45P/H-M-P displays a colorful coma and long ion tail on Dec. 22, 2016. Credit: Gerald Rhemann
Comet 45P/Honda-Mrkos-Pajdusakova captured in its glory on Dec. 22, 2016. It displays a bright, well-condensed blue-green coma and long ion or gas tail pointing east. Comet observers take note: a Swan Band filter shows a larger coma and increases the comet’s contrast. Credit: Gerald Rhemann
Merry Christmas and Happy Holidays all! I hope the day finds you in the company of family or friends and feeling at peace. While we’ve been shopping for gifts the past few weeks, a returning comet has been brightening up in the evening sky. Named 45P/Honda-Mrkos-Pajdusakova, it returns to the hood every 5.25 years after vacationing beyond the planet Jupiter. It’s tempting to blow by the name and see only a jumble of letters, but let’s try to pronounce it: HON-da — MUR-Koz — PIE-doo-sha-ko-vah. Not too hard, right?
Tonight, the comet will appear about 12. 5 degrees to the west of Venus in central Capricornus. You can spot it near the end of evening twilight. Use larger binoculars or a telescope. Stellarium
Comet 45P is a short period comet — one with an orbital period of fewer than 200 years — discovered on December 3, 1948 by Minoru Honda along with co-discoverers Antonin Mrkos and Ludmila Pajdusakova. Three names are the maximum a comet can have even if 15 people simultaneously discover it. 45P has a history of brightening rapidly as it approaches the sun, and this go-round is proof. A faint nothing a few weeks back, the comet’s now magnitude +7.5 and visible in 50mm or larger binoculars from low light pollution locations.
You can catch it right around the end of dusk this week and next as it arcs across central Capricornus not far behind the brilliant planet Venus. 45P will look like a dim, fuzzy star in binoculars, but if you can get a telescope on it, you’ll see a fluffy, round coma, a bright, star-like center and perhaps even a faint spike of a tail sticking out to the east. Time exposure photos reveal a tail at least 3° long and a gorgeous, aqua-tinted coma. I saw the color straight off when observing the comet several nights ago in my 15-inch reflector at low power (64x).
Use this map to help you follow the comet night to night. Tick marks start this evening (Dec. 25) and show its nightly position through Jan. 8 around 6 p.m. local time or about an hour and 15 minutes after sunset. Venus, at upper left, is shown through the 28th with stars to magnitude +7. Click the chart for a larger version you can save and print out for use at your telescope. Created with Chris Marriott’s SkyMap software
Right now, and for the remainder of its evening apparition, 45P will never appear very high in the southwestern sky. Look for it a little before the end of evening twilight, when the sky is reasonably dark and the comet is as high as it gets — about a fist above the horizon as seen from mid-northern latitudes. That’s pretty low, so make the best of your time. I recommend you being around 1 hour 15 minutes after sunset.
The further south you live, the higher 45P will appear. To a point. It hovers low at nightfall this month and next. That will change in February when the comet pulls away from the sun and makes a very close approach to the Earth while sailing across the morning sky.
How about a helping hand? On New Year’s Eve, the 2-day-old crescent Moon will be just a few degrees from 45P. This simulation shows the view through 50mm or larger binoculars with an ~6 degree field of view for the Central time zone. Map: Bob King, Source: Stellarium
45P reaches perihelion or closest distance to the sun on Dec. 31 and will remain visible through about Jan. 15 at dusk. An approximately 2-week hiatus follows, when it’s lost in the twilight glow. Then in early February, the comet reappears at dawn and races across Aquila and Hercules, zipping closest to Earth on Feb. 11 at a distance of only 7.7 million miles. During that time, we may even be able to see this little fuzzball with the naked eye; its predicted magnitude of +6 at maximum is right at the naked eye limit. Even in suburban skies, it will make an easy catch in binoculars then.
I’ll update with new charts as we approach that time, plus you can check out this earlier post by fellow Universe Today writer David Dickinson. For now, enjoy the prospect of ‘opening up’ this cometary gift as the last glow of dusk subsides into night.
When it comes to helping others find something in the night sky, a green laser makes it a piece of cake. Credit: Bob King
Devious humans have given green lasers a bad name. Aiming a laser at an aircraft or the flight path of an aircraft is illegal according to a 2012 U.S. federal law. Jail time awaits offenders. Don’t point at a police officer either. To get a taste of the dark side of green lasers, check out these rap sheets.
A standard 5 milliwatt (mW) laser can cause temporary flashblindness or at the very least distract a pilot up to around 11,000 feet (3,350 meters). Beyond that, it’s indistinguishable from other ground lighting. Credit: Wikipedia
But if you mind your manners, a green laser is one of the best tools available to amateur astronomers eager to share the wonders of the night sky with the public. There’s simply nothing better to point out constellations, comets, individual stars and satellites in the night sky. Amateurs love ’em! So does the public. Go to a star party and pop out the laser, and you’ll get everyone’s attention. There’s magic in being able to point out our favorite points of light with a beam of light.
Not only are lasers helpful when pointing out stars, many amateurs use them to point zero in on deep sky objects with their telescopes. Credit: Bob King
First, let’s look at laser etiquette to ensure the safety of our fellow stargazers:
*Always gather the group around you first, raise the laser above the crowd and ask everyone to look up. Then turn on the beam and aim. That way no one will accidentally face into the light. This is crucial when aiming low above the horizon, where the beam, nearly horizontal, has a better chance of striking someone in the eye. Take extra precaution to make sure the group is close. The closer the gathering, the brighter and easier the beam will be to see. Viewers too far off to one side or another will see a weaker, less intense light.
*Green lasers often use AAA batteries and draw a good amount of power especially on chilly nights. You’ll only get a few minutes of operation if you leave it out in the cold. Store your laser in an inside pocket to keep it warm until you need it. Tuck it back in between pointing sessions. Have a fresh pair of batteries around and keep those in your pocket, too!
*If you see an airplane headed in your direction, avoid using the laser light for a couple minutes just to be on the safe side.
*Never give your laser to someone in the dark to “try out.” Especially a child! They won’t be familiar with its safe use.
* Store your laser in a safe place when not in use, so kids can’t accidentally find it.
Red, green and violet lasers with a high enough output to trace a line in the night sky are all available these days for reasonable prices. These three beams come from 50 mW lasers. Multiple rays result from the subject not being able to hold the lasers steady during the time exposure! Credit: Bob King
The most common green laser available is rated at 5 milliwatts (mW), just adequate for night sky pointing. That said, be aware that brightness from one manufacturer to another can vary. Some 5mW pointers produce nearly as much light as a 30 mW model, practically a light saber! Others, like my first green laser, did the job on moonless nights, but proved too weak by first quarter phase. 30mW and 50mW are much better and significantly amp up the wow factor when you’re out with the crowd. They’re also much easier to see for larger groups and remain visible even in bright moonlight.
Back in olden days, 5 mW red and green lasers were as bright as they came, and the green ones were pricey. But nowadays, you can get powerful pointers in green, red, blue and violet. All will trace a visible beam across the night sky with green the brightest by far because our eyes are most sensitive to green light.
Green, violet and red lasers. Lasers emit very specific colors of light. Green appears brightest and sharpest; red and blue beams look fuzzier to our eyes. Credit: Netweb01 / CC BY-SA 3 / Wikimedia
I should add that yellow lasers have also recently become available. Like green, they’re superb for long-distance applications, but prices — oh, my — will burn a hole in your wallet. How about 300 bucks! You can get a 5 mW green laser for $5-10 that’s similarly bright. No matter what kind of laser pen you buy, they all operate on the same principle: a laser diode, related to an LED (light-emitting diode), powered by AA batteries emits a narrow, coherent beam of light when switched on.
Coherent light is light of a single wavelength where all the crests and troughs (remember, light is a wave) are in lockstep with one another. Each crest precisely overlaps the next; each trough snugly fits within the other. Regular light contains a garden salad mix of every wavelength each vibrating out of stop, to its own drummer as it were. Because laser light is coherent, it stays focused over great distances, forming a narrow beam ideal for pointing.
Laser light literally illuminates the air and anything in it. The intense beam scatters off air molecules, water vapor and dust in the air. In this photo, I spun the beam around the planet Jupiter on a humid, slightly foggy night. Dust and water vapor illuminated by the beam creates a mesmerizing sparkle effect you have to see to believe. Credit: Bob King
Lasers are not only rated by power (milliwatts) but also the specific wavelength they emit. Green lasers beam light at 532 nanometers (nm), blue at 445 nm, violet at 405 nm, red at 650 nm and yellow at 589 nm. Green laser pointers generate their light from an infrared laser beam within the pen’s housing. Normally, any infrared light should be filtered from the final beam but in the majority of inexpensive laser pointers, it beams out right along with the green. We can’t see it, but concentrated infrared laser light poses an additional hazard when directed into the eyes. When you hear of lasers being used to pop balloons or light a match, it’s the leaky infrared that’s doing the popping. Yet another reason to use your laser with care!
Lasers can be artistic tools, too. Every year, a friend holds a star party near a towering grain silo. Late at night, we take a break, open the camera shutter and paint the silo with laser light. In this case — a rocket. Credit: Bob King
Lower-powered laser pointers use AAA batteries. For instance, both my 5 mW and 55 mW green lasers use AAA batteries. Higher-powered pointers in the 5-watt range use a single #18650 (or 16340) 3.7 volt lithium ion rechargeable battery. You can either purchase these online (Orbitronics makes an excellent one for $12.99) or at your local Batteries Plus store. You’ll need a charger, too, which runs anywhere from about $8 for a single battery model to around $30 for a multiple battery version with different charging speeds. Be sure you get one with an LED light that will alert you when the batteries are done charging.
Whether sold in the U.S. or elsewhere, nearly every laser comes from China. We’ll talk about that in a minute, but if you purchase a laser that uses rechargeable batteries, beware of no-name chargers and off-brand batteries that lack safeguards. Some of these inexpensive batteries have been known to explode!
What to buy? I can’t speak to every firm that offers laser pointers, and there are many, but some of the more popular ones include:
I’ve bought from Optotronics, based in Colorado and the LED Shoppe, out of Hong Kong. I took a chance on the LED Shoppe’s lasers and have been pleasantly surprised at the low cost, free shipping and good customer service. While power ratings can vary from what the label reads, I’ve been especially pleased with both the 55 mW from Optotronics and the 5-watt (yes, FIVE WATTS) green and red pointers from the LED Shoppe. Their 50 mW green version does a great job, too. Just a disclaimer — I don’t work for and am not associated with either company.
Bottom line: If you’re looking for a effective pointer for public star parties, I recommend a 50 mW or higher green pointer. Anything in that range will provide a lovely bright beam you can use to literally dazzle your audience when sharing the beauty of the night. Before you make your decision, check your country or state’s laser use laws where for the U.S.orworldwide. If buying in the U.S., speak to the business owner if you have any questions.
Have a Merry Green, Red, Blue and Violet Christmas!
The Moon about to occult Aldebaran on December 23rd, 2015. Image credit and copyright: Paul Campbell.
It’s a busy week for the Moon. While our large solitary natural satellite reaches Full and interferes with the 2016 Geminids, it’s also beginning a series of complex bright star occultations of Aldebaran and Regulus, giving us a taste of things to come in 2017.
First up, here’s the lowdown on this week’s occultation of Aldebaran by the Moon, coming right up tonight:
The footprint for tonight’s occultation of Aldebaran by the Moon. You can find specific ingress and egress times for major cities near you on the IOTA event page. Credit: Occult 4.2.
The 99% illuminated waxing gibbous Moon occults the +0.9 magnitude star Aldebaran on Monday, December 12th. The Moon is just 19 hours and 30 minutes before reaching Full during the event. Both are located 167 degrees east of the Sun at the time of the event. The central time of conjunction is 4:37 Universal Time (UT). The event occurs during the daylight hours over Hawaii at dusk during Moonrise, and under darkness for Mexico, most of Canada and the contiguous United States. The event also includes the United Kingdom and southwestern Europe at Moonset near early dawn. This is the final occultation of Aldebaran by the Moon for 2016; The Moon will next occult Aldebaran on January 9th, 2017. This is occultation 26 in the current series of 49, running from January 29th, 2015 to September 3rd, 2018.
The view from Gibraltar just prior to this week’s occultation of Aldebaran by the Moon. Credit: Stellarium.
Four 1st magnitude stars are along the Moon’s path in the current epoch: Regulus, Aldebaran, Antares and Spica. In the current century, (2001-2100 AD) the Moon occults Aldebaran 247 times, topped only by Antares (386 times) and barely beating out Spica (220 times). The Moon also occults Regulus 220 times this century, and occultations of Spica and Antares resume on May 2024 and July 2023, respectively.
And yes, this Supermoon 3 of 3 for 2016, though actual perigee occurs at 23:28 UT tonight, 39 minutes past our own ’24 hour from Full’ rule. The Moon reaches Full on Wednesday, December 14th at just past midnight at 00:07 UT. This is also the closest Full Moon to the December 21st winter solstice next week, and the Full Moon will ride high in the sky this week for northern hemisphere observers on long winter nights.
Keep an eye out for Geminid meteors tonight as well… sure, 2016 may be an off year for this usually spectacular shower, but a few brighter fireballs may still punch through the lunar light pollution.
Clouded out? Be sure to catch the Supermoon action tomorrow night live online starting at 16:00 UT, courtesy of Gianluca Masi and the Virtual Telescope Project.
And there’s more. This coming weekend marks the start of an upcoming new cycle of occultations of Regulus by the Moon. These run right through 2018, as the Moon visits the bright star Regulus five days after crossing the Hyades and occulting Aldebaran for every lunation pass in 2017.
Here’s the specifics for Sunday’s event:
The footprint for Sunday’s occultation of Regulus by the Moon. You can find specific ingress and egress times for major cities near you on the IOTA event page. Credit: Occult 4.2.
The 73% illuminated waning gibbous Moon occults the +1.4 magnitude star Regulus on Sunday, December 18th. The Moon is just four days past Full during the event. Both are located 117 degrees west of the Sun at the time of the event. The central time of conjunction is 18:38 Universal Time (UT). The event occurs during the daylight hours over Tasmania, and under darkness for the southwestern tip of Australia, including Perth. The Moon will next occult Regulus on January 15th, 2017. This is the first occultation in a new series of nineteen, running from this weekend to April 24th, 2018.
The view of Sunday’s event from Perth, Australia. Credit: Stellarium.
It’s worth noting that the graze line for Sunday’s occultation of Regulus by the Moon runs just north of the Australian city of Perth and the Perth Observatory… let us know if anyone ‘Down Under’ witnesses the first occultation of Regulus in the new cycle.
Can you spy Regulus’ white dwarf companion? Located 77 light years distant, the Regulus system has at least four components: a B/C pair shining at a combined magnitude of +8, with an apparent separation of 3”, (5,000 AU physical distance in a ~600 year orbit) and an unseen white dwarf companion in a tight 40 day orbit. We know that said white dwarf companion exists from spectroscopic analysis… and it would shine at an easy magnitude +13, were it not near dazzling Regulus shining over 10,000 times brighter. Could this elusive companion turn up just moments before the reappearance of Regulus from behind the Moon? Remember, the dark limb of the Moon leads the way during waxing phases, then trails as the Moon wanes. These and other amazing facts are included in our forthcoming free guide to 101 Astronomical Events to watch out for in 2017.
Every occultation of Regulus for the upcoming cycle. Credit: Occult 4.2.
Follow that Moon, and don’t miss these fine astro-events coming to sky above you this week!
A partial solar eclipse rising over the VAB. Image by author.
It’s that time of year again… time to look ahead at the top 101 astronomical events for the coming year.
And this year ’round, we finally took the plunge. After years of considering it, we took the next logical step in 2017 and expanded our yearly 101 Astronomical Events for the coming year into a full-fledged guide book, soon to be offered here for free download on Universe Today in the coming weeks. Hard to believe, we’ve been doing this look ahead in one form or another now since 2009.
This “blog post that takes six months to write” will be expanded into a full-fledged book. But the core idea is the same: the year in astronomy, distilled down into the very 101 best events worldwide. You will find the best occultations, bright comets, eclipses and much more. Each event will be interspersed with not only the ‘whens’ and ‘wheres,’ but fun facts, astronomical history, and heck, even a dash of astronomical poetry here and there.
It was our goal to take this beyond the realm of a simple almanac or Top 10 listicle, to something unique and special. Think of it as a cross between two classics we loved as a kid, Burnham’s Celestial Handbook and Guy Ottewell’s Astronomical Calendar, done up in as guide to the coming year in chronological format. Both references still reside on our desk, even in this age of digitization.
And we’ve incorporated reader feedback from over the years to make this forthcoming guide something special. Events will be laid out in chronological order, along with a quick-list for reference at the end. Each event is listed as a one- or two-page standalone entry, ready to be individually printed off as needed. We will also include 10 feature stories and true tales of astronomy. Some of these were culled from the Universe Today archives, while others are new astronomical tales written just for the guide.
Don’t miss 2017’s only total solar eclipse, crossing the United States! Image credit: Michael Zeiler/The Great American Eclipse.
The Best of the Best
Here’s a preview of some of the highlights for 2017:
-Solar cycle #24 begins to ebb in 2017. Are we heading towards yet another profound solar minimum?
-Brilliant Venus reaches greatest elongation in January and rules the dusk sky.
-45P/Honda-Mrkos-Pajdusakova passes 0.08 AU from Earth on February 11th, its closest passage for the remainder of the century.
-An annular solar eclipse spanning Africa and South America occurs on February 26th.
A sample occultation map from the book. Image credit: Occult 4.1.2.
-A fine occultation of Aldebaran by the Moon on March 5th for North America… plus more occultations of the star worldwide during each lunation.
-A complex grouping of Mercury, Venus, Mars and the Moon in mid-September.
-Saturn’s rings at their widest for the decade.
Getting wider… the changing face of Saturn’s rings. Image credit and copyright: Andrew Symes (@FailedProtostar).
-A fine occultation of Regulus for North America on October 15th, with occultations of the star by the Moon during every lunation for 2017.
-Asteroid 335 Roberta occults a +3rd magnitude star for northern Australia…
And that’s just for starters. Entries also cover greatest elongations for the inner planets and oppositions for the outer worlds, the very best asteroid occultations of bright stars, along with a brief look ahead at 2018.
Get ready for another great year of skywatching!
And as another teaser, here’s a link to a Google Calendar download of said events, complied by Chris Becke (@BeckePhysics). Thanks Chris!
The 2015 Geminids over the LAMOST observatory in China. Image credit and copyright: SteedJoy.
One of the best yearly meteor showers contends with the nearly Full Moon this year, but don’t despair; you may yet catch the Geminids.
The Geminid meteor shower peaks next week on the evening of Tuesday night into Wednesday morning, December 13th/14th. The Geminids are always worth keeping an eye on in early through mid-December. As an added bonus, the radiant also clears the northeastern horizon in the late evening as seen from mid-northern latitudes. The Geminids are therefore also exceptional among meteor showers for displaying early evening activity.
The Geminid radiant, looking east around 11 PM local on the evening of December 13th. Note the nearby Moon in the same constellation. Image credit: Stellarium.
First, though, here is the low down of the specifics for the 2016 Geminids: the Geminid meteors are expected to peak on December 13th/14th at midnight Universal Time (UT), favoring Western Europe. The shower is active for a two week period from December 4th to December 17th and can vary with a Zenithal Hourly Rate (ZHR) of 50 to 80 meteors per hour, to short outbursts briefly topping 200 per hour. In 2016, the Geminids are expected to produce a maximum ideal ZHR of 120 meteors per hour. The radiant of the Geminids is located at right ascension 7 hours 48 minutes, declination 32 degrees north at the time of the peak, in the constellation of Gemini.
The Moon is a 98% illuminated waning gibbous just 20 degrees from the radiant at the peak of the Geminids, making 2016 an unfavorable year for this shower. In previous years, the Geminids produced short outbursts topping 200 per hour, as last occurred in 2014.
The Geminid meteors strike the Earth at a relatively slow velocity of 35 kilometers per second, and produce many fireballs with an r vaule of 2.6. The source of the Geminid meteors is actually an asteroid: 3200 Phaethon.
The orientation of the radiant versus the Sun, Moon and Earth’s shadow just past midnight Universal Time on the evening of December 13th/14th. (Created using Orbitron).
A moderate shower in the late 20th century, the Geminids have increased in intensity during the opening decade and a half of the 21st century, surpassing the Perseids for the title of the top annual meteor shower.
The orbit of 3200 Phaethon. Image credit: NASA JPL.
The Geminid shower seems to have breached the background sporadic rate around the mid-19th century. Astronomers A.C. Twining and R.P. Greg observing from either side of the pond in the United States and the United Kingdom both first independently noted the shower in 1862.
Orbiting the Sun once every 524 days, 3200 Phaethon wasn’t identified as the source of the Geminids until 1983. The asteroid is still a bit of a mystery; reaching perihelion just 0.14 astronomical units (AU) from the Sun, (interior to Mercury’s orbit) 3200 Phaethon is routinely baked by the Sun. Is it an inactive comet nucleus? Or a ‘rock comet’ in a transitional state?
Observing meteors is as simple as setting out in a lawn chair, laying back and watching with nothing more technical than a good ole’ Mk-1 pair of human eyeballs. Our advice for 2016 is to start watching early, like say this weekend, before the Moon reaches Full on Wednesday, December 14th. This will enable you to watch for the Geminids after morning moonset under dark skies pre-peak, and before moonrise on evenings post-peak.
Two other minor showers are also active next week: the Coma Bernicids peaking on December 15th, and the Leo Minorids peaking on December 19th. If you can trace a suspect meteor back to the vicinity of the Gemini ‘twin’ stars of Castor and Pollux, then you’ve most likely spied a Geminid and not an impostor.
And speaking of the Moon, next week’s Full Moon is not only known as the Full Cold Moon (For obvious reasons) from Algonquin native American lore, but is also the closest Full Moon to the December 21st, northward solstice. This means that next week’s Full Moon rides highest in the sky for 2016, passing straight overhead for locales sited along latitude 17 degrees north, including Guatemala City and Mumbai, India.
A 2015 Geminid over Sariska Palace in Rajastan, India. Image credit and copyright: Abhinav Singhai.
Photographing the Geminids is also as simple as setting a camera on a tripod and taking wide-field exposures of the sky. We like to use an intervalometer to take automated sequences about 30 seconds to 3 minutes in length. Said Full Moon will most likely necessitate shorter exposures in 2016. Keep a fresh set of backup batteries handy in a warm pocket, as the cold December night will drain camera batteries in a pinch.
Our humble meteor imaging rig. Credit: Dave Dickinson.
And although the Geminids might be a bust in 2016, another moderate shower, the Ursids has much better prospects right around the solstice… more on that next week!
An artificial meteor shower coming to a sky-scape near you? Image credit: Sky Canvas.
A company named Sky Canvas plans to launch a colorful artificial meteor shower barrage via micro-satellite.
In the ‘strange but true department’ and a plan that would make any super-villain envious, a Japanese start-up plans to shoot meteoroids at the Earth to create the first orchestrated artificial meteor shower. The effort is benign in a bid to study the behavior of meteors and reentry characteristics, while also putting on a good show.
The idea is brainchild of Lena Okajima, who started the ALE Company which is funding the project.
“I’m very excited about this project, not only because it will turn my childhood dream into a reality, but also because it can contribute to fundamental scientific research in a new form without relying on public funds and donations,” Okajima said on her biography on the ALE website.
First, a clarification: despite what several news sites have reported, Sky Canvas/ALE have not made a formal bid to incorporate the proposal as part of the 2020 Olympics in Japan, though they’re certainly open to the idea. An artificial meteor shower during the opening ceremonies for the 2020 Olympics in Japan would definitely be a unique first!
A meteor shower-dispensing satellite in low Earth Orbit. Image credit: Sky Canvas.
Early testing and a first satellite launch with an as-yet unannounced carrier may occur in the later half of 2017, with another launch per year, each year following.
Long a dream of astronomer Lena Okajima, an artificial meteor shower may soon grace a sky near you.
A ball-bearing sized artificial meteor on reentry. Image credit: Sky Canvas.
Visibility Prospects
The meteoric payload will be carried into low Earth orbit aboard a small 50x 50x 50 centimetre cubical satellite dispenser. Different pellets will burn blue, orange and green. The team won’t reveal the ‘secret formula’ for the colors, but you only have to think back to high school chemistry class and Bunsen Burner flame tests to imagine the elements probably used. (hint: the green isn’t kryptonite). Laboratory tests suggest that the artificial meteors should be visible from about 200 kilometers (120 miles) away. Said satellite dispenser will carry about a 300-500 pellets. At say, a meteor a second, such a display would last from five to just over eight minutes in duration.
A rainbow of elemental colors. Image credit: Sky Canvas.
A test carried out in the lab verified that the brightness for the pellets should be right around apparent magnitude -0.86, just a bit fainter than the brightest star in the sky Sirius at magnitude -1.5.
Looking for an artificial meteor shower to light up your next event? Well, such a performance isn’t cheap. With a roughly eight million dollar price tag, an artificial meteor shower breaks down to about $16,000 USD per meteor.
The plan is to place the 50 kilogram satellite (fully loaded) in a sun-synchronous orbit. This is a highly inclined retrograde polar orbit, also favored by Earth-observing and (supervillians take note) spy satellites.
The visibility prospects for Sky Canvas over a major urban area. Image credit: Sky Canvas.
The Sky Canvas system will also have the ability to ‘weather abort’ about 100 minutes prior to the event in case of inclement weather. Once in low Earth orbit, said satellite will orbit the planet once every 90 minutes. Such a dispenser is a one shot affair, and will burn up shortly after use.
Are artificial meteor showers a great idea? On one hand, it might be a great educational resource, and a way to get the general public excited about space and astronomy. Still, for those of us who have endured many an early morning vigil for the occasional surprise flash of a meteor, there’s perhaps something a bit kitschy about meteor showers on demand. It’s also slightly reminiscent of the early Space Age ideas to create nighttime illumination via large mirrors floating in space, or place advertising (!) in low Earth orbit. Streaks of artificial satellites already routinely photobomb deep sky images… do we want to contend with orbiting Pepsi logos as well?
Some may also bemoan the advent of yet more artificial light – however ephemeral — streaking across the already brightening sky. And here’s another possible dilemma: will a -1 magnitude artificial meteor appear all that impressive from the already garish glare of downtown Tokyo, Las Vegas or Dubai? Still, I’d make the trip to see the world’s first artificial meteor shower… and humanity already routinely creates similar unheralded “shows” every time a piece of space junk reenters the Earth’s atmosphere.
I also can’t help but think of the fictional metal band Disaster Area from Douglas Adams’ Hitchhiker’s Guide to the Galaxy, which ended each concert with a sun-diving spaceship.
There are also possible practical applications for the project, including understanding meteor showers, spacecraft reentry, studying the upper atmosphere, etc. And though this may seem far-fetched, NASA already uses luminous chemicals dispersed from sounding rockets to do the same thing.
JAXA has already performed similar artificial meteor experiments here on Earth using an arc-heated wind tunnel laboratory, mimicking and modeling the Chelyabinsk meteor and the asteroid sample return mission Hayabusa-1 and the future return of Hayabusa-2.
Just maybe though, light pollution awareness might prove to be the project’s greatest strength. An artificial meteor shower might just cause city dwellers and urban planners to turn the lights down, and simply gaze up at the night sky for a brief moment.
A 2001 Leonid over Puerto Rico. Image credit and copyright: Frankie Lucena.
A flash of light recently reminded us of the most stunning sight we ever saw.
We managed to catch an early Leonid meteor this past Saturday morning while waiting for the new Chinese space station Tiangong-2 to pass over southern Spain. The Leonids are active this week, and although the light-polluting just past Super Moon lurks nearby, we’ve learned to never ignore this shower, even on an off year.
First though, here’s a rundown on what’s up with the Leonids in 2016:
The Leonid meteors are expected to peak on the night of Thursday, November 17th into the morning of Friday, November 18th. The shower is active for a 25 day span from November 5th to November 30th and though the Leonids can vary with an Zenithal Hourly Rate (ZHR) of thousands of meteors per hour, and short outbursts briefly topping hundreds of thousands per hour, in 2016, the Leonids are expected to produce a maximum ideal ZHR of only 10 to 15 meteors per hour. The radiant of the Leonids is located at right ascension 10 hours 8 minutes, declination 21.6 degrees north at the time of the peak, in the Sickle or backwards Question Mark asterism of the astronomical constellation of Leo the Lion.
The rising radiant of the Leonids versus the nearby waning gibbous Moon. Image credit: Stellarium.
The source of the Leonids is periodic Comet 55P/Tempel-Tuttle.
Now, for the bad news. The Moon is an 82% illuminated, waning gibbous phase at the peak of the Leonids, making 2016 an unfavorable year for this shower. In fact, the Moon is located just 42 degrees from the shower’s radiant in the nearby constellation of Gemini at the shower’s peak on Friday morning. In previous years, the Leonids produced a ZHR numbering in the 15-20 per hour. The estimated ZHR last topped 100 in 2008.
The Leonid meteors strike the Earth at a moderate/fast velocity of 71 km/s, and produce many fireballs with an r value of 2.5.
The Leonids are notorious for producing storms of epic proportions every 33 years. This last occurred in years surrounding 1999, and isn’t expected to occur again until around 2032. Some older observers still remember the great Leonid meteor storm over the southwestern United States in 1966, and the U.S. East Coast witnessed a massive storm in 1833.
A woodcut engraving depicting the 1833 Leonids over Niagara Falls. Public Domain image.
We can attest to what the Leonids are capable of. We saw an amazing display from the shower in 1998 from Al Jaber Air Base in Kuwait, with an estimated rate of around 900 per hour towards dawn. When a shower edges towards a zenithal hourly rate of 1,000, you’re seeing meteors every few seconds, with fireballs lighting up the desert night.
And it is possible to defeat the waning gibbous Moon. Though the Moon is near the zenith as seen from the mid-northern latitudes in the early AM hours (the best time to watch the shower,) its almost always possible to view the shower with the Moon blocked behind a house or hill… unless you have the bad luck of viewing from latitude 20 degrees north, where the Moon crosses directly through the zenith on Friday morning.
But take heart, as we’re past the halfway mark in 2014, headed to the Leonid ‘storm years’ of the early 2030s.
Don’t miss the 2016 Leonids… if for no other reason, to catch a flash of storms to come.
Comet 45P/Honda-Mrkos-Pajdušáková From October 1st, 2011 taken with a 10"/3.8 Newtonian and CCD imager. Image credit and copyright: Michael Jäger.
Looking for a good binocular comet? Well, if luck is on our side, we should be getting our first looks at periodic Comet 45P/Honda-Mrkos-Pajdušáková as it tops +10th magnitude in dusk skies over the next few weeks.
The swift path of Comet 45P/Honda-Mrkos-Pajdušáková on the nights of February 9th to February 12th. Image credit: Starry Night.
Comet 45P/Honda-Mrkos-Pajdušáková is expected to reach maximum brightness around late February 2017. Discovered independently by astronomers Minoru Honda, Antonin Mrkos and L’udmila Pajdušáková on December 3rd, 1948, Comet 45P/Honda-Mrkos-Pajdušáková orbits the Sun once every 5.25 years on a short period orbit. Comet 45P/Honda-Mrkos-Pajdušáková is set to break binocular +10th magnitude brightness in mid-December 2017, and may reach a maximum brightness of magnitude +7 from January through February 2017.
Slovak astronomer ?udmila Pajdušáková, co-discoverer of 5 comets, including Comet 45P/Honda-Mrkos-Pajdušáková. Image credit: The Skalnaté Pleso Observatory.
Currently and through the end of 2016, the comet sits towards the center of the Milky Way Galaxy in Sagittarius at a faint +15th magnitude in the evening sky. The comet may break +10th magnitude and become very briefly visible in the first few weeks of December before getting too close to the Sun to observe in late 2016 and crossing into the morning sky in early 2017.
The path of Comet 45/P from mid-November through December 15th, 2016. Image credit: Starry Night.
Visibility prospects: At its brightest, Comet 45P/Honda-Mrkos-Pajdušáková will be passing through the constellation Hercules during closest approach on February 11th. The comet then passes through the constellations of Corona Borealis, Boötes, Canes Venatici, Ursa Major into Leo through to the end of February as it recedes. In the second week of February, the comet is visible in the dawn sky 82 degrees west of the Sun at maximum brightness. This apparition favors the northern hemisphere. The comet will reach perihelion on December 29th, 2016 at 0.53 Astronomical Units (AU) from the Sun, and the comet passes just 0.08 AU (7.4 million miles) from the Earth on February 11th at 14:44 UT. The comet made a slightly closer pass in 2011, and was a fine binocular object that time around. At its closest, the comet will cross nine degrees of sky from one night to the next. Some notable dates for comet 45P/Honda-Mrkos-Pajdušáková are:
November 23rd: Venus passes 6′ from the comet.
December 12th: May break 10th magnitude.
December 14th: Passes near M75.
December 15th: Crosses into the constellation Capricornus.
January 4th: Passes near the +4th magnitude star Theta Capricorni
January 10th: Crosses the ecliptic northward.
January 16th: Passes into Aquarius.
January 22nd: Passes near NGC 7009, M72 and M73.
January 25th: Passes 8 degrees from the Sun and into the dawn sky.
January 28th: Crosses into Aquila.
February 3rd: Crosses the celestial equator northward.
February 4th: Passes 4′ from the star +3.3 magnitude star Delta Aquilae.
February 6th: Crosses the Galactic equator.
February 7th: Crosses into Ophiuchus.
February 9th: Crosses into Hercules.
February 16th: makes a wide pass near M3.
February 19th: Drops back below +10th magnitude.
The path of Comet 45P/Honda-Mrkos-Pajdušáková through the inner solar system. Image credit: NASA/JPL.
This is the final close (less than 0.1 AU) passage of Comet 45P/Honda-Mrkos-Pajdušáková near the Earth for this century.
On July 1st 1770, Comet D/1770 L1 Lexell passed 0.0151AU from the Earth; a comet in 1491 may have passed closer. Next year’s passage of 45P/Honda-Mrkos-Pajdušáková ranks as the 21st closest passage of a comet near the Earth.
Why do comets end up with such cumbersome names? Well, comets derive their names from the first three discovers that submit the find within a 24 hour period to the Minor Planet Center’s Central Bereau for Astronomical Telegrams, which, in fact, received its last ‘telegram’ during the discovery of Comet Hale-Bopp around two decades ago. Increasingly, comets are receiving names of all sky surveys such as LINEAR and PanSTARRS from robotic competition against amateur hunters. It does seem like you need an umlaut or the chemical symbol for boron to in your moniker to qualify these days… rare is the ‘Comet Smith.’ But hey, it’s still fun to watch science journalists try and spell the Icelandic volcano Eyjafjallajökull and comet Churyumov-Gerasimenko over and over… Perhaps, we should insist that our first comet discovery is actually spelled Comet Dîckînsðn…
And Comet 45/P is just one of the fine binocular comets on deck for 2017. We’re also expecting Comet 41P/Tuttle-Giacobini-Kresák, 2/P Encke, C/2015 ER61 PanSTARRS Comet C/2015 V2 Johnson to break +10th magnitude next year… and the next great naked eye ‘Comet of the Century’ could light up the skies at any time.
Goldstone radar pings comet 45/P back in 2011. Image credit: NASA.
Binoculars are the best tool to observe bright comets, as they allow you to simply sweep the star field and admire the full beauty of a comet, coma, tail(s) and all. Keep in mind, a comet will often appear visually fainter than its quoted brightness… this is because, like nebulae, that intrinsic magnitude is ‘smeared out’ over an extended area. To my eye, a binocular comet often looks like a fuzzy, unresolved globular cluster that stubbornly refuses to snap into focus.
Don’t miss your first looks at Comet 45/P 45P/Honda-Mrkos-Pajdušáková, as it spans 2016 into 2017.
The 2015 Supermoon. Image credit and copyright: Wils 888.
What’s that, rising in the sky?
By now, you’ve heard the news. We’ll spare you the “it’s a bird, it’s a plane…” routine to usher in the Supermoon 2016. This month’s Full Moon is not only the closest for the year, but the nearest Full Moon for a 80 year plus span.
Like Blue and Black Moons, a Supermoon is more of a cultural phenomenon than a true astronomical event. The Moon’s orbit is elliptical, taking it from 362,600 to 405,400 km from the Earth in the course of its 27.55 day anomalistic orbit from one perigee to the next. For the purposes of this week’s discussion, we consider a Supermoon as when the Full Moon occurs within 24 hours of perigee, and a Minimoon as when the Full Moon occurs within 24 hours of apogee. From the Earth, the Moon varies in apparent size from 29.3” to 34.1” across. This month, the Moon reaches perigee on November 14th at 356,511 kilometers distant, 2 hours and 22 minutes before Full.
A perigee ‘Supermoon’ versus an apogee ‘Minimoon’. Image credit and copyright: Raven Yu.
This is the closest perigee Moon for 2016, beating out the April 7th, 2016 perigee Moon by just 652 kilometers. Perigee can vary over a span of 2,800 kilometers. In the 21st century, the farthest lunar perigee (think the ‘most distant near point’) occurs on January 3rd, 2100 at 370,356 kilometers distant, while the closest perigee of the century (356,425 kilometers) occurs on December 6th , 2052.
When the Moon reaches Full on November 14th at 13:51 UT, it’s just 356,520 kilometers distant, (that is , as measured from the Earth’s center) the closest Full Moon since January 26th, 1948 (356,490 km) and until November 25th , 2034 (356,446 km) losing out to either dates by just 21 kilometers.
Why does perigee vary? Well, as the Moon orbits the Earth, the Sun tugs our large natural satellite’s orbit around as well, in an 8.85 year cycle known as the precession of the line of apsides. Earth’s orbit is elliptical as well, and the tugging of the Sun (and to a much lesser degree, the other planets in the solar system) alters the perigee and apogee points slightly based on where the Earth-Moon pair fall in their swing about a common barycenter.
The November Full Moon is also known as the Full Beaver Moon by the Algonquin Native Americans, a good time to ensure a supply of winter furs before the swamps froze over. A good sign that even in 2016, ‘Winter is Coming.’
Does the Moon look any larger to you than usual as it rises to the east opposite to the setting Sun on Monday night? When the Moon reaches Full, it passes the zenith as seen from the central Indian Ocean region just south of Sri Lanka, 354,416 km distant. Of course, as the Moon rises, it’s actually one full Earth radii more distant than when straight overhead at the zenith.
A side-by-side ‘Super’ vs ‘Minimoon.’ Image credit and copyright: Marco Langbroek.
Would you notice any difference in the size of the November Full Moon, if you didn’t know better? The 4′ odd difference between an apogee and perigee Full Moon is certainly discernible in side-by-side images… but it’s interesting to note that early cultures did not uncover the elliptical nature of the Moon’s motion, though it certainly would have been possible. Crystalline spheres ruled the day, a sort of perfection that was just tough to break in the minds of many.
Be sure to enjoy the rising Full Moon on Monday night, the largest for many years to come.
The author enjoys a pretty display of the northern lights on October 23, 2016 under a starry sky. His new book, “Night Sky with the Naked Eye,” explores all the amazing things you can see in the sky without special equipment including satellites, planets, meteor showers and of course, the aurora.
My book Night Sky with the Naked Eye publishes today. It would have never seen the light of day much less ever been conceived were it not for Fraser Cain, publisher of Universe Today, and Nancy Atkinson, an editor and writer for the same. Several years ago, Nancy invited me to write for UT. I hopped at the chance. Before her contact, I’d been writing a daily blog on astronomy called Astro Bob (and still do).
Fast forward to last summer when I got an email from Nancy saying Page Street Publishing had contacted her about writing a book about space missions. The publisher also wanted a book about night sky observing without fancy equipment for which she recommended me. Me? I felt like the luckiest guy on the planet!
Book writing proceeds in many stages. First, the table of contents had to be prepared and approved. Then followed a sample chapter. The publisher chose the one on artificial satellites, which I wrote in about a week. The tone was right, but he asked for changes in the organization, which I dutifully made. By November, a contract followed and the project was underway with a first draft due to my editor in about 10 weeks.
Cover of my book that publishes today. Credit: Bob King
Writing is hard work. But it’s a special place all writers come back to again and again. We can’t help but keep trying to find just the right words to capture a concept or emotion. And when we do, a quiet pleasure flows down the spine like warmth creeping into cold fingers splayed in front of a fire. Not that these moments always come easily. Writer Colson Whitehead describes the experience of writing as “crawling through glass.” I would soon become well-acquainted with that feeling, too.
Nancy wrote her book Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos at nearly the same time. We were grateful for each other’s support, and it was a kick to follow her progress as well as bounce ideas around. With a tight deadline in front of me, I set to work immediately, taking more than two weeks of vacation from my regular job to make sure the draft was done on time. No way was I going to compromise an opportunity of a lifetime.
Maybe you’ve thought of writing a book, starting a blog or hope one day to write for Universe Today or another online astronomy site. There’s plenty of good advice for writers out there. I’ll share what worked for me.
#1:Put your butt in the chair and keep it in the chair. My wife reminded me of this often, adding that the book wasn’t going to write itself. Temptations are everywhere. Answering the phone, making another cup of tea, staring out the window and my favorite, shoveling the driveway. I had the cleanest driveway in the neighborhood. Even an inch of new snow was enough to grab the shovel and happily scrape down to the gravel. So yes, I did occasionally get out of the chair, but many times it did me good, freeing up the brain to see more clearly into a topic. Or dream up a fitting photo or illustration.
Creativity comes at odd little moments. It can flow while tapping away in front of a glowing screen or sneak into consciousness when you’re bending down to feed the dog. So a mix of activities seemed the best but with extra emphasis on staying put. I rarely hiked last winter and kept my walks in the neighborhood brief. Instead of observing at night, I wrote or gathered photos. By January, I joked to my friends that I’d voluntarily put myself under house arrest.
#2: Spill your guts, worry about the details later. It’s incredibly tempting when writing to continuously edit one’s work, going back over every sentence to make each “perfect”. This is a muse-killer. Though difficult to stick to, once you let your thoughts flow onto paper without worrying about spelling, clauses and the whole lot of burdensome rules, you’ll become a wild horse running free on the prairie. Let it out, let it out and worry about the commas later. I don’t play a musical instrument, but free-flow writing — just getting the ideas out — must feel something like riffing on a jazz melody.
#3: When stuck, move on to another topic, take a walk, listen to music. Struggling to describe an important concept or connecting your thoughts in a way that flows on the page can drive you nuts, even bring you to tears. Sure, you can keep beating on the idea like a madman hammering on a bent nail, but why why torture yourself? A little distraction can be good. Move on to another part of the story or a different chapter or get up and take a short walk. Defocusing allows the ideas you’re having a tug-of-war with to come of their own accord.
To keep track of ideas, topics and the photos I’d need for the book, I kept a notebook filled to the gills with lists. Checkmarks indicate tasks accomplished. Credit: Bob King
As the February 1 deadline approached, time took on a physical dimension under the intense pressure to get everything done. I cut time into little blocks that when added up would get me to the finish line on the first draft. I made it just in time, shipped off my copy via e-mail, got in the car to go to work and turn up the music really LOUD. For a fews days I was on top of the world. Invincible.
My editor, Elizabeth, contacted me later with positive comments and then returned the manuscript with “developmental edits” or questions about descriptions and organization. We pitched the ever-refined draft back and forth over the next few months. Each time I read through the ten chapters and made both suggested changes and other refinements. I also added photos during this stage and worked via e-mail with the layout staff to place the best images and graphics at the best places in the text. I shot more images and requested photos from talented astrophotographers, prepared the acknowledgments and sought our recommendations from respected scientists and writers.
This diagram from the book uses the human face to illustrate how changing lighting angles causes the phases of the moon. Credit: Bob King
The editors at Page Street were quite generous with photo usage, a joy for me because that’s what I do for a living. I’ve been a photographer and photo editor at the Duluth News Tribune in Duluth, Minn. for many years. My favorite subjects are people, but I slip in an aurora or eclipse now and again. And that’s the irony. I never saw myself as a writer.
Like many, I started by keeping a journal of my observations through the telescope and reflections about the night sky. The Astro Bob blog took that a step further and writing for Universe Today and Sky & Telescope let me find my voice. So I maybe I have a voice, and I like to think I can be a helpful guide at your side, but writer? That still seems too lofty a term to describe what I do. But here we are.
After several edits including the final one, when I was sent a thick stack of low-res black and white pages of the book to mark up and return, I rested briefly before beginning the final phase: publicity. This is the weird part, where you tell everyone what a nice book you’ve written and how it would make a great Christmas gift for that budding astronomer in the family. When I held the first copy in my hands I couldn’t believe that all those hours of work at the computer became a physical object, a beautiful one even.
This map from the book shows Saturn’s location around the time of opposition through 2021. Credit: Bob King, Source: Stellarium
I’m biased of course, but I think both beginning and amateur astronomers will find the book useful. It includes lots of suggested activities – set off in separate boxes – to encourage you to get out under the stars. I make regular mention of the Web and phone apps as ways to become more familiar with the constellations, learn of newly-discovered bright comets and even find a dark sky.
Besides the easy naked eye topics like how to find the brightest constellations or see the best meteor showers of the year, the book offers visual challenges. Have you ever seen craters on the Moon without optical aid or the midnight glow of the gegenschein? You’ll find out how in my book. As a photographer, I’ve included tips on how to focus a digital camera and use it to photograph the aurora or a space station pass.
I’d be willing to bet that most books aren’t as complete as their authors would hope. I had to cut precious photos, graphics, 3 years of a sky calendar and other bits and pieces from mine. Ouch! To this day, I’m still thinking of ways to improve it with a fresh photo, new diagram or change of wording. Now it’s your turn to be the judge.
The zodiacal light punctuated by the planet Jupiter towers over northern Wisconsin along Lake Superior near Duluth, Minn. this morning (Nov. 8). The book describes nighttime lights such as the zodiacal, gegenschein, airglow in addition to lunar halo and corona phenomena. Credit: Bob King
Throughout, Nancy and I rooted for one another and shared our ups and downs. Incredible Stories was to publish within a week of Night Sky, but a type corruption error discovered in several chapters put the book on hold. Her new publication date is December 20, and I encourage you to pre-order a copy, so it arrives in time for Christmas. Order a copy of my book also, and I promise the two of us will keep you company on those long winter nights ahead.
Can I share one final tip? Once you’ve found your passion, say ‘yes’ to every opportunity that furthers it. You’ll be amazed at the places that one word will take you to.
*** To order a copy of Night Sky with the Naked Eye just click an icon to go to the site of your choice — Amazon, Barnes & Noble or Indiebound. It’s currently available at the first two outlets for a very nice discount. It should also be at your local B&N bookstore. And don’t forget to vote today!
