Hey, remember Comet C/2012 S1 ISON? Who can forget the roller-coaster ride that the touted “Comet of the Century” took us on last year. Well, ISON could have one more trick up its cosmic sleeve –although it’s a big maybe — in the form of a meteor shower or (more likely) a brief uptick in meteor activity this week.
In case you skipped 2012 and 2013, or you’re a time traveler who missed their temporal mark, we’ll fill you in on the story thus far.
Comet ISON was discovered by Artyom Novichonok and Vitali Nevski on September 21st, 2012 as part of the ongoing International Scientific Optical Network (ISON) survey. Shortly after its discovery, researchers knew they had spotted something special: a sungrazing comet already active at over 6.4 Astronomical Units (A.U.s) from the Sun. The Internet then did what it does best, and promptly ran with the story. There were no shortage of Comet ISON conspiracy theories for science writers to combat in 2013. It’s still amusing to this day to see predictions for comet ISON post-perihelion echo through calendars, almanacs and magazines compiled and sent to press before its demise.
ISON back in the day. Credit-Efrain Morales Rivera, Jaicoa Observatory Aguadilla, Puerto Rico
The frenzy for all things ISON reached a crescendo on U.S. Thanksgiving Day November 28th 2013, as ISON passed just 1.1 million kilometres from the surface of the Sun. Unfortunately, what emerged was a sputtering ember of the comet formerly known as ISON, which faded from view just as it was slated to reenter the dawn sky.
Hey, we were crestfallen as well… we had our semi-secret dark sky site pre-selected for ISON imaging post-perihelion and everything. Despite heroic searches by ground and space-based assets, we’ve yet to see any compelling recoveries of Comet ISON post-perihelion.
This week, however, Comet ISON may put on its last hurrah, in the form of a minor meteor shower. We have to say from the outset that we’re highly skeptical that an “ISON-id meteor outburst” will grace the skies. Known annual showers are fickle enough, and it’s nearly impossible to predict just what might happen during a meteor shower with no past track record.
But you won’t see anything if you don’t try. If anything is set to occur, the night of January 15th into the 16th might just be the time to watch. This is because the Earth will cross the orbital plane of ISON’s path right around 9:00 PM EST/2:00 UT. Last year, ISON passed within 3.3 million kilometres of the Earth’s orbit on its inbound leg. Earlier last year, ISON was estimated to have been generating a prodigious amount of dust, at a rate of about 51,000 kilograms per minute. Any would-be fragments of ISON outbound would’ve passed closest to the Earth at 64 million kilometres distant on the day after Christmas last year. Veteran sky observer Bob King wrote about the prospects for catching ISON one last time during this month back in December 2013.
A simulation showing Earth crossing the plane of Comet ISON’s orbit early on January 16th. Credit: NASA/JPL Solar System Dynamics Small Body Database Browser.
Another idea out there that is even more unlikely is the proposal that dust from Comet ISON may generate an uptick in noctilucent cloud activity. And already, a brief search of the internet sees local news reports attempting to tie every meteor observed to ISON this week, though no conclusive link to any observed fireball has been made.
The radiant to watch for any possible “ISON-ids” sits near the +3.5 magnitude star Eta Leonis in the sickle of Leo. Robert Lundsford of the American Meteor Society notes in a recent posting that any ISON-related meteors would pass through our atmosphere at a moderate 51 kilometres a second, with a visible duration of less than one second.
Note that meteor activity has another strike against it, as the Moon reaches Full on the same night. In fact, the Full Moon of Wednesday January 15th sits in the constellation Gemini,just 32 degrees away from the suspect radiant!
Another caveat is in order for any remaining dooms-dayers: no substantial fragments of ISON are (or ever were) inbound and headed towards our fair planet. Yes, we’re seeing rumblings to this effect in the pseudoscience netherworlds of ye ole Internet, along with ideas that ISON secretly survived, NASA “hid” ISON, ISON cloaked like a Romulan Bird of Prey, you name it. Just dust grains, folks… a good show perhaps, but nothing more.
As near as we can tell, talk of a possible meteor shower generated from Comet ISON goes all the way back to a NASA Science News article online from April 2013. Radio observers of meteor showers should be alert for a possible surge in activity this week as well, and it may be the case that more radio “pings” will be noted than visual activity what with the light-polluting Full Moon in the sky. The radiant for any would-be “ISON-ids” transits highest in the sky for northern hemisphere observers at around 2 AM local.
But despite what it has going against it, we’d be thrilled if ISON put on one last show anyhow. It’s always worth watching for meteor activity and noting the magnitude and from whence the meteor came to perhaps note the pedigree as to the shower it might belong to.
The next annual dependable meteor shower won’t be until the night of April 21st to the 22nd, when the Spring Lyrids are once again active. And this year may just offer a special treat on May 24th, when researchers have predicted that the Earth may encounter debris streams laid down by Comet 209P LINEAR way back in 1803 and 1924… Camelopardalids, anyone? Now, that’s an exotic name for a meteor shower that we’d love to see trending!
-Catch sight of any “ISON-ids?” we’d love to see ‘em… be sure to post said pics at Universe Today’s Flickr pool.
Albert Einstein during a lecture in Vienna in 1921.
Credit: National Library of Austria/F Schmutzer/Public Domain
One of the benefits of being an astrophysicist is your weekly email from someone who claims to have “proven Einstein wrong”. These either contain no mathematical equations and use phrases such as “it is obvious that..”, or they are page after page of complex equations with dozens of scientific terms used in non-traditional ways. They all get deleted pretty quickly, not because astrophysicists are too indoctrinated in established theories, but because none of them acknowledge how theories get replaced.
For example, in the late 1700s there was a theory of heat known as caloric. The basic idea of caloric was that it was a fluid that existed within materials. This fluid was self-repellant, meaning it would try to spread out as evenly as possible. We couldn’t observe this fluid directly, but the more caloric a material has the greater its temperature.
Ice-calorimeter from Antoine Lavoisier’s 1789 Elements of Chemistry. (Public Domain)
From this theory you get several predictions that actually work. Since you can’t create or destroy caloric, heat (energy) is conserved. If you put a cold object next to a hot object, the caloric in the hot object will spread out to the cold object until they reach the same temperature. When air expands, the caloric is spread out more thinly, thus the temperature drops. When air is compressed there is more caloric per volume, and the temperature rises.
We now know there is no “heat fluid” known as caloric. Heat is a property of the motion (kinetic energy) of atoms or molecules in a material. So in physics we’ve dropped the caloric model in terms of kinetic theory. You could say we now know that the caloric model is completely wrong.
Except it isn’t. At least no more wrong than it ever was.
The basic assumption of a “heat fluid” doesn’t match reality, but the model makes predictions that are correct. In fact the caloric model works as well today as it did in the late 1700s. We don’t use it anymore because we have newer models that work better. Kinetic theory makes all the predictions caloric does and more. Kinetic theory even explains how the thermal energy of a material can be approximated as a fluid.
This is a key aspect of scientific theories. If you want to replace a robust scientific theory with a new one, the new theory must be able to do more than the old one. When you replace the old theory you now understand the limits of that theory and how to move beyond it.
In some cases even when an old theory is supplanted we continue to use it. Such an example can be seen in Newton’s law of gravity. When Newton proposed his theory of universal gravity in the 1600s, he described gravity as a force of attraction between all masses. This allowed for the correct prediction of the motion of the planets, the discovery of Neptune, the basic relation between a star’s mass and its temperature, and on and on. Newtonian gravity was and is a robust scientific theory.
Then in the early 1900s Einstein proposed a different model known as general relativity. The basic premise of this theory is that gravity is due to the curvature of space and time by masses. Even though Einstein’s gravity model is radically different from Newton’s, the mathematics of the theory shows that Newton’s equations are approximate solutions to Einstein’s equations. Everything Newton’s gravity predicts, Einstein’s does as well. But Einstein also allows us to correctly model black holes, the big bang, the precession of Mercury’s orbit, time dilation, and more, all of which have been experimentally validated.
So Einstein trumps Newton. But Einstein’s theory is much more difficult to work with than Newton’s, so often we just use Newton’s equations to calculate things. For example, the motion of satellites, or exoplanets. If we don’t need the precision of Einstein’s theory, we simply use Newton to get an answer that is “good enough.” We may have proven Newton’s theory “wrong”, but the theory is still as useful and accurate as it ever was.
Unfortunately, many budding Einsteins don’t understand this.
Binary waves from black holes. Image Credit: K. Thorne (Caltech) , T. Carnahan (NASA GSFC)
To begin with, Einstein’s gravity will never be proven wrong by a theory. It will be proven wrong by experimental evidence showing that the predictions of general relativity don’t work. Einstein’s theory didn’t supplant Newton’s until we had experimental evidence that agreed with Einstein and didn’t agree with Newton. So unless you have experimental evidence that clearly contradicts general relativity, claims of “disproving Einstein” will fall on deaf ears.
The other way to trump Einstein would be to develop a theory that clearly shows how Einstein’s theory is an approximation of your new theory, or how the experimental tests general relativity has passed are also passed by your theory. Ideally, your new theory will also make new predictions that can be tested in a reasonable way. If you can do that, and can present your ideas clearly, you will be listened to. String theory and entropic gravity are examples of models that try to do just that.
But even if someone succeeds in creating a theory better than Einstein’s (and someone almost certainly will), Einstein’s theory will still be as valid as it ever was. Einstein won’t have been proven wrong, we’ll simply understand the limits of his theory.
Last month's rising "Mini-Moon" of 2013. (Photo by Author)
Last month, (and last year) we wrote about the visually smallest Full Moon of 2013. Now, in a followup act, our natural satellite gives us an even more dramatic lesson in celestial mechanics with an encore performance just one lunation later with the smallest Full Moon of 2014.
We’ve noted the advent of the yearly Mini-Moon, a bizzaro twin to the often over-hyped “SuperMoon,” or Proxigean Full Moon. Occurring approximately six months apart, you can always expect lunar apogee to roughly coincide with the instant of a Full Moon about half a year after it coincides with perigee. In fact, the familiar synodic period that it takes the Moon to return to like phase (such as Full back to Full) of 29.5 days has a lesser known relative known as the anomalistic month, which is the period of time it takes the Moon to return to perigee at 27.55 days.
But the circumstances for “Mini-Moon 2014” are exceptional. The first Full Moon of the year occurs on the night of January 15th at 11:52 PM EST/4:52 Universal Time (on January 16th). This is just 2 hours and 59 minutes after the Moon reaches apogee at 406,536 kilometres distant at 8:53 PM EST/1:53 UT. This isn’t the farthest apogee that occurs in 2014, but it’s close: the Moon is just 32 kilometres more distant on July 28th, 2014. Apogee can vary from 404,000 to 406,700 kilometres, and this month’s apogee falls just 164 kilometres short of the maximum value.
As you can see, this year’s Mini-Moon falls extremely close to apogee… in fact, you have to go all the way back to the Full Moon of November 18th, 1994 to find a closer occurrence, and this year’s won’t be topped until May 13th, 2052! The Moon will appear only 29’ 23” in size on Wednesday night at moonrise, very close to its minimum possible value of 29’ 18”. This is also almost 5 arc minutes smaller than the largest “Super-Moon” possible.
Cool factoid: you actually move closer to the Moon as it rises, until it transits your local meridian and you begin moving away from it, all due to the Earth’s rotation. You can thus gain and lose a maximum of one Earth radii distance from the Moon in the span one night.
We also just passed the most northern Moon of 2014, as it reached a declination of 19 degrees 24’ north this morning at 8:00 UT/3:00 AM EST. This is a far cry from the maximum that can occur, at just over 28 degrees north. This is because we’re headed towards a “shallow year” as the Moon’s motion bottoms out relative to the ecliptic in 2015 and once again begins to widen out in its 18+ year cycle to its maximum in 2024-25.
The position of the Moon Monday night on January 13th in Orion. Credit: Stellarium
This week’s Moon also visits some interesting celestial targets as well. The waxing gibbous Moon sits just 5.1 degrees south of the open cluster M35 tonight. Notice something odd about the Moon’s position Monday night? That’s because it is passing through Orion the Hunter, one of the six non-zodiacal constellations that it can be found in. Can you name the other five? Hint: one was the “13th sign of the zodiac that created a non-traversy a few years back.
On Tuesday evening, the Moon passes six degrees from the planet Jupiter. This presents a fine time to try and spot the planet in the daytime to the Moon’s upper left, just a few hours prior to sunset.
The Moon will also occult the +3.6 magnitude star Lambda Geminorum on January 15th for observers in northwestern North America. In fact, viewers along a line crossing central British Columbia will witness a spectacular graze along the lunar limb as the star winks out behind lunar mountains and pops into view as it shines through lunar valleys along the edge of the Moon. This can make for an amazing video capture, we’re just throwing that out there…
The occultation footprint for Lambda Geminorum for January 15th. (Created using Occult 4.10.11 software)
In addition to being this year’s Mini-Moon, the January Full Moon is also known as the Wolf Moon in the tradition of the Algonquin Native Americans, as January was a time of the mid-winter season when starving wolf packs would howl through the long cold night. The January Full Moon is also sometimes referred to as “The Moon after Yule,” marking the first Full Moon after Christmas.
And just when is the next Super Moon, you might ask? Well, 2014 has three Full Moons occurring within 24 hours of perigee starting on July 15th and finishing up on September 8th. But the most notable is on August 10th, when the Moon passes perigee just 27 minutes from Full. Expect it to be preceded by the usual lunacy that surrounds each annual “Super Moon” as we once again bravely battle the forces of woo and describe just exactly what a perigee Full Moon isn’t capable of. Yes, we still prefer the quixotic term “Proxigean Moon,” but there you go.
Also, be sure to wave a China’s Chang’e-3 lander and rover in the Bay of Rainbows (Sinus Iridum) as you check out this week’s Full Moon, as it just experienced its first lunar sunrise this past week.
Be sure to send those Mini-Moon pics and more in to Universe Today, and let’s get this week’s #MiniMoon trending on Twitter!
New LED lighting along Michigan Street in downtown Duluth, Minn. has brightened and whitened up the area considerably compared to the days of high-pressure sodium lighting. Credit: Bob King
You may have noticed a change underway in your city lighting. High pressure sodium lights, with their familiar orange glow, are quickly being replaced by new, energy efficient blue-white LED (light emitting diode) lighting. Is this the beginning of a new assault on the night or an opportunity to use light more wisely? Many of us first became aware of LEDs in amplifiers, computers and the flashlights we use for seeing our star charts at night. More recently, LEDs became a big hit with Christmas lighting. And why not? Although they cost considerably more, the bulbs last much longer, use a fraction of the energy compared to incandescent and sodium lighting and don’t contain materials like mercury – common in fluorescent lighting – that can harm the environment. A typical incandescent bulb lasts about 750 hours while an LED bulb can glow for up to 50,000 hours. What’s not to like?
Small individually colored LED lights. LEDs light up when an electric current excites electrons inside a semidconductor to produce photons of light. Click to learn more. Credit: Piccolo Namek
The changeover to LED street lighting is already underway in my own city of Duluth, Minn. U.S. I noticed this one night this fall while driving home from work. Buildings and intersections that had been orange the night before were bathed in a far more intense blue-white light. Don’t get me wrong. Our city engineers deserve high marks for adhering to good lighting standards by packaging the new lights in shielded housings with minimal light spill upwards and to the sides. Light in those directions not only creates unwanted glare but seriously brightens the night sky, robbing many of the joys of stargazing.
Comparison of lighting colors and intensity of the new LED streetlights (left) and the older high-pressure sodium vapor lamps.
Still, everything was not OK. The LED street lights were INTENSELY bright, much more so than the “old-fashioned” sodiums. Looking up was like staring into the sun. If you have the opportunity, step under an orange sodium street light and then under an LED. You’ll be amazed at the difference in light intensity. To gauge the approximate difference in brightness between the two, I pulled out my camera and took a light meter reading on the pavement beneath an LED lamp and then under a high-pressure sodium lamp. The LED was brighter by more than more than one camera “stop” or more than twice as bright.
You can’t complain about the color rendition – the whiter LED light is far better – but the increased intensity doesn’t bode well for stargazers.
Direct comparison of two consecutive light standards – LED in the foreground, high pressure sodium behind it. Notice that both lights are well-shielded, ie. no part of the bulb extends beyond its housing. Credit: Bob King
As long as LEDs are shielded, light spill and glare are relatively well-controlled, but light reflected from the ground also goes up into space to light the sky. Here in the northern U.S. where snow typically covers the ground from November through March, winter night skies are the most light polluted; LED street lighting will only exacerbate the situation.
Inexpensive LED wall pack lighting lights a sidewalk and produces large amounts of glare and wasted light. Credit: Bob King
In the big picture however, that’s only a minor headache. LEDs are a wonderful technology, but the benefits they provide in cost savings and long life ultimately guarantee their proliferation in ornamental, building and parking lot illumination. Much of that lighting is unshielded and heavy on glare, making driving at night more difficult, wasting energy and preserving what dark sky remains more challenging. Indeed, the transition is already underway.
Brilliant, unshielded LED ornamental lighting at a new housing development. The full moon is seen at top. Credit: Bob King
Like an outbreak of mushrooms, LED “wall pack” lights – the ones that shine directly outward without any shielding – have started to appear on the outside walls of buildings as a cheap solution for lighting up walkways and parking lots. They’re replacing the equally bad but half as bright sodium lamps. Ornamental LED lamps in a new housing development in town recently turned night into day. Residents complained and wrote letters to the editor. To their credit, the owners dimmed the lights, but the fixtures were poorly designed to start and still too bright for many.
Closeup of LED ornamental light fixtures with little shielding. Credit: Bob King
One additional issue with LED ornamental and street lighting has to do with color. Although natural color LED lighting is available, high-efficiency LED lights emit a much bluer light than sodium vapor. Blue-rich light not only increases the amount of glare sensed by the human eye but also the amount of visible light pollution. Other effects of light trespass and glare include sleeping problems and even an increased risk for certain cancers. We humans need the night more than we know.
LEDs are only part of the problem of course. The real issue is the ever-increasing amount of light pollution worldwide and the potential for new LEDs to make it worse. True, we can take advantage of the ability to adjust and dim current lighting to more suitable levels. LEDs are also highly directional, making it easy to point them just where they’re needed. Finally, new high-efficiency more natural (less blue) LEDs are now available that can help reduce light pollution.
First electric lighting: New York City around 1880.
I encourage everyone to learn all you can about the new lighting and work with you local city councils and town boards to use the light wisely, particularly in new developments, parking lots and for building illumination. There’s no question that LED lighting can be used wisely to make everyone happy – stargazers, drivers, shoppers and walkers. For help and more information, the International Dark-Sky Association(IDA)is a great place to start. Here are some additional resources:
An artist's concept of the latest, highly accurate measurement of the Universe from BOSS. The spheres show the current size of the "baryon acoustic oscillations" (BAOs) from the early universe, which have helped to set the distribution of galaxies that we see in the universe today. Galaxies have a slight tendency to align along the edges of the spheres — the alignment has been greatly exaggerated in this illustration. BAOs can be used as a "standard ruler" (white line) to measure the distances to all the galaxies in the universe. Credit: Zosia Rostomian, Lawrence Berkeley National Laboratory
When it comes to accuracy, everyone strives for a hundred percent, but measuring cosmic distances leaves a bit more to chance. Just days ago, researchers from the Baryon Oscillation Spectroscopic Survey (BOSS) announced to the world that they have been able to measure the distance to galaxies located more than six billion light-years away to a confidence level of just one percent. If this announcement doesn’t seem exciting, then think on what it means to other studies. These new measurements give a parameter to the properties of the ubiquitous “dark energy” – the source of universal expansion.
“There are not many things in our daily lives that we know to one-percent accuracy,” said David Schlegel, a physicist at Lawrence Berkeley National Laboratory (LBNL) and the principal investigator of BOSS. “I now know the size of the universe better than I know the size of my house.”
The research team’s findings were presented at the meeting of the American Astronomical Society by Harvard University astronomer Daniel Eisenstein, the director of the Sloan Digital Sky Survey III (SDSS-III), the worldwide organization which includes BOSS. They are detailed in a series of articles submitted to journals by the BOSS collaboration last month, all of which are now available as online preprints.
“Determining distance is a fundamental challenge of astronomy,” said Eisenstein. “You see something in the sky — how far away is it? Once you know how far away it is, learning everything else about it is suddenly much easier.”
When it comes to measuring distances in space, astronomers have employed many methods. To measure distances to planets has been accomplished using radar, but it has its constraints and going further into space means a less direct method. Even though they have been proved to be amazingly accurate, there is still an uncertainty factor involved – one that is expressed as a percentage. For example, if you were to measure the distance from an object 200 miles away to within a true value of 2 miles, then you have measured with an accuracy of 1%. Cosmically speaking, just a few hundred stars and a handful of star clusters are actually close enough to have their distances so accurately predicted. They reside within the Milky Way and are just a few thousand light-years away. BOSS takes it to the extreme… its measurements go well beyond our galactic boundaries, more than a million times further, and maps the Universe with unparalleled accuracy.
Thanks to these new, highly-accurate distance measurements, BOSS astronomers are making headway in the field of dark energy. “We don’t yet understand what dark energy is,” explained Eisenstein, “but we can measure its properties. Then, we compare those values to what we expect them to be, given our current understanding of the universe. The better our measurements, the more we can learn.”
Just how is it done? To achieve a one-percent measurement at six billion light years isn’t as easy as measuring a solar system object, or even one contained within our galaxy. That’s where the BOSS comes into play. It’s the largest of the four projects that make up the Sloan Digital Sky Survey III (SDSS-III), and was built to take advantage of this technique: measuring the so-called “baryon acoustic oscillations” (BAOs), subtle periodic ripples in the distribution of galaxies in the cosmos. These ripples are the signature of pressure waves which once cruised the early Universe at a time when things were so hot and dense that photons marched along with baryons – the stuff which creates the nuclei of atoms. Since the size of the ripple is known, that size can now be measured by mapping galaxies.
“With these galaxy measurements, nature has given us a beautiful ruler,” said Ashley Ross, an astronomer from the University of Portsmouth. “The ruler happens to be half a billion light-years long, so we can use it to measure distances precisely, even from very far away.
Using its specialized instrumentation which can make detailed measurements of a thousand galaxies at a time, BOSS took on a huge challenge – mapping the location of more than a million galaxies. “On a clear night when everything goes perfectly, we can add more than 8000 galaxies and quasars to the map,” said Kaike Pan, who leads the team of observers at the SDSS-III’s Sloan Foundation 2.5-meter Telescope at Apache Point Observatory in New Mexico.
Although the BOSS research team presented its early galaxy maps and beginning BAO measurements a year ago, this new data covers twice as much territory and gives an even more accurate measurement – including those to nearby galaxies. “Making these measurements at two different distances allows us to see how the expansion of the universe has changed over time, which will help us understand why it is accelerating,” explained University of Portsmouth astronomer Rita Tojeiro, who co-chairs the BOSS galaxy clustering working group along with Jeremy Tinker of New York University.
Also doing a similar study is Mariana Vargas-Magana, a postdoctoral researcher at Carnegie Mellon University. To enable even more accuracy, she’s looking into any subtle effects which could influence the BOSS measurements. “When you’re trying to reach one percent, you have to be paranoid about everything that could go even slightly wrong,” said Vargas-Magana — for example, slight differences in how galaxies were identified could have thrown off the entire measurement of their distribution, so different parts of the sky had to be checked carefully. “Fortunately,” Vargas-Magana said, “there are plenty of careful people on our team to check our assumptions. By the time all of them are satisfied, we are sure we didn’t miss anything.”
As of the present, these new BOSS findings would seem to be consistent with what we consider to be form of dark energy – a constant found throughout the history of the Universe. According to the news release, this “cosmological constant” is one of just six numbers required to create a model which coincides with the scale and structure of the Universe. Schlegel compares this six-number model to a pane of glass, which is pinned in place by bolts that represent different measurements of the history of the Universe. “BOSS now has one of the tightest of those bolts, and we just gave it another half-turn,” said Schlegel. “Each time you ratchet up the tension and the glass doesn’t break, that’s a success of the model.”
The "Hand ( or Fist?) of God" nebula enshrouding pulsar PSR B1509-58. The upper red cloud structure is RCW 89. The image is a composite of Chandra observations (red & green), while NuSTAR observations are denoted in blue.
One star player in this week’s findings out of the 223rd meeting of the American Astronomical Society has been the Nuclear Spectroscopic Telescope Array Mission, also known as NuSTAR. On Thursday, researchers revealed some exciting new results and images from the mission, as well as what we can expect from NuSTAR down the road.
NuSTAR was launched on June 13th, 2012 on a Pegasus XL rocket deployed from a Lockheed L-1011 “TriStar” aircraft flying near the Kwajalein Atoll in the middle of the Pacific Ocean.
Part of a new series of low-cost missions, NuSTAR is the first of its kind to employ a space telescope focusing on the high energy X-ray end of the spectrum centered around 5-80 KeV.
Daniel Stern, part of the NuSTAR team at JPL Caltech, revealed a new X-ray image of the now-famous supernova remnant dubbed “The Hand of God.” Discovered by the Einstein X-ray observatory in 1982, the Hand is home to pulsar PSR B1509-58 or B1509 for short, and sits about 18,000 light years away in the southern hemisphere constellation Circinus. B1509 spins about 7 times per second, and the supernova that formed the pulsar is estimated to have occurred 20,000 years ago and would’ve been visible form Earth about 2,000 years ago.
A diagram of the NuSTAR satellite. (NASA/JPL/Caltech)
While the Chandra X-ray observatory has scrutinized the region before, NuSTAR can peer into its very heart. In fact, Stern notes that views from NuSTAR take on less of an appearance of a “Hand” and more of a “Fist”. Of course, the appearance of any nebula is a matter of perspective. Pareidolia litter the deep sky, whether it’s the Pillars of Creation to the Owl Nebula. We can’t help but being reminded of the mysterious “cosmic hand” that the Guardians of Oa of Green Lantern fame saw when they peered back at the moment of creation. Apparently, the “Hand” is also rather Simpson-esque, sporting only three “fingers!”
An diagram of the Hand of God. Credit: NASA/JPL/Caltech/McGill).
NuSTAR is the first, and so far only, focusing hard X-ray observatory deployed in orbit. NuSTAR employs what’s known as grazing incidence optics in a Wolter telescope configuration, and the concentric shells of the detector look like layers on an onion. NuSTAR also requires a large focal length, and employs a long boom that was deployed shortly after launch.
The hard X-ray regime that NuSTAR monitors is similar to what you encounter in your dentist’s office or in a TSA body scanner. Unlike the JEM-X monitor aboard ESA’s INTERGRAL or the Swift observatory, which have a broad resolution of about half a degree to a degree, NuSTAR has an unprecedented resolution of about 18 arc seconds.
The first data release from NuSTAR was in late 2013. NuSTAR is just begging to show its stuff, however, in terms of what researchers anticipate that it’s capable of.
“NuSTAR is uniquely able to map the Titanium-44 emission, which is a radioactive tracer of (supernova) explosion physics,” Daniel Stern told Universe Today.
NuSTAR will also be able to pinpoint high energy sources at the center of our galaxy. “No previous high-energy mission has had the imaging resolution of NuSTAR,” Stern told Universe Today. ”Our order-of-magnitude increase in image sharpness means that we’re able to map out that very rich region of the sky, which is populated by supernovae remnants, X-ray binaries, as well as the big black hole at the center of our Galaxy, Sagittarius A* (pronounced “A-star).”
NuSTAR identifies new black hole candidates (in blue) in the COSMOS field. The discoveries in the image above are overlayed on previous black holes spotted by Chandra in the same field, which are denoted in red and green. (Credit-NASA/JPL-Caltech/Yale University).
Yale University researcher Francesca Civano also presented a new image from NuSTAR depicting black holes that were previously obscured from view. NuSTAR is especially suited for this, gazing into the hearts of energetic galaxies that are invisible to observatories such Chandra or XMM-Newton. The image presented covers the area of Hubble’s Cosmic Evolution Survey, known as COSMOS in the constellation Sextans. In fact, Civano notes that NuSTAR has already seen the highest number of obscured black hole candidates to date.
“This is a hot topic in astronomy,” Civano said in a recent press release. “We want to understand how black holes grew and the degree to which they are obscured.”
To this end, NuSTAR researchers are taking a stacked “wedding cake” approach, looking at successively larger slices of the sky from previous surveys. These include looking at the quarter degree field of the Great Observatories Origins Deep Survey (GOOD-S) for 18 days, the two degree wide COSMOS field for 36 days, and the large four degree Swift-BAT fields for 40 day periods hunting for serendipitous sources.
Interestingly, NuSTAR has also opened the window on the hard X-ray background that permeates the universe as well. This peaks in the 20-30 KeV range, and is the combination of the X-ray emissions of millions of black holes.
“For several decades already, we’ve known what the sum total emission of the sky is across the X-ray regime,” Stern told Universe Today. “The shape of this cosmic X-ray background peaks strongly in the NuSTAR range. The most likely interpretation is that there are a large number of obscured black holes out there, objects that are hard to find in other energy bands. NuSTAR should find these sources.”
And NuSTAR may just represent the beginning of a new era in X-ray astronomy. ESA is moving ahead with its next generation flagship X-ray mission, known as Athena+, set to launch sometime next decade. Ideas abound for wide-field imagers and X-ray polarimeters, and one day, we may see a successor to NuSTAR dubbed the High-Energy X-ray Probe or (HEX-P) make it into space.
But for now, expect some great science out of NuSTAR, as it unlocks the secrets of the X-ray universe!
What’s the oldest thing you’ve ever held in your hand? A piece of petrified wood? A fossilized trilobite? A chunk of glacier-carved granite? Those are some pretty old things, sure, but there are even older objects to be found across the world… that came from out of this world. And thanks to “Meteorite Men” co-host, author, and educator Geoff Notkin and his company Aerolite Meteorites, you can own a truly ancient piece of the Solar System that can date back over 4.5 billion years.
Founded in 2005, Aerolite (which is an archaic term for meteorite) offers many different varieties of meteorites for sale, from gorgeous specimens worthy of a world-class museum to smaller fragments that you could proudly — and economically — display on your desk. Recently I had the opportunity to talk in depth with Geoff about Aerolite and his life’s work as a meteorite collector and dealer. Here are some of the fascinating things he had to say…
So Geoff, what initially got you interested in meteorites and finding them for yourself?
“It’s been a lifelong passion for me, but I’m lucky in that I can really put my finger on a specific event when I was a kid and that was my mother taking me to the Geological Museum in London when I was six or seven… I was already a rock hound, I loved collecting fossils, and my dad was a very keen amateur astronomer. And so I had this love of astronomy and this fascination with other worlds for as long as I can remember. I’m a very tactile person; I’m very hands-on. I like to know how things work… I want to know all the bits and pieces. I was frustrated a bit, because I wanted to know more about astronomy. I could see all these planets and places through the ‘scope, but I couldn’t touch them. But I could touch rocks and fossils.
“So I’m six or seven years old, and I’m on the second floor of the Museum in the Hall of Rocks and Minerals. And at the back was this small display area that’s very dark. And you walked through an arch, it’s almost like walking into a cave. And it was very low light back there, and that was the meteorite collection.
“There were a couple of large meteorites on stands, and in those days — it was the late 60s — security wasn’t the issue that it is today. So you could touch the big specimens, and so I put my hands on these giant meteorites and I was absolutely enthralled. And I had this sort of epiphany: meteorites were the locus between my two interests, astronomy and rock-hounding. Because they’re rocks… they’re rock samples from outer space. I promised myself as a kid that one day I would have an actual meteorite.
“By finding or owning meteorites, you are forging a solid and tangible connection with astronomy.”
“Of course at the time there was no meteorite business, no meteorite magazines, there was no network of collectors like there is today. Back in the late 60s when I gave myself this challenge it was like saying I was going to start my own space program! But not only did it come true, it’s become my career.”
What makes Aerolite such a great place to buy meteorites?
“I think the caring for the subject matter really shows on the website. We have the best photography in the entire meteorite industry. I think we have the largest selection… we certainly spend a great deal of time discussing the history and importance of pieces… every single meteorite on our website has a detailed description and in most cases multiple photographs. My view is if you’re going to do something, you should really do it to the best of your ability. We don’t cut any corners, we don’t sell anything unless we’re one hundred percent sure of what it is and where it came from.
“I want buyers and visitors to look at the website and share my sense of wonder about meteorites. I think meteorites are the most wonderful things in existence, they’re actual visitors from outer space — they’re inanimate aliens that have landed on our planet.”
“We do this because we want to share our passion. We stand by every piece that we sell.”
How can people be sure they are getting actual meteorites (and not just funny-looking rocks?)
“This is something that’s more important to pay attention to now than ever. Are there fakes, are there shady people? Yes and yes. If you go on eBay at any given time you will find numerous pieces that are being offered for sale that are either not meteorites at all or are one thing being passed off as another thing. Sometimes this is malicious, sometimes people just don’t know any better. So the best way to buy a meteorite and know that it’s real is to buy from a respected dealer who has a solid history in the field.
“I’m by no means the only person who does this. There are a number of very well-established dealers around the world, and a good place to start is the International Meteorite Collectors Association(of which Geoff is a member) which is an international group with hundreds of members — collectors and dealers… it’s sort of a watchdog group that tries to maintain high standards of integrity in the field.
“My company has a very strict policy of never offering anything that’s questionable.”
“I see fakes all the time,” Geoff added. “On eBay, on websites, in newspaper ads… you do have to be careful. My company has a very strict policy of never offering anything that’s questionable. And we do get offered questionable things. There are some countries that have strict policies about exporting meteorites — Australia and Canada being two of them — and we work very closely with academia in both countries, and we have legally exported meteorites from those countries. Not only do we abide by international regulations, we actively support them.”
So you not only offer meteorites for sale to the general public, but you also donate to schools and museums.
“We work very closely with most of the world’s major meteorite institutions. I have provided specimens to the American Museum of Natural History in New York, the British Museum of Natural History in London, the Vienna Museum of Natural History, the Center for Meteorite Studies… we work with almost everyone. When we find something that is new or different or exciting, we always donate a piece or pieces to our colleagues in academia. It’s just the right thing, it’s the right thing to do if you discover something important to make it available to science.
“Most universities and museums don’t have acquisitions budgets and can’t afford to buy things that they might like to have. In return they classify the meteorites that we found, and they go into the permanent literature and become more valuable as a result. A meteorite with a history and a name and classification is worth more than a random meteorite that somebody just found in a desert. So everybody benefits, it’s a really good match.”
In other words, you really are making a contribution to science as opposed to just “looting.”
“Exactly. And I have, a very few times, gotten emails from disgruntled viewers who didn’t understand what we were doing, saying ‘what makes you think it’s okay to come to Australia and take our meteorites,’ for example. So I wrote a very courteous email back saying that we were in Australia with the express permission and cooperation of the Australian park services and one of the senior park rangers was there with us. And not only did we follow the proper procedure in having those specimens exported from Australia, I donated rare meteorites to collections just as a ‘thank you’ for working with us. It wasn’t a trade, it was a thank you. So everywhere we go, whatever we do, we try and leave a good impression.”
Geoff added, “I do this out of love… this isn’t the best way to make a living! Being a meteorite hunter is probably not the best capital return on your time but it’s a very exciting and rewarding life in every other way.”
And thus, by buying meteorites from Aerolite, customers aren’t just helping pay for your expeditions and your work but also supporting research and education too.
“People who purchase from us are really participating in the growth of this science. Also, something very near and dear to my heart is science education for kids. You know that I am the host of an educational series called STEM Journals, which is a very — I think — amusing, entertaining, funny, fast-paced look at science, technology, engineering, and math topics. But you can’t make a living doing television shows like that. This is a labor of love… we do it because we think it’s important. If I didn’t have a commercial meteorite company to help underwrite the costs of educational programming and educational books, we just couldn’t do it. It’s as simple as that.
“So we always try to give back. That’s why I speak at schools and universities and give away meteorites to deserving kids at gem shows… because it was done to me when I was seven years old. The look of wonder you see on a kid’s face when you connect with them and they start to grasp the wonder of science… that’s something they’ll never forget.”
That’s great. And it sounds like you haven’t forgotten it yet either!
“I must say after all these years, I’ve been doing this close to full time for nearly twenty years and you never lose the amazement and the wonder of when a meteorite’s found or uncovered. I never go ‘oh, jeez, it’s just another billion-year-old space rock that fell to Earth!’ So it is a privilege to be in a work field where almost daily something wondrous happens.”
As we here at Universe Today know, when it concerns space that’s a common occurrence!
“Exactly!”
One last thing Geoff… do you think we’ll ever run out of meteorites?
“The meteorite collecting field has grown tremendously in the past ten years, and Meteorite Men is part of that. There is a finite supply of meteorites. Of course there are more landing all the time, but not enough to replenish the demand. Periodically there is a new very large discovery made, such as the Gebil Kamil iron in Egypt a couple of years ago. But what is happening is a significant increase in price and a decrease in selection, so some of the real staples we used to see… you can’t get them anymore.
“Still, people who want a meteorite collection, now is a great time for them to be buying because there are more meteorites available than in the past — but it’s not going to stay that way for very long. It’s like any other collectible that has a finite supply.”
Makes sense… I’ll take that as ‘inside advice’ to place an order soon!
______________
My thanks to Geoff for the chance to talk with him a little bit about his fascinating past, his passion, and his company. And as an added bonus to Universe Today readers, Geoff is extending a special 15% off on orders from Aerolite Meteorites — simply mention the code UNIVERSETODAY when you place an order!* (Trust me — once you browse through the site you’ll find something you want.) Also, if you’re in the Tucson area, Geoff Notkin and Aerolite Meteorites will have a table at the Tucson Gem and Mineral Show starting Jan. 31.
One of several meteorite-hunting books by Geoff, featuring an introduction by Neil Gaiman.
Be sure to check out Geoff’s television show STEM Journals on COX7 — the full first two seasons can be found online here and here, and shooting for the third season will be underway soon.
Want to know how to find “inanimate aliens” for yourself? You can find Geoff’s books on meteorite hunting here, as well as some of the right equipment for the job.
An illustration of the triple millisecond pulsar with its two white dwarf companions. According to the new model, this remarkable system has survived three phases of mass transfer and a supernova explosion, and yet it remained dynamically stable. Credit: Thomas Tauris
If you’re looking for something truly unique, then check out the cosmic menage aux trois ferreted out by a team of international astronomers using the Green Bank Telescope (GBT). This unusual group located in the constellation of Taurus includes a pulsar which is orbited by a pair of white dwarf stars. It’s the first time researchers have identified a triple star system containing a pulsar and the team has already employed the clock-like precision of the pulsar’s beat to observe the effects of gravitational interactions.
“This is a truly remarkable system with three degenerate objects. It has survived three phases of mass transfer and a supernova explosion, and yet it remained dynamically stable”, says Thomas Tauris, first author of the present study. “Pulsars have previously been found with planets and in recent years a number of peculiar binary pulsars were discovered which seem to require a triple system origin. But this new millisecond pulsar is the first to be detected with two white dwarfs.”
This wasn’t just a chance discovery. The observations of 4,200 light year distant J0337+1715 came from an intensive study program involving several of the world’s largest radio telescopes including the GBT, the Arecibo radio telescope in Puerto Rico, and ASTRON’s Westerbork Synthesis Radio Telescope in the Netherlands. West Virginia University graduate student Jason Boyles was the first to detect the millisecond pulsar, spinning nearly 366 times per second, and captured in a system which isn’t any larger than Earth’s orbit around the Sun. This close knit association, coupled with the fact the trio of stars is far denser than the Sun create the perfect conditions to examine the true nature of gravity. Generations of scientists have waited for such an opportunity to study the ‘Strong Equivalence Principle’ postulated in Einstein’s theory of General Relativity. “This triple star system gives us the best-ever cosmic laboratory for learning how such three-body systems work, and potentially for detecting problems with General Relativity, which some physicists expect to see under such extreme conditions,” says first author Scott Ransom of the National Radio Astronomy Observatory (NRAO).
“It was a monumental observing campaign,” comments Jason Hessels, of ASTRON (the Netherlands Institute for Radio Astronomy) and the University of Amsterdam. “For a time we were observing this pulsar every single day, just so we could make sense of the complicated way in which it was moving around its two companion stars.” Hessels led the frequent monitoring of the system with the Westerbork Synthesis Radio Telescope.
Not only did the research team tackle a formidable amount of data, but they also took on the challenge of modeling the system. “Our observations of this system have made some of the most accurate measurements of masses in astrophysics,” says Anne Archibald, also from ASTRON. “Some of our measurements of the relative positions of the stars in the system are accurate to hundreds of meters, even though these stars are about 10,000 trillion kilometers from Earth” she adds.
Leading the study, Archibald created the system simulation which predicts its motions. Using the solid science methods once employed by Isaac Newton to study the Earth-Moon-Sun system, she then combined the data with the ‘new’ gravity of Albert Einstein, which was necessary to make sense of the information. “Moving forward, the system gives the scientists the best opportunity yet to discover a violation of a concept called the Strong Equivalence Principle. This principle is an important aspect of the theory of General Relativity, and states that the effect of gravity on a body does not depend on the nature or internal structure of that body.”
Need a refresher on the equivalence principle? Then if you don’t remember Galileo’s dropping two different weighted balls from the Leaning Tower of Pisa, then perhaps you’ll recall Apollo 15 Commander Dave Scott’s dropping of a hammer and a falcon feather while standing on the airless surface of the Moon in 1971. Thanks to mirrors left on the lunar surface, laser ranging measurements have been studied for years and provide the strongest constraints on the validity of the equivalence principle. Here the experimental masses are the stars themselves, and their different masses and gravitational binding energies will serve to check whether they all fall towards each other according to the Strong Equivalence Principle, or not. “Using the pulsar’s clock-like signal we’ve started testing this,” Archibald explains. “We believe that our tests will be much more sensitive than any previous attempts to find a deviation from the Strong Equivalence Principle.” “We’re extremely happy to have such a powerful laboratory for studying gravity,” Hessels adds. “Similar star systems must be extremely rare in our galaxy, and we’ve luckily found one of the few!”
A composite x-ray and optical image of a dwarf galaxy showing the x-ray transcient in the inset. Credit-CFHT (Optical), NASA/CXC/University of Alabama/GSCF/UMD/W.P. Maksym, D.Donato et al.
This week, astronomers announced the detection of a rare event, a star being torn to shreds by a massive black hole in the heart of a distant dwarf galaxy. The evidence was presented Wednesday January 8th at the ongoing 223rd meeting of the American Astronomical Society being held this week in Washington D.C.
Although other instances of the death of stars at the hands of black holes have been witnessed before, Chandra may have been the first to document an intermediate black hole at the heart of a dwarf galaxy “in the act”.
The results span observations carried out by the space-based Chandra X-ray observatory over a period spanning 1999 to 2005. The search is part of an archival study of observations, and revealed no further outbursts after 2005.
“We can’t see the star being torn apart by the black hole, but we can track what happens to the star’s remains,” said University of Alabama’s Peter Maksym in a recent press release. A comparison of with similar events seen in larger galaxies backs up the ruling of “death by black hole.” A competing team led by Davide Donato also looked at archival data from Chandra and the Extreme Ultraviolet Explorer (EUVE), along with supplementary observations from the Canada-France-Hawaii Telescope to determine the brightness of the host galaxy, and gained similar results.
The dwarf galaxy in the Abell 1795 cluster that was observed has the name WINGS J134849.88+263557.5, or WINGS J1348 for short. The Abell 1795 cluster is about 800 million light years distant.
WINGS denotes the galaxy’s membership in the WIde-field Nearby Galaxy-cluster Survey, and the phone number-like designation is the galaxy’s position in the sky in right ascension and declination.
Like most galaxies associated with galaxy clusters, WINGS J1348 a dwarf galaxy probably smaller than our own satellite galaxy known as the Large Magellanic Cloud. The Abell 1795 cluster is located in the constellation Boötes, and WINGS J1348 has an extremely faint visual magnitude of +22.46.
An optical view of the Abell 1795 galaxy cluster. Credit- NASA/CFHT/D. Donato et al.
“Scientists have been searching for these intermediate mass black holes for decades,” NASA’s Davide Donato said in a recent press release “We have lots of evidence for small black holes and very big ones, but these medium-sized ones have been tough to pin down.”
Maksym notes in an interview with Universe Today that this isn’t the first detection of an intermediate-mass black hole, which are a class of black holes often dubbed the “mostly” missing link between stellar mass and super massive black holes.
The mass range for intermediate black holes is generally pegged at 100 to one million solar masses.
What makes the event witnessed by Chandra in WINGS J1348 special is that astronomers managed to capture a rare tidal flare, as opposed to a supermassive black hole in the core of an active galaxy.
A closeup view of the bright, long duration flare witnessed by Chandra pre-2005. Credit- NASA/CXC/University of Alabama/W.P. Maksym et al.
“Most of the time, black holes eat very little, so they can hide very well,” Maksym said in the AAS meeting on Wednesday.
This discovery pushes the limits on what we know of intermediate black holes. By documenting an observed number of tidal flare events, it can be inferred that a number of inactive black holes must be lurking in galaxies as well. The predicted number of tidal events that occur also have implications for the eventual detection of gravity waves from said mergers.
And more examples of these types of X-ray flare events could be waiting to be uncovered in the Chandra data as well.
“Chandra has taken quite a few pictures over the past 13+ years, and collaborators and I have an ongoing program to look for more tidal flares,” Maksym told Universe Today. “We’ve found one other this way, from a larger galaxy, and hope to find more. Abell 1795 was a particularly good place to look because as a calibration source, there were tons of pictures.”
Use of Chandra data was also ideal for the study because its spatial resolution allowed researchers to pinpoint an individual galaxy in the cluster. Maksym also notes that while it’s hard to get follow-up observations of events based on archival data, future missions dedicated to X-ray astronomy with wider fields of view may be able to scour the skies looking for such tidal flaring events.
The NuSTAR satellite was the latest X-Ray observatory to launch in 2012. NASA’s Extreme Ultraviolet Explorer picked up a strong ultraviolet source in 1998 right around the time of the tidal flare event, and ESA’s XMM-Newton satellite may have detected the event in 2000 as well.
This was also one of the smallest galaxies ever observed to contain a black hole. Maksym noted in Wednesday’s press conference that an alternative explanation could be a super-massive black hole in a tiny galaxy that just “nibbled” on a passing star, but said that new data from the Gemini observatory does not support this.
“It would be like looking into a dog house and finding a large ogre crammed in there,” Maksym said at Wednesday’s press conference.
This discovery provides valuable insight into the nature of intermediate mass black holes and their formation and behavior. What other elusive cosmological beasties are lying in wait to be discovered in the archives?
Congrats to Maksym and teams on this exciting new discovery, and the witnessing of a rare celestial event!
Zodiacal light over Charleston, RI (Scott MacNeill, Frosty Drew Observatory)
The result of sunlight reflected off fine particles of dust aligned along the plane of the Solar System, zodiacal light appears as a diffuse, hazy band of light stretching upwards from the horizon after sunset or before sunrise. Most people have never seen zodiacal light because it’s very dim, and thus an extremely dark sky is required. But thanks to recent dark sky regulations that were passed in the coastal Rhode Island town of Charlestown, this elusive astronomical phenomenon has become visible — to the particular delight of one local observatory.
Frosty Drew Observatory is a small, privately-run observatory featuring a Meade Schmidt Cassegrain LX200 16″ telescope mounted on an alt-azimuth pier inside a dome that stands among the sports fields, parking areas, and nature trails of Ninigret Park and Wildlife Refuge in southern Rhode Island. Being a good distance from urban centers and developed areas, the skies there are some of the darkest in the state. But situated along the eastern seaboard of the United States, even Charlestown’s coast lies beneath a perpetual haze of light pollution.
A new town ordinance, passed in 2012, helped to darken the skies a notch. And while watching comet ISON one evening, astronomer Scott MacNeill became aware of the results.
The following is an excerpt from a Jan. 7 article by Cynthia Drummond of The Westerly Sun, reprinted with permission:
Scott MacNeill was in Ninigret Park, his telescope trained on the comet “Ison,” when he saw something he had never seen before: a celestial phenomenon called “zodiacal light.” After several decades of being obscured by light pollution, the feature was visible again, thanks to the town’s “dark sky” ordinance.
At first, MacNeill, an astronomer and the assistant director of the Frosty Drew observatory, didn’t believe what he was seeing. The cone of light, which he initially thought was light pollution, turned out to be a faint, white glow that astronomers at the observatory hadn’t glimpsed in recent memory.
A line of visitors is cast in silhouette against the evening sky as they wait to go into the Frosty Drew Observatory. (Susannah Snowden / The Westerly Sun)
“To see it in New England, period, is amazing, Zodiacal light is a common marker for the quality of a dark sky location.”
– Scott MacNeill, Astronomer, Frosty Drew Observatory
“I was sitting back for a minute, just looking at the sky, and I said ‘wait a minute. This is the southeast, and to the southeast is the ocean. What is coming up in the southeast?’ And then I noticed the cone. And I’m like ‘no way. That can’t be zodiacal light.’ I’ve heard so many stories about the days of old at Frosty Drew when you used to see zodiacal light here,” he said.
MacNeill credits Charlestown’s dark sky ordinance with reducing light pollution to the point where zodiacal light can be seen again. The ordinance, adopted in October 2012, regulates commercial outdoor lighting in order to improve the town’s dark sky for star-gazers, and to protect residents, wildlife and light-sensitive plants from the effects of light pollution.
One of the provisions of the ordinance requires that new lighting fixtures be designed to focus downward so light does not radiate up into the sky. Lighting installed before the ordinance was passed is exempt from the new regulations.
Building and Zoning Official Joe Warner explained that after the ordinance passed, two major sources of light pollution near the observatory were modified so they would be less polluting.
“At Ninigret Wildlife Refuge, some of the pole lights were changed to dark sky compliant lighting. The Charlestown Ambulance barn also replaced their lights with dark sky compliant lights,” he said.
Charlestown has been recognized as one of the only dark spots on the New England coast — a rare treat for people who enjoy looking at the night sky.
It’s fantastic to see results like this both occurring and being publicized, as dark skies have become quite rare in many populated areas of the world. People who live in or near major metropolitan areas — even in the surrounding sprawling suburbs — often never truly get a dark sky, not such that the dimmer stars, the Milky Way, meteor showers — and yes, the zodiacal light — can be readily seen on an otherwise clear night. The view of a star-filled night sky that has been a part of the human existence for millennia has steadily been doused by the murky glow of artificial lighting. Luckily groups like the International Dark Sky Association are actively trying to change that, but change isn’t always welcome — or quick.
At least, in one Rhode Island town anyway, a small victory has been won for the night.
(HT to Brown University’s Ladd Observatory in Providence for the heads-up on this story.)
