This map shows the view through binoculars around 10 p.m. CDT. Moon is to scale. Source: Stellarium

Now that the eclipse is behind us, the moon has trotted off to the east out of the limelight.

It’s in that lengthly phase called waning gibbous, a period of 6+ days between full moon and last quarter. Can I coax you out for another look?

Tonight the moon will cross the Hyades star cluster that forms the V-shaped face of Taurus the Bull. Merely having the moon in Taurus hints at how close we are to the start of winter. Two months hence, the Bull, along with Orion the Hunter, will dominate the southern sky at 10 o’clock.

Taurus the Bull from the 19th century star atlas Urania’s Mirror.

But tonight around 10, Taurus makes its appearance in the eastern sky. Because the moon is still fat and bright you’ll better appreciate its passage through the Hyades with binoculars. By happy circumstance, the entire cluster neatly fits into the field of view of most pairs.

Orange-red Aldebaran is Taurus’ brightest star and completes the cluster’s V with a flourish. Don’t be deceived. This star is an impostor that by chance lies in the same line of sight as the star cluster. The Hyades form a gravitationally bound group of stars 153 light years distant and were born from the same cloud of gas and dust 625 million years ago. Aldebaran? Only 65 light years away and as solitary as our sun.

The moon moves its own diameter every hour as it orbits the Earth. You can see that motion overnight tonight as the moon approaches and then conjuncts with Aldebaran tomorrow morning. The map shows the view from northern Minnesota / Wisconsin. Source: Stellarium

Over the course of the night, the moon will slowly work its way across the Bull’s face, occulting or covering a number of fainter cluster stars along the way. One such star is 63 Tauri shining at magnitude +5.6. A small telescope 4-inches or larger will show the moon creep up to the star and suddenly blank it from view around 10:10 p.m. Central Daylight Time. Depending on your location, the moon’s path across the Hyades will shift a little north or south, and you may see different stars occulted.

Aldebaran-Sun comparison. Aldebaran is an orange giant star 44 times the sun’s size. The sun will also puff out like Aldebaran several billion years in the future when it starts burning helium in its core as Aldebaran is today. Credit: Wikipedia

By 5 a.m. CDT tomorrow morning Oct. 12 the moon will be in conjunction with Aldebaran about 1º to its north. Here we see yet another of nature’s illusions. The moon not only outshines Aldebaran by 26,000 times, it’s huge in comparison. But make no mistake, Aldebaran’s the giant here. Next to it, the sun looks puny and faint.

With a diameter 44 times solar, Aldebaran’s searing orange photosphere would reach all the way to the planet Mercury if put in place of the sun and overall shine 500 times as bright.

Another noteworthy star to look for in your binoculars is the pair called Theta 1,2 Tauri. Both belong to the Hyades although small uncertainties in their distances make it unclear if they’re a physical double star or like Aldebaran, a chance alignment. Once the moon’s out of the way, this is a fun star to try and split with your naked eye. Like two tiny pearls in a starry brooch, they make for a pleasing sight.

Total lunar eclipse – what a beauty!

The moon just coming out of eclipse over Spring Lake north of Duluth, Minn. this morning October 8. Details: 200mm telephoto, ISO 800, 1 second exposure. Credit: Bob King

I hope your sky was clear for the total lunar eclipse. It sure wasn’t here. A big bank of clouds moved in before totality. I was shocked when I looked at the window to see a clear sky in the east and not a single star – or moon – in the west. That’s why man invented the car.

Moon around mid-totality with the planet Uranus (left) for company. Credit: Bob King

25 miles north of town the burnt orange moon slid out from under the clouds. It was already mid-eclipse, but no matter. I pulled over to the side of the road to enjoy the sight as twilight crept up from behind.

In binoculars Uranus was plain to see near the lower edge of the moon where the color was deep, rich and red. Up along the lunar topside the color graded to a pale straw yellow.

The full moon departs Earth’s shadow over a spruce bog tinged with fall color north of Duluth Wednesday morning around 7 a.m. Credit: Bob King

Clouds threatened again sending me fleeing to a lake shore and finally another roadside. Around 6:30 a.m. traffic picked up. Everyone driving south or west on their way to work and school got the astronomical treat of their life – the moon emerging from total eclipse right out the front windshield. Sweet!

The partially eclipsed moon glows against Earth’s setting shadow (the purple band) this morning. Full moons are directly opposite the sun, setting around sunrise and rising at sunset. When you look at the moon during eclipse you’re staring directly down the shadow cone cast by the planet. Credit: Bob King

For a total lunar eclipse to happen, the moon must be full and lie in the same plane as Earth’s orbit. Since the moon’s orbit is tilted 5°, it normally misses Earth’s shadow at full, passing a few degrees above or below it.

The moon partially covered in Earth’s shadow seen from Dayton, Ohio this morning. At the moon’s distance, the planet’s shadow is surprisingly small – only big enough to cover the Seven Sisters (Pleiades) star cluster. Credit: John Chumack

The full moon orbits behind the Earth opposite the sun; as the sun rises the moon sets. At the moon’s distance of 240,000 miles, the Earth’s shadow, both penumbra and umbra, spans a little more than 2° or about the size of the Pleiades star cluster.

Seems pretty small, doesn’t it?

But viewed from the ground, Earth’s shadow reaches from one end of the western horizon to the other. In the evening, the shadow is equally broad but appears in the eastern sky. This morning we had the unique opportunity to see the partially eclipsed moon in Earth’s distant shadow at the same time as seeing the much bigger near-shadow of the planet. Wild thought.

Full sequence of this morning’s total lunar eclipse. Details: Canon 6D camera, 80mm refractor, 2-second exposure at ISO 6400. Credit: John Chumack

Lunar eclipse photo tips, times, live streams

On Wednesday morning October 8, Earth’s shadow will nibble away at the moon during the wee hours eclipsing it for the second time this year. Credit: Bob King

Ready for Wednesday’s morning lunar eclipse? Some people – and I envy them at times – treat an eclipse more casually. They enjoy the show with no desire to set up a telescope or take a photo. For those of us can’t part with our cameras, here’s a little guide to help you get better pictures.

As a photographer, I’m compelled to shoot at least a few photos of an event as rare as a total eclipse. Someday I’ll let it all go and just kick back in a lawn chair as the shutters clack around me. But until then the camera will be at my side.

From Philadelphia and other eastern U.S. cities the partial phases of the eclipse will take place with the moon well up in the western sky. By the start of totality, the moon will have dropped to within about 6º of the horizon as shown here. Source: Stellarium

If you’re also into photography and would like to grab a few shots, here are a few tips on what equipment you’ll need and camera settings. This eclipse offers unique opportunities especially for the eastern half of the country because the eclipsed moon will be low in the western sky near the start of and during morning twilight.

In the Midwest at the start of the hour-long totality, the red moon will be about 20º (two fists) above the western horizon. From the East Coast the moon slips into total eclipse only a half hour before sunrise 6-7º high. So if you live in the eastern half of the country, find a site with a good view to the west.

Seen from Denver, total eclipse begins with the moon 30º high (three fists). All of totality and all partial phases of the eclipse will be visible from western Midwest west to Hawaii and Alaska. Source: Stellarium

A low moon means easier framing with a pleasing foreground like a grove of fall trees, a church or distant line of mountain peaks. And the lower it drops, the longer the telephoto lens you can use to enlarge the moon relative to the foreground. When the moon is high in the sky it’s more difficult to find a suitable foreground.

Sometimes it’s nice to have a foreground object to add character to your eclipse photos. Last April’s totally eclipsed moon joins the old Central High School clock tower in downtown Duluth, Minn. Mars at upper right. Details: 80mm lens, f/5, 1.6-second exposure at ISO 400 on a tripod. Credit: Bob King

As the scene brightens during twilight, balancing the light of the moon, your photos will get even more interesting. Textures and details in foreground objects will stand out instead of appearing as silhouettes.

Use the table below to plan when to watch depending on your time zone. The blanks mean the moon will have set by the time of the event.

Eclipse Events                         EDT                 CDT                MDT                 PDT

Penumbra first visible 4:45 a.m. 3:45 a.m. 2:45 a.m. 1:45 a.m.
Partial eclipse begins 5:15 a.m. 4:15 a.m. 3:15 a.m. 2:15 a.m.
Total eclipse begins 6:25 a.m. 5:25 a.m. 4:25 a.m. 3:25 a.m.
Mid-eclipse 6:55 a.m. 5:55 a.m. 4:55 a.m. 3:55 a.m.
Total eclipse ends 7:24 a.m. 6:24 a.m. 5:24 a.m. 4:24 a.m.
Partial eclipse ends ——— 7:34 a.m. 6:34 a.m. 5:34 a.m.
Penumbra last visible ——— ——— 7:05 a.m. 6:05 a.m.

Exposures and lens settings

Partial phase during the April 14-15 eclipse this year. Details: Telescope (=1300mm telephoto lens) at f/11, 1/250 second at ISO 400. Credit: Bob King

The full moon and even the partially eclipsed moon (up to about half) are so bright you can shot a handheld photo without resorting to a tripod. Exposures at ISO 400 are in the neighborhood of f/8 at 1/250-1/500 second. Only thing is, all you’ll get is the moon surrounded by blackness. These exposures are so brief almost nothing will show in your foreground except for possibly moonlit clouds. That’s usually fine for the early partial phases.

To capture the encroaching shadow during partial phases you’ll need to overexpose the sunlit part of the moon. Details: f/11, 2-second exposure at ISO 400. Credit: Bob King

Once the moon is more than half smothered in shadow, open up the lens to a wider setting – f/2.8 to f/4 – or increase the exposure.

Let the back of the camera be your guide. If the images look too bright, dial back. If too dim, increase exposure or open the lens to a wider aperture.

While you can continue to shoot the partially eclipsed moon at f/8 from 1/30-1/125 second, you’ll miss the best part – the portion filling up with Earth’s red shadow. To capture that, break out the tripod, open your lens all the way up – f/2.8-f/4 – and expose at ISO 400 between 1/4 and 1 second. You can also shoot at ISO 800 and cut those times in half, important if you’re using a longish telephoto lens. Remember, Earth’s rotation means the moon’s on the move and will show trailing if you expose longer than a few seconds.

Wide scene from April’s total eclipse with Spica below the moon and Mars to the right. Details: 24mm lens at f/2.8, 8-second exposure at ISO 800. The moon was deliberately overexposed to show it in a field of stars. You can vary the exposure to your taste but the shorter it is,  the fewer stars. Longer exposures will show trailing. Credit: Bob King

During totality, expose anywhere from 1/2-5 seconds at f/2.8-4.5 at ISO 400. Let’s assume you want to include both a foreground and stars in the picture using a standard or wide angle lens. Dial up to ISO 800 with you lens wide open and exposure of 6-10 seconds. On the 6-second end you’ll catch only the brightest stars but the moon won’t show trailing; on the longer end you’ll get lots more stars with some overexposure of the eclipsed moon.

The partial lunar eclipse of June 4, 2012, pre-dawn at moonset, from home in southern Alberta. This is a single exposure with the Canon 60Da and 18-200mm Sigma lens at 115mm and at f/5.6 for 0.4 sec at ISO 160. Copyright: Alan Dyer

Where parts of the eclipse happen in twilight, even mobile phones may suffice. There should be enough light to capture a pretty scene with the moon just emerging from total eclipse and during the ensuing partial phases.

If you’re clouded out or on the wrong side of the planet for the eclipse, you can catch live webcasts from the following sites:

* Gianluca Masi’s Virtual Telescope
* Griffith Observatory in Los Angeles
* SLOOH 

Clear skies!

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!

How long would it take to drive to the sun?

My old Subaru achieved lunar orbit when the odometer hit 238,000 miles several years back. Credit: Bob King

I spend way too much time in the car, mostly on the job as a photojournalist. Every day, there are places to be at this time and that. Like many who drive around for a living,  I’ve accumulated a few miles on my vehicles.

Once, in an older Subaru, I achieved a one-time dream of reaching the moon. The odometer rolled past the 238,000 mile mark – just under the average lunar distance but easily within perigee range. I would have pushed the vehicle further, but the brakes seized up and soon after I sold the car. I recall it leaving the driveway on a flatbed like a patient being wheeled away to the emergency room.

The sun is some 387 times farther from Earth than the moon. Credit: Bob King

The years of driving it took to “get to the moon” got me wondering how long it would take to drive to the sun, which lies some 93 million miles (150 million km) from Earth or 387 times farther away than the moon.  According to the Guinness Book of World Records, the record vehicle mileage goes to a 1966 Volvo P-1800S with more than  2,850,000 miles (4,586,630 km). Owned by Irvin Gordon of East Patchogue, New York, the car is still driven daily.

A commercial jet flying at 550 mph would need 19 years to reach the sun. Credit: Bob King

While that trashes my record, it’s still only 3% of the way to the sun, a nice start but barely there. Instead, let’s drive non-stop at 60 mph (97 kph). How long would it take before we would complete our journey? An amazingly long time – 177 years. Strange, isn’t it? The sun seems so close because we can feel its warmth and watch it ripen our tomatoes. But it’s out there, w-a-y out there.

Even in a commercial jet flying at 550 mph (885 kph) it would still take 19 years. I’m afraid I just don’t have that kind of time or patience. Even the 5-hour trip to Hawaii from Los Angeles made me twitchy. The Helios probes, the fastest moving space vehicles ever, reached speeds of 157,000 mph as they orbited around the sun sensing the solar wind. At that rate, the sun could be reached in just 24.7 days.


Bill Nye demonstrates the distances between the planets.

How about a planet? Let’s choose picturesque Saturn, now low in the southwestern sky at dusk. Its average distance from the sun is 891 million miles (1.4 billion km) or 1,695 years in a car. That means if we started driving in 320 A.D. when ancient Rome still dominated the western world, we’d finally arrive today. Aw heck, I’d rather take a plane and get there in just 185 years.

Maps showing the planets and layout of the solar system give a false impression of sizes and distances. But you can hardly blame the creators. There’s just too much empty space between the planets compared to their tiny sizes to squeeze it all a useful diagram. Credit: NASA

Even in the solar system, never mind the stars, distances are so immense we can hardly comprehend them. If we reduced the sun to the size of a grapefruit, Earth would be a poppy seed 35 feet (10.7 m) away, Saturn a pea at 335 feet (102 m) and the nearest star system, Alpha Centauri, a pair of grapefruits 1,800 miles (2,900 km) away. There’s so much emptiness and so little stuff, it’s mind-boggling.

Goodmorning moon / Tomorrow’s Titan flyby

Look east Monday morning around 6 a.m. to spot the goodmorning moon. Only 2.5% of the moon will be illuminated by the sun; the remainder by ghostly earthshine. Venus will be about a fist held at arm’s length to the moon’s lower left. Stellarium

Like a lot of parents, we read Goodnight Moon by Margaret Wise Brown to our kids to get them ready for bed at night. The calming words and repetition soothed child and adult alike at the end of the day.

Maybe a sequel titled “Goodmorning Moon” will be written someday about waking up to the smiling crescent in the east and getting ready for the day. Tomorrow morning we’ll see exactly that, a very thin moon, low in the eastern sky at dawn. Its delicate arc will surely make you stop and realize how much beauty nature puts on the plate for enjoyment and study every day.

Venus seekers can use the moon to make one last attempt to find the planet, now nestled very low in the east just a degree or two above the horizon 40 minutes before sunrise.

Animation showing clouds of methane moving over Ligeia Mare, a large sea of liquid methane near Titan’s north pole, between July 20 and 22, 2014 as Cassini departed the moon during the last flyby. Credit: NASA/JPL-Caltech/SSI

While we’re on the topic of planets, NASA’s Cassini spacecraft will make a close flyby of Saturn’s moon Titan tomorrow September 22nd. At 3,201 miles (5,150 km) across, Titan is the solar system’s second largest moon, only 79 miles smaller than Jupiter’s Ganymede. It’s also unique in having a very thick atmosphere – 1.5 times thicker than Earth’s – a feature usually found only on planets.

It’s still not known how Titan managed to hold onto all its air, which consists of primarily nitrogen mingled with methane and various other hydrocarbons that react in sunlight to create an orange smog that gives the moon its distinctive color. Several other moons such as Ganymede, Rhea and even our own moon have atmospheres, but they’re exceedingly thin compared to Titan’s.

In this photo taken by Cassini, Saturn’s airless, cratered moon Dione is juxtaposed with Titan. Titan appears smaller because it’s 600,000 miles farther away from the spacecraft’s perspective. To see beneath the clouds and map the surface, Cassini observes the moon in infrared light and with radar. Credit: NASA/JPL-Caltech

It’s thought that Titan maintains and replenishes its atmosphere through outgassing from its interior. The bitter cold temperatures at Saturn’s nearly billion mile distance from the sun along with Titan’s considerable gravitational pull undoubtedly help preserve and hang on to its air. Comet impacts may also contribute to the moon’s stockpile of ices and organic compounds.

Along with an atmosphere come clouds, though of methane rather than the water vapor variety found on Earth. Temperatures at the surface hover just 90 degrees above absolute zero (-290º F, -179º C), chill enough for methane clouds to form and supply at least some of the precipitation to lakes of liquid ethane, methane and propane below.

This will be Cassini’s 9th flyby of Titan this year. During a flyby, the craft zips by the moon at high speed while keeping its instruments precisely pointed at the target using either its reaction wheels or thrusters, which spin the spacecraft to track the moon as it passes by. Thrusters are also used to keep Cassini from tumbling when it experiences drag while passing through Titan’s upper atmosphere during close flybys.


Descent through Titan’s atmosphere made by the Huygens probe on January 14, 2005

On Monday, Cassini will be traveling at 13,000 mph (21,000 km/hr) and come within 870 miles of Titan’s surface as it photographs seas and lakes – including Ligeia Mars shown above – around the north pole. Another instrument will observe Titan’s southern hemisphere atmosphere in ultraviolet light by observing the dimming of Alkaid, the star at the end of the Big Dipper’s handle as its light passes through the moon’s varied atmospheric layers.

Jupiter-moon conjunction / Space station expecting guests / Hello Mars!

Tomorrow morning September 20th the crescent moon will be lined up in conjunction with the planet Jupiter ahead of the Sickle of Leo. This view shows the sky a little more than an hour before sunrise. Stellarium

Getting a little extra sleep these September mornings? That benefit comes from later sunrises as we approach the fall equinox. I don’t know about you, but I sleep better in a darkened bedroom.

The rate of change has really picked up in the past few weeks with the sun now rising around 7 o’clock, a far cry from late June’s 5:15.

Later sunrises also mean a chance to catch an early morning sky event. Many of us are active around 6 a.m. prepping for work or getting your children ready for school. If you can find a few minutes to spare, tomorrow morning offers up two fine sights.

Look east in the brightening dawn and you’ll see a slender crescent moon in conjunction with the brightest of the planets, Jupiter. The two will just 5º apart meaning you’ll be able to squeeze three fingers held at arm’s length between them. Then, between 5:30-6:15 a.m. now through at least next week, the International Space Station (ISS) will be making regular passes across the northern sky from many locations across the U.S., Canada and Europe.

To find out exactly when and where to look, key in your zip code at Spaceweather’s Satellite Flybys site or select your city at Heavens Above. The ISS looks like the brightest “star” in the sky and travels from west to east. A typical complete pass takes about 5 minutes.

An earlier SpaceX Dragon capsule docking with the space station in March 2013. Astronauts will use the grapple arm to grab the capsule Monday morning Sept. 22 at around 6:30 a.m. CDT. Berthing begins around 8:45. Click to enlarge. Credit: NASA

The three current astronauts aboard the space station await the arrival of the other half of their crew next week. NASA astronaut Barry Wilmore, Soyuz Commander Alexander Samokutyaev and Flight Engineer Elena Serova will launch aboard their Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan on Sept. 25 to begin a six-hour, four-orbit trek to the orbiting complex.

Before that, SpaceX’s unmanned Dragon ship will launch tomorrow morning Sept. 20 at 1:14 a.m. Central time to deliver cargo and crew supplies to the ISS early Monday morning Sept. 22nd.

Among the items are the first 3D printer in space, the ISS-RapidScat instrument to monitor ocean winds for climate research and weather forecasting and a commercial experiment designed to make a better golf club. The printer will allow astronauts to make their own tools and replacement parts that would otherwise cost a lot of money to ship up from Earth.

Fruit flies such as these spent one month aboard the International Space Station during an earlier study. More are on the way. Credit: NASA / Dominic Hart

20 female mice and 30 fruit flies will also go along for the ride. The mice will be housed in the new Rodent Research habitat, where they’ll be studied for the effects of spaceflight on the human body. In space, rodents don’t spend their time floating around. They’re very physically active but tend to hold onto the walls.

Fruit flies will be monitored for the effects of oxidative stress changes which happen in organisms ranging from fruit flies to humans. Oxidative stress involves a build up of harmful molecules inside cells that can cause cell damage, and it’s associated with infections and disease.

Artist view of India’s Mars orbiter at Mars. Arrival and orbit insertion is expected for Sept. 24. Credit: ISRO

There’s much more in the works for space mission news as Mars welcomes two new emissaries from Earth. NASA will insert the MAVEN spacecraft into orbit around Mars Sunday night, and India’s Mars Orbiter Mission (MOM) will arrive at the planet only three days later on Sept. 24.

The MAVEN mission will study Mars’ climate present and past as scientists try to figure out how the planet evolved from a warmer, wetter past to the current dry, cold desert. MOM is India’s first-ever mission to another planet. While primarily a demonstration and testing of that country’s technology, MOM will also photograph the Red Planet and study its mineral makeup from orbit.

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.