There are no turkeys in the sky, but there is Thanksgiving

Four of the nine constellations representing birds Cygnus the Swan, Corvus the Crow, Tucana the Toucan and Apus the Bird-of-Paradise. Credit: Urania’s Mirror, Johann Bode

There are nine different fowl represented among the 88 constellations. You’ll probably won’t find a single one of them on your Thanksgiving meal plate unless you like eating crow (Corvus). The others – an eagle, bird-of-paradise, dove, swan, crane, peacock, toucan and the mythical phoenix – aren’t regular holiday fare though I’ve heard tundra swan and crane are tasty.

The mythical Phoenix rises from the fire. You’ll find this bird frozen in flight in the southern hemisphere sky. Credit: Johann Doppelmayr

As far as I know, no one has ever considered putting a turkey in the heavens, though if we could start all over again and re-draw the constellations, it might have a fighting chance. After all, somehow the fly (Musca) and the poop deck (Puppis) made it up there.

In this imaginary reboot, I’d suggest placing it near Orion the Hunter just for the story line.

And four more … Columba the Dove, Aquila the Eagle, Pavo the Peacock and Grus the Crane.Credit: Urania’s Mirror and Johann Doppelmayr

Look hard enough though and you will find a trace of turkey up there, sliced and wrapped in foil and ready to be devoured by the 6-member crew of Expedition 42 aboard the International Space Station. Like millions of Americans on Thursday they’ll celebrate Thanksgiving with a hearty meal.

Expedition 42 commander Barry Wilmore describes Thanksgiving dinner plans on the International Space Station. He’s holding a bag of smoked turkey. Click to watch the video. Credit: NASA

Breakfast features grits and butter, a favorite of commander Barry “Butch” Wilmore, who later plans to brew up some sweet tea for the big meal. NASA food scientists have zero-g versions of many Thanksgiving favorites. Come suppertime, the astronauts will pick from smoked turkey with cornbread dressing, green beans and mushrooms, candied yams, cherry-blueberry cobble and cranberry pie.

Sounds delish! (But I still wouldn’t trade it for the turkey, pumpkin pie, stuffing and mashed potatoes my wife is preparing.)

Happy Thanksgiving!

The Moon, still young after all these years / See a Callisto eclipse!

The Moon and Mars gather in the west at dusk this evening. Stellarium

Tonight the returning young crescent Moon puts down stakes near the planet Mars in Sagittarius. Look for the pair low in the southwestern sky at dusk.

We’re used to hearing how ancient the Moon is. Its origin goes back to 4.48 billion years ago when a Mars-sized planet sideswiped the Earth, blasting debris into space that quickly coalesced into our satellite. While it’s true that most of the Moon’s crust and craters date from then, recent close-up photos from NASA’s Lunar Reconnaissance Orbiter (LRO) suggest the Moon remained volcanically active until not that very long ago. At least on geological time scales.

Ina Caldera, a classic IMP, sits atop a low, broad volcanic dome or shield volcano, where lava once oozed from the moon’s crust. The darker patches in the photo are blobs of older lunar crust. They  form a series of low mounds higher than the younger, jumbled terrain around them. Credit: NASA

100 million years ago, when dinosaurs cracked jokes about the early mammals, lava oozed from cracks in the Moon’s crust to create what astronomers nowadays call IMPs or Irregular Mare Patches. They’re characterized by a mixture of smooth, shallow mounds next to patches of rough, blocky terrain. Only one, called Ina, is large enough to see in amateur telescopes. The others, liberally sprinkled across the lunar nearside, are generally less than 1/3 mile (500 m) across. Using the LRO, a team of researchers led by Sarah Braden of Arizona State University has found 70 landscapes similar to Ina.

When it comes to the big picture, 100 million years is a small slice of Earth’s history. Credit: NASA

Maria (plural of “mare”) are those big dark spots the make up the face of the man in the moon. They’re actually huge expanses of lava that welled up from cracks in the Moon’s crust several billion years ago after asteroid impacts. IMPs are much more recent. Some may be as “young” as 50 million years old. This was well after the dinosaurs succumbed to major climate changes induced by the impact of a 6-mile-wide asteroid hit here on Earth. Now the mammals are cracking jokes about the dinos.

A selection of some of the 70 IMPs discovered during the survey. Credit: NASA

“Discovering new features on the lunar surface was thrilling!” says Braden. “We looked at hundreds of high-resolution images, and when I found a new IMP it was always the highlight of my day.”

Astronomers determine ages of lunar features by doing crater counts. The more lightly cratered an area is, the younger.

Here’s the scene tomorrow morning November 26th with all four of Jupiter’s bright moons. Callisto, which sits right next to Europa, will dramatically fade over several minutes time starting about 4:50 a.m. CST. Meanwhile, 15 minutes later at 5:05 a.m., Ganymede will exit its eclipse and return to view. Add one hour for EST, subtract an hour for MST and two hours for PDT. South is up. Stellarium

Some of you may be early morning observers. Well, I’ve got a special event to share with you. Tomorrow morning November 26th, Jupiter’s bright moon Callisto will be eclipsed by Jupiter’s shadow starting at 4:50 a.m. (CST) and disappear for nearly five hours.

Just 15 minutes after Callisto disappears, Ganymede emerges from eclipse at 5:05 a.m. (CST). One disappears, the other reappears. Pretty cool! Jupiter will be the brightest thing in the sky high in the south in Leo at the time. You can always find out what Jupiter’s moons anytime of day or night by visiting Sky and Telescope’s Jupiter’s Moons site.

What’s inside Mars? We’ll need InSight to find out

This artist’s concept depicts the stationary NASA Mars lander known by the acronym InSight at work studying the interior of Mars with a probe to measure heat flowing through the planet’s crust. The solar cells provide power to the lander. The mission will be an international one with instruments provided by several different space agencies. Credit: NASA

We’ve photographed Mars from orbit, drilled into its surface and sniffed its atmosphere looking for clues on how a warmer, wetter world went cold and dry. Now it’s time to go deep.

NASA’s InSight Mars Lander just before propulsion pressure testing in a Lockheed Martin clean room. Credit: NASA/Lockheed Martin

In March 2016, NASA plans to launch the InSight Mission that will place a single lander on Mars to study its deep interior. Named InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport), it will land in September and spend the next two years investigating the planet’s interior to determine the makeup of the Martian core, the thickness of the the crust and the composition of the mantle, the broad zone of rock between crust and core.

Using the SEIS seismometer, we’ll learn about the number and distribution of marsquakes caused by both internal stresses and meteorite impacts. The information will also help us unravel the structure of Mars’ hidden interior just as the study of earthquakes here on Earth has taught us much about the internal structure of the ball beneath our feet. We know that Earth’s center is avocado-like with a solid inner core of iron-nickel surrounded by a softer, liquid outer core.

Artist concept of the interior of Mars. Mars has a low density compared to the other rocky planets leading astronomers to believe it has less iron in its core. The lack of a global magnetic field around the planet also suggests the core is solid. Currents within Earth’s liquid outer core are believed responsible for generating the planet’s magnetic field. Credit: NASA-JPL-Caltech

The lander packs a unique “mole” or heat probe that can hammer over 16 feet (5-meters) into the Martian crust, deeper than all previous drills, scoops, arms and probes, to learn how much heat flows from the planet’s interior. As the mole burrows down in the crust it will pull a tether of heat sensors along to measure the increase in temperature with depth. Heat flow sounds obscure but it’s critical in understanding where and how mountain ranges and volcanoes form.

Another experiment, the Rotation and Interior Structure Experiment or RISE, will use variations in the receive time of the lander’s radio signals to measure minute wobbles in Mars’ rotation axis that will tell us more about the size of the core and whether it’s solid or not.

InSight will land near Mars’ equator not far from the Curiosity Rover. Credit: NASA

Because Mars has been less geologically active than the Earth – it lacks plate tectonics that recycles and renews its crust – it actually retains a more complete record of its history in its own basic planetary building blocks of core, mantle and crust. Scientists hope that insights from InSight will help us understand the forces that shaped not only Mars but all the rocky planets across the solar system.

Three ancient volcanoes rise from the the giant bulge on Mars known as Tharsis in this Viking 1 image taken in 1980. From bottom to top: Arsia Mons, Pavonis Mons and Ascraeus Mons. It’s thought that Tharsis overlies an enormous hot spot where huge quantities of lava were released as long ago as 3.7 billion years to create both the bulge and volcanoes. The cracks may have formed from the weight of the overlying lavas. Credit: NASA

Don’t forget the cameras! InSight will carry a navigation camera similar to those on the the Mars rovers mounted on the lander’s arm. In addition to black and white panoramas, it will shoot photos of the instruments on the lander’s deck and a 3-D view of the ground where the seismometer and heat flow probe will be placed. Mission controllers will also use it to guide them in the placing of the instruments to the ground. A second wider angle camera like the hazcams on the rovers will provide a second perspective on the scene.

I don’t know about you, but I can never get enough Mars. I’m eager to see the mission underway.

Sun keeps close company with the planets / New color maps of Saturn’s moons

Although not an official conjunction, three planets and the Moon are grouped within about 10 degrees of the Sun today. Except for the Moon, which will move on into the evening sky, the planets will be near the Sun the next few days. Stellarium

Hidden by sunlight today, the New Moon and three planets parade across the sky in the constellations Libra and Scorpius. It’s a big celestial gathering and one of the reasons few planets are visible in the evening sky this month — they’re all too close to the Sun.

Hanging like a dewdrop from a blade of grass, Saturn’s moon Tethys (TEE-thiss) is about 660 miles (1062 km) across and made of mostly ice. The narrow F-ring and wider A-ring cross in front of the moon in this image released last month and taken by the Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute

Mars escapes the glare and so does Jupiter, which comes up in the east like a spark yellow fire around 11 o’clock. Saturn, east of the Sun, is now in the morning sky though still lost in the solar glare. Let’s stop by that planet and its largest moons today and look at some brand new maps made with NASA’s Cassini orbiter.

Color map of Enceladus. The yellow and magenta colors show differences in the depth of surface deposits. The blue “tiger stripes” in the southern hemisphere, where the moon vents water vapor and other material as geysers, show brightly in ultraviolet light. Researchers think it might be due to large-grained ice exposures. Credit: NASA/JPL-Caltech/Space Science Institute/Lunar and Planetary Institute

With its rings and butterscotch clouds, few planets rival Saturn for beauty, but its moons are equally fascinating for their strange colors, textures and alien features. NASA recently released a series of global, color mosaics of six of its largest moons based on 10 years of images taken by NASA’s Cassini spacecraft as it orbited the Saturn system. These are the first global color maps of these moons produced from the Cassini data. The colors are broader than what the human eye sees, extending into the ultraviolet and infrared (beyond red) part of the spectrum. They’re also VERY detailed – just click on any of them for a close-up. I’ve included four of the six. To see them all, click HERE.

Iapetus (eye-APP-eh-tuss) looks very strange with one hemisphere bright and icy and the other covered in about a foot of darker material. Iapetus rotates very slowly – once every 79 days. It’s thought that an impact of a darker object long ago coated part of  its surface, causing that area to absorb more sunlight over the long day. More heat meant more ice vaporized which then re-condensed as frost/ice on the moon’s bright side, further concentrating the darker material. This expanded in a positive feedback loop that eventually led to an ever-whitening hemisphere while the other grew blacker. Credit: NASA/JPL-Caltech/Space Science Institute/Lunar and Planetary Institute

On Tethys, scientists think the dark colors of the moon’s trailing hemisphere are due to changes in ice and minerals caused by bombardment from high-speed particles and radiation in Saturn’s powerful magnetic field. The lighter-colored leading hemisphere is coated with icy dust from Saturn’s E-ring, formed from tiny particles ejected from Enceladus’ south polar geysers. The purplish equatorial band gets its color from high-energy electrons in Saturn’s magnetic field slamming into the moon. Credit: NASA/JPL-Caltech/Space Science Institute/Lunar and Planetary Institute

Meet Dione, a 698-mile-wide moon. Its color variations are believed to be caused by the same factors affecting Tethys – radiation and high-speed particles weathering the trailing hemisphere ice and the effects of icy mist spewed by Enceladus on the leading hemisphere. Credit:  NASA/JPL-Caltech/Space Science Institute/Lunar and Planetary Institute 

Awesome Iceland aurora time-lapse and a bear claw sunspot

Joe Capra’s recently released time lapse of aurora over Iceland and Greenland

Nice work! Take a peek at Joe Capra’s recent 10-day shoot of the aurora and you’ll be licking your chops to fly to Greenland on the next available plane. Capra used three Canon 5D Mark III cameras with various Canon lenses to shoot hundreds of individual photos that he later stacked into a video. The reflections on ice and water are spectacular.

A low, green aurora in the northern sky on November 19th sparked by a coronal hole. Credit: Bob King

Here in the northern U.S., the aurora’s been snoozing. Even though gusts of solar wind from a leaky coronal hole have tickled Earth’s magnetic domain the past few nights, conditions have remained below storm level. The aurora’s been a constant but quiet presence like the embers of an overnight fire.

More low aurora simmers in the north last night (Nov. 20) around 11 o’clock. The band of northern lights, called the aurora oval, hovers directly over places like Iceland and Greenland, so people there get to see displays nearly every dark night of the year. It takes coronal holes, flares and other kinds of heightened solar activity to expand the oval so skywatchers in lower latitudes get their chance. Credit: Bob King

Expect the same horizon-hugging aurora for the next couple nights as the hole in the Sun’s magnetic canopy continues to send pinging particles our way.

That giant sunspot that’s made it through a second rotation of the Sun has been nothing but a tease when it come to flares. On its return a week ago, the group possessed the magnetic complexity to unleash powerful X-class flares, but so far, all’s been quiet on the solar front.

Sunspot group 2209 (older 2192) mimics a bear claw in this photo taken on November 19th by French amateur astronomer Philippe Tosi with an 8-inch telescope. Earth shown for size. Click to see more of his amazing high-resolution Sun image. Credit: Philippe Tosi

Flares aside, the region makes a great sight in the telescope. Shaped like a bear claw, the main spot in the group still spans more than three Earths. Philippe’s photo beautifully shows the fiber-like texture of the outer penumbra fringing the darker umbras.

Sunspots are cooler regions on the Sun’s surface – the reason they appear darker – where strong magnetic fields insulate those areas from their hotter surroundings. Notice the rice grain texture of the background. Called granules, each one’s about the size of Texas and represents an individual cell of hot solar gas rising from below like bubbles in a pot of boiling water. At the surface, the gas cools and sinks back down along the tiny, dark channels separating one from another. Re-heated, they rise again.

Crunch! Listen to Philae landing on Rosetta’s comet

Nice crunch! Click the arrow to hear the sound of Philae touching down on Comet 67P/C-G on November 12, 2014. To hear the file as many times as you’d like, click the SoundCloud icon that appears after the first play.

Listen. Hear it? Mixed with the sound of flexing landing pads when Philae first touched down on the comet’s surface is – what sounds to my ear – like the crunch of comet grit. Sensors in the feet of the lander recorded the moment of contact during Philae’s first attempt at landing on November 12th.

It was recorded by the instrument SESAME-CASSE, which was turned on during the descent and clearly registered the first touchdown in the form of vibrations detected in the soles of the lander’s feet. We’re listening to a real sound file - a recording of mechanical vibrations at acoustic frequencies – not a simulation. No changes in frequency were made, so it sounds just the way it would if you could have stuck your head inside Philae with your ear in contact with the landing gear when it made contact with the surface.

Sensors are located in the three feet as well as in the units of the APXS (centre) and MUPUS-Pen (to the upper right of centre) instruments. SESAME stands for Surface Electric Sounding and Acoustic Monitoring Experiment. Click to learn more about the instrument. Credits: ESA/ATG medialab

Klaus Seidensticker from the DLR Institute of Planetary Research says: “Our data record the first touchdown and show that Philae’s feet first penetrated a soft surface layer – possibly a dust layer – several centimeters thick until they hit a hard surface – probably a sintered ice-dust layer – a few milliseconds later.”

Data from SESAME and other instruments indicate that activity in the form of vaporizing ice at Philae’s final landing site is low. Almost all the instruments in the lander did their jobs and returned data to mission control. Early results indicate that organic (carbon-based) molecules were detected, the drill performed as expected and at least went through the motions of delivering a soil sample to the probe’s oven for heating and analysis. What’s unclear is whether it gathered a sample in the first place.

A close up view of Philae’s first landing site on the comet after which it bounced a kilometer high. Scientists are still trying to pinpoint the lander’s final touchdown location. Credit: ESA/Rosetta/OSIRIS

Philae landed on a layer of dust about 4-8 inches (10-20 inches) deep. Beneath this relatively soft cover lies a bitter cold and firm crust of water ice. The MUPUS experiment hammered into the comet as hard as it could but was only able to penetrate a few millimeters. No wonder – the temperature just above the surface measures a nippy –243°F (–153°C). That’s some tough ice!

When the probe was lowered into the dust, the temperature dropped another 10 degrees Celsius.

Rosetta’s orbit, focusing on the maneuvers after November 12th. Credit: ESO

With its batteries drained, Philae’s now in hibernation until at least next spring when the angle of the Sun on the comet will have changed to illuminate the solar panels. Assuming they begin producing electricity to recharge the batteries, there’s a chance we’ll be back in touch and downloading fresh information about the comet by summer.

Meanwhile, the Rosetta orbiter moves to the forefront:

“With lander delivery complete, Rosetta will resume routine science observations and we will transition to the ‘comet escort phase’,” said Flight Director Andrea Accomazzo.

Rosetta will have its “fingers” all over comet 67P/Churyumov-Gerasimenko during the upcoming mapping mission.

Rosetta is expected to stay with the comet at least through December 2015, so we can expect plenty of good science and (hopefully) a lot more close-up photos. On December 3, the craft will move down to a height of just 12.4 miles (20 km) above the surface for about 10 days, after which it will return to 18.6 miles (30 km). Team scientists want to get as close as possible to 67P/C-G before activity from jets of gas and dust becomes too risky to the spacecraft.

The upcoming low orbital volleys will be used to map the icy nucleus at high resolution and collect information on the comet’s gas, dust and plasma (molecules and atoms electrified by the Sun’s UV light).

Quasars Mysteriously Align Across Billions of Light Years

Artist’s rendering of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun. Some of the matter falling into the hole gets beamed back into space along the axis of the spinning disk’s rotation. Credit: ESO/M. Kornmesser

Quasar. One of the coolest words ever. It’s really shorthand for “quasi stellar radio source”. When radio telescopes were developed in the latter half of the 20th century, astronomers eagerly used them to find new objects in the sky, many invisible in visible light. One of the things they found were these star-like objects glowing brightly in radio waves but appearing only as undistinguished stars in optical telescopes.

Further study revealed they were extremely distant – billions of light years – as far as the most remote galaxies. For such a tiny object to shine across such vast distances, it must be powered by something extraordinary.

We now know that quasars are galaxies with very active supermassive black holes at their centers. Matter falling a black hole gets spun into a whilring disk, releasing tremendous amounts of energy before it finally goes “down the drain” for good. Some the incandescent matter beams back into space in long jets perpendicular to the disk.

This artist’s impression shows the mysterious alignments between the spin axes of quasars and the large-scale structures that they inhabit that observations with ESO’s Very Large Telescope have revealed. These alignments are over billions of light-years and are the largest known in the universe. The large-scale structure is shown in blue and quasars are marked in white with the rotation axes of their black holes indicated with a line. This picture is for illustration only and does not depict the real distribution of galaxies and quasars. Credit: ESO/M. Kornmesser

Today, according to a news announcement by the European Southern Observatory (ESO), a European research team has found that the rotation axes of the central supermassive black holes in a sample of 93 quasars are parallel to each other over distances of billions of light-years. The team has also found that the rotation axes of these quasars tend to be aligned with the vast structures in the cosmic web in which they reside. We see the 93 quasars at a time when the universe was just a third of its current age.

Admittedly, these sounds like pretty obscure stuff, but why should these objects that are not only far from us but billions of light years from each other, be connected? It’s such an intriguing mystery, but before we look at why, let’s stop to examine the large scale structure of the universe.

This simulation, created by the Millennium Simulation Project, represents a 2 billion- light-year-wide chunk of the universe and more than 20 million galaxies. The purple strands represent dark matter around which normal matter (the bright yellow clumps of galaxies) has clustered into filaments of billions of galaxies surrounded by empty voids of space. Credit: Millenium Simulation Project

When we sit back and take in the really, really big picture, the billions of galaxies out there are arranged in dense filaments and strands resembling a pile of spaghetti or neurons in the human brain. The strands in turn are clustered about the still-mysterious dark matter, of which there’s far more of than the bright stuff like stars and galaxies. To refresh your memory, the universe is composed of 73% dark energy, 23% dark matter and only 4% bright matter.

Large pockets of relatively galaxy-free space called cosmic voids lie betwixt and between the strands. The entire texture strikingly shown in the simulation (and visible on smaller scales in maps and photos) is linked to dark matter, which though invisible, is both plentiful and makes its presence known through gravity. Dark matter forms the backbone for all the beautiful galaxies we see in our telescopes and in photos taken by the Hubble. It’s the coral reef and the galaxies are the fish, crabs and all the rest.

Artist concept of a supermassive black hole powering a quasar. Black holes that form from the collapse of a star during a supernova explosion are only a few miles across. Supermassive ones, built up over billions of years from matter straying too close the hole’s event horizon, are the size of the solar system. Our Milky Way harbors such a supermassive black hole, but it’s currently not active like those seen in quasars. Credit: Wiki

The new VLT results indicate that the rotation axes of the quasars tend to be parallel to the large-scale structures in which they find themselves. So, if the quasars are located in one of the spaghetti noodle, then the spins of the central black holes will point along the axis of that noodle. The researchers estimate that the probability that these alignments as simply the result of chance is less than 1%.

Take a journey through the large-scale structure of the universe in this video version of the photo above.

By the way, the research team, led by Damien Hutsemékers from the University of Liège in Belgium, could not see the rotation axes directly but inferred them by measuring the polarization (light waves vibrating in a preferred direction) of the quasars’ light.

So the “why” of these spooky alignments is this: we don’t know … yet:

The alignments in the new data, on scales even bigger than current predictions from simulations, may be a hint that there is a missing ingredient in our current models of the cosmos,” concludes Dominique Sluse.

Are they following the dictates of the unseen dark matter? Hmmm … questions as always. This is the beauty of going where no one has ventured before.

Winter got you down already? Sample spring and a lovely conjunction at dawn

The crescent Moon, just a few days before new, sits atop Virgo’s brightest star, Spica tomorrow morning at dawn. This map shows the sky facing southeast about 50 minutes before sunrise. Stellarium

November nights are long, long, long. You can start the evening with the Summer Triangle, catch wintery Orion at midnight and by dawn it’s already spring! Celestially speaking anyway. Here at 47 degrees north latitude in Duluth, Minn. night takes up the lion’s share of the day with nearly 15 hours of the dark stuff between sunset and sunrise.

If winter’s already nudging into your comfort zone, why not head outside tomorrow morning for a dose of spring stars and a beautiful conjunction of the crescent Moon and Virgo’s brightest luminary, Spica? You can see them even earlier than the map shows when the sky is still dark.

The Moon, just 3 days before new phase, resides in the springtime constellation Virgo. Not far off you’ll also see the little trapezoid of Corvus the Crow. Higher up to the left or north, sparkling Arcturus sputters and twinkles in the cold air.

You can’t stop the Earth from rotating. Once the Sun’s well up in the east, the early summer stars come into view, or they would, if there was no atmosphere. They’re there alright but hidden by scattered sunlight that colors the sky blue. By mid-day, summer’s in full swing. Come sunset, the cycle repeats itself again. And that’s how we roll.

Rosetta captures spectacular photos of Philae drifting above comet

These incredible images show the  Philae lander’s journey as it approached and then rebounded from its first touchdown. You can even see the landing pad impressions (top inset). Pictures taken by the Rosetta OSIRIS camera 9.6 miles (15.5 km) from the surface. Click to enlarge. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Just amazing! And a little sad, too. It’s Philae coming in for its first landing attempt on comet 67P/Churyumov-Gerasimenko. You’ll recall the lander touched down without the use of its reverse thruster or the harpoons to fix it to the surface. Given the near zero-G gravity at the comet, Philae immediately rebounded to the tune of 1 kilometer (0.6 miles) and set off on a brand new path high above the comet. Rosetta was there to see it happen.

Close-up of the first touchdown site before Philae landed (left) and after clearly shows the impressions of its three footpads in the comet’s dusty soil. Times are CST. Philae’s 3.3 feet (1-m) across. Credit: ESA et. all

Rosetta captured Philae’s descent (from left to right) to the comet, the first touchdown point (top inset) and subsequent rebound and drifting off to the right or east. The craft was moving only at a walking pace (1.6 feet/sec) at the time of first contact with the comet. According to the Rosetta blog:

“The mosaic comprises a series of images captured by Rosetta’s OSIRIS camera over a 30 minute period spanning the first touchdown. The time of each of image is marked on the corresponding insets and is in Greenwich Mean Time. A comparison of the touchdown area shortly before and after first contact with the surface is also provided.”

The Rosetta spacecraft spotted Philae and its shadow shortly after the lander touched down and stirred up some dust (dark spot in larger red circle) at 9:30 a.m. (CST). The Philae image was shot five minutes later. Credit: SA/Rosetta/NAVCAM; pre-processed by Mikel Canania

We still don’t know exactly where the lander is, but after two bounces, it finally settled down for good at 11:32 a.m. (CST) a considerable distance east of the original landing site. Expect photos soon of Philae. Mission controllers are hard at work combining the CONSERT ranging data with OSIRIS high resolution and navigation camera images from the orbiter along with photos from Philae’s ROLIS and CIVA cameras to reveal to lander’s location.

Note: The two identical times in the top inset photos are correct even though they both show the same time. When the 15:43 picture was taken, Philae had moved on, but the impressions of its footpads remained.

Lively Leonid meteor shower peaks tomorrow, Tuesday

The annual Leonids peak this week. About a dozen per hour will be visible from a dark site. The shower’s known for fireballs that often leave persistant “smoke trails” or trains. Tony Hallas captured two Leonids in a single frame with glowing trains during the 2001 shower. Credit: Tony Hallas

Watch out for flammable comet dust the next few nights. ‘Tis the season of the Leonids. This annual meteor shower, which originates from dust dribbled by comet 55P/Temple-Tuttle, peaks tomorrow and Tuesday mornings November 17-18.

About every 33 years the Leonids produce a spectacular display. This illustration from a newspaper at the time captures the intensity of the shower on November 13, 1833. The next Leonid storm is expected in 2034.

Every 33 years, when the comet swings into the inner solar system, Leonid numbers swell into the hundreds if not thousands per hour and create what’s better described as a meteor storm. The most recent storm unfolded in 2000-2001; now we’re down to the Leonids’ usual peak of 10-15 per hour.

Admittedly, that’s more like a light drizzle than a shower, but what the Leonids lack in numbers in off-years, they make up for in character. Because the Leonid stream travels around the Sun in a direction opposite to the planets, Earth hits Tempel-Tuttle’s debris head-on at very high speed. Leonids pepper the planet at speeds upwards of 158,000 miles per hour (70 km/sec), the fastest of any shower.

They often burn brightly as fireballs and leave glowing streaks of ionized air in their wakes called trains. Upper atmospheric winds can distort and stretch the trains over several minutes time, a sight well worth watching. In 2001, we saw a fair number of these long-lasting “smoke trails” after the appearance of fireballs.


This map shows the sky facing east around 3 a.m. Monday November 17th. The radiant is well-placed near Jupiter in Leo. The thick crescent Moon rises around 2 a.m. Monday and 3 a.m. Tuesday. Stellarium

Watching the Leonids is easy as long as you’re willing to wake up in the wee hours. Patience helps too. You may see nothing in the first 10-15 minutes and then all at once a swift blade of light slices the sky. The radiant or point in the sky from which the meteors originate rises around 11:30 p.m. local time in Leo near Jupiter. But the best time to view the shower is from about 3 a.m. till dawn when the radiant is high in the east-southeast.

Both Monday and Tuesday mornings are good for shower watching. Light from the crescent Moon will hardly be a bother. Dress warmly and get comfy under a blanket in a reclining lawn chair facing east or south. Relax back and watch the stars slowly parade above you. Every meteor you see will come both as a pleasant surprise and reminder that Earth is continually touched by comets.