Observing Archives

October 28, 2014December 23, 2015 by David Dickinson

Comet K1 PanSTARRS: See It Now Before it Heads South

Comet C/2012 K1 PanSTARRS, one of the most dependable comets of 2014, may put on its encore performance over the coming weeks for southern hemisphere observers.

First, the story thus far. Discovered as a +19th magnitude smudge along the borders of the constellations Ophiuchus and Hercules in mid-May 2012 courtesy of the Panoramic Survey Telescope And Rapid Response System (PanSTARRS) based atop Haleakala on the Hawaiian island of Maui, astronomers soon realized that comet C/2012 K1 PanSTARRS would be something special.

The comet broke +10^th magnitude to become a visible binocular object in early 2014, and wowed northern hemisphere observers as it vaulted across the constellations of Boötes and Ursa Major this past spring.

NASA’s NEOWISE mission spies K1 PanSTARRS on May 20th as it slides by the galaxy NGC 3726 (blue). Credit: NASA/JPL.

The comet is approaching the inner solar system on a retrograde, highly-inclined orbit tilted 142 degrees relative the ecliptic. This bizarre orbit also assures that the comet will actually reach opposition twice in 2014 as seen from our earthly vantage point: once on April 15^th, and another opposition coming right up on November 7^th.

As was the case with comet Hale-Bopp way back in 1997, had C/2012 K1 PanSTARRS arrived six months earlier or later, we would’ve been in for a truly spectacular show, as the comet reached perihelion on August 27^th, 2014, only 0.05 A.U.s (4.6 million miles or 7.7 million kilometres) outside the orbit of the Earth! But such a spectacle was not to be… back in ’97, Hale-Bopp’s enormous size — featuring a nucleus estimated 40 to 60 kilometres across — made for a grand show regardless… fast forward to 2014, and the tinier nucleus of K1 PanSTARRS has been relegated to binocular status only.

From here on out, K1 PanSTARRS is headed south “with a bullet” and into memory for most northern hemisphere observers. We spied the comet this morning low to the south near +3^rd magnitude Nu Puppis in the pre-dawn sky with our trusty 15×45 binocs from Yuma, Arizona, for what will probably be our last time. This also means that the time to catch a last glimpse of K1 PanSTARRS for northern hemisphere viewers is now. This week sees the comet transiting just 20 degrees above the southern horizon at 3:00 to 4:00 AM local for observers based from latitude 30 degrees north as it crosses the constellation Puppis. The bright star Sirius nearly shares the same position as the comet in right ascension this week, and K1 PanSTARRS sits about 24 degrees south of the Dog Star.

K1 PanSTARRS jaicoa — Comet K1 PanSTARRS imaged on June 14th. Credit: Efrain Morales.

Halloween sees the comet even lower, crossing the southern meridian at only 13 degrees elevation as seen from latitude 30 degrees north. Draw a straight line from Sirius to the south celestial pole around this date to find the comet just 5 degrees to the north of Canopus.

But the show is just beginning for southern hemisphere residents. Observing from the town of Bright Australia, Robert Kaufmann recently noted in a posting on the Yahoo Groups Comet Observer’s message board that the comet currently exhibits a 4’ wide coma shining at about magnitude +7.3 with an elevation of 28 degrees above the horizon on October 25^th.

And if the comet holds steady in brightness, it may break the visual threshold and become a naked eye object as seen from a dark sky site in early November.

Light curve — The projected light curve of K1 PanSTARRS with brightness observations (black dots). The vertical pink line marks the comet’s perihelion passage in late August. Credit: Seiichi Yoshida’s *Weekly Information on Bright Comets*.

The comet will be literally “hauling tail” across the constellation Dorado as it nears its second opposition of the year on November 7^th, moving about 1.5 degrees a day – 3 times the apparent diameter of the Full Moon – on closest approach.

Currently, the comet has been observed to have an estimated magnitude holding steady at+7 and is predicted to peak at perhaps magnitude +6 early next month. And while it would’ve been great had it arrived 6 months earlier or later, the aforementioned high retrograde inclination of its orbit assured that K1 PanSTARRS was a top performer for both hemispheres in 2014.

Perihelion passage occurred two months ago, but to paraphrase a famous Monty Python skit, Comet K1 PanSTARRS is “not dead yet.” Here are some key observing dates coming right up as the comet gains prominence in the southern hemisphere sky:

(Note that close passages of less than one degree near stars +4^th magnitude or brighter only are mentioned).

Oct 31^st: Passes closest to Earth, at 0.953 A.U.s distant.

Nov 1^st: Crosses into the constellation Pictor.

Nov 2^nd: Passes near the +3.8 magnitude star Beta Pictoris.

Nov 6^th: Crosses into the constellation Dorado.

Nov 6^th: Full Moon occurs, marking the beginning of an unfavorable week for comet hunting.

Nov 7^th: The second opposition of the comet for 2014 occurs at 3:00 UT.

Nov 8^th: Passes near the +3.3 magnitude star Alpha Doradus.

Nov 11^th: Crosses into the constellation Reticulum.

Nov 13^th: Crosses into the constellation Horologium.

Nov 14^th: Passes 34 degrees from the South Celestial Pole.

Nov 20^th:Crosses into the constellation Eridanus.

Nov 22^nd: New Moon occurs, marking a week long span optimal for comet-hunting.

Nov 25^th: Crosses into the constellation Phoenix.

The path of K1 PanSTARRS from October 27th through December 1st. Created by the author using Starry Night Education Software.

Dec 6^th: Full Moon occurs.

Dec 12^th: Passes near the +2.8 magnitude star Alpha Phoenicis (Ankaa).

Dec 18^th: Crosses into the constellation Sculptor.

Dec 22^nd: New Moon occurs.

Looking at 2015, K1 PanSTARRS will probably fall back below +10^th magnitude by late January. The comet will then head back out into the depths of the outer solar system, its multi-million year orbit only slightly altered by its inner solar system passage down into the ~700,000 year range. What will Earth be like on that far off date? Will human eyes greet the comet once again, and will anyone remember its appearance way back in the mists of time in 2014? All thoughts to ponder as we bid fair well to Comet C/2012 K1 PanSTARRS, a fine binocular comet indeed.

October 22, 2014December 23, 2015 by Bob King

Beastly Sunspot Amazes, Heightens Eclipse Excitement

Ron Cottrell captured the sunspot in all its swirly magnetic goodness in hydrogen-alpha light on October 19. To appreciate its size, he included the Earth (lower left) for reference. Credit: Ron Cottrell

That’s one big, black blemish on the Sun today! Rarely have we been witness to such an enormous sunspot. Lifting the #14 welder’s glass to my eyes this morning I about jumped back and bumped into the garage.

Properly shielded, it was very easy to see with the naked eye. Unlike some other naked eye sunspots, this one showed structure. The eastern end was darker, the western half grayer and more extended.

Watch the giant spot rotate into view and grow right before your eyes in this 72-hour time-lapse video taken by SOHO’s HMI imager Oct. 18-20, 2014

Through a small telescope, the mix of dark umbras scattered amid weirdly sculpted penumbral “islands” was incredible to see. Photographs like the one above are wonderful documents, but witnessing this beautiful complex magnetic mess with your own eyes is another experience altogether. Region 2192 continues to grow and size and complexity and is now the largest sunspot group of solar cycle 24 which began in 2009 – more than five years ago!

Active region 2192 is now the largest sunspot group to appear in over five years. Credit: Alex Young — Active region 2192 is now the largest sunspot group to appear in over five years. Compare to Jupiter and the Earth. Credit: SDO/HMI/Alex Young

Every sunspot marks a region on the Sun’s shiny outer skin called the photosphere where magnetic energy is concentrated. Strong magnetic fields within a sunspot group quell the turbulent churning of the photosphere, chilling the region by several thousand degrees. Sunspots appear dark against the Sun’s blazing disk because they’re cooler. Cooler meaning 8,000 F instead of 11,000 F, so yes, they’re still VERY hot.

Watch as Region 2192 crackles with energy and flares as seen in far ultraviolet light with NASA’s Solar Dynamics Observatory.

Energy stored in sunspots’ twisted magnetic fields can suddenly be released in violent, explosions called solar flares. Billions of tons of solar plasma – the sizzling mix of protons and electrons that composes the Sun – are heated to millions of degrees during the explosion and rapidly accelerated into space. Radiation from radio waves to X-rays and gamma rays fans out at the speed of light. Fortunately for us, our atmosphere and planetary magnetic field protect us from most of what flares can fling our way.

NASA's Solar Dynamics Observatory took this photo of the sun and Jupiter-sized sunspot 2192 this morning Oct. 22 at 8:45 a.m. CDT. The view in a small telescope equipped with a safe solar filter is even better! Credit: NASA — NASA’s Solar Dynamics Observatory took this photo of the Sun and Jupiter-sized sunspot region 2192 this morning Oct. 22 at 8:45 a.m. CDT. The view in a small telescope equipped with a safe solar filter is even better! Credit: NASA

But as the Sun rotates this monster into our line of sight, possibilities for Earth-directed flares and coronal mass ejections increase as do geomagnetic storms, the bringer of auroras. Already in the past 48 hours, the spot has dished out seven M-class flares and a powerful X-1 flare even before it has fully come into view. There’s more to come – Region 2192 harbors an unstable beta-gamma-delta magnetic field ripe for additional flaring including more of the X-class variety.

The sun on October 21 showing smaller sunspot regions along with our featured group. Credit: Sarah and Simon Fisher — The Sun on October 21 showing smaller sunspot regions along with our featured group. Credit: Sarah and Simon Fisher

There’s no doubt now that this behemoth will stick around to add a whole new dimension to tomorrow’s partial solar eclipse. I can’t wait to see the Moon’s black curve approach and at least partially occult the group from view. If you’re interested in getting some one-of-a-kind pictures of the scene, please see our own Dave Dickinson’s excellent guide on photographing the partial eclipse.

A sliver of a Moon rises in morning twilight today October 22 just a day away from its appointment with the Sun. Credit: Bob King

While we’re on the Moon, early morning risers had the pleasure of its company just one day before New Moon and solar eclipse. I was out watching the Orionid meteor shower. While not rich like the Perseids or Geminids I managed to catch a few including a few lucky shots with the camera.

An Orionid meteor slashes across the top of the frame directly above the constellation Orion early this morning October 22, 2014. Details: 24mm lens, f/2.8, 30-seconds at ISO 1600. Credit: Bob King

The shower has peaked but will still be active the remainder of the week if you’re inclined to take a look. And I can’t resist. How about one last sweet close-up photo of sunspot group 2192? I have a feeling you won’t mind.

Monster Sunspot AR12192 taken by Karzaman Ahmad on October 21, 2014 from Langkawi Nagtional Observatory, Malaysia credit: Karzaman Ahmad and shared at spaceweather.com — Monster Sunspot AR12192 taken by Karzaman Ahmad on October 21, 2014, from Langkawi Nagtional Observatory, Malaysia. Credit: Karzaman Ahmad and shared at spaceweather.com. Click the image to see additional animations and photos on Alex Young’s site

October 21, 2014December 23, 2015 by David Dickinson

How to Take Great Photographs of the October 23rd Partial Solar Eclipse and More

The Partially eclipsed Sun rising over the Vehicle Assembly Building on the Florida Space Coast on November 3rd, 2013.

Get those solar viewers out… the final eclipse of 2014 occurs this Thursday on October 23^rd, and most of North America has a front row seat. Though this solar eclipse will be an exclusively partial one as the Moon takes a ‘bite’ out the disk of the Sun, such an event is always fascinating to witness. And for viewers across the central U.S. and Canada, it will also provide the chance to photograph the setting crescent Sun along with foreground objects.

Michael Zieler — A map showing the eclipse prospects over the CONUS. (click to enlarge). Credit: Michael Zeiler @EclipseMaps, www.thegreatamericaneclipse.com.

The shadow or ‘antumbra’ of the Moon just misses northern limb of the Earth on October 23^rd, resulting in a solar eclipse that reaches a maximum of 81% partial as seen from the high Canadian Arctic. The eclipse would be annular in any event had the Moon’s shadow touched down on Earth’s surface, as the Moon just passed apogee on October 18th. The penumbral cone of the Moon’s shadow touches down at 19:38 UT in the Bering Sea just west of the International Date Line before racing eastward across North America to depart the Earth over southern Texas at 23:52 UT.

An animated .gif of this week’s partial solar eclipse. Credit: NASA/GSFC/A.T. Sinclair.

The farther northwest you are, the greater the eclipse: For example, Anchorage and Seattle will see 54.8% and 54.5% of the Sun obscured by the Moon, while Mexico City and Phoenix, Arizona will see 4.8% and 33% of the Sun’s disk obscured.

A key region will be the zone of longitude running a few hundred miles east and to the west of Ontario, the Great Lakes and the Mississippi River, which will see the Sun setting during greatest eclipse.

Simulated views of the October 23rd partial solar eclipse from around North America. Created using Stellarium.

Successful sunset viewing of the eclipse will call for a clear, uncluttered western horizon. As of 48+ hours out, the current weather prospects call for clear skies across most of the U.S. on Thursday, with the exception of the U.S. northwest… but you only need a gap in the clouds to observe an eclipse!

Predicted cloud cover for the CONUS hours prior to the start of the Oct 23 partial solar eclipse. Credit: NWS/NOAA.

It’s also worth noting that massive sunspot region AR 2192 is currently turned Earthward and will make for a very active and photogenic Sun during Thursday’s eclipse.

Sunspot activity leading up to this week’s eclipse. Credit: NASA/SDO/HMI

Proper safety precautions must be taken while observing the Sun through all stages of a partial solar eclipse. Don’t end up like 19^th century psychologist Gustav Fechner, who blinded himself staring at the Sun! With the recent interest in the event, we’ve been fielding lots of questions on eclipse imaging, which presents safety challenges of its own.

blogger-image-845084267 — An homemade solar optical filter using Baader film. Credit: Eric Teske/Stellar Neophyte.

Imaging the Sun with a solar filter is pretty straightforward. Glass solar filters for telescopes fitting over the full aperture of the instrument can be had from Orion for about $100 USD, and we’ve made inexpensive filter masks out of Baader AstroSolar Safety Film for everything from binoculars to DLSR cameras to telescopes. Make sure these fit snugly in place, and inspect them for pin holes prior to use. Also, be sure to cover or remove any finderscopes as well. And throw away those old screw-on eyepiece filters sold by some department store scope manufacturers in the 60s and 70s, as they can overheat and crack!

Catching the eclipsed Sun with a silhouetted foreground requires more practice. We’ve had great luck using a DSLR and a neutral density filter to take the f-stop and glare down while preserving the foreground view. Remember, though, an ND filter is for photographic use only… never stare at the Sun through one! Likewise, you’ll need to physically block off your camera’s viewfinder to resist the same temptation of looking while aiming. Shooting several quick frames at 1/1000^th of a second or faster will help get the ISO/f-stop settings for the local illumination just right. Even 1% sunlight is surprisingly bright, as we noticed observing the May 10^th 1994 annular eclipse from the shores of Lake Erie.

You’ll also need a lens with a focal length of 200mm or better to have the Sun appear larger than a dot in your images. Several key landmarks, such as the Saint Louis Arch and the Sears Tower in Chicago lie along the key sunset zone Thursday and would make great potential foreground shots… our top pick would be the 1978 World’s Fair Sunsphere Tower in Knoxville, Tennessee for a photo with a true visual double entendre. Scout out the geometry of such a shot the evening beforehand, and remember that you’ll need a good amount of distance (half a mile or more) for a building or foreground object to appear equal in size to the Sun.

And don’t miss the spectacle going on around you during an eclipse as well. Projecting the disk of the Sun using a pinhole camera or binoculars onto a piece of paper makes for a great shot. Hundreds of crescents may litter the ground, caused by natural “pinhole projectors” such as gaps in leaves or latticework. And photographs of everyday folks wearing eclipse glasses standing enthralled by the ongoing event can be just as captivating as the eclipse itself.

Imaging a partial solar eclipse via a homemade shoebox binocular projector. Photo by author.

Up for a challenge? Another unique opportunity awaits eclipse viewers in the northwest, as the International Space Station will cross the disk of the Sun around ~21:08 UT during the eclipse. You’ll need to run video to catch such a speedy (about a second in duration) event, but it would make for a great capture! Be sure to check CALSky for predictions of ISS solar and lunar transits within 48 hours of the event.

ISS path — The path of the ISS over the US during the partial eclipse. Credit: Orbitron.

Robotic eyes in low Earth orbit will be watching the eclipse as well. JAXA’s Hinode and ESA’s Proba-2 routinely observe the Sun and will catch fleeting eclipses on successive passes on Thursday… in the case of Hinode, it may score a direct “hit” with an annular eclipse seen from space around 21:03 UT:

And don’t forget, we’re now less than three years out from the next total solar eclipse to (finally!) grace the United States from coast to coast on August 21^st, 2017. This week’s partial solar eclipse offers a great test run to hone your photographic technique!

-Send those eclipse pics in to Universe Today’s Flickr forum.

October 20, 2014December 23, 2015 by Bob King

How to Safely Enjoy the October 23 Partial Solar Eclipse

The partially eclipsed sun sets over Island Lake north of Duluth, Minn. on May 20, 2012. Credit: Jim Schaff

2014 – a year rich in eclipses. The Moon dutifully slid into Earth’s shadow in April and October gifting us with two total lunars. Now it’s the Sun’s turn. This Thursday October 23 skywatchers across much of the North America and Mexico will witness a partial solar eclipse. From the eastern U.S. the eclipse will reach maximum around the time of sunset, making for dramatic picture-taking opportunities. Further west, the entire eclipse will occur with the sun up in the afternoon sky. Either way, you can’t go wrong.

During a solar eclipse, the orbiting Moon passes between the Sun and Earth completely blocking the Sun from view as shown here. In Thursday's partial eclipse, the moon will pass a little north of a line connecting the three orbs, leaving a piece of the sun uncovered for a partial eclipse. Credit: Wikipedia — During a solar eclipse, the orbiting Moon passes between the Sun and Earth completely blocking the Sun from view as shown here. In Thursday’s eclipse, the moon will pass a little north of a line connecting the three orbs, leaving a portion of the sun uncovered. To view a partial solar eclipse, a safe solar filter is necessary. Credit: Wikipedia

Solar eclipses occur at New Moon when the Moon passes between the Sun and the Earth and blocks the Sun from view. During a total solar eclipse, the Sun, Earth and Moon are exactly aligned and the Moon completely hides the brilliant solar disk. Partial eclipses occur when the Moon passes slight north or south of the line connecting the three bodies, leaving a slice of the Sun uncovered. For that reason, a safe solar filter is required to protect your eyes at all times. We’ll delve into that in a minute, but first let’s look at the particulars of this eclipse.

Map showing times and percentage of the sun covered during Thursday's partial solar eclipse. Times are Pacific Daylight - add 1 hour for MDT, 2 hours for CDT and 3 hours for EDT. Credit: NASA, F. Espenak with additions by the author — Map showing times and percentage of the sun covered during Thursday’s partial solar eclipse. Times are Pacific Daylight – add 1 hour for MDT, 2 hours for CDT and 3 hours for EDT. Interpolate between the lines to find your approximate viewing time. The arc marked A shows where the eclipse begins at sunset; B = Maximum eclipse at sunset and C = Eclipse ends at sunset. Credit: NASA, F. Espenak,with additions by Bob King

Nowhere will this eclipse be total. At best, polar bears and musk oxen in Canada’s Nunavut Territory near Prince of Wales Island will see 81% of the sun covered at sunset at maximum eclipse. Most of the rest of us will witness about half the Sun covered with the northern U.S. getting around 65% and the southern states closer to 40%. In Minneapolis, Minn. for instance, the eclipse begins at 4:23 p.m. CDT, reaches a maximum of 62% at 5:35 p.m. and continues on till sunset at 6:14 p.m. For times, coverage and other local circumstances for your town, click over to U.S. cities and cities in Canada and Mexico.

Safe solar filters for looking at the sun come in several different varieties. Read down to learn more about each kind. Photo: Bob King — Safe solar filters come in several varieties ranging from plastic glasses to a #14 welder’s glass for visual observation and snug-fitting optical filters that fit over the end of a telescope. Credit: Bob King

There are several ways to observe a partial eclipse safely, but they all start with this credo: Never look directly at the Sun. Dangerous ultraviolet and infrared light focused on your retinas will damage your vision for life. Nothing’s worth that risk. Happily, filters and indirect viewing methods are available. Eclipse glasses fitted with mylar or polymer lenses are a great choice. I’ve used them all but my favorite’s still the classic #14 welder’s glass because it slips in the pocket easily and takes a beating. Make sure it’s a #14, not a #13 or lower.

You can mount binoculars on a tripod, cover one lens with a lenscap and project the sun's image safely onto a sheet of white cardboard. Credit: Bob King — You can mount binoculars on a tripod, cover one lens with a lenscap and project the sun’s image safely onto a sheet of white cardboard. Credit: Bob King

Telescopes should be outfitted with an optical mylar or aluminized glass solar filter that fits snugly over the top end of the tube. A welder’s glass gives a green solar image, mylar a blue one and black polymer a pale orange. Filters work by only allowing a fraction of the Sun’s light to reach the eye. At the end of this article I’ve listed several sites that sell a variety of safe solar filters for naked eye and telescopic use.

Easy guide to building a pinhole projector for solar eclipse viewing

Indirect methods for safe viewing include projecting the Sun’s image through a small telescope or pair of binoculars onto a sheet of white paper or cardboard. You can also build a pinhole projector shown in the video above. A box and piece of aluminum foil are all you need.

Tiny gaps along the length of this palm frond created a series of solar crescents during the July 1991 eclipse. Credit: Bob King

If for some reason you aren’t able to get a solar filter, all is not lost. The tiny spaces between leaves on a tree act like pinhole projectors and will cast hundreds of images of the Sun on the ground below during the eclipse. To see the effect even better, bring along a white sheet or blanket and spread it out beneath the tree. You can even cross your hands over one another at a right angle to create a pattern of small “holes” that will reveal the changing shape of the Sun as the eclipse proceeds.

The white crescents show how much of the Sun will be visible from a variety of locations at maximum eclipse. The farther north you go, the deeper the eclipse. Credit: Jay Anderson

Now that you’re rockin’ to go, here are some other cool things to look for during the eclipse:

* Sunspots appear black when viewed through a filtered telescope, but they’re no match for the opaque-black Moon silhouetted against the Sun. Compare their unequal degrees of darkness. With a little luck, the giant sunspot region 2192 will provide a striking contrast with the moon plus add interest to the eclipse. This region only recently rotated onto the Sun’s front side and will be squarely in view on Thursday.

* The moon may look smooth and round to the eye, but its circumference is bumpy with crater rims and mountain peaks. Watch for these tiny teeth to bite into the solar disk as the eclipse progresses.

* From locations where half or more the Sun’s disk is covered, look around to see if you can tell the light has changed. Does it seem somehow “grayer” than normal? Is the blueness of the sky affected?

As I learned from comet discoverer and author David Levy many years ago, every eclipse involves the alignment of four bodies: Sun, Earth, Moon and you. We wish you good weather and a wonderful eclipse, but if clouds show up, you can still watch it via live stream on SLOOH.

Not only will the sun be eclipsed this afternoon but the planet Venus shines just 1.1 degrees to its north. Venus is very close to superior conjunction which occurs early Saturday. In the photo, the planet is in the background well behind the Sun. Don’t count on seeing Venus – too much glare! This photo was taken from space by NASA’s Solar and Heliospheric Observatory this afternoon using a coronagraph to block the Sun from view. Credit: NASA/ESA — UPDATE: Not only will the sun be eclipsed Thursday afternoon but the planet Venus will shine just 1.1 degrees to its north. Venus is just two days from superior conjunction. In the photo, the planet is in the background well behind the Sun. Don’t count on seeing it – too close and too much dangerous glare! This photo was taken from space by NASA’s Solar and Heliospheric Observatory early Thursday Oct. 23 using a coronagraph to shade the Sun. Credit: NASA/ESA

Solar filter suppliers – for a #14 welder’s glass, check your local phone book for a welding supply shop:

* Thousand Oaks Optical — Large variety of solar filters for telescopes and cameras. Sheets of black polymer available if you want to make your own.
* Rainbow Symphony — Eclipse glasses and solar viewers as well as filters for binoculars and telescopes. The basic glasses cost less than a buck apiece, but you’ll need to buy a minimum of 25 pairs.
* Opt Corp — Offers high-quality Baader mylar optical filter material to make your own.
* Orion Telescopes — Glass and mylar filters for telescopes and binoculars.
* Amazon.com – Filters for naked eye use

October 15, 2014December 23, 2015 by Elizabeth Howell

Observing Wow! 28 Moon Pictures Captured In A Single Collage

A collage of moon photos that photographer David Blanchflower took between March and October 2014 from Newcastle upon Tyne, United Kingdom, using a Nikon Coolpix L810 camera. One picture used a telescope (Skywatcher Explorer 200P).

We think of the Moon as a grey and unchanging world, but throw in the effects of Earth’s atmosphere and orbit and you get some really cool effects. It can look yellow or red or almost blue. It changes from a full disc to a crescent and back again. It gets bigger and smaller as the Moon drifts forward and backward in its orbit. Sometimes it’s even eclipsed.

Remarkably, one photographer has captured many of these moods in a single collage. The picture above from David Blanchflower was recently posted to the Universe Today Flickr pool, showing images between March and October 2014.

“All from Newcastle upon Tyne with a Nikon Coolpix L810 Camera,” Blanchflower wrote. “One of the pictures was taken with the aid of a telescope (Sky-Watcher Explorer 200P). They show a variety of colours and phases.”

We’d love to see your shots of the moon as well, so please feel free to contribute to the Flickr pool. Posting a picture means we could use it in a future story.

By the way, we have used Blanchflower’s work before in this recent collection of SuperMoon photos.

October 15, 2014December 23, 2015 by David Dickinson

Comet A1 Siding Spring vs Mars: Views in Space and Time

Oh, to be a stranded astronaut on the surface of the planet Mars this week. There’s a great scene from Andy Weir’s recent novel The Martian where chief protagonist Mark Watney uses the swift moving moons of Phobos and Deimos to roughly gauge his direction while travelling across the expansive Martian desert.

This week, the skies over Mars will also be graced by an unforgettable and spectacular sight: the extremely close passage of Comet C/2013 A1 Siding Spring. The first comet discovered in 2013, A1 Siding Spring was spotted by veteran comet hunter Robert McNaught from the Siding Spring Observatory in Australia. Dozens of comets are discovered in any given year, but this one soon gained the attention of astronomers when it was found that the comet could possibly hit Mars in October 2014.

And although further observations refined A1 Siding Spring’s orbit and ruled out such an impact, the particulars of the close passage of the comet past Mars are still stunning: A1 Siding Spring will pass within 87,000 miles (139,500 kilometres) from the center of Mars on Sunday, October 19^th at 18:27 Universal Time (UT) or 2:27 PM EDT.

And although we’ve yet to set “boots” on Mars, a fleet of spacecraft arrayed throughout the inner solar system are set to study the comet from both near and far. NASA has taken measures to assure that spacecraft in orbit are afforded maximum protection from incoming cometary debris, and the exciting possibility exists that we’ll be able to study first-hand the interaction of the comet’s tail with the Martian atmosphere.

Credit NASA — Mars-based spacecraft set to observe Comet A1 Siding Spring: a scorecard. Credit: NASA.

Universe Today has written extensively on the scientific efforts to study the event, how to observe the comet from Earth, and the unprecedented amateur and professional campaign in progress to witness the close pass.

What we’d like to do now is imagine the unparalleled view under alien skies as the comet slides gracefully overhead.

The nucleus of A1 Siding Spring is thought to be 700 metres across, and the coma extends 19,300 km in diameter. The comet’s closest passage is just under six times the distance of Mars’ outer moon Deimos, and at closest approach, the coma will appear almost 8 degrees in size to any would-be Martian — that’s 16 times the diameter of a Full Moon as seen from the Earth — and will be crossing the skies at a staggering 1.5 degrees a minute. You would be able to easily see the motion of the comet as it moves across the Martian sky with the unaided (well, space suit helmet protected) eye after just a few dozen seconds worth of watching! The comet’s magnitude may reach -5 as seen from Mars, though that would also be extended over its huge expanded surface area.

The enormous tail of the comet would also span the sky, and NASA has already released several mind blowing simulations to this effect. We’ve also constructed some brief simulations using Starry Night that show the view of the encounter from Earth, Phobos, and the perspective from the comet itself:

There’s also been some discussion as of late that A1 Siding Spring has slowed down in terms of its predicted brightening, though this is not unusual or unexpected.

From Acidalia Planitia (the setting for The Martian) located in the mid-northern latitudes on the surface of Mars, the comet would be a fine morning object, sitting 48 degrees above the northeastern horizon at dawn at closest passage for one morning only, and perhaps staying visible even after sunrise. Earth would be in the picture too, shining at magnitude -2.5 in the Martian dawn.

And the view from the comet? Now that would be a truly spectacular ride, as Mars swells to 3 degrees in diameter as it approaches and recedes. The comet itself is on a million year plus orbit, never to again visit the realm of the inner solar system in our lifetimes.

Such a view has never been seen in recorded history from the Earth. The closest confirmed passage of a large comet near our planet was Comet D/1770 L1 Lexell, which passed over 15 times more distant than A1 Siding Spring from Mars, at 2.2 million km from Earth on July 1^st, 1770. Note that an even closer cometary passage in 1491 remains unverified. In more recent times, Comet Hyakutake passed 15.8 million km from Earth on March 25^th, 1996, with a tail that spanned half the sky as seen from a dark sky site, and long-time comet observers might also remember the 1983 passage of Comet IRAS-Araki-Alcock, which passed just 4.7 million kilometres from the Earth.

And then there was the historic impact on Comet Shoemaker-Levy 9 into Jupiter in 1994, reminding us that cosmic catastrophes can and do indeed occur… the upper size limit estimate for the nucleus of A1 Siding Spring compares to 70% the size of Fragment G, and an impact on Earth or Mars of such a dirty snowball would be a very bad day, for rovers or the humans. An extinction level event such as the Chicxulub impactor, however, was estimated to be much larger, at about 10 km in size.

Thankfully, we’ve merely got a front row seat to the show this weekend, and our planet is not the main event. From Earth, Comet A1 Siding Spring will be a binocular object, shining at magnitude +9 as it passes 3’ from +0.9 magnitude Mars. Both will be visible briefly in dusk skies, and the Virtual Telescope Project also plans to broadcast the event live starting at 16:45 UT on October 19th.

Don’t miss the historic passage of Comet A1 Siding Spring past Mars… by this time next week, we fully expect more images of the comet — both amateur and professional — to grace the cyber-pages of Universe Today!

Imaging A1 Siding Spring and/or Mars? Send those astro-pics into Universe Today at our Flickr forum.

October 13, 2014December 23, 2015 by David Dickinson

Get Ready for the Fireballs of October

A recent fireball captured over the UK on October

On October 31^st 2005, trick-or-treaters across the central U.S. eastern seaboard were treated to a brilliant fireball, a celestial spectacle that frequently graces October skies.

Mid- to late October is fireball season, a time when several key meteor showers experience a broad peak. We’re already seeing an uptick in fireball activity as monitored by numerous all-sky cameras this month, including NASA’s system positioned across the United States. Three lesser known but fascinating showers are the chief culprits.

The main meteor shower on tap for the month of October is the Orionids. This shower radiates from the Club of the constellation Orion, and is the product of that most famous comet of them all, 1P Halley. Halley’s Comet is actually the source of two annual meteor showers, the October Orionids and the May Eta Aquarids. We’re seeing the inward stream of Halley debris in October, and Orionid velocities average a swift 66 kilometres a second. The radiant rides highest for northern hemisphere observers at 4 AM local, and 2014 sees an estimated zenithal hourly rate (ZHR) of 20 predicted to arrive on the mornings of October 21^st through the 22^nd. The Orionids experience a broad peak spanning October 21^st through November 7^th, and 2014 sees the peak arrive just two days prior to the Moon reaching New phase. The Orionids have exhibited an uptick in activity as high as 50-75 per hour from 2005-2007, and it’s been suggested that a 12 year peak cycle may govern the Orionids, as the path of meteoroid debris stream is modified by the gravitational influence of the giant planet Jupiter.

Two other nearby radiants in the sky also produce an exceptionally large number of fireballs in late October: the Southern Taurids and Northern Taurids. These are complex streams laid down by the periodic comet 2P Encke, which possesses the shortest orbital period of any comet known at 3.3 years. Though the ZHR for both is only slightly above the background sporadic rate for northern hemisphere Fall at about five per hour, the Taurids also produce a high ratio of fireballs. The southern Taurids peak in early October and are already active, and the Northern Taurids peak in late October through early November, earning them the nickname the “Fireballs of Halloween”. Unlike many meteor showers, the Northern Taurids are approaching the Earth from behind in our orbit and have a slow relative atmospheric entry velocity of 28 kilometres per second. This makes for long, stately meteor trains often visible in the evening hours before local midnight.

The Taurids also seem to exhibit a seven year periodicity that begs for further study. 2008 was a fine year for Taurid fireballs… could 2015 be next?

Of course, the exact definition of a “fireball” meteor varies by source, though we prefer the definition of a fireball as a meteor brighter than magnitude -3. A fireball reaching -14 (a Full Moon equals magnitude -13, about 2.5 times fainter) is often termed a bolide.

Halley's orbit — Comet 1P/Halley’s orbital path through the inner solar system. (Credit: NASA/JPL).

Observing meteor showers such as the Orionids is as simple as sitting back and patiently watching the skies. Our own personal rule while starting a meteor vigil is to scan the skies for 10 minutes; one or more meteor sightings is a good sign to keep on watching, while no meteors means it’s time to pack it in and instead maybe write about astronomy. Dark, moonless skies are key, and you can report how many meteors you see to the International Meteor Organization. Be sure to keep a pair of binoculars handy to examine any lingering smoke trails post-fireball passage.

The positions of the radiants of the Orionids and the Taurids, with peak dates. Credit: Stellarium.

Of course, seeing a Taurid fireball is largely a matter of luck and looking at the right place in the sky at the right time. All-sky cameras work great in this regard, and many amateurs now use tripod mounted DLSRs set to take wide-field exposures of the sky automatically throughout the night. Just watch out for dew! Nearly every meteor we’ve caught on camera turned up only in post review, a testament to how much of the sky a lone pair of eyes still misses.

Spot a fireball? The American Meteor Society maintains a great online database of recent sightings and reports. Keep in mind, lots of “meteor-wrongs” inevitably crop up on Facebook and Twitter during any event, posted by folks eager for likes and retweets. Faves of such spoofers are: the Peekskill meteor train, the reentry of Hyabusa, Mir, and scenes (!) from the movie Armageddon. We’ve seen ‘em all passed off as legit, though you’re more than welcome to try and be original… a majority of initial meteor images almost always come from dash cams (remember Chelyabinsk?) and security cameras.

Finally, in addition to fireballs, there’s another astronomical tie-in for Halloween, as it’s one of four cross-quarter tie-in days approximately mid-way between a solstice and an equinox. The other three are: Lammas Day (August 1st), Groundhog’s Day (February 2nd) and May Day (May 1^st). We just think that it’s great — if a bit paradoxical — to see modern day suburbanites dress up as ghouls and goblins as they reenact archaic rites and holidays…

Don’t forget to keep an eye out for the fireballs of October this Halloween!

October 2, 2014December 23, 2015 by David Dickinson

Our Complete Guide to the October 8th “Hunter’s Moon” Total Lunar Eclipse

October 2014 means eclipse season 2 of 2 for the year is upon us.

Don’t fear the ‘Blood Moon’ that’s currently infecting the web, but if you find yourself on the correct moonward facing hemisphere of the planet, do get out and observe the total lunar eclipse coming right up on the morning of Wednesday, October 8^th. This is the second and final total lunar eclipse of 2014, and the second of four in a quartet series of lunar eclipses known as a tetrad.

And the good news is, the eclipse once again favors nearly all of North America. From the western U.S. and Canada, the Moon will be high in the western skies when partial phases begin early in the morning on October 8^th. The western U.S., Canada and Alaska will see the entire 61 minute span of totality, just 18 minutes shorter than last April’s lunar eclipse. The Moon will be high in the sky during totality for the Hawaiian Islands, and viewers in Australia and the Pacific Far East will witness the eclipse in the evening hours.

Visibility — The visibility regions for the total lunar eclipse. Credit: NASA/GSFC/Espenak.

This lunar eclipse is part of saros 127, and marks number 42 of a series of 72 for that particular saros. If you witnessed the total lunar eclipse visible from North America and Europe on September 27^th, 1996, you caught the last of the series, and if you catch the next eclipse in the saros on October 18^th, 2032, you’ve earned a veteran lunar eclipse-watchers badge of seeing an exeligmos, or “triple saros” of eclipses.

The path of the Moon through the Earth’s umbra on October 8th. Adapted from NASA/GFSC.

Timings for key phases of the eclipse are as follows:

P1- Penumbral phase begins: 8:14 UT/4:14 EDT/1:14 PDT

U1- Umbral (partial) phase begins: 9:15 UT/5:14 EDT/2:14 PDT

U2- Totality begins: 10:24 UT/6:24 EDT/3:24 PDT

Mid-totality- 10:55 UT/6:55 EDT/3:55 PDT

U3- Totality ends: 11:25 UT/7:25 EDT/4:25 PDT

U4- Umbral phase ends: 12:35 UT/5:35 PDT

P4- Penumbral phase ends: 13:35/6:35 PDT

Not all total lunar eclipses are the same when it comes to color. Totality can appear anywhere from a dark brick color, as happened during the December 9^th, 1992, eclipse following the eruption of Mount Pinatubo, when the Moon nearly disappeared during totality, to a bright coppery red, as seen during the April eclipse earlier this year. The Moon passes to the north of the dark central core of the Earth’ shadow next Wednesday, so expect a brighter than normal eclipse, especially along the Moon’s northeast limb. Grab a painter’s wheel and compare the eclipsed Moon to swatches of orange through red: what colors do you see? What you’re seeing is the combinations of all the world’s sunsets refracted into the cone of the Earth’s shadow, which is about three times the size of the Moon at its average distance as seen from Earth. Remember, the Moon is experiencing a total solar eclipse as we watch the lunar eclipse unfold!

This color can be quantified and described on what is known as the Danjon Scale, with 0 being a very dark eclipse with the Moon barely visible, to a 4, meaning a very bright eclipse.

And yes, each total lunar eclipse is now receiving the “Blood Moon” meme thanks to ye ole Internet. Expect the conspiracy-minded to note that this eclipse occurs on the Jewish holiday of Sukkot starting at sundown on the 8th, which isn’t really all that wondrous as the Jewish calendar is a luni-solar one, and total lunar eclipses have to occur during a Full Moon by definition. Wait long enough, and an occasional “Sukkot total lunar eclipse” does indeed occur.

Uranus occultation — The footprint of the October 8th occultation of Uranus by the Moon during totality. (Credit: Occult 4.1.0).

But a truly rare event does occur during this eclipse, as the Moon actually occults (passes in front of) the planet Uranus during totality for observers in northern Alaska and northeast Asia. The rest of us in the observing zone will see a near miss. Can you spy Uranus with binoculars near the lunar limb during totality? Another such rarity occurred during Shakespeare’s time on December 30^th, 1591, involving Saturn and the eclipsed Moon, and another such odd occurrence transpires in 2344 A.D.

The circumstances of the 2344 eclipse/occultation. Credit: Starry Night, NASA/GSFC & Occult 4.0.1.

The brightest star to be occulted by the total eclipsed Moon as it crosses the constellation Pisces is +7.9^th magnitude HIP 4231 for the northern U.S. and Canada.

And speaking of historical eclipses, there’s a Columbus Day tie-in with the phenomenon as well. Like many mariners of his day, Columbus was well-versed in celestial navigation, and used a total lunar eclipse to get a good one-time fix on his longitude at sea, an experiment that you can easily replicate. Columbus also wasn’t above using prior knowledge of an impending lunar eclipse to get himself and his crew out of a bind with the locals when the need arose.

An outstanding sequence of images taken during the April 15th, 2014 total lunar eclipse. Credit: Michael Zeiler (Eclipse-Maps) Used with permission. — An outstanding sequence of images taken during the April 15th, 2014, total lunar eclipse. Credit: Michael Zeiler (Eclipse-Maps) Used with permission.

Photographing an eclipse with a DSLR is as easy as shooting an image of the Moon. Try this a few evenings before the big event. A minimum focal length of 200mm is needed to render the Moon larger than a white dot in the image, and remember that the Moon is much darker during total eclipse, and you’ll need to step the exposure times rapidly down from 1/100^th of a second to 2 to 4 seconds during totality.

A long-running effort by Sky & Telescope has been looking for amateur observations of precise crater contacts along the rim of the umbra in an effort to measure variations in the diameter of the Earth’s shadow.

starry night — The Moon versus Uranus as seen from Napa, California just past mid-eclipse on the morning of October 8th. Credit: Starry Night Education Software.

As always, weather prospects are the big question mark when it comes to eclipses. Typically, the southwestern U.S. experiences 13-20 clear days in the month of October; prospects worsen to the northwest, with an average of 3-12 days. We’ll be looking at resources such as NOAA, Skippy Sky and ClearSkyChart on the evenings leading up to the 8^th. The great thing about a lunar eclipse is, you don’t need a 100% clear sky to see it: just a clear view of the Moon!

Up for a challenge? We’ve yet to see a capture of a shadow transit of the International Space Station in front of the eclipsed Moon. This time around, such a capture should be possible across southern coastal California and the Baja peninsula just minutes prior to the onset of totality.

A shadow pass of the International Space Station just prior to the onset of totality. Note the position of the Moon. Created using Orbitron.

Another bizarre catch, known as a selenelion — witnessing the end of lunar totality after sunrise — may just be possible across the northeastern U.S. into the Canadian Maritimes as the eclipsed Moon sets during totality. The more elevation you can get the better! This works because the Moon lingers a bit in the large shadow of the Earth, plus atmospheric refraction gives the low altitude Sun and Moon a slight boost.

Clouded out? On the wrong side of the planet? You can watch the eclipse online at the following links:

– Live views courtesy of Gialuca Masi and the Virtual Telescope starting at 10:00 UT on October 8th.

– A live webcast starting at 9:00 UT courtesy of Slooh:

– A Columbia State University broadcast, (time to be determined).

Planning an ad-hoc broadcast? Let us know!

And as the eclipse wraps up, the biggest question is always: When’s the next one? Well, lunar eclipse number three of the four eclipse tetrad occurs next year on April 4^th, 2015… but in just two weeks time, the western United States and Canada will also witness a fine partial solar eclipse on Oct 23^rd…

Stay tuned!

Got images of the total lunar eclipse? Send ‘em in to Universe Today’s Flickr forum!

Interested in eclipse sci-fi? Check out our latest short stories Exeligmos and Shadowfall.

September 29, 2014December 23, 2015 by Bob King

PanSTARRS K1, the Comet that Keeps Going and Going and Going

Comet C/2012 K1 PANSTARRS photographed on September 26, 2014 by Rolando Ligustri. Like most comets, we see two tails. K1's dust tails points off to the left, it's gas or ion tail to the right. Credit: Rolando Ligustri

Thank you K1 PanSTARRS for hanging in there! Some comets crumble and fade away. Others linger a few months and move on. But after looping across the night sky for more than a year, this one is nowhere near quitting. Matter of fact, the best is yet to come.

This new visitor from the Oort Cloud making its first passage through the inner solar system, C/2012 K1 was discovered in May 2012 by the Pan-STARRS 1 survey telescope atop Mt. Haleakala in Hawaii at magnitude 19.7. Faint! On its the inbound journey from the Oort Cloud, C/2012 K1 approached with an orbit estimated in the millions of years. Perturbed by its interactions with the planets, its new orbit has been reduced to a mere ~400,000 years. That makes the many observing opportunities PanSTARRS K1 has provided that much more appreciated. No one alive now will ever see the comet again once this performance is over.

Comet C/2012 K1 PanSTARRS' changing appearance over the past year. Credit upper left clockwise: Carl Hergenrother, Damian Peach, Chris Schur and Rolando Ligustri — Comet C/2012 K1 PanSTARRS’ changing appearance over the past year. Credit upper left clockwise: Carl Hergenrother, Damian Peach, Chris Schur and Rolando Ligustri

Many amateur astronomers first picked up the comet’s trail in the spring of 2013 when it had brightened to around magnitude 13.5. My observing notes from June 2, 2013, read:

“Very small, about 20 arc seconds in diameter. Pretty faint at ~13.5 and moderately condensed but not too difficult at 142x . Well placed in Hercules.” Let’s just say it was a faint, fuzzy blob.

K1 PanSTARRS slowly brightened in Serpens last fall until it was lost in evening twilight. Come January this year it returned to the morning sky a little closer to Earth and Sun and a magnitude brighter. As winter snow gave way to frogs and flowers, the comet rocketed across Corona Borealis, Bootes and Ursa Major. Its fat, well-condensed coma towed a pair of tails and grew bright enough to spot in binoculars at magnitude 8.5 in late May.

Skywatchers can find C/2012 K1 PanSTARRS in the morning just in Hydra-Puppis just before dawn. The map shows its location daily with stars to magnitude 8.5. The numbers next to some stars are standard Flamsteed atllas catalog numbers. Source: Chris Marriott's SkyMap — Skywatchers can find C/2012 K1 PanSTARRS in the morning sky in the Hydra and Puppis just before dawn when it’s highest in the southeastern sky. The map shows its location daily with stars to magnitude 8.5. The numbers next to some stars are standard Flamsteed atlas catalog numbers. Click for a larger version. Source: Chris Marriott’s SkyMap

By July, it hid away in the solar glare a second time only to come back swinging in September’s pre-dawn sky. Now in the constellation Hydra and even closer to Earth, C/2012 K1 has further brightened to magnitude 7.5. Though low in the southeast at dawn, I was pleasantly surprised to see it several mornings ago. Through my 15-inch (37-cm) reflector at 64x I saw a fluffy, bright coma punctuated by a brighter, not-quite-stellar nucleus and a faint tail extending 1/4º to the northeast.

Mid-northern observers can watch the comet’s antics through mid-October. From then on, K1 will only be accessible from the far southern U.S. and points south as it makes the rounds of Pictor, Dorado and Horologium. After all this time you might think the comet is ready to depart Earth’s vicinity. Not even. C/2012 K1 will finally make its closest approach to our planet on Halloween (88.6 million miles – 143 million km) when it could easily shine at magnitude 6.5, making it very nearly a naked-eye comet.

PanSTARRS K1’s not giving up anytime soon. Southern skywatchers will keep it in view through the spring of 2015 before it returns to the deep chill from whence it came. After delighting skywatchers for nearly two years, it’ll be hard to let this one go.

September 24, 2014December 23, 2015 by Dan Majaess

A Splash of Color Across the Supermoon

Color variations observed a day after the supermoon are indicative of compositional differences over the Lunar surface (image credit: Noel Carboni).

A software engineer from Florida recently captured an image of the day-old supermoon in September that clearly conveys color variations across its surface. Such variations are often imperceptible, but the brightness and color differences were digitally enhanced to make them easier to discern. The color variations are indicative of compositional differences across the Lunar surface (e.g., iron content and impact ejecta).

A supermoon is a full Moon that is observed during the satellite’s closest approach to Earth. The Moon’s orbit is described by a marginally elongated ellipse rather than a circle, and hence the Moon’s distance from Earth is not constant. The Moon will achieve its largest apparent diameter in the Sky during that closest approach, which in part gives rise to the supermoon designation.

Noel Carboni, who imaged the supermoon a day after the full phase, told Universe Today that he, “created the image using 17 frames shot with a Canon EOS-40D, which was mounted to a 10-inch Meade telescope.” He added that, “each exposure was 1/40th of a second, and a workstation was used to stitch the image which is more than 17,000 pixels square.”

Carboni noted that, “Ever since the 1980s, I have harbored a growing interest in digital imaging. It is exciting that nowadays affordable and high quality image capture equipment are available to consumers, and that formidable digital image processing tools are available to just plain folks!”

His astrophotography may be well known to readers of Universe Today, as his work has been featured on NASA’s Astronomy Picture of the Day (APOD) and elsewhere. A gallery of Carboni’s astrophotography can be viewed at his webpage.

Readers desiring to learn more about the Moon and its surface can join the Moon Zoo Citizen Science Project, and glance at images from NASA’s Lunar Reconnaissance Orbiter. The Moon Zoo project aims to inspect millions of images captured by that instrument, which will invariably help scientists advance our understanding of the Moon.