Astronomy Archives

May 21, 2014December 23, 2015 by Bob King

Potential Weekend Meteor Shower Will Pelt the Moon Too!

the shaded or speckled area indicates where May Camelopardalids can stoke the lunar surface. telescopic observers will want to point their telescopes to the shaded dark area at the top right of the lunar disk.

If the hoped-for meteor blast materializes this Friday night / Saturday morning (May 23-24) Earth won’t be the only world getting peppered with debris strewn by comet 209P/LINEAR. The moon will zoom through the comet’s dusty filaments in tandem with us.

Bill Cooke, lead for NASA’s Meteoroid Environment Office, alerts skywatchers to the possibility of lunar meteorite impacts starting around 9:30 p.m. CDT Friday night through 6 a.m. CDT (2:30-11 UTC) Saturday morning with a peak around 1-3 a.m. CDT (6-8 UTC).

While western hemisphere observers will be in the best location, these times indicate that European and African skywatchers might also get a taste of the action around the start of the lunar shower. And while South America is too far south for viewing the Earth-directed Camelopardalids, the moon will be in a good position to have a go at lunar meteor hunting. Find your moonrise time HERE.

Earlier lunar impact on the earthlit portion of the moon. Credit: NASA — Earlier lunar impact on the earthlit portion of the moon recorded by video camera. Credit: NASA

The thick crescent moon will be well-placed around peak viewing time for East Coast skywatchers, shining above Venus in the eastern sky near the start of morning twilight. For the Midwest, the moon will just be rising at that hour, while skywatchers living in the western half of the country will have to wait until after maximum for a look:

“Anyone in the U.S. should monitor the moon until dawn,” said Cooke, who estimates that impacts might shine briefly at magnitude +8-9.

Any meteors hitting the moon will also be burning up as meteors in Earth's skies from the direction of the dim constellation Camelopardalis the Giraffe located in the northern sky below Polaris in the Little Dipper. Stellarium — Any meteors hitting the moon will also be burning up as meteors in Earth’s skies from the direction of the dim constellation Camelopardalis the Giraffe located in the northern sky below Polaris in the Little Dipper. Stellarium

“The models indicate the Camelopardalids have some big particles but move slowly around 16 ‘clicks’ a second (16 km/sec or 10 miles per second). It all depends on kinetic energy”, he added. Kinetic energy is the energy an object possesses due to its motion. Even small objects can pack a wallop if they’re moving swiftly.

Bright lunar meteorite impact recorded on video on September 11, 2013. The estimated 900-lb. space rock flared to 4th magnitude.

Lunar crescents are ideal for meteor impact monitoring because much of the moon is in shadow, illuminated only by the dim glow of earthlight. Any meteor strikes stand out as tiny flashes against the darkened moonscape. For casual watching of lunar meteor impacts, you’ll need a 4-inch or larger telescope magnifying from 40x up to around 100x. Higher magnification is unnecessary as it restricts the field of view.

I can’t say how easy it will be to catch one, but it will require patience and a sort of casual vigilance. In other words, don’t look too hard. Try to relax your eyes while taking in the view. That’s why the favored method for capturing lunar impacts is a video camera hooked up to a telescope set to automatically track the moon. That way you can examine your results later in the light of day. Seeing a meteor hit live would truly be the experience of a lifetime. Here are some additional helpful tips.

Meteorite impact flashes seen from 2005 to the present. Fewer are seen in the white areas (lunar highlands) because flashes blend in compared to those occurring on the darker lunar 'seas' or maria. Credit: NASA — Meteorite impact flashes seen from 2005 to the present. Fewer are recorded in the white areas (lunar highlands) because the flashes blend into the landscape compared to those occurring on the darker lunar ‘seas’ or maria. Click for more information on lunar impacts. Credit: NASA

On average, about 73,000 lbs. (33 metric tons) of meteoroid material strike Earth’s atmosphere every day with only tiny fraction of it falling to the ground as meteorites. But the moon has virtually no atmosphere. With nothing in the way, even small pebbles strike its surface with great energy. It’s estimated that a 10-lb. (5 kg) meteoroid can excavate a crater 30 feet (9 meters) across and hurl 165,000 lbs. of lunar soil across the surface.

A meteoroid that size on an Earth-bound trajectory would not only be slowed down by the atmosphere but the pressure and heat it experienced during the plunge would ablate it into very small, safe pieces.

NASA astronomers are just as excited as you and I are about the potential new meteor shower. If you plan to take pictures or video of meteors streaking through Earth’s skies or get lucky enough to see one striking the moon, please send your observations / photos / videos to Brooke Boen ([email protected]) at NASA’s Marshall Space Flight Center. Scientists there will use the data to better understand and characterize this newly born meteor blast.

On the night of May 23-24, Bill Cooke will host a live web chat from 11 p.m. to 3 a.m. EDT with a view of the skies over Huntsville, Alabama. Check it out.

May 21, 2014December 23, 2015 by Shannon Hall

Physicists Pave the Way to Turn Light into Matter

This artist's conception shows two photons (in green) colliding. Image Credit: ATLAS / LHC

E = mc². It’s one of the most basic and fundamental equations throughout astrophysics. But it does more than suggest that mass and energy are interconnected, it implies that light can be physically transformed into matter.

But can it really — physically — be done? Scientists proposed the theory more than 80 years ago, but only today have they paved the way to make this transformation routinely on Earth.

The concept calls for a new kind of photon-photon collider. It sounds like science fiction, but it could be turned into reality with existing technology.

“Although the theory is conceptually simple, it has been very difficult to verify experimentally,” said lead researcher Oliver Pike from London’s Imperial College in a press release. “We were able to develop the idea for the collider very quickly, but the experimental design we propose can be carried out with relative ease.”

In 1934, two physicists Gregory Breit and John Wheeler proposed that it should be possible to turn light into matter by smashing together only two photons, the fundamental particles of light, to create an electron and a positron. It was the simplest method of turning light into matter ever predicted, but it has never been observed in the laboratory.

Past experiments have required the addition of massive high-energy particles. We’ve seen from the development of nuclear weapons and fission reactors that a tiny amount of matter can yield a tremendous amount of energy. So it seems Breit and Wheeler’s theory would require the opposite effect: tremendous amounts of energy from photons to yield a tiny amount of matter.

This experiment will be a first in that it doesn’t require the addition of massive high-energy particles. It will be performed purely from photons.

The concept calls for using a high-intensity laser to speed up electrons to just below the speed of light, and then smash them into a slab of gold to create a beam of photons a billion times more energetic than visible light. At the same time, another laser beam would be blasted onto a hohlraum — a small gold container meaning “empty can” in German — that would create a radiation field with photons buzzing inside.

The initial photon beam would be directed into the center of the hohlraum. When the photons from the two sources collide, some would be converted into pairs of electrons and positrons. A detector would then pick up the signatures form the matter and antimatter as they flew out of the container.

Theories describing light and matter interactions. Image Credit: Oliver Pike, Imperial College London

“Within a few hours of looking for applications of hohlraums outside their traditional role in fusion energy research, we were astonished to find they provided the perfect conditions for creating a photon collider,” Pike said. “The race to carry out and complete the experiment is on!”

The demonstration, if carried out successfully, would be a new type of high-energy physics experiment. It would complete physicists’ list of the fundamental ways in which light and matter interact, and both recreate a process that was important 100 seconds after the Big Bang and a process visible in gamma ray bursts, the most powerful explosions in the cosmos.

The paper has been published in Nature Photonics.

May 21, 2014December 23, 2015 by Elizabeth Howell

Dramatic Starscape Helps Astronomers Learn About Our Own Galaxy

Star cluster NGC 3590 seen in a 2.2 -meter telescope located at the European Southern Observatory's La Silla Observatory in Chile. Credit: ESO/G. Beccari

Such stars, much science! Shining in front of darker dust, this star cluster (NGC 3590) is about 7,500 light-years from Earth. And because the cluster is located in a spiral arm of the Milky Way, looking at the new European Southern Observatory can help astronomers figure out more about our how galaxy came to be.

“These spiral arms are actually waves of piled up gas and stars sweeping through the galactic disc, triggering sparkling bursts of star formation and leaving clusters like NGC 3590 in their wake. By finding and observing young stars like those in NGC 3590, it is possible to determine the distances to the different parts of this spiral arm, telling us more about its structure,” ESO stated.

“Typical open clusters can contain anything from a few tens to a few thousands of stars, and provide astronomers with clues about stellar evolution. The stars in a cluster like NGC 3590 are born at around the same time from the same cloud of gas, making these clusters perfect test sites for theories on how stars form and evolve.”

As a spiral galaxy, the Milky Way has multiple “arms”. The one this cluster is located in is called the Carina spiral feature (part of the Carina-Sagittarius minor arm) after the constellation in which it is “most prominent.”

Source: European Southern Observatory

May 20, 2014December 23, 2015 by David Dickinson

Going Low for Omega Centauri: How to Spot a Southern Hemisphere Jewel from Mid-Northern Latitudes

47 Tucanae… the Coal Sack… Magellanic Clouds large and small… sure, it can be argued that the southern hemisphere sky has got all the “good stuff.” We’ve journeyed below the equator half a dozen times ourselves and we always make it a point to carry our trusty Canon 15x 45 image stabilized binocs – or track someone down with a serious ‘scope – even when astronomy isn’t the main focus of our particular away mission.

But did you know that you can glimpse one of the jewels of the southern hemisphere sky from mid-northern latitudes in May and June?

We’re talking about Omega Centauri in the constellation Centaurus. At a declination of -47 degrees south, it clears 5 degrees above the horizon as seen from around 37 degrees north, which corresponds to the latitudes of Richmond Virginia, Wichita Kansas and Sacramento, California in the United States and Seville Spain, Adana Turkey and Seoul South Korea worldwide.

Omega Centauri as imaged from near Oracle, Arizona at latitude 32 degrees 30′ north. Credit: Mike Weasner/Cassiopeia observatory.

In fact, it would be a fun project to see just how far north you could spot Omega Centauri from… located at right ascension 13 hours 26 minutes and declination -47 29’, Omega Centauri would theoretically juuusst clear the southern horizon at 52 degrees north, well into Canada… but has anyone caught sight of it that far north?

There’s evidence that Ptolemy knew of and recorded Omega Centauri in his Almagest as far back as 150 A.D. It was erroneously misidentified as a star over the centuries, hence the “Omega” designation. It was also too low in the southern sky to be included Charles Messier’s Paris-based catalog of deep sky objects, though it would’ve easily have made the cut had it been located farther north. Omega Centauri was first described by Edmond Halley in 1677 and made its catalog debut in 1746 when astronomer Jean-Philippe de Cheseaux listed it along with 21 other southern sky nebulae.

Shining at magnitude +4, Omega Centauri actually covers a section of sky slightly larger than the apparent size of a Full Moon and is an easy naked eye object from the southern hemisphere. From south of the equator we can easily pick out Omega Centauri from a dark sky site. On a recent trip to the Florida Keys, we could easily detect Omega Centauri riding high to the south over the Straits of Florida at local midnight. In fact, Arthur Upgreen muses in his fantastic book Many Skies just what Florida skies would look like if Omega Centauri were much closer to Earth, filling up the southern horizon scene.

The view from latitude 30 degrees north looking south at 10:30 PM local: click to enlarge. Created using Starry Night software.

Now for the wow factor of what you’re seeing. The largest of the 150-odd known globular clusters associated with our Milky Way Galaxy, Omega Centauri is almost 16,000 light years distant and weighs in at an estimated 4 million solar masses. Globular clusters are ancient structures and Omega Centauri contains millions of Population II stars dating from an age of about 12 billion years ago. The density at the core of the cluster is equal to a star per every 1/10^th of a light year apart, and any planets orbiting said stars would host truly dazzling skies.

The bright star Spica (Alpha Virginis) in the constellation of Virgo the Virgin makes a good guide to find Omega Centauri from the northern hemisphere, as both have nearly the same right ascension to within 10 arc minutes of each other. Both currently transit the southern meridian at around 11:00 AM local in late May, and Omega Centauri lies just 35 degrees — about 3 ½ hand widths held at arm’s length — south of Spica.

Approximate cutoff latitudes for spotting Omega Centauri and Gacrux to the south in May and June. Credit: USGS.

And speaking of Centaurus, the constellation was also recently host to a naked eye nova last year as well. Nova Cen 2013 topped out at magnitude +3.3, though it was placed much farther south than Omega Centauri.

Another unique target in the constellation Centaurus is known as Przybylski’s Star. A seemingly nondescript +8^th magnitude star, Przybylski’s Star has some peculiar spectral properties of rare trace elements. It also sits near the same declination as Omega Centauri at -46 43’ and has a right ascension of 11 hours 38’.

Finally, there’s another southern hemisphere treat peeking just above the southern horizon on late May and June evenings… look about 13 degrees to the lower right of Omega Centauri at around 10:30 PM local in late May, and you might just spy Gacrux (Gamma Crucis), the +1.6 magnitude star that makes up the “head” of the constellation Crux, the Southern Cross. This tough to spot target just tops out at 5 degrees above the southern horizon from here in Tampa Bay, Florida, beckoning northern hemisphere observers on these sultry May and June evenings to the jewels that lie just beyond the horizon to the south.

May 20, 2014December 23, 2015 by Bob King

How to See 209P/LINEAR, the Comet Brewing Up Saturday’s Surprise Meteor Shower

Comet 209P/LINEAR may still be faint but it's a beautiful object in this time exposure by Austrian astrophotographer Michael Jaeger. The stars appear as trails because the photographer followed the comet during the exposure.

As we anxiously await the arrival of a potentially rich new meteor shower this weekend, its parent comet, 209P/LINEAR, draws ever closer and brighter. Today it shines feebly at around magnitude +13.7 yet possesses a classic form with bright head and tail. It’s rapidly approaching Earth, picking up speed every night and hopefully will be bright enough to see in your telescope very soon.

As it approaches Earth in the coming nights, comet 209P/LINEAR will appear to move quickly across the sky, traveling from Leo Minor to southern Hydra in little over a week. All maps created with Chris Marriott's SkyMap software — As it approaches Earth in the coming nights, comet 209P/LINEAR will move quickly across the sky, traveling from Ursa Major to southern Hydra in just 10 days. When closest on May 28-29, the comet will cover 10 degrees per day or just shy of 1/2 degree per hour. All maps created with Chris Marriott’s SkyMap software

The comet was discovered in Feb. 2004 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) automated sky survey. Given its stellar appearance at the time of discovery it was first thought to be an asteroid, but photos taken the following month photos by Rob McNaught (Siding Spring Observatory, Australia) revealed a narrow tail. Unlike long period comets Hale-Bopp and the late Comet ISON that swing around the sun once every few thousand years or few million years, this one’s a frequent visitor, dropping by every 5.09 years.

This detailed map shows the comet's path from Leo Minor across the backside of the Sickle of Leo May 23-26. Hopefully it will be bright enough then to spot in an 8-inch or larger telescope. Click to enlarge and then print out for use at the telescope. — This detailed map shows the comet’s path from Leo Minor across the backside of the Sickle of Leo May 23-26. Hopefully it will be bright enough then to spot in an 8-inch or larger telescope. On May 25, it passes close to the colorful double star Gamma Leonis and a pair of NGC galaxies. Stars plotted to magnitude +9. Click to enlarge and then print out for use at the telescope.

209P/LINEAR belongs to the Jupiter family of comets, a group of comets with periods of less than 20 years whose orbits are controlled by Jupiter. When closest at perihelion, 209P/LINEAR coasts some 90 million miles from the sun; the far end of its orbit crosses that of Jupiter. Comets that ply the gravitational domain of the solar system’s largest planet occasionally get their orbits realigned. In 2012, during a relatively close pass of that planet, Jupiter perturbed 209P’s orbit, bringing the comet and its debris trails to within 280,000 miles (450,000 km) of Earth’s orbit, close enough to spark the meteor shower predicted for this Friday night/Saturday morning May 23-24.

Track of the comet through from May 27-29 through the dim constellation Sextans south of Leo. — Track of the comet from May 27-29 through Sextans to the Hydra-Crater border with positions shown every 3 hours. Times are CDT. Click to enlarge.

This time around the sun, the comet itself will fly just 5.15 million miles (21 times the distance to the moon) from Earth around 3 a.m. CDT (8 hours UT) May 29 a little more than 3 weeks after perihelion, making it the 9th closest comet encounter ever observed. Given , you’d think 209P would become a bright object, perhaps even visible with the naked eye, but predictions call for it to reach about magnitude +11 at best. That means you’ll need an 8-inch telescope and dark sky to see it well. Either the comet’s very small or producing dust at a declining rate or both. Research published by Quanzhi Ye and Paul A. Wiegert describes the comet’s current dust production as low, a sign that 209P could be transitioning to a dormant comet or asteroid.

Light curve for comet 209P/LINEAR predicts a maximum magnitude of around 11. Click for more information. Credit: Seiichi Yoshida — Light curve for comet 209P/LINEAR forecasts a maximum magnitude of around 11. Dates are shown along the bottom and magnitude scale along the side. Click for additional information. Credit: Seiichi Yoshida

Fortunately, the moon’s out of the way this week and next when 209P/LINEAR is closest and brightest. Since we enjoy comets in part because of their unpredictability, maybe a few surprises will be in the offing including a brighter than expected appearance. The maps will help you track down 209P during the best part of its apparition. I deliberately chose ‘black stars on a white background’ for clarity in use at the telescope. It also saves on printer ink!

A brand new meteor shower shooting 100 and potentially as many as 400 meteors an hour may radiate from the dim constellation Camelopardalis below the North Star Saturday morning May 24. Each is crumb or pebble of debris lost by 209P/LINEAR during earlier cycles around the sun. This map shows the sky facing north around 2 a.m. from the Saturday May 24 from the central U.S. Stellarium

We’re grateful for the dust 209P/LINEAR carelessly lost during its many passes in the 19th and early 20th centuries. Earth is expected to pass through multiple filaments of debris overnight Friday May 23-24 with the peak of at least 100 meteors per hour – about as good as a typical Perseid or Geminid shower – occurring around 2 a.m. CDT (7 hours UT).

If it’s cloudy or you’re not in the sweet zone for viewing either the comet or the potential shower, astrophysicist Gianluca Masi will offer a live feed of the comet at the Virtual Telescope Project website scheduled to begin at 3 p.m. CDT (8 p.m. Greenwich Time) May 22. A second meteor shower live feed will start at 12:30 a.m. CDT (5:30 a.m. Greenwich Time) Friday night/Saturday morning May 23-24.

SLOOH will also cover 209P/LINEAR live on the Web with telescopes on the Canary Islands starting at 5 p.m. CDT (6 p.m. EDT, 4 p.m. MDT and 3 p.m. PDT) May 23. Live meteor shower coverage featuring astronomer Bob Berman of Astronomy Magazine begins at 10 p.m. CDT. Viewers can ask questions by using hashtag #slooh.

A very exciting weekend lies ahead!

May 20, 2014May 9, 2016 by Elizabeth Howell

Did That Star Eat A Planet? Rocky Elements Could Tell The Tale

Earth scorched by red giant Sun — Artist's impression of the Earth scorched by our Sun as it enters its Red Giant Branch phase. Credit: Wikimedia Commons/Fsgregs

It’s amazing what astronomers can figure out from afar, and this now might include whether a star ate a few planets sometime during its history. Through looking at the predicted elements that make up a star, and any changes, this could be a key to figuring out if any planets were swallowed up by the star.

“Imagine that the star originally formed rocky planets like Earth. Further, imagine that it also formed gas giant planets like Jupiter,” stated Trey Mack, a graduate student in astronomy at Vanderbilt University who led the research.

“The rocky planets form in the region close to the star where it is hot and the gas giants form in the outer part of the planetary system where it is cold. However, once the gas giants are fully formed, they begin to migrate inward and, as they do, their gravity begins to pull and tug on the inner rocky planets. If enough rocky planets fall into the star, they will stamp it with a particular chemical signature that we can detect.”

Stars are mostly made up of hydrogen and helium (98%), meaning other elements only make up about 2% of the star. These elements (all of which are heavier than hydrogen and helium) are referred to as metals and when it comes to iron abundance, you will sometimes see the term “metallicity” referred to, concerning the ratio of iron to hydrogen.

To expand on previous studies concerning metallicity and how planets form, Mack examined sun-like stars to see the abundance of 15 elements, especially those such as aluminum, silicon, calcium and iron — considered to be the foundation of rocky planets such as the Earth.

The astronomers examined binary sun-like stars HD 20781 and HD 20782, which started with the same chemical compositions since they both came to be in the same gas and dust cloud. One star hosts two Neptune-sized planets, while the other has a Jupiter-sized planet.

“When they analyzed the spectrum of the two stars, the astronomers found that the relative abundance of the refractory elements was significantly higher than that of the Sun,” Vanderbilt University stated. “They also found that the higher the melting temperature of a particular element, the higher was its abundance, a trend that serves as a compelling signature of the ingestion of Earth-like rocky material.”

One of these stars (the one with the Jupiter-sized planet) probably ate up 10 Earth masses while the other star ate about 20 Earth masses. Between the star’s chemical composition and the fact that the gas giants are either in close or eccentric orbits, this implies there would be no rocky planets in the systems. More generally, if other stars are found to meet up with these explanations, this could be a clue to finding rocky planets.

“When we find stars with similar chemical signatures, we will be able to conclude that their planetary systems must be very different from our own, and that they most likely lack inner rocky planets,” added Mack. “And when we find stars that lack these signatures, then they are good candidates for hosting planetary systems similar to our own.”

The study was published earlier this month in the Astrophysical Journal.

Source: Vanderbilt University

May 20, 2014December 23, 2015 by Elizabeth Howell

Updated! Zoomable Poster Now Shows Off 54 Years Of Space Exploration

Cosmic Journey by Sean McNaughton, Samuel Velasco, 5W Infographics, Matthew Twombly and Jane Vessels, NGM staff, Amanda Hobbs.

We humans are busy creatures when it comes to exploring the solar system. This new graphic (which updates one from four years ago) showcases all the planets we have visited in the past half-century. Both successful missions and failures are included on this updated list, although sadly you won’t find much about the various visits to comets and asteroids.

“The only downside to this spectacular map is the absence of orbits around minor bodies,” wrote Franck Marchis, a researcher at the Carl Sagan Center of the SETI Institute, in a blog post describing the graphic — which he often uses in public talks.

“Samuel Velasco, one of its creators, told me me that missions to asteroids and comets were not included because the graphic was getting too difficult to read. Tough choices had to be made.”

Other features of the graphic worth noting are the growing number of moon and Mars missions and the current locations of spacecraft in the outer solar system (or in Voyager 1’s case, beyond the solar system).

Explore the full resolution version by clicking on the lead image or here.

May 19, 2014December 23, 2015 by David Dickinson

Can You Say Camelopardalids? Observing, Weather Prospects and More for the May 24th Meteor Shower

It could be the best of meteor showers, or it could be the…

Well, we’ll delve into the alternatives here in a bit. For now, we’ll call upon our ever present astronomical optimism and say that one of the best meteor showers of 2014 may potentially be on tap for this weekend.

This is a true wild card event. The meteor shower in question hails from a periodic comet 209P LINEAR discovered in 2004 and radiates from the obscure and tongue-twisting constellation of Camelopardalis.

But whether you call ‘em the “209/P-ids,” the “Camelopardalids,” or simply the “Cams,” this weekend’s meteor shower is definitely one worth watching out for. The excitement surrounding this meteor shower came about when researchers Peter Jenniskens and Esko Lyytinen noticed that the Earth would cross debris streams laid down by the comet in 1803 and 1924. Discovered by the LIncoln Near-Earth Asteroid Research (LINEAR) automated all-sky survey located at White Sands, New Mexico, comet 209P LINEAR orbits the Sun once every 5.1 years. 209P LINEAR passed perihelion at 0.97 AUs from the Sun this month on May 6^th.

The meteor shower peaks this coming U.S. Memorial Day weekend on Saturday, May 24^th. The expected peak is projected for right around 7:00 Universal Time (UT) which is the early morning hours of 3:00 AM EDT, giving North America a possible front row seat to the event. Estimates for the Zenithal Hourly Rate (ZHR) of the Camelopardalids run the gamut from a mild 30 to an outstanding 400 per hour. Keep in mind, this is a shower that hasn’t been witnessed, and it’s tough enough to forecast the timing and activity of known showers. It’s really a question of how much debris the 1803 and 1924 streams laid down on those undocumented passages. One possible strike against a “meteor storm” similar to the 1998 Leonids that we witnessed from Kuwait is the fact that the “Cams” have never been recorded before. Still, you won’t see any if you don’t try!

Cams — The orientation of the Earth, the day/night terminator, the Sun, Moon and radiant of the meteor shower on May 24th at 7:00 UT. Created by author.

Comet 209P/LINEAR passes 0.055 AUs — about 8.3 million kilometres — from the Earth on May 29^th, shining at +11^th magnitude and crossing south into the constellation of Leo Minor in late May. Interestingly, it also passes 0.8 degrees from asteroid 2 Pallas on May 26^th. Though tiny, comet 209P/LINEAR’s 2014 passage ranks as the 9^th closest recorded approach of a comet to the Earth.

The Moon is also at an ideal phase for meteor watching this coming weekend as it presents a waning crescent phase just 4 days from New and rises at around 4:00 AM local.

The expected radiant for the Cams sits at Right Ascension 8 hours and declination 78 degrees north in the constellation of Camelopardalis, the “camel leopard…” OK, we’ve never seen such a creature, either. (Read “giraffe”). Unfortunately, this puts the radiant just 20 degrees above the northern horizon as seen from +30 degrees north latitude here in Florida at 7:00 UT. Generally speaking, the farther north you are, the higher the radiant will be in the sky and the better your viewing prospects are. Canada and the northern continental United States could potentially be in for a good show. Keep in mind too, the high northern declination of the radiant means that it transits the meridian (crosses upper culmination) a few hours before sunset Friday night at 6 PM local; this means it’ll have an elevation of about 38 degrees above the horizon as seen from 30 degrees north latitude just after sunset. It may well be worth watching for early activity after dusk!

Weather — A look ahead at the cloud cover prospects for the morning of May 24th. Credit: NOAA.

Clouded out or live on the wrong side of the planet to watch the Camelopardalids? Slooh will be carrying a live broadcast of the event starting at 3:00 PM PDT/ 6:00 PM EDT/ 22:00 UT. Also, the folks at the Virtual Telescope Project will carry two separate webcasts of the event, one featuring the progenitor comet 209P LINEAR starting at 20:00 UT on May 22^nd and another featuring the meteor shower itself starting at 5:30 UT on May 24^th.

Observing meteors is fun and easy and requires nothing more than a good pair of “mark-1 eyeballs” and patience. And although the radiant may be low to the north, meteors can appear anywhere in the sky. We like to keep a pair of binocs handy to examine any lingering smoke trains left by bright fireballs. Counting the number of meteors you see from your location and submitting this estimate to the International Meteor Organization may help in ongoing efforts to understand this first time meteor shower. And capturing an image of a meteor is as simple as setting a DSLR on a tripod with a wide field of view and taking time exposures of the sky… something you can start practicing tonight.

P_20140518_110518 — Our humble meteor observing rig… (Photo by author).

Don’t miss what could well be the astronomical event of the year… I’d love to see a meteor shower named after an obscure constellation such as the #Camelopardalids trending. And we fully expect to start fielding reports of “strange rocks falling from the sky” this week, which the cometary dust that composes a meteor shower isn’t. In fact, Meteorite Man Geoffrey Notkin once noted that no confirmed meteorite fall has ever been linked to a periodic meteor shower.

Don’t miss the celestial show!

-Got pics of the Camelopardalids? Send ‘em to Universe Today. There’s a good chance that we’ll run an after-action photo-round up if the Cams kick it into high gear.

-Read more about the Camelopardalids here in a recent outstanding post by Bob King on Universe Today.

May 18, 2014December 23, 2015 by Bob King

If Pigs Could Fly – A Quick Guide to Solar Halos and Other Curiosities

A circumscribed halo encloses the more common 22-degree halo around the sun Saturday morning (May 17. Credit: Bob King

Call it a porcine occultation. It took nearly a year but I finally got help from the ornamental pig in my wife’s flower garden. This weekend it became the preferred method for blocking the sun to better see and photograph a beautiful pair of solar halos. We often associate solar and lunar halos with winter because they require ice crystals for their formation, but they happen during all seasons.

Nature keeps it simple. Light refracting through or reflecting from six-sided plate and column (pencil-shaped) ice crystals in high clouds is responsible for almost all halos and their variations.

Lower clouds, like the puffy cumulus dotting the sky on a summer day, are composed of water droplets. A typical cumulus spans about a kilometer and contains 1.1 million pounds of water. Cirrostratus clouds are much higher (18,000 feet and up) and colder and formed instead of ice crystals. They’re often the first clouds to betray an incoming frontal system.

Cirrostratus are thin and fibrous and give the blue sky a milky look. Most halos and related phenomena originate in countless millions of hexagonal plate and pencil-shaped ice crystals wafting about like diamond dust in these often featureless clouds.

This is the top end of a hexagonal column-shaped ice crystal. Light refracting (bending) through billions of these crystals spreads out to form a typical solar halo. Credit: Donalbein — This is the top end of a hexagonal column-shaped ice crystal. Light refracting (bending) through the 60-degree angled faces of millions of these crystals is concentrated into a ring of light 22 degrees from the sun. As light leaves the crystal, the shorter blue and purple wavelengths are refracted slightly more than red, tinting the outer edge of the halo blue and inner edge red. Credit: Donalbein with additions by the author

In winter, the sun is generally low in the sky, making it hard to miss a halo. Come summer, when the sun is much higher up, halo spotters have to be more deliberate and make a point to look up more often. The 22-degree halo is the most common; it’s the inner of the two halos in the photo above. With a radius of 22 degrees, an outstretched hand at arm’s length will comfortably fit between sun and circle.

Light refracted or bent through millions of randomly oriented pencil-shaped crystals exits at angles from 22 degrees up to 50 degrees, however most of the light is concentrated around 22 degrees, resulting in the familiar 22-degree radius halo. No light gets bent and concentrated at angles fewer than 22 degrees, which is why the sky looks darker inside the halo than outside. Finally, a small fraction of the light exits the crystals between 22 and 50 degrees creating a soft outer edge to the circle as well as a large, more diffuse disk of light as far as 50 degrees from the sun.

The sun on Dec. 6, 2013 with a 22-degree halo and two luminous canine companions or sundogs. Credit: Bob King — The sun on Dec. 6, 2013 with a 22-degree halo and two luminous canine companions or sundogs. Similar halos and ‘moondogs’ can be seen around a bright moon. Credit: Bob King

Sundogs, also called mock suns or parhelia, are brilliant and often colorful patches of light that accompany the sun on either side of a halo. Not as frequent as halos, they’re still common enough to spot half a dozen times or more a year. Depending on how extensive the cloud cover is, you might see only one sundog instead of the more typical pair. Sundogs form when light refracts through hexagonal plate-shaped ice crystals with their flat sides parallel to the ground. They appear when the sun is near the horizon and on the same horizontal plane as the ice crystals. As in halos, red light is refracted less than blue, coloring the dog’s ‘head’ red and its hind quarters blue. Mock sun is an apt term as occasionally a sundog will shine with the intensity of a second sun. They’re responsible for some of the daytime ‘UFO’ sightings. Check this one one out on YouTube.

An especially colorful sundog with a 'tail' from 2008. Credit: Bob King — An especially colorful sundog with a ‘tail’. Red light is bent less than blue as it emerges from the ice crystal, tinting the sundog’s inner edge. Blue is bent more and colors the outer half. If you look closely, all colors of the rainbow are seen. Credit: Bob King

Wobbly crystals make for taller sundogs. Like real dogs, ice crystal sundogs can grow tails. These are part of the much larger parhelic circle, a rarely-seen narrow band of light encircling the entire sky at the sun’s altitude formed when millions of both plate and column crystals reflect light from their vertical faces. Short tails extend from each mock sun in the photo above.

A couple hours after the flying pig image, the sun was beyond 50 degrees altitude. The circumscribed halo had vanished! Credit: Bob King — About 2 hours after the flying pig image, the sun climbed beyond 50 degrees altitude. The circumscribed halo vanished! Credit: Bob King

There’s almost no end to atmospheric ice antics. Many are rare like the giant 46-degree halo or the 9 and 18-degree halos formed from pyramidal ice crystals. Oftentimes halos are accompanied by arcs or modified arcs as in the flying pig image. When the sun is low, you’ll occasionally see an arc shaped like a bird in flight tangent to the top of the halo and rarely, to its bottom. When the sun reaches an altitude of 29 degrees, these tangent arcs – both upper and lower – change shape and merge into a circumscribed halo wrapped around and overlapping the top and bottom of the main halo. At 50 degrees altitude and beyond, the circumscribed halo disappears … for a time. If the clouds persist, you can watch it return when the sun dips below 29 degrees and the two arcs separate again.

Maybe you’re not a halo watcher, but anyone who keeps an eye on the weather and studies the daytime sky in preparation for a night of skywatching can enjoy these icy appetizers.

May 16, 2014December 23, 2015 by Elizabeth Howell

UPDATE: NASA Senior Review Declines WISE Spacecraft Data Usage Idea

Kevin Luhman discovered the brown dwarf pair in data from NASA's Wide-field Infrared Survey Explorer (WISE; artist's impression). Image: NASA/JPL-Caltech — Artist's impression of the WISE satellite

CORRECTION: This story corrects a previously stated misinterpretation of the NASA Senior Report that the WISE spacecraft itself was denied an extension.

NASA has denied funding to an idea to use NEOWISE image exposures for additional processing for science purposes, according to Amy Mainzer, the deputy project scientist for the Wide-field Infrared Survey Explorer (WISE) at NASA’s Jet Propulsion Laboratory. The project, called MaxWISE, was supposed to run for three years and to use NEOWISE data for other purposes.

“We were hoping it would be possible to combine data from the prime mission, with the NEO mission, to look at
things that vary on different timescales,” Mainzer said in an interview Friday (May 16) with Universe Today.

Its goals would have included measuring the motions and distances for stars and brown dwarfs near the sun, examining variable stars and setting up a “transient detection and alerts program” for certain astronomical phenomena.

This is a mosaic of the images covering the entire sky as observed by the Wide-field Infrared Survey Explorer (WISE), part of its All-Sky Data Release. Image Credit: NASA/JPL-Caltech/UCLA

In its review, the panel said it was “concerned that the proposed transient detection program would yield little science considering how much it cost”, and approved the program at half of the budgetary levels originally requested. NASA, however, wrote that it would decline the proposal altogether.

“The MaxWISE proposal was recommended for selection by the senior review. However, the only source of funding would be to displace funding from higher rated operating missions in the senior review. Due to constrained budget conditions, the MaxWISE proposal is declined,” NASA wrote in its response.

“It’s tremendously disappointing,” Mainzer said of the decision, adding it is a tough NASA budget environment overall. She is encouraging people to get in touch with their elected representatives if they want to see changes.

Other approved missions included a Kepler space telescope repurposing and extended operations for the Hubble and Chandra telescopes, among other missions. Spitzer officials were declined their request and asked to send a revised budget for consideration in fiscal 2016 negotiations.

WISE J104915.57-531906 as seen in NASA’s All-WISE survey (centered) and resolved to show its binary nature by the Gemini Observatory (inset). (Credit: NASA/JPL/Gemini Observatory/AURA/NSF).

After its launch in 2009 and successful prime mission, WISE was put into hibernation in 2011 before being turned on again last summer to look for asteroids that could pose a threat to Earth, and possibly to participate in NASA’s asteroid mission by looking for a space rock that could be captured and explored.

NEOWISE is expected to run until about 2016 or 2017, depending on how active the Earth’s atmosphere becomes. Since the spacecraft is in a relatively low orbit of 311 miles (500 km), if the sun’s activity increases molecule interactions in the atmosphere and expands it, the spacecraft can be somewhat twisted out of its orbit. Also, more scattering can occur. Both would make it harder for the spacecraft to carry out its mission, Mainzer said.

In the meantime, amateur astronomers can follow along with one of NEOWISE’s recent discoveries: the spacecraft recently found a fairly large near-Earth asteroid, about 1.24 miles to 1.86 miles (2 to 3 km) in size. It’s called 2014 JH 57 and you can get more orbital parameters on it at this page after typing in “2014 JH57” (no quotes) into the search bar.