Observing Archives

August 30, 2016 by David Dickinson

Our Guide to This Week’s ‘Ring of Fire’ Annular Eclipse

In Africa this week? The final solar eclipse of 2016 graces the continent on Thursday, September 1st. This eclipse is annular only, as the diminutive Moon fails to fully cover the disk of the Sun.

The 99.7 kilometer wide path crosses the African countries of Gabon, Republic of the Congo, Democratic Republic of the Congo, Tanzania, Mozambique and Madagascar. The antumbra (the ‘ring of fire path of the shadow annulus as viewed from Earth) touches down in the southern Atlantic at 7:20 Universal Time (UT) on September 1^st, before racing across Africa and departing our fair planet over the Indian Ocean over four hours later at 10:55 UT. Partial phases for the eclipse will be visible across the African continent as far north as southern Morocco, Egypt and the southwestern portion of the Arabian peninsula.

Path. Credit: Xavier Jubier. — The path of this week’s eclipse across Africa. Credit: Xavier Jubier.

Tales of the Saros

This eclipse is member 39 of 71 solar eclipses for saros 135, which runs from July 5^th, 1331 to August 17^th, 2593. This series finally produces its first total solar eclipse on March 29, 2359.

A daguerreotype of an annular eclipse from 1854, part of the same saros 154 cycle. Public domain image.

Annular eclipses occur when the Moon is too distant to cover the Sun as seen from the Earth. The Moon reaches apogee, or its most distant point from the Earth on September 6th, just five days after New and the September 1st eclipse.

How common (or rare) are solar eclipses, annular or total? It’s worth noting that as the 2017 total solar eclipse crossing the contiguous United States approaches, creationist websites are again promoting the idea that the supposed ‘perfection’ of solar eclipses is evidence for intelligent design. If solar eclipses are an example of a higher plan to the cosmos, they’re not a very good one… in fact, in our current epoch, partial eclipses, to include annulars, are much more prevalent. If, for example, the Moon’s orbit was aligned with the ecliptic, we’d see two eclipses – one lunar and and one solar – every month, a much rarer circumstance… a creator could have really used that to really get our attention. And Earth isn’t alone in hosting total solar eclipses: in our own solar system, you can make a brief visit to Jupiter’s large moons and also witness total solar eclipse perfection.

Unlike a total solar eclipse, proper eye protection must be worn throughout all stages of an annular eclipse. We witnessed annularity from the shores of Lake Erie back in 1994, and can attest that a few percent of the Sun is still surprisingly bright. The tireless purveyors of astronomy over at Astronomers Without Borders are working to distribute eclipse glasses to schools and students along the eclipse path.

An animation of Thursday's eclipse. Credit: NASA/GSFC. — An animation of Thursday’s eclipse. Credit: NASA/GSFC.

Are you in the path of this week’s annular eclipse? Let us know, and send those images in to Universe Today on Flickr.

We’ll most likely see more than a few images of the eclipse from space as well. And no, we’re not talking about the cheesy composite that now makes its rounds during every eclipse… solar observing satellites to include the European Space Agency’s Proba-2 and the joint JAXA/NASA Hinode mission typically capture several successive eclipses as they observe the Sun from their vantage point in low Earth orbit.

At this stage, we only know of one webcast set to broadcast the eclipse live: the venerable Slooh website.

Let us know if you’re planning on setting up an ad hoc live webcast of the eclipse, even from outside the path of annularity.

And of course, the big question on every eclipse-chaser’s mind is: when’s the next one? Well, we’ve got a subtle penumbral eclipse on September 16^th, 2016, and then the next solar eclipse is another annular favoring Argentina, Chile and the west coast of southern Africa on February 26^th, 2017.

Don’t miss this week’s annular solar eclipse, either live online or in person, for a chance to marvel at a celestial phenomenon we all share in time and space.

-Eclipse… science fiction? Yup… read Dave Dickinson’s eclipse-fueled tales Peak Season, Exeligmos, Shadowfall and The Syzygy Gambit.

August 24, 2016 by Nancy Atkinson

Experience the Glorious Night Sky Over Yellowstone National Park

A still from the timelapse video 'Hades Exhales,' a timelapse journey through several of Yellowstone National Park's geyser basins. Credit and copyright: Harun Mehmedinovic/Skyglow Productions.

Tomorrow, August 25, 2016, the US National Park Service celebrates its 100th anniversary, and the NPS has been celebrating all year with their “Find Your Park” promotion. But the first national park, Yellowstone National Park, was created 144 years ago. Yellowstone is known for its dramatic canyons, lush forests, and flowing rivers, but might be most famous for its hot springs and gushing geysers.

This new timelapse offers you a chance to “find your dark skies” at Yellowstone, and features the many geysers there, showing the dramatic geothermal features under both day and night skies. But the night skies over these geyser explosions steal the show! It was filmed by Harun Mehmedinovicas part of the Skyglow Project, an ongoing crowdfunded project that explores the effects and dangers of urban light pollution in contrast with some of the most incredible dark sky areas in North America.

SKYGLOWPROJECT.COM : HADES EXHALES from Harun Mehmedinovic on Vimeo.

The Skyglow Project works in collaboration with International Dark-Sky Association, a nonprofit organization fighting to educate the public about light pollution and to preserve the dark skies around the world.

Coming up this weekend, you can enjoy free admission to all 412 national parks from August 25-28, 2016. You can “find your park” and read about special events happening all around the country at FindYourPark.com

A still from the timelapse video 'Hades Exhales,' a timelapse journey through several of Yellowstone National Park's geyser basins. Credit: Harun Mehmedinovic/Skyglow Productions. — A still from the timelapse video ‘Hades Exhales,’ a timelapse journey through several of Yellowstone National Park’s geyser basins. Credit: Harun Mehmedinovic/Skyglow Productions.

Many thanks to Harun Mehmedinovic and Gavin Heffernan of Sunchaser Pictures for continuing their great work with the Skyglow Project and for sharing their incredible videos with Universe Today. Consider supporting their work, as all donations go towards the creation of more videos and images.

A still from the video 'Hades Exhales,' a timelapse journey through several of Yellowstone National Park's geyser basins. Credit and copyright: Harun Mehmedinovic/Skyglow Productions. — A still from the video ‘Hades Exhales,’ a timelapse journey through several of Yellowstone National Park’s geyser basins. Credit and copyright: Harun Mehmedinovic/Skyglow Productions.

August 22, 2016 by Bob King

5 Days, 2 Spectacular Conjunctions

Two planets close and up close. This is the view through a telescope during the extremely close conjunction of Jupiter and Venus on August 27. Credit: Stellarium

Saturn, Mars and Antares are shown on Sunday night August 21 two nights before their lineup. Mars is still far and away the brightest object in the bunch at magnitude -0.5. Details: 35mm lens, f/2.8, ISO 400, 10 seconds. Credit: Bob King — Saturn, Mars and Antares are shown on Sunday night August 21 two nights before their lineup. Mars is still the brightest of the bunch at magnitude –0.5. It will with Saturn at +0.4 and Antares at +1.0. Details: 35mm lens, f/2.8, ISO 400, 10 seconds. Credit: Bob King

Conjunctions of bright planets make for jewelry in the sky. This week, get ready for some celestial shimmer. If you’ve been following the hither and thither of Mars and Saturn near Antares this summer, you know these planets have been constantly on the move, creating all kinds of cool alignments in the southern sky.

On Tuesday night (August 23) the hopscotching duo will fall in line atop Antares in the southwestern sky at nightfall. Mars will sit just 1.5° above the star and Saturn 4° above Mars. Viewed from the Americas and Europe, the line will appear slightly bent. To catch them perfectly lined up, you’ll have to be in central Asia on the following evening, but the view should be pleasing no matter where you live.

This will be the scene facing south at nightfall from the central U.S. on Tuesday night August 23. The two planets and star form a compact gathering that's sure to grab your attention. Credit: Stellarium — This will be the scene facing southwest at nightfall from the central U.S. on Tuesday night August 23. The two planets and star form a compact gathering that’s sure to grab your attention. The moment of conjunction between Mars and Saturn occurs at 11:00 UT (7 a.m. Eastern Aug. 24), but they’ll be below the horizon at that time for the Americas and Europe. Credit: Stellarium

Nice as it is, the Mars-Saturn-Antares lineup is only the warm-up for the big event: the closest conjunction of the two brightest planets this year. On Saturday evening, August 27, Venus and Jupiter will approach within a hair’s breadth of each other as viewed with the naked eye — only 0.1° will separate the two gems. That’s one-fifth of a full moon’s width! While Mars and Saturn will be a snap to spot low in the southwestern sky during their conjunction, Venus and Jupiter snuggle near the western horizon at dusk.

Look for Venus and Jupiter right next to each other 4 degrees (about three fingers held together horizontally) above the western horizon about a half-hour after sunset on August 27. Map: Bob King; source: Stellarium — Look for Venus and Jupiter right next to each other 4° (about three fingers held together horizontally) above the western horizon about a half-hour after sunset on August 27. This map shows the view from across the central U.S. at about 40°N latitude. The two planets will be closest at 22:00 UT (6 p.m. Eastern, 7 p.m. Central, 8 p.m. Mountain and 9 p.m. Pacific). Map: Bob King; source: Stellarium

To make sure you see them, find a place in advance of the date with a wide open view to the west. I also suggest bringing a pair of binoculars. It’s so much easier to find an object in bright twilight with help from the glass. You can start looking about 25 minutes after sunset; Venus will catch your eye first. Once you’ve found it, look a smidge to its lower right for Jupiter. If you’re using binoculars, lower them to see how remarkably close the two planets appear using nothing but your eyeballs. Perhaps they’ll remind you of a bright double star in a telescope or even the twin suns of Tatooine in Star Wars.

Here's what the two planets will look like through a telescope at medium and high magnification, when both will comfortably fit into the same field of view. Stellarium — The two planets will be only 6 arc minutes apart Saturday evening and easily fit in the same field of view of a telescope at high magnification. Jupiter’s four brightest moons will be obvious. If you’re patient and wait for the air to settle, you’ll be able to make out Venus’s waxing gibbous phase. Credit: Stellarium

Have a small telescope? Take it along — Jupiter and Venus are so close together that they easily fit in the same high magnification field of view. Jupiter’s four brightest moons will be on display, and Venus will look just like a miniature version of the waxing gibbous moon. Rarely do the sky’s two brightest planets nearly fuse, making this a not-to-miss event.

Venus and Jupiter do a little square dance over the nights of August 26-28. Jupiter is headed westward toward conjunction with the sun, while Venus is moving away from the sun from our perspective. Stellarium — Venus and Jupiter do a little square dance over the nights of August 26-28. Jupiter is headed westward toward conjunction with the sun, while Venus is moving away from the sun in the opposite direction from our perspective. Credit: Stellarium

If cloudy weather’s in the forecast that night, you can still spot them relatively close together the night before and night after, when they’ll be about 1° or two full moon diameters apart. I get pretty jazzed when bright objects approach closely in the sky, and I’m betting you do, too.

I also don’t mind being taken in by illusion once in a while. During a conjunction, planets only appear close together because we view them along the same line of sight. Their real distances add a dose of reality.

On Saturday evening Venus will be 143 million miles (230 million km) away vs. 592 million miles (953 million km) for Jupiter. In spite of appearing to almost touch, Jupiter is more than four times farther than the goddess planet.

The showpieces in this week's conjunction parade: Jupiter, Venus, Mars and Saturn. Credit: NASA/ESA — The showpieces in this week’s conjunction parade: Jupiter, Venus, Mars and Saturn. Credit: NASA/ESA

That distance translates to the chill realm of the giant gaseous planets where sunlight is weak and ice is common. Try stretching your imagination that evening to sense as best you can the vast gulf between the two worlds.

You might also try taking a picture of them with your mobile phone. I suggest this because the sky will be light enough to get a hand-held photo of the scene. Photos or not, don’t miss what the planets have in store for earthlings this week.

August 16, 2016 by David Dickinson

One Year to the 2017 Total Solar Eclipse

https://www.flickr.com/photos/auraluu/7085004603/in/photolist-bN5v2M-dufbuU-pzUHQi-nZQkxQ-6KdhJ7-9TLjD4-dtvX13-pidJNx-dtvUxY-dxAA8r-n8uzjn-hx1CzU-du9zKv-c4eHhw-F1szSh-hx2yTc-dv7Y5W-dubgHK-du9zB6-FvPkNQ-drNyGZ-Eg3Msj-F4kfHb-zpuHFU-yUCmvN-yuSXP5-DqsCRp-zfU1bR-zbbFV9-FrtBYE-hdVRQm-rkh8fd-dufbHG-6KGxbK-dufbmf-du9zQe-ryZmAb-FtsHpn-EAUwcK-Ct6Fma-6KLF1b-FiThUB-EEgQjh-E8uHFM-yUC28b-rqtfQ3-yTR8jt-tsa14t-rHcxrz-rXwEhJ — Totality! The view of the last total solar eclipse to cross a U.S. state (Hawaii) back in 1991. Image credit and copyright: A. Nartist (shot from Cabo San Lucas, Baja California).

One. More. Year. Quick; where will you be this time next year on August 21^st, 2017? We’re now just one year out this weekend from a fine total solar eclipse gracing the United States from coast to coast. If you think one year out is too early to start planning, well, umbraphiles (those who chase the shadow of the Moon worldwide) have been planning to catch this one now for over a decade.

The shadow of the March 9th, 2016 solar eclipse as seen from the Himawari-8 Earth-observing satellite. image credit: JAXA/JMA/Himawari/CIMSS — The shadow of the March 9th, 2016 solar eclipse (the dark spot on the right) as seen from the Himawari-8 Earth-observing satellite. Image credit: JAXA/JMA/Himawari/CIMSS.

Get set for the Great American Eclipse. The last time a total solar eclipse made landfall over a U.S. state was Hawaii on July 11^th, 1991, and the path of totality hasn’t touched down over the contiguous ‘Lower 48’ United States since February 26^th, 1979. And you have to go all the way back over nearly a century to June 8^th, 1918 to find an eclipse that exclusively crossed the United States from the Pacific to the Atlantic Coast.

The path of the 2017 total solar eclipse across the U.S. image credit and copyright: Michael Zeiler/The GreatAmercianEclipse — The path of the 2017 total solar eclipse across the U.S. Image credit and copyright: Michael Zeiler/The GreatAmercianEclipse

Totality for the August 21^st, 2017 eclipse crosses over many major cities, including Columbia South Carolina, Nashville, St. Louis and Salem, Oregon. The inner shadow of the Moon touches on 15 states as it races across the U.S. in just over an hour and a half. The length of totality is about 2 minutes in duration as the shadow makes landfall near Lincoln City, Oregon, reaches a maximum duration of 2 minutes, 42 seconds very near Carbondale, Illinois, and shrinks back down to 2 minutes and 35 seconds as the shadow heads back out to sea over Charleston, South Carolina.

The eclipse will be a late morning affair in the northwest, occurring at high noon over western Nebraska, and early afternoon to the east. ‘Getting your ass to totality,’ is a must. “But I’ve seen a partial solar eclipse,” is a common refrain, “aren’t they all the same?”

Nope. We witnessed the May 10^th, 1994 annular eclipse from the shores of Lake Erie, and can tell you that even less than 1% of the Sun’s intensity is still pretty bright, a steely blue luminosity equivalent to a cloudy day.

We crisscrossed the United States along the eclipse path back in 2014, chronicling preparations in towns such as Columbia and Hopkinsville, Kentucky. Last minute accommodation is already tough to come by, even one year out. Cabins in the Land Between the Lakes region near Paducah, Kentucky, for example, were booked full as soon as the August 21^st date became available. Think Mardi Gras and DragonCon, rolled into one. Hopkinsville also has an annual Roswell-style UFO-fest on the same date, celebrating the 1955 Kelly-Hopkinsville UFO incident.

Will it be ‘umbraphiles versus aliens?’

Out west, enticing locales include the Grand Teton National Park and Jackson Hole, Wyoming and the northern edge of the Craters of the Moon National Monument site in Idaho. It’s also worth noting that the western United States is a better bet cloud cover-wise, as afternoon summer thundershowers tend to be the norm for the southeast during late August.

Millions live within an easy day drive of the eclipse path, and it happens during prime camping season, to boot. The annual Sturgess motorcycle rally held near Rapid City, South Dakota is just one week prior to totality, and bikers returning from the pilgrimage southward could easily stop to greet the Earth’s shadow on the road home.

2017 Eclipse Panorama from Michael Zeiler on Vimeo.

There’s been talk that Cosmoquest may mount an eclipse expedition based out of Nashville, Tennessee (more to come on that).

Maintaining mobility is the best bet. Our master plan is to return to the States a week or so prior, rent a camper van from Vegas, and head northward. Like millions of Americans, this will be our first total solar eclipse, and the event promises to spark a whole new generation of umbraphiles. And stick around just seven more years, and totality will again cross the United States on August 8^th, 2024 from the southwest to the northeast. The Illinois, Missouri and Kentucky tri-state region sees this eclipse as well. This one is special for us, as it crosses over our hometown of Presque Isle, Maine. I remember looking up the next total solar eclipse over northern Maine as a kid, way back when, and figuring out just how old I would be. The top of Mount Katahdin and selected sites along the Maine Solar System model would all be choice locales to view this one. Check out this great old vid of the aforementioned 1979 eclipse over the U.S.:

We also plan on taking the veteran eclipse-chaser’s mantra of ‘experience your first eclipse; but photograph your second one.’ to heart. Lots of fascinating projects are afoot leading up to the 2017 total solar eclipse, including The Eclipse MegaMovie Project to produce a complete video documentary of the eclipse path, plans by a student group to fly and observe the eclipse from balloons during totality, proposals to replicate famous eclipse experiments and more. It’s also worth noting that the bright star Regulus will sit just one degree from the Sun during totality… perhaps someone will manage to measure its deflection via General Relativity in a manner similar to Sir Arthur Eddington’s famous 1919 observation?

Unlike the paths of most eclipses, which seem to have an affinity for wind-swept tundra or remote swaths of desert, this one is sure to draw in the ‘astronomy-curious’ and may just be the most witnessed total solar eclipse in history.

Here’s some eclipse tales and facts to ponder leading up to totality. If you caught the August 11^th, 1999 eclipse across Europe, then you saw the last eclipse in the same saros series 145. If you caught the eclipse before that in the same series on July 31^st, 1981 across northeast Asia, then you’ll complete a 54 year long triple-saros period after seeing next summer’s eclipse, known as an exeligmos. This cycle also brings the eclipse path very nearly back around to the same longitude.

Regulus near the eclipsed Sun next August. Credit: Stellarium.

The Sun is about 400 times larger than the Moon in diameter, but the Moon is 400 times closer. We’ve actually heard this fact tossed out as evidence for intelligent design, though it’s just a happy celestial circumstance of our present era. In fact, annular eclipses are now slightly more common than totals in our current epoch, and will continue to become more so as the Moon slowly recedes from the Earth. Just under a billion years ago, the very first annular eclipse of the Sun as seen from the Earth occurred, and 1.4 billion years hence, the Earth will witness one last brief total eclipse.

But you won’t have to wait that long. Don’t miss the greatest show in the universe next August!

-Check out Michael Zeiler’s (@EclipseMaps) 10-foot long strip map of the entire eclipse path.

-Eclipses, both lunar and solar have played a role in history as well.

-Curious about eclipses in time and space? Read our eclipse-fueled sci-fi tales, Exeligmos, The Syzygy Gambit and Shadowfall, with more to come!

August 9, 2016 by David Dickinson

Get Ready for the 2016 Perseids

Out camping under the August sky? The coming week gives us a good reason to stay up late, as the Perseid meteor shower graces the summer sky. An ‘old faithful’ of annual meteor showers, the Perseids are always sure to produce.

The 2016 Perseids present a few challenges, though persistent observers should still see a descent show. The Perseids are typically active from July 17^th to August 24^th, with the peak arriving this year right around 13:00 to 15:30 Universal Time on Friday, August 12^th. This will place the radiant for the Perseids high in the sky after local midnight for observers in the northern Pacific, though observers worldwide should be vigilant over the next week. Meteor showers don’t read predictions and prognostications, and an arrival of the peak just a few hours early would place North America in the cross-hairs this coming Friday. The Perseids typically produce an average Zenithal Hourly Rate of 60-200 per hour, and the International Meteor Organization predicts a ZHR of 150 for 2016.

Looking to the northeast from latitude 50 degrees north at 1AM local on the morning of August 12th. Image credit: Stellarium.

The nemesis of the 2016 is the Moon, which reaches Full on August 18^th, six days after the shower’s peak. The time to start watching this shower is now, before the waxing Moon becomes a factor. The farther north you are, the earlier the Moon sets this week:

Moonset on the evening of August 11/12^th:

Latitude versus Moonset ( in local daylight saving time)

20 degrees north – 1:30 AM

30 degrees north – 1:14 AM

40 degrees north – 0:56 AM

50 degrees north – 0:30 AM

Early morning is almost always the best time to watch any meteor shower, as the Earth-bound observer faces in to the meteor stream head on. The December Geminids only recently surpassed the Perseids in annual intensity in the past few years.

The orientation of the Earth's shadow versus, the Sun, Moon and the radiant of the Perseids at the start of the projected peak on August 12th. Image credit: Orbitron. — The orientation of the Earth’s shadow versus the Sun, Moon and the radiant of the Perseids at the start of the projected peak on August 12th. Image credit: Orbitron.

The radiant of the Perseids drifts through the constellations of Cassiopeia, Perseus and Camelopardalis from late July to mid-August. The Perseids could just as easily have received the tongue-twisting moniker of the ‘Cassiopeiaids’ or the ‘August Camelopardalids.’ The source of the Perseids is comet Comet 109P/Swift-Tuttle discovered by Lewis Swift and Horace Tuttle in 1862. Comet Swift-Tuttle reached perihelion on 1992, and visits the inner solar system once again in 2126.

The Perseids are also sometimes referred as the “Tears of Saint Lawrence” who was martyred on a hot grid iron on August 10th, 258 AD.

The Perseids have been especially active in recent decades, following the perihelion passage of Comet Swift-Tuttle. Meteor showers come and go. For example, the Andromedids were a shower of epic storm proportions until the late 19^th century. We have records of the Perseids back to 36AD, but on some (hopefully) far off date, the debris path of Comet Swift-Tuttle will fail to intersect the Earth’s orbit annually, and the Perseids will become a distant memory. During previous years, the Perseids exhibited a peak of ZHR= 95 (2015), 68 (2014), 110 (2013), 121 (2012) and 58 (2011). Keep in mind, the Perseids have also sometimes displayed a twin peak during previous years, as well.

An early snapshot of the activity for the 2016 Perseids. image credit: The International Meteor Organization. — An early snapshot of the activity for the 2016 Perseids. Image credit: The International Meteor Organization.

Observing the Perseids

The best instrument to observe the Perseids with is a pair of old fashioned, ‘Mk-1 eyeballs.’ Simply lay back, warm drink in hand, and watch. Remember, the quoted ZHR is an ideal rate that we all strive for, though there are strategies to maximize your chances of catching a meteor. Watching early in the morning when the radiant rides highest (around sunrise in the case of the Perseids), seeking out dark skies, and enlisting a friend to watch in an opposite direction can raise your hourly meteor count.

Keep a pair of binoculars handy to examine any persistent glowing trains and lingering smoke trails from bright fireballs. Monitoring the FM band for the pings of accompanying radio meteors can add another dimension to an observation session. The ionized trail of a meteor can very occasionally reflect the signal of a distant radio station, bringing it through clear for a few seconds before fading out.

@Astroguyz I wasn’t aiming for #Perseid images, wanted to grab Milky Way shots and it sneaked into one of the frames pic.twitter.com/BuGE8xrsVH

— irv (@irvb) August 9, 2016

Also, keep an ear out for an even stranger phenomenon, as bright meteors are sometimes accompanied by a hissing or crackling sound. Long thought to be a psychological phenomenon, a team of Japanese astronomers managed to catch recordings of this strange effect during the 1988 Perseid meteors.

Imaging meteors is also pretty straight forward. Simply tripod mount a DSLR with a wide field lens, take some test exposures of the sky to get the ISO, f-stop and exposure combination just right, and begin taking exposures 30 seconds to five minutes long. An intervalometer can automate the process, freeing you up to kick back and watch the show.

Got science? Be sure to send those meteor counts into the International Meteor Organization (IMO) and watch their live updated graph as the shower progresses.

Also, be sure to tweet those meteor sightings to #Meteorwatch.

August 1, 2016August 2, 2016 by David Dickinson

Lights in the Sky: Meteors, Reentry, or E.T.?

A fireball lights up the skies over Dayton, Ohio. Image credit and copyright: John Chumack.

It happens a few times every year.

Last week, we poured our morning coffee, powered up our laptop and phone, and prepared to engage the day.

It wasn’t long before the messages started pouring in. ‘Bright fireball over the U.S. West Coast!’ ‘Major event lights up the California skies!’ and variations thereof. Memories of Chelyabinsk came immediately to mind. A bit of digging around ye ole web revealed video and a few authentic stills from the event.

Now, I always like to look these over myself before reading just what other experts might think. Chelyabinsk immediately grabbed our attention when we saw the first videos recording the shock wave of sound generated by the blast. ‘That sucker was close,’ we realized.

Thursday’s (Wednesday evening Pacific Time) event was less spectacular, but still interesting: the nighttime reentry of the Long March CZ-7 rocket body NORAD ID 2016-042E as it broke up over the U.S. West Coast.

How do we know this, and what do we look for? Is that flash a meteor, bolide, reentry or something stranger still?

Most good meteor footage comes from video recorders that are already up and running when the event occurs, to include security and dashboard cameras, and mobile phones already recording another event, such as a concert or game. How fast can YOU have your smartphone camera out and running? We only recently learned that a quick double tap of the home button will bring the camera on our Android to bear, no unlock needed.

If the event occurs on a Friday or Saturday night with lots of folks out on the town on a clear evening, we might see multiple captures come streaming-in of the event. Just such a fireball was witnessed over the United Kingdom on Friday evening, September 21st, 2012.

Likewise, the fakes are never far behind. We’ve seen ’em all, though you’re welcome to try and stump us. Such ‘meteor-wrongs’ that are commonly circulated as authentic are the reentry of Mir, the 1992 Peekskill meteor, Chelyabinsk, the reentry of Hayabusa, and screen grabs from the flick Armageddon… has anyone ever been fooled by this one?

Meteors generally have a very swift motion, and occur with a greater frequency as the observer rotates forward into the path of Earth’s motion around the Sun past local midnight. Remember, it’s the front of the windshield that picks up the bugs rolling down the highway.

Evening meteors, however, can have a dramatic slow, stately motion across the sky, as they struggle to catch up with the Earth. If they reach a brilliance of magnitude -14 — about one whole magnitude brighter than a Full Moon — said meteor is known as a bolide.

Sometimes, such a fireball can begin shedding fiery debris, in a dramatic display known as a meteor train or meteor precession. Such an event was witnessed over the northeastern United States on July 20^th, 1860.

The 1860 meteor train. Painting by Frederic Church.

Bright meteors may exhibit colors, hinting at chemical competition. Green for nickel (Not kryptonite!) is typically seen. MeteoriteMen’s Geoffrey Notkin once told us a good rule of thumb: if you hear an accompanying sonic boom a few minutes after seeing a meteor, it’s close. Folks often think what they saw went down behind a hill or tree, when it was actually likely more than 50 miles distant — if it hit the ground at all.

Is that a meteor or a reentry? Reentries move slower still, and will shed lots of debris. Here’s what we’re looking at to judge suspect sighting as a reentry:

Heavens-Above: A great clearing house for satellite passes by location. One great tool is that Heavens-Above will generate a pass map for your location juxtaposed over a sky chart.

Aerospace Corp current reentries: Follows upcoming reentries of larger debris with refined orbits.

Space-Track: The U.S. Joint Space Operations Command’s tracking center for artificial objects in orbit around Earth. Access is available to backyard satellite spotters with free registration. The most accurate source for swiftly evolving orbital elements.

SeeSat-L: This message board always lights up with chatter whenever a possible reentry lights up the skies worldwide.

Stranger Skies

Bizarre sights await the keen eyed. A tumbling rocket booster can often flare in a manner similar to Iridium satellites. Satellites way out in geostationary orbit can flare briefly into naked eye visibility during ‘GEOSat flare season’ near the weeks surrounding either equinox.

Some gamma ray bursts, such as GRB 080319B flare up briefly above magnitude +6 into naked eye visibility from far across the Universe. As of yet, there’s never been a reliable observer sighting of such an event, though it should be possible… probably someone far back in humanity’s history witnessed just such a brief flash in the sky, pausing silently to wonder just what it was…

Kaboom! Image credit: NASA/Pi of the Sky.

Going further back still, a nearby supernova or gamma-ray burst would leave a ghostly blue afterglow from Cerenkov radiation as it pummeled our atmosphere… though it would be a deadly planet-sterilizing indigo glow, not something you’d want to see. Thankfully, we live in the ‘Era of Mediocrity,’ safely outside of the 25-50 light year ‘kill zone’ for any potential supernova.

And what if those lights in the sky really were the vanguard of an alien invasion force? Well, if they really did land rayguns ablaze on the White House lawn, you’ll read it first here on Universe Today!

July 27, 2016 by Bob King

See a Wonderful Aldebaran Occultation with a Spectacular Twist

This map shows the 23% illuminated crescent Moon from the central U.S. around 10:00 UT Friday morning. Observers who begin observing earlier may also see stars in the Hyades cluster occulted. Credit: Stellarium — This map shows the 23% illuminated crescent Moon from the central U.S. around 10:00 UT Friday morning. Observers who start observing earlier may also see stars in the Hyades cluster occulted. Credit: Stellarium

We’re in for a celestial show from two of the sky’s glitterati this week. On Friday morning July 29 around 10:00 UT (5 a.m. CDT), the crescent Moon will occult the star Aldebaran from the eastern and southern U.S. south of a line from Toledo, Ohio through St. Louis, Tulsa and El Paso, Texas. North of that line, the Moon will slide just south of the star in a spectacular conjunction. But the real action lies within a half-mile of either side of the line, where lucky observers will see a grazing occultation.

Use this map to help you plan your occultation adventure. Much of North and South America will see a wonderful conjunction, while many areas will witness the occultation. If you can drive to the graze line, do it! Credit: David Dunham

As the Moon’s orbital motion carries it eastward at the rate of one lunar diameter per hour, Aldebaran will appear to approach the sunlit northern cusp and then scrape along the Moon’s northern limb. You’ll need binoculars or a small telescope to see the initial approach, but once star reaches the semi-dark, earthlit portion of the Moon, the graze will be visible with the naked eye.

This diagram shows the the grazing path of Aldebaran. As the Moon moves east, the star will appear to move to the right or west. Credit: David Dunham — This diagram shows the the grazing path of Aldebaran. As the Moon moves east, the star will appear to move to the right or west. Be sure not to miss it — the entire grazing event lasts just 3 minutes. Credit: David Dunham

The edge or limb of the Moon appears smooth to the eye, but it’s rife with polar mountain peaks. As Aldebaran creeps along the craggy limb, it will repeatedly flash in and out of view as peaks and cliffs momentarily block it from sight. And here’s the truly amazing thing. Observers along the western section of the graze line, where the event takes place in fairly dark sky, can watch the star blink in and out of view without optical aid when it reaches the dark part of the lunar disk. Wow!

Aldebaran's large size means it won't disappear instantaneously when it's covered either by the lunar limb during occultation or by mountains along the grazing path. Credit: Wikipedia — Aldebaran’s large size means it won’t disappear instantaneously when it’s covered either by the lunar limb during occultation or by mountains along the grazing path. Credit: Wikipedia

Aldebaran is no small star. An orange giant 67 light years from Earth, it’s 44 times the diameter of the Sun. That means that sometimes only a part of the star at a time will covered at a time in some cases, so the length of the flashes will vary. According to David Dunham, president of the International Occultation Timing Association (IOTA), Aldebaran will disappear for one-tenth of a second up to a second as the Moon rolls east, allowing some observers to sense the size of the star. Wow x 100!

Aldebaran, the brightest star in Taurus the Bull hangs near the edge of the moon two minutes before it was covered up. The star was easily visible through the telescope. Credit: Bob King — Aldebaran hangs near the edge of the moon two minutes before it was occulted last October in this photo taken with a smartphone. The star was easily visible through the telescope. Credit: Bob King

Skywatchers further east along the graze line and in other areas where the occultation / conjunction takes place after sunrise shouldn’t pass up the chance to see the event. During last October’s occultation of Aldebaran, I was able to see and photograph the star in my 10-inch scope in daylight no problem. The moon will be closer to the Sun this time around, but give it try anyway. This is the best grazing occultation of Aldebaran visible from North America in the current 4-year series.

For the many who live either north or south of the graze line, the views will still be fantastic. You’ll either see an occultation and subsequent reappearance of the star at the dark limb … or a fine conjunction. The forecast looks good for my city, so I plan on heading out to watch an orange giant meet the skinny Moon. I wish you clear skies and happy shooting!

For more information about the event including detailed weather forecasts and grazing maps, check out the IOTA’s public announcement page. Click here for Universal Times for the disappearance and reappearance of the star for over 1,000 cities.

July 26, 2016 by David Dickinson

Celestial Photobomb: Rare Occultation of Mercury by the Moon Set for Next Week

Mercury and the Moon over the ramparts of Assilah, Morocco. Photo by author

Have you caught sight of Mercury yet? This coming week is a good time to try, looking low to the west at dusk. We just managed to to nab it with binoculars for the first time during the current apparition this past Sunday from the rooftop of our Air BnB in Casablanca, Morocco.

Mercury is a tough grab under any circumstance, that’s for sure. Brilliant Venus and Jupiter make great guides to finding the elusive planet in late July, as it ping-pongs between the two. The waxing crescent Moon joins the scene in the first week of August, and for a very lucky few, actually occults (passes in front of ) the diminutive innermost world shortly after passing New.

Mercury (arrowed) near the Moon on the morning of June 3rd, 2016. Image credit: Dave Dickinson.

Here’s the low down on everything Mercurial, and circumstances for the coming weeks.

Mercury passes 18′ from the star Regulus on Saturday, July 30^th at 19:00 Universal Time (UT), representing the closest passage of a planet near a first magnitude star for 2016.

The Moon then reaches New phase, marking the start of lunation 1158 on August 2^nd at 20:45 UT. The Moon then moves on to occult Mercury on Thursday, August 4^th at 22:00 UT, just over 48 hours later. The occultation is visible at dusk for observers based in southern Chile and southern Argentina. The rest of us see a close pass. Note that although it is a miss for North America, viewers based on the continent share the same colongitude and will see Mercury only a degree off of the northern limb of the Moon on the night of August 4^th. Mercury shines at magnitude +0.01, and presents a 67% illuminated disk 6.3” in size, while the Moon is a slender 5% illuminated.

Occultations of Mercury for 2016. Credit: Occult 4.2. (click image to enlarge).

How early can you see the waxing crescent Moon? Catching the Moon with the naked eye under transparent clear skies isn’t usually difficult when it passes 20 hours old. This cycle, first sightings favor South Africa westward on the night of August 3^rd.

Mercury reaches greatest elongation 27.4 degrees east of the Sun 12 days after this occultation on August 16^th.

How rare is it? Well occultations of Mercury by the Moon are the toughest to catch of all the naked eye planets, owing to the fact that the planet never strays far from the Sun. Nearly all of these events go unwitnessed, as they occur mainly under daytime skies. And while you can observe Mercury in the daytime near greatest elongation with a telescope, safety precautions need to be taken to assure the Sun is physically blocked from view. Astronomers of yore did exactly that, hoping to glimpse fleeting detail on Mercury while it was perched higher in the sky above the murk of the atmosphere low to the horizon.

In fact, a quick search of ye ole web reveals very few convincing captures of an occultation of Mercury (see the video above). The closest grab thus far comes from astrophotographer Cory Schmitz on June 3^rd 2016 based in South Africa:

Image credit: — Can you see it? The Moon about to occult Mercury on June 3rd. Image credit and copyright: Cory Schmitz.

Can’t wait til next week? The Moon crosses the Hyades open star cluster this week, occulting several stars along the way. The action occurs on the morning of Friday, July 29^th culminating with an occultation of +1 magnitude Aldebaran by the 23% illuminated Moon. Texas and Mexico are well-placed to see this event under dark skies. A small confession: we actually prefer occultations of planets and stars by the waxing Moon, as the dark edge of the Moon is leading during ingress, making it much easier to witness and the exact moment the Moon blots out the object.

Still want more? The Moon actually goes on to occult Jupiter on August 6^th for the South Pacific. Viewers farther west in southeast Asia might just spy this one in the daytime. This is the second occultation of Jupiter by the Moon in a series of four in 2016.

Looking west on the evening of August 4th. Image credit: Stellarium.

Keep and eye on those planets in August, as they’re now all currently visible in the dusk sky. The Moon, Regulus and Venus also form a tight five degree triangle on the evening of August 4^th, followed by a slightly wider grouping of Venus, Jupiter and the Moon around August 25^th.

More to come on that soon. Be sure to check the planet Mercury off of your life list this coming week, using the nearby waxing crescent Moon as a guide.

June 20, 2016June 25, 2016 by David Dickinson

Seeking the Summer Solstice

A summer solstice sunset. Image credit and copyright: Sarah and Simon Fisher.

Can you feel the heat? If you find yourself north of the equator, astronomical summer kicks off today with the arrival of the summer solstice. In the southern hemisphere, the reverse is true, as today’s solstice marks the start of winter.

Thank our wacky seasons, and the 23.4 degree tilt of the Earth’s axis for the variation in insolation. Today, all along the Tropic of Cancer at latitude 23.4 degrees north, folks will experience what’s known as Lahiana Noon, as the Sun passes through the zenith directly overhead. Eratosthenes first noted this phenomena in 3^rd century BC from an account in the town of Syene (modern day Aswan), 925 kilometers to the south of Alexandria, Egypt. The account mentioned how, at noon on the day of the solstice, the Sun shined straight down a local well, and cast no shadows. He went on to correctly deduce that the differing shadow angles between the two locales is due to the curvature of the Earth, and went on to calculate the curvature of the planet for good measure. Not a bad bit of reasoning, for an experiment that you can do today.

Eratosthenes' classic experiment. Wikimedia Commons image in the Public Domain. — Eratosthenes’ classic experiment. Wikimedia Commons image in the Public Domain.

And although we call it the Tropic of Cancer, and the astrological sign of the Crab begins today as the Sun passes 90 degrees longitude along the ecliptic plane as seen from Earth, the Sun now actually sits in the astronomical constellation of Taurus on the June northward solstice. Thank precession; live out a normal 72 year human life span, and the solstice will move one degree along the ecliptic—stick around about 26,000 years, and it will complete one circuit of the zodiac. That’s something that your astrologer won’t tell you.

The tilt of the Earth's axis during the June northward solstice. Image credit: NASA. — The tilt of the Earth’s axis during the June northward solstice. Image credit: NASA.

The solstice in the early 21^st century actually falls on June 20th, thanks to the ‘reset’ the Gregorian calendar received in 2000 from the addition of a century year leap day. The actual moment the Sun reaches its northernmost declination today and slowly reverses its apparent motion is 22:34 Universal Time (UT). In 2016, the Moon reaches Full just 11 hours to the solstice. The last time a Full Moon fell within 24 hours of a solstice was December 2010, and we had a total lunar eclipse to boot. Such a coincidence won’t occur again until December 2018. You get a good study in celestial mechanics 101 tonight, as the Full Moon rises opposite to the setting Sun. The Moon occupies the southern region of the sky where the Sun will reside this December during the other solstice, when the Full Moon will then ride high in the night sky, and gets ever higher as we head towards a Major Lunar Standstill in 2025.

The back alley of our Morocco Air BnB mimics Eratosthenes’ well. Image credit: Dave Dickinson

Of course, this motion of the Sun through the year is all an illusion from our terrestrial biased viewpoint. We’re actually racing around the Sun to the tune of 30 kilometers per second. You wouldn’t know it as summer heats up in the northern hemisphere, but we’re headed towards aphelion or the farthest point from the Sun for the Earth on July 4th at 152 million kilometers or 1.017 astronomical units (AU) distant. And the latest sunset as seen from latitude 40 degrees actually occurs on June 27^th at 7:33 PM (not accounting for Daylight Saving Time) go much further north (like the Canadian Maritimes or the UK) and true astronomical darkness never occurs in late June.

And speaking of the Sun, we’re wrapping up the end of the 11 year solar cycle this year… and there are hints that we may be in for another profound solar minimum similar to 2009. We’ve already had a brief spotless stretch last month, and some solar astronomers have predicted that solar cycle #25 may be absent all together. This means a subsidence in aurorae, and an uncharacteristically blank Sol.

But don’t despair and pack it in for the summer. As a consolation prize, high northern latitudes have in recent years played host to electric blue noctilucent clouds near the June solstice. Also, the International Space Station enters a second period of full illumination through the entire length of its orbit from July 26th to 28th, making for the possibility of seeing multiple passes in a single night.

A display of noctilucent clouds over Blackrod, UK. Image credit and copyright: Dave Walker.

And folks in the Islamic world (and travelers such as ourselves currently in Morocco) can rejoice, as the Full Moon means that we’re half way through the fasting lunar month Ramadan. This is an especially tough one, as Ramadan 2016 goes right through the summer solstice, making for only a brief six hour span to break the fast each night and prepare for another 18 hour long stretch… and to repeat this pattern for 29 days straight. It’s a fascinating time of night markets and celebration, but for travelers, it also means odd opening hours and delays.

Searching for the solstice and other strange astronomical alignments at M'Soura, Morocco. Image credit: Dave Dickinson — Searching for the solstice and other strange astronomical alignments at M’Soura, Morocco. Image credit: Dave Dickinson

See any curious solstice shadow alignments in your neighborhood today?

Happy Lahiana Noon… from here on out, northern viewers slowly start to take back the night!

June 14, 2016 by David Dickinson

Peering for Pluto: Our Guide to Opposition 2016

An enviable view, of the most distant eclipse seen yet, as New Horizons flies through the shadow of Pluto. Image credit: NASA/JPL.

What an age we live in. This summer marks the very first opposition of Pluto since New Horizons’ historic flyby of the distant world in July 2015. If you were like us, you sat transfixed during the crucial flyby phase, the climax of a decade long mission. We now live in an era where Pluto and its massive moon Charon are a known worlds, something that even Pluto discoverer Clyde Tombaugh never got to see.

Pluto in 2016

And this summer, with a little skill and patience and a good-sized telescope, you can see Pluto for yourself. Opposition 2016 sees the remote world looping through the star-rich fields of eastern Sagittarius. Hovering around declination 21 degrees south, +14.1 magnitude Pluto is higher in the June skies for observers in the southern hemisphere than the northern, but don’t let that stop you from trying. Opposition occurs on July 7th, when Pluto rises opposite from the setting Sun and rides across the meridian at 29 degrees above the southern horizon for observers based along 40 degrees north latitude at local midnight.

Pluto actually crossed the plane of the galactic equator in 2009, and won’t cross the celestial equator northward until 2109. Fun fact: astronomer Clyde Tombaugh discovered Pluto as it drifted through the constellation Gemini in 1930. Here we are 86 years later, and Pluto has only moved six zodiacal constellations along the ecliptic eastward in its 248 year orbit around the Sun.

A close up look at the path of Pluto for the remainder of 2016. Note the position of New Horizons and KBO 2014 MU69 at the end of the year thrown in as well. Image credit: Starry Night Pro 7.

And Pluto is getting tougher to catch in a backyard scope, as well. The reason: Pluto passed perihelion or its closest point to the Sun in 1989 inside the orbit of Neptune, and it’s now headed out to aphelion about a century from now in 2114. Pluto is in a fairly eccentric orbit, ranging from 29.7 astronomical units (AU) to 49.4 AU from the Sun. This also means that Pluto near opposition can range from a favorable magnitude +13.7 near perihelion, to three magnitudes (16 times) fainter near aphelion hovering around magnitude +16.3. Clyde was lucky, in a way. Had Pluto been near aphelion in the 20^th century rather than headed towards perihelion, it might have waited much longer for discovery.

2016 sees Pluto shining at +14.1, one magnitude (2.5 times) above the usual quoted mean. See Mars over in the constellation Libra shining at magnitude -1.5? It’s 100^3 (a 5-fold change in magnitude is equal to a factor of 100 in brightness), or over a million times brighter than Pluto.

The inner and outermost planet(?) Mercury meets Pluto earlier this year in January. Image credit and copyright: Shahrin Ahmad (@Shahgazer).

You often see Pluto quoted as visible in a telescope aperture of ‘six inches or larger,’ but for the coming decade, we feel this should be amended to 8 inches and up. We once nabbed Pluto during public viewing using the 14” reflector at the Flandrau observatory.

And how about Pluto’s large moon, Charon? Shining at an even fainter +16th magnitude, Charon never strays more than 0.9” from Pluto… still, diligent amateurs have indeed caught the elusive moon… as did Wendy Clark just last year.

Pluto: imaged last year during New Horizons' historic encounter. Image credit and copyright: Wendy Clark — Pluto: imaged last year during New Horizons’ historic encounter. Image credit and copyright: Wendy Clark.

Lacking a telescope? Hey, so are we, as we trek through Morocco this summer… never fear, you can still wave in the general direction of Pluto and New Horizons on the evening of June 21^st, one day after the northward solstice and the Full Moon, which passes three degrees north of Pluto.

The location of Pluto in relation to the rising Full Moon on the night of June 21st. Image credit: Stellarium.

And follow that spacecraft, as New Horizons is set to make a close pass by Kuiper Belt Object 2014 MU69 in January 2019 on New Year’s Day.

A key date to make your quest for Pluto is June 26^th, when Pluto sits just 3′ minutes to the south of the +2.9 magnitude star Pi Sagittarii (Albaldah), making a great guidepost.

Does the region of Sagittarius near Pi Sagittarii sound familiar? That’s because the Wow! Signal emanated from a nearby region of the sky on August 15^th, 1977. Pluto will cross the border into the constellation Capricornus in 2024.

After opposition, Pluto heads into the evening sky, towards solar conjunction on January 7^th, 2017.

Observing Pluto requires patience, dark skies, and a good star chart plotted down to about +15^th magnitude. One key problem: many star charts don’t go down this faint. We use Starry Night Pro 7, which includes online access to the USNO catalog and a database of 500 million stars down to magnitude +21, more than enough for most backyard scopes.

Don’t miss a chance to see Pluto for yourself this summer!