Gaga for the Geminids – 2014′s best meteor shower fires up this weekend

The Geminids peak on both Saturday and Sunday nights this weekend December 13-14. The radiant – where the meteors appear to stream from – lies near Castor and Pollux in Gemini and rises high enough by 9:30 p.m. local time to begin shower watching. Source: Stellarium

Get ready for the year’s best meteor shower. The reliable, rich and colorful Geminids will climax on not one but two nights. Even better, it all happens this weekend before midnight. No arising at 4 a.m. on a Tuesday.

A bright Geminid slices the sky in this time exposure taken on December 13, 2012. Each meteor represents a vaporized fragment of dust or rock lost by asteroid 3200 Phaethon, the Geminids’ parent. Credit: Bob King

Most sources will tell you that we’ll see up to 120 meteors per hour, but 60-80 is more realistic from light polluted location. I’ll take it. That’s plenty of meteors to take the sting out of stepping into the cold. Maximum occurs on Sunday morning at 6 a.m. but that’s near dawn and the moon will be up – not ideal conditions for viewing. That’s why Saturday and Sunday evenings are best.

The Geminids radiate from near the twin bright stars Castor and Pollux in Gemini. Most major meteor showers don’t really get going until the morning hours because their radiants either haven’t risen or are still too low before midnight. The Geminid radiant on the other hand climbs high enough by 9:30 in the evening to cast a nice spread of meteors before moonrise.

Oh yes, the moon. It rises around midnight Saturday night and 1 a.m. Monday morning. Its light will cut into meteor counts, but since Gemini’s well up in the east before moonrise, we have 2-3 hours of great meteor watching under dark skies.

See what I mean – this shower’s ideal for family viewing since you don’t have to be up too late. It’s also the richest shower of the year, having surpassed the more familiar August Perseids some years ago. Now all we have to do is hope for good weather.

Unlike most meteor showers, which originate with dust spewed by comets, the Geminids are tiny pieces of asteroid 3200 Phaethon, sometimes called a “rock comet”. Here it sprouts a tenuous tail (points to lower left) when near the Sun in this image taken by NASA’s STEREO Sun-observing spacecraft in 2012. Credit: Credit: Jewitt, Li, Agarwal /NASA/STEREO

Observing a meteor shower requires no special equipment outside of a warm coat, heavy gloves, insulated boots, electric sock warmers, hand warmers and one of those plug-in Amish fireplaces. Just kidding of course, but not about the gloves, jacket and boots! Aw, chuck it all and just watch from a hot tub.

I like to lay back in a recliner under a blanket to stay warm and comfortable. A little hot cocoa or tea doesn’t hurt either. Face east or south between 10 and midnight from a reasonably dark sky location and you’re certain to see at least a few Geminids.

The Perseids and many other meteor showers are the spawn of comets. Earth plows through the dust left by vaporizing comet ices and it burns up in the atmosphere as meteors. Every year in mid-November we travel across the orbit of Comet Temple-Tuttle and wow to the Leonids.

Italian astronomer Gianluca Masi will webcast live coverage of the Geminid meteor shower this weeked. Click image for details. Credit: Gianluca Masi

Not so with our featured shower. It and the January Quadrantids are the only major showers with asteroid parents. 3200 Phaethon, a 3.2 mile-wide asteroid that comes surprisingly close to the Sun (13 million miles) and orbits it every 1.4 years, is mama and papa to the Geminids.

Long observed to be nothing more than an inert space rock, in the late 2000s astronomers watched in amazement as Phaethon developed a short, dusty tail.

It’s thought that the intense solar heat during closest approach fractures or pulverizes rocks or it may even open up a pocket of ice long covered by debris. Perhaps Phaethon is an extinct comet or a hybrid mix of ice and rock.

I hope you have clear skies at least one night this weekend. If you do or don’t, you can always check out Italian astronomer Gianluca Masi’s Geminids webcast starting at 8 p.m. CST December 13th (2 a.m. UT Dec. 14) on his Virtual Telescope Project site.

Curiosity Rover discovers Gale Crater was once a massive lake

Simulated view of Gale Crater Lake on Mars receiving runoff from snow melting on the crater’s northern rim. Evidence that NASA’s Curiosity rover has found of ancient streams, deltas and lakes suggests the crater held a lake such as this more than three billion years ago.  Credit: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS

Evidence gathered by NASA’s Curiosity Rover during its 2-year-plus study of soil and rocks in Gale Crater points to a startling conclusion: this 96-mile-wide crater once held a lake some 900 feet deep.

Gale Crater now with Mt. Sharp at center. Credit: NASA/JPL-Caltech

Mount Sharp, the crater’s broad central peak, stands about 3 miles (5 km) tall and was built by sediments deposited in the lake over tens of millions of years by wind, rivers and material settling to the lake bottom. Curiosity is currently investigating the lower 500 feet (150-meters) of sedimentary rock at the base of the mountain where hundreds of layers of rock are exposed like so many layers of a Vienna torte.

This picture shows a vertical cross section through geological layers deposited by rivers, deltas and lakes. Deposits from a series of successive deltas build out increasingly high in elevation as they fan out toward the center of the crater over the lake deposits. 10 centimeters equals about 4 inches. Credit: NASA/JPL-Caltech/Imperial College

All this activity occurred an estimated 3 billion years ago when the atmosphere of Mars had to be much denser than it is today. For water to exist out in the open on a planet, sufficient atmospheric pressure is needed to prevent it from vaporizing into thin air. Literally. Mars’ atmospheric pressure today is 1/1000 that of Earth, much too tenuous to keep water down.

“We are making headway in solving the mystery of Mount Sharp,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology in Pasadena. “Where there’s now a mountain, there may have once been a series of lakes.”

This view from the Mastcam on NASA’s Curiosity Mars rover shows an example of cross-bedding that results from water passing over a loose bed of sediment in one direction and then another. It was taken Nov. 2, 2014, at a target called “Whale Rock” within the “Pahrump Hills” outcrop at the base of Mount Sharp. Credit: NASA/JPL-Caltech/MSSS

Only problem is, scientists still can juggle the models to arrive at a satisfactory explanation for why the Martian climate was so radically different in the distant past. Hypotheses abound. Was it the decay of the planet’s magnetic field and stripping of its atmosphere by the solar wind or did intense asteroid bombardment send it flying into the vacuum of space?

Whatever happened, over time, the water evaporated, vaporized or seeped away, and sediments hardened into rock. Winds howling for hundreds of millions of years carved away at the material between the crater’s rim and what is now the edge of the expansive Mt. Sharp, exposing layer upon layer of the crater’s past.

This series of images reconstructs the geology of the region around Mars’ Mount Sharp, where NASA’s Curiosity Mars rover is now exploring. The images, taken on Earth, have been altered for the illustration of how sediments can accumulate in alternating dry periods and wet periods. A dry period is shown at left, wet at center and dry again at right. Over time, sediments accumulate and are piled higher on the crater floor through the action of water. Credit: NASA/JPL-Caltech

“We found sedimentary rocks suggestive of small, ancient deltas stacked on top of one another,” said Curiosity science team member Sanjeev Gupta of Imperial College in London. “Curiosity crossed a boundary from an environment dominated by rivers to an environment dominated by lakes.”

Scientists are left with a conundrum — how did Mars produce the conditions that would keep liquid water stable for millions of years, long enough for lakes and rivers to deposit hundreds of feet of sediments? For now, it’s just enough to know it happened, and that what appears to be a dusty, rocky depression once held more water than Lake Erie.


Did Jupiter deport 8 billion asteroids to the Oort Cloud?

1996 PW has a highly elongated orbit  just like a comet from the Oort Cloud – except it’s an asteroid. Astronomers now think they know how it got there. 1996 PW is about 5-10 miles (8-16 km) across. Credit: NASA/JPL-Horizons

Our view of the solar system will forever be incomplete. While frustrating at first blush, it means that fresh discoveries are always just around the corner. Case in point. On August 9, 1996 astronomers atop Mt. Haleakala in Maui, Hawaii discovered a most peculiar asteroid. 1996 PW has a highly elongated that looks like a Frisbee seen from the side and takes 5,900 years to make one trip around the Sun.

When farthest, 1996 PW is 48.8 billion miles away or 104 times more distant than Pluto. That places it among the billions of icy comets that comprise the Oort Cloud, a roughly spherical cocoon centered on the Sun and extending up to a light year from it in all directions.

Like moths around the solar flame, some 500 billion comets and perhaps 8 billion asteroids occupy a vast region of space called the Oort Cloud. The Kuiper Belt is a second asteroid belt that lies beyond the orbit of Neptune.

Odd thing was, 1996 PW was an asteroid – it never exhibited a fuzzy coma or tail typical of a comet and appeared spectroscopically to be made of rock. No dust or gas of any kind was detected even when the object was closest to the Sun. So what was it doing so far from home?

Some astronomers thought it may have been an active comet long ago but depleted its ices to where it’s now unrecognizable from an asteroid. Maybe.

A new study by Andrew Shannon (University of Cambridge), based on simulations of the rolling-stone-ways of the giant planets early in the solar system’s history, points to 1996 PW once being much closer to the Sun.

The planets haven’t always been in their present day orbits. In particular, Jupiter, the largest and most gravitationally potent planet, roamed inward to the orbit of Mars before backing out to its present orbit. Gravitational interactions with the dusty disk of material around the Sun called the solar nebula pulled the planet in. Later, interaction with Saturn yanked it back out. Scientists dub the back-and-forth shimmy the “Grand Tack”.

Interaction between the dusty-gassy solar nebula surrounding the Sun the young solar system and Saturn caused Jupiter to migrate first inward and then outward, scattering the hapless asteroids as it came and went. Credit: NASA

“We refer to Jupiter’s path as the Grand Tack, because the big theme in this work is Jupiter migrating toward the sun and then stopping, turning around, and migrating back outward,” writes Kevin Walsh of the Southwest Research Institute in Boulder, Colorado in a 2011 paper in Nature. “This change in direction is like the course that a sailboat takes when it tacks around a buoy.”

Jupiter’s gravitational might profoundly affected the asteroid belt at the time. Based on Shannon’s computer simulations, the giant planet’s do-si-do created chaos, with some asteroids kicked toward the Sun, others moved to a newly-created main belt and still others booted right out of the solar system.

Many were also flung to the icy realm of the Oort just short of leaving the Sun’s domain altogether. Shannon estimates that 4% or 8 billion rocky asteroids that once orbited within 2.5 times Earth’s distance from the Sun now mingle among the cloud’s half-trillion comets. Heck, that’s more asteroids than populate the main asteroid belt!

Very few “Oort asteroids” have been discovered and you can guess why. They’re small, generally dark and incredibly far away. A comet gives itself away with a bright coma and tail. Not these guys.They’re lurkers. To find them we’ll need dedicated, large telescope surveys like the upcoming Large Synoptic Survey Telescope with its 8-meter mirror slated for “first light” in 2019. But even that great eye will be challenged – Shannon predicts only a dozen discoveries a decade with the wide-field survey telescope.

One interesting sidelight about Oort Cloud asteroids. Like comets, they do drop in on the inner solar system from time to time. 1996 PW comes within just 232 million miles (373 million km) of the Sun. If one ever did have Earth in its sights, it would be hard to spot in advance and more difficult to divert because its much faster speed. One the bright side, Shannon and team estimate an impact would occur only once every billion years. I guess I can handle those odds and drag myself to work another day.

Orion rises! / Dawn’s best view of dwarf planet Ceres

In a burst of orange flames, the unmanned Orion space capsule launches atop the 235-foot-tall (72-meter) Delta 4 Heavy rocket yesterday near sunrise from Cape Canaveral. The Delta Heavy produces 1.5 million pounds of thrust and is most powerful rocket currently in use today. Credit: NASA

“Liftoff at dawn, the dawn of Orion and a new era of American space exploration,” said NASA announcer Michael Curie as the Orion spacecraft ascended from the launch pad at Cape Canaveral Air Force Station yesterday morning.

Every step, from the launch, stage separation to splashdown 270 miles west of Baja 4 1/2 hours later went flawlessly. Three hours and 6 minutes after launch, the capsule reached an altitude of 3,604 miles, higher than any spacecraft designed for human space travel has gone since December 1972 when the final Apollo mission launched for the moon.

NASA administrator Charles Boldan proclaimed: “This is Day 1 of the Mars era.”

Scene from video taken by a camera mounted on the Orion spacecraft showing the panels from the service module being jettisoned shortly before the spacecraft reached orbit. Credit: NASA

I like that NASA is thinking beyond Earth orbit when it comes to sending humans into space. Many of us feel it’s long overdue. Like a lot of kids in the in the ’60s, I wanted to become an astronaut. While that never happened, there’s no question Mercury, Gemini and Apollo inspired and sustained my love of the stars. I’m hoping this new beginning will fire the imaginations of our children and inspire an interest in science and space travel.

Orion’s maiden flight

Orion is the first step in the manned exploration of deep space. It will be the foundation for trips to the moon, asteroids and Mars. But we must be patient. The next test is planned for 2018, when the Space Launch System with four times the thrust of the Delta IV Heavy, will send the Orion capsule on a round trip to the moon. Mars? Still about 20 years away unless some other country (or private enterprise) gets there first.

From about three times the distance from Earth to the moon, NASA’s Dawn spacecraft homes in on the dwarf planet Ceres. This zoomed-in image just 9 pixels across was taken on Dec. 1, 2014 by Dawn. Ceres is 590 miles (950 kilometers) or about as big as Texas. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Meanwhile, back in the realm of robotic space probes, NASA’s Dawn spacecraft draws ever closer to its second target, the dwarf planet Ceres. The agency released a new photo taken from 740,000 miles (1.2 million kilometers) away showing the clearest view of the largest object in the main asteroid belt.

Ceres as seen by the Hubble Space Telescope. Dawn, launched in 2007, orbited the rocky asteroid Vesta from mid-2011 to late 2012. It’s now closing in on Ceres and will arrive next spring. Credit: NASA/ESA

Dawn will be captured into Ceres’ orbit in late March 2015, marking the first visit to a dwarf planet by a spacecraft. Beginning early next year, Dawn will begin sending photos at a resolution much better than the Hubble Space Telescope. The picture here was taken as a final calibration for Dawn’s science camera.

Ceres is about 590 miles across or about half the size of the moon. This pale pink world is believed to contain large amounts of water beneath its surface. In a surprise discovery, the European Space Agency’s Herschel Space Telescope detected plumes of water vapor jetting into space from Ceres earlier this year.

Four months after Dawn arrives at Ceres, NASA’s New Horizons spacecraft will swing by the most famous dwarf planet of all – Pluto. 2015 promises to be a big year for small planets!


What? Two Full Moons this weekend?

A bright waxing gibbous moon dons a colorful corona as passing altocumulus clouds diffract its light earlier this week. Click photo to find the time of moonrise where you live. Credit: Bob King

Lovers of moonlight, this is your weekend. The moon’s essentially full two nights in a row. Full phase doesn’t occur until 6:27 a.m. (CST) tomorrow morning or midway between the two nights. That means tonight’s moon appears in the east about 12 hours before full, while an equally filled-out moon will shine just 12 hours after full Saturday night.

Only a sharp-eyed observer would notice a half-day’s difference in the moon’s phase, so for most of us, the moon will look full both nights. What’s more, it happens to be in one of the coolest places in the sky, smack in the middle of the Hyades star cluster not far from Taurus’ brightest star Aldebaran.

Tonight’s moon will appear in the middle of the V-shaped Hyades star cluster. At a distance of 153 light years, it’s the closest star cluster to the solar system. Stellarium

The moon’s brilliance will make the star cluster difficult to see with the naked eye, but binoculars will offer up a fabulous view of our satellite ensconced in Hyades like an ornament amid twinkling holiday lights.

You can also watch the moon glide eastward and approach Aldebaran during the hours before midnight. At 11 p.m. (CST), they’ll be just 1.4° apart.

Aldebaran is more than twice as close to Earth as the Hyades; it hovers in the foreground and is unrelated to the cluster. Looking up tonight, our gaze will plumb all three dimensions of the sky in a single glance – from the relatively closeness of the moon to the middle distance of Aldebaran and further to the more distant Hyades.

Click play and see the aurora sizzle and blaze in real time

Singe frame from the new video “Soaring”, one of the best real-time aurora videos. It was taken with a Sony A7S camera. This image shows a vivid coronal aurora near the zenith. Credit: Ole Solomonsen

We’ve often shared pictures and videos of the northern lights here, but wait till you see the latest video from Norwegian landscape photographer Ole Salmonsen. Salomonsen has been shooting still images and time-lapse video of the aurora for years. This week he posted a brand new movie of the aurora shot from late August through mid-November in real-time. You heard correctly – no sped-up, compressed time.This is the aurora moment-to-moment just the way you’d see it live.

“Soaring” by Ole Salomonsen

There are lots of nice touches in the video including scenes of Tromsø, Norway (where Ole is based), a woman staring into the sky and several truly amazing panned sequences that look to me like they were shot with a drone. What’s your opinion?

Although Ole’s work isn’t the first real-time aurora movie, this might be the best effort to date. The slowness of the initial sequences makes a striking contrast with later views of the coronal aurora unfolding at lightning speed and helps us to appreciate the complex rhythms that pulse through active displays.

I love it and hope you will too. For more on how the film was done, check out Ole’s site. Salomonsen tells me this work is just a small sample of what’s to come. Stay tuned!

Japan launches imaginative mission to a carbon-rich asteroid

Japan’s Hayabusa 2 asteroid mission rockets into space Tuesday. Credit: JAXA

On Tuesday at 10:22 p.m. (CST) the Hayabusa 2 mission launched from Tanegashima Space Center in southern Japan. Destination: 1999 JU3, a C-type carbon-rich asteroid nearly 3,000 feet (900 meters) across.

C-type space rocks are the most common and may have delivered some of the essential chemical building blocks important to the origin of life on Earth during the formation of the planets 4.5 billion years ago. Scientists hope to detect water and organic molecules on this never-before-explored world-let.

Anybody want a peanut? This close up photo of 25143 Itokawa was taken by Hayabusa 1 in 2005. The Mars-crossing asteroid spans just 1,755 feet (535-meters). Credit: JAXA

This is Japan’s second mission to an asteroid. The first – Hayabusa 1 – made a round trip journey to 25143 Itokawa, a rocky asteroid just a third of a mile across some 123 million miles from the Sun, from 2003 to 2010. Even though that mission encountered numerous technical problems including a pointing system failure, a fuel leak and a malfunction of the device used to collect rock samples, engineers babied it back to Earth.

At the time, no one was knew for certain whether any samples had been gathered at all, but upon re-entry, scientists discovered a tiny fraction of material inside the craft landing vehicle. Success!

Artist depiction of Hayabusa 2 in orbit around the dark, carbon-rich asteroid 1999 JU3. Credit: JAXA

“We changed a lot of parts on Hayabusa 2,” said Hitoshi Kuninaka, JAXA’s Hayabusa 2 program manager. “We installed four reaction wheels, and Hayabusa 1 had only three. The sampling system also has some improvements. Our operations software was upgraded for better proximity operations around the asteroid.”

Like the first probe, Hayabusa 2 will propel itself with an ion engine, where ionized (electrified) xenon gas is accelerated through a strong electric field and expelled at high speed to produce a steady thrust. This time around, the engines were upgraded to produce more thrust. A new antenna system will beam back data at four times the previous rate.

One of the four MINERVA II robotic landers that will hop around the asteroid taking pictures and measurements. Credit: JAXA

The spacecraft will arrive at 1999 JU3, which orbits between Earth and Mars, in June 2018. Before dispatching four landing robots, the main spacecraft will study and map the surface from a distance of about 12 miles (20 km).The landers are mobile and able to hop across the asteroid to study its environment from several locations.

Warning – don’t hop too hard! 1999 JU3 is even smaller than Rosetta’s Comet with a gravitational pull 60,000 times weaker than Earth. It wouldn’t be difficult to bounce off the asteroid and not return to the surface for a long time much as what happened to the Philae lander.

Hayabusa 2 will remain at the asteroid for a year and a half, long enough to move in close and use its collection tube to gather rocks from three different locations. In an audacious move, the spacecraft will fire a 2-kilogram (4.4-pound) copper disk into the asteroid to blast out an artificial crater about 10 feet (several meters) across and 3 feet deep. Why? To sample more pristine rocks not exposed to direct solar radiation.

Hayabusa 2 samples the crater floor after the blast, gathering fresh rocks shielded from the damaging effects of cosmic and solar radiation. Credit: Akihiro Ikeshita / JAXA

After the explosion, the spacecraft will swing by and use its sampler arm to fire tiny “bullets” made of the element tantalum into the crater and funnel debris that ricochets up from the surface into its collection tube. Mission planners hope to harvest at least 1/10 of a gram of asteroid dust.

As the spacecraft returns to Earth’s vicinity, it will eject a container with the dust that will drop through the atmosphere and land by parachute in the Australian outback in December 2020.

This is a big week for rocket launches. NASA’s new Orion space capsule is scheduled to launch into orbit on an unmanned test flight at 6:05 a.m. (CST) tomorrow. If all goes well, this could be our first step toward a manned mission to Mars. You can watch the launch live on NASA TV.

This amazing short film will put you in outer space

Wanderers, a short film by Erik Wernquist

Sometimes just reveling in space imagery is enough. To go along for the ride and imagine visiting  the fantastic places our spaceships have traveled. Places we hope our descendants will see up close with their own eyes.

This shot shows a person floating just above the plane of Saturn’s rings. The rings themselves are seen here only as a mess of tumbling blocks of ice, as the camera is in the middle of them, but their full shape is hinted in the shadow they cast on the northern hemisphere of Saturn, far in the distance. From the movie “Wanderers” / Erik Wernquist

This beautiful film by Erik Wernquist with words by the late Carl Sagan touch our imaginations. What is it about Sagan’s voice? Honestly, he could read the ingredients off a ketchup bottle and make us think deep thoughts.

Wernquist describes his work this way: “The locations depicted in the film are digital recreations of actual places in the solar system, built from real photos and map data where available. Without any apparent story, other than what you may fill in by yourself, the idea with the film is primarily to show a glimpse of the fantastic and beautiful nature that surrounds us on our neighboring worlds – and above all, how it might appear to us if we were there.”

This scene shows a group of people hiking across the icy plains of Jupiter’s moon Europa. Jupiter itself as well as Io are seen beyond the horizon. The hike takes place on the night side of Europa, so the landscape is lit entirely by reflected sunlight off Jupiter (and to a small extent off Io). From “Wanderers” / Erik Wernquist

It’s the human presence woven into striking images sent back by unmanned spacecraft that makes Wernquist’s work such a pleasure to watch. For the first time, I really got a sense of how it might feel to float among the icebergs that compose Saturn’s rings. The ride on the space elevator, a technology in its infancy, was fun, too. And who wouldn’t don a pair of bat wings and swoop through Titan’s orange air?

License was taken in a few scenes, but the future has always been a place where we imagine the impossible.

For more details and images featuring individual scenes in the movie, check out Erik’s gallery.

Trio of close asteroid encounters begins tonight with 2014 WC201

Tonight the recently discovered asteroid 2014 WC201 will zoom just 1.4 lunar distances from Earth. Click photo to watch a live webcast starting 5 p.m. CST. Courtesy: Gianluca Masi

The steady pace of discovery of Earth-approaching asteroids in recent years means we’re treated to several close shaves nearly every month. Tonight, an 88 1/2-foot-wide (27 meters) space rock named 2014 WC201 will pass within 336,000 miles or 1.4 lunar distances of Earth around 10:52 p.m. (CST). That’s a comfortable distance, but it does remind us that the solar system continues to offer rocky surprises. Small asteroids that cross Earth’s orbit number in the millions and guarantee we’ll need to keep watch for a long, long time.

2014 WC201 is only about 20 feet larger than the Chelyabinsk meteoroid that fireballed to Earth over Russia in February 2013. The good news is that even asteroids this size are often broken into smaller pieces by the beating they receive from the atmosphere while plunging toward the ground at thousands of miles an hour. That’s exactly what happened with Chelyabinsk and why most of the pieces you see for sale on eBay are small and broken.

Italian astrophysicist and curator of science at the Planetarium of Rome, Gianluca Masi will once again fire up his telescope and webcast 2014 WC201′s flyby live starting at 5 p.m. CST (23:00 Greenwich Time). You’ll be able to see real-time images and listen in on commentary from staff scientists.

In the spirit of holiday discounts, the coming week offers a special 3-for-1 asteroid deal. On December 7 around 2 p.m. (CST), another recent discovery, 2014 WX202, will dare to fly even closer to our blue planet. That afternoon it skims by at a distance of 232,500 miles (374,175 km) or a tad closer than the Moon. Measuring about 20 feet across or the size of a large boulder, this one’s just a baby.

Then on Wednesday December 10th, 23-foot 2014 WU200 zips some 279,000 miles or 1.2 lunar distances away from Earth around 10 a.m. (CST). Because these last two asteroids are extremely faint and will be plagued by a bright Moon, Masi has no plans at present to webcast their arrival.

The 60-inch (1.5-m) Cassegrain reflecting telescope used for the Mt. Lemmon near-Earth-object survey. Credit: Mt. Lemmon / CSS

None will be bright enough to track visually even using a large amateur telescope, but capable astrophotographers might succeed in getting photos. All three will appear identical to faint stars and moving like bats out of hell. 2014 WC201 tracks southeast through Canes Venatici the Hunting Dogs at closest approach; WX202 will slice southwest across Aquarius and WU200 passes near the head of Draco the Dragon.

Keep in mind, none are impact risks. All were discovered between November 22-24 by the Mt. Lemmon Survey at Steward Observatory in the Catalina Mountains north of Tucson. The survey is part of the overall Catalina Sky Survey with a Congressionally-mandated goal of tracking down better than 90% of the 140-meter (459-feet) or larger Near Earth Objects or NEOs. Thankfully, it snags plenty of smaller ones in the process.

Happy nights adrift on the Moon’s Sea of Showers

Over 700 miles across, Mare Imbrium (Sea of Rains) is the largest lunar sea. Its roughly circular shape is defined by a series of mountains ranges just coming into good view tonight and the next few nights. Credit: Joseph Brimacombe

If you’re looking for a great little place to point a small telescope the next few nights, let me suggest Mare Imbrium, the largest of the lunar “seas”. That’s Latin for Sea of Showers or Sea or Rains. Lovely name. The last time it rained there was never.

Wide view of the whole Moon with the Imbrium basin circled. While Imbrium is the largest lava-filled “sea”, the largest basin, the South Pole-Aitkin Basin, is 1,600 miles in diameter. Credit: Silvercat/Wikipedia

All the Moon’s seas are enormous basins excavated by asteroid impacts between 3.1 and 4.2 billion years ago. Cracks and fissures in the Moon’s crust from the collisions served as conduits for deeper lava to rise and fill the basins with molten rock. These great pools cooled and solidified, forming the large grey spots that make up the face of the Man in the Moon that even a child notices today.

Ruptures in the Moon’s crust caused by the impact of large meteorites/asteroids creates what astronomers call multi-ringed basins. They look like bulleyes, a fitting comparison under the circumstances. Credit: Steven Dutch

Many of the seas are ringed by mountain ranges formed by faulting of the lunar crust during the impacts aided by slumping of material off the fresh slopes.

Earth’s mountains in contrast are lifted up when tectonic plates collide or pile up during volcanic eruptions.

Three ranges shape the outer boundary of the Sea of Rains – the Carpathians, the majestic Apennines and Caucasus. The Alps form part of a second inner ring of peaks. Each is named for its sibling range in Europe. Over the next few nights we’ll see all four cast awesome shadows as the Sun rises over their craggy peaks.

This is how our featured region of the Moon will appear tonight from the Americas. Mountain ranges are labeled in black, craters in white. Credit: Virtual Moon Atlas / Patrick Chevalley and Christian Legrande

Tonight features the Alps, Apennines and Caucasus and the spectacular craters Plato and Copernicus. Tomorrow night, the Carpathians, north of Copernicus, come into view. The reason these features look most dramatic now rather than closer to full Moon is because the terminator cuts across the region. Along the terminator, the boundary separating lunar day from night, the Sun is just rising and every little peak casts a shadow.

The Apennines Mountains is host to the Moon’s tallest mountain, Mt. Huygens, with an elevation of 18,046 feet (5.5 km). Credit: M. Galfalk, G. Olofsson, and H.-G. Floren; SIRCA camera Nordic Optical Telescope with annotation by the author

While binoculars will reveal Plato, Copernicus and the mountain rings, a small telescope will show the scene best. I wish you a clear and not-too-cold night!