Space and astronomy news
A remote annular solar eclipse bookends the final eclipse season for 2024.
The final eclipse of the year is almost upon us. If skies are clear, a few lucky observers and intrepid eclipse-chasers will get to witness the passage of the Moon in front of the Sun one last time on Wednesday, October 2nd during an annular solar eclipse.
Continue reading “An October Annular Solar Eclipse Rounds Out 2024”
Don’t miss the final solar eclipse of the year: a striking ‘ring of fire’ annular solar eclipse.
If skies are clear, observers across a swath of the western United States, Mexico, and Central and South America are in for a treat this coming Saturday, October 14th, as the antumbral shadow of the Moon crosses the Earth in a fine ‘ring of fire’ annular solar eclipse.
Continue reading “Ring of Fire: Catching This Weekend’s ‘Great North American Annular Solar Eclipse’”
Remember how exciting it was in 2017 when a total solar eclipse crossed the United States? We’re in for two more well-placed eclipses over the next year, so it’s time to get organized to take advantage of these unparalleled celestial events.
On October 14, 2023, an annular eclipse will be visible to millions of people in the US, crossing northwest to south central, from the coast of Oregon down to the Texas Panhandle.
Then, on April 8, 2024, a total solar eclipse will be visible to millions more, crossing south central to northeast, from southern Texas to Eastern Canada. It will be visible in parts of Mexico, too.
Now is the time to make plans of where you want to be for either or both events. But, if you live near San Antonio, don’t go anywhere! You’ll get to see both eclipses right from your backyard.
No matter where you live, if you have the opportunity to see a solar eclipse – whether it is annular or total – DO IT!
Continue reading “It's Time to Start Planning Your 2023/2024 Eclipse Adventures”
The only annular eclipse of 2021 will produce a fine spectacle across most of North America and Europe.
Got those solar glasses handy from 2017? If skies are clear on the morning of Thursday June 10th, you may once again find good use for them, as an annular ‘ring-of-fire’ eclipse crosses northeastern Canada into the Arctic.
Continue reading “Solar Horns at Sunrise: Our Guide to the June 10th Annular Solar Eclipse”
Ready for the first solar eclipse of the year? This weekend sees one of the top draw astronomical events for 2020, with a ‘ring of fire’ annular solar eclipse spanning eastern Africa and southern Asia on Sunday, June 21st.
Continue reading “Catch a Solstice ‘Ring of Fire’ Annular Solar Eclipse Over Africa and Asia This Weekend”
Ready for the final ‘Ring of Fire’ solar eclipse of 2019? The final eclipse of the year kicks off this week on Wednesday, early on December 26th the day after Christmas, with an annular solar eclipse spanning the Indian Ocean region from the Middle East to the western Pacific.
Continue reading “Our Guide to the December 26th Annular ‘Ring of Fire’ Eclipse”
‘Tis the season… eclipse season that is, as a spectacular “ring of fire” annular solar eclipse marks the end of the first of two eclipse cycles for 2017. And although the annular path for this eclipse passes through some sparsely populated parts of the southern hemisphere, we just might get some amazing live views, courtesy of modern technology and some intrepid observers willing to adventurously trek after the shadow of the Moon.
Unlike many of the uncertainties in life, eclipses are sure to happen, a certainty ordained by orbital mechanics. Well, okay, the Vogons could always blow the Moon to smithereens this fine Thursday afternoon… but otherwise, we’re in for a true celestial show.
Eclipse circumstances: Prospects and prognostications.
The eclipse begins far out in the South Pacific at sunrise, and the path of annularity makes first landfall along the southern coast of Chile at 13:31 Universal Time (UT). The eclipse antumbra then races eastward over Argentina at 2.5 kilometers per second, as the “ring of fire” heads out over the South Atlantic where it reaches “maximum annularity” of just 44 seconds 900 kilometers southeast of Brazil. Finally, the 30 kilometer wide path touches down over Angola, nicks Zambia and ends at sunset over a southern track along the Democratic Republic of the Congo. The eclipse is partial across southern portion of South America, the Falkland Islands a swath of Antarctica and southwestern Africa.
Here are the partial prospects for select cities:
City – Maximum obscuration – Time
La Paz, Bolivia – 5% – 13:37 UT
Buenos Aires – 67% – 13:53 UT
The Falkland Islands – 71% – 13:56 UT
Palmer Station, Antarctica – 31% – 14:01 UT
Cape Town, South Africa – 41% – 15:59 UT
Luanda, Angola – 83% – 16:32 UT
Annular vs. Total
Sunday’s eclipse is the first of two solar eclipses for 2017, and the only annular eclipse for the year. We get an annular eclipse when the Moon is near apogee (which occurred eight days ago on February 18th) and the Earth is near perihelion (which occurred last month on January 4th). At this time, the apparent size of the Moon is too small to cover the Sun as seen from the Earth, resulting instead in a brilliant annulus or “ring of fire” in the sky. Likewise, we refer to the shadow trace of this ring across the Earth as an antumbra, instead of the familiar umbra of a total solar eclipse.
Strange as it may seem, annular eclipses are slightly more common than total solar eclipses in our current epoch, and will become increasingly more so as the Moon slowly recedes from the Earth.
Observing and Eclipse Safety
Unlike a total solar eclipse, safety precautions must be taken during all phases of an annular solar eclipse. We witnessed the 1994 annular eclipse from the shores of Lake Erie, and can attest that 1% of the Sun is still pretty darn bright. Use only telescope and camera filters or glasses designed specifically for solar observing, even during the annular phase. Venus should also be a splendid sight for those observing near sunset from Africa, as the Cytherian world shines at -4.3 magnitude 34 degrees east of the Sun. Viewers in southwestern African nations will also be treated to a setting Sun during the eclipse, affording the chance to include the spectacle in shots along with foreground objects on the local horizon if skies are clear.
Clouded out? Live on the wrong part of the planet? There are actually several options to watch the eclipse live:
the venerable SLOOH plans to webcast the eclipse.
Time and Date will provide a webcast starting at 12:05 UT from Angola:
Watch this space: we’ll be dropping in more live webcasts of the eclipse as they turn up.
Update: VTR Chile may provide a live broadcast come eclipse time.
Plan on doing an ad hoc webcast of Sunday’s eclipse from anywhere along the annular or partial track? Let us know!
Sunspot activity is currently at a lull, and the Earthward face of Sol may well be blank come eclipse day. At an eclipse magnitude of 99.22%, this eclipse juuuusst misses being a hybrid/total. It’s also possible to catch the brief flashes of Bailey’s Beads along the edge of the antumbral graze line.
Tales of the Saros
This eclipse is member 29 of 71 for saros cycle 140, stretching all the way back to April 16th, 1512 and running out to June 1st, 2774. If you caught the February 16th, 1999 annular eclipse from the Australian Outback, then you witnessed the last eclipse in saros 140. Stick around until March 9th, 2035 and you can then complete an exeligmos or triple saros cycle, joining an elite club of eclipse-chasing adventurers, indeed.
Eclipses occur in pairs or sometimes triplets, when the nodes where the Moon’s orbit intersect the position of the Sun and the Earth’s shadow along the ecliptic plane. These nodes move due to orbital precession of the Moon’s path around the Earth. If the Moon weren’t inclined relative to the ecliptic, we’d see a lunar and solar eclipse every synodic month. The February 11th penumbral eclipse ushered in the current eclipse season, which ends with this weekend’s annular eclipse.
ISS and Views from Space (-ace -ace) Prospects
There is an ISS transit over SW Africa at around 15:45 UT, offering a chance to catch a transit of the station across the partially eclipsed Sun. Sun observing spacecraft in low Earth orbit including Hinode and Proba-2 also usually get good views of the eclipse.
New Moon sightings: And for the rest of the world, the hunt will be on to recover the slim waxing crescent Moon post-eclipse on the evening of Monday, February 27th. This lunation, first sighting opportunity without optical assistance favors southeast Asia.
Then, its on to eclipse season number two, featuring a partial lunar eclipse on August 7th, and then the big ticket event: the total eclipse of the Sun spanning the contiguous United States from coast to coast. Umbraphiles have been planning for this one and its brief 160 seconds maximum of totality for well over a decade now, no lie. Where will YOU be?
-Send those eclipse pics in to Universe Today Flickr.
-Read more about eclipses, occultations, comets and more for the year in our free e-book: 101 Astronomical Events for 2017.
-Eclipse science fiction? Read our original sci-fi tales Exeligmos, The Syzygy Gambit, Peak Season and more.
Astronomy turns up in fascinating junctures in history. Besides just the romantic angle, we can actually pin down contextual events in ancient history if we can tie them in with a spectacle witnessed in the heavens. A recent look at the story of ‘Joshua’s eclipse’ is one such possible tale.
Lunar and solar eclipses are especially dramatic events, something that would have really made the ancients stop and take notice. A recent study published in an edition of the Beit Mikra Journal (in Hebrew) by researchers from Ben Gurion University may have pinpointed a keypoint in biblical history: the date of the Battle of Gibeon.
This study first came to our attention via the Yahoo! SEML eclipse message board and a recent Times of Israel article. The article makes mention of NASA eclipse data, which is free for anyone to peruse looking over the five millennium canon of solar and lunar eclipses… hey, it’s what we do for fun.
We did obtain a look at a translation of the abstract from the paper, which ends with the following:
“In the period between 1500-1000 BCE which is the relevant time for the biblical story, there were only three eclipses seen from Jerusalem, one total eclipse and two annular eclipses. We show that the most appropriate one is the annular solar eclipse that occurred on October 30 in 1206 BCE at sunset, an appropriate date for the time of conquest and the early settlement period, at the time of Marneptah’ rule in Egypt.”
Joshua 10:12 reads: “Sun, stand still upon Gibeon; and you, Moon, in the valley of Ayalon.”
According to tradition, Joshua commanded the Sun to stand still long enough to defeat the Canaanite kings. Of course, the Sun and the Moon still move during an eclipse be it lunar or solar, though its mostly our planet that’s doing the moving. Still, the actual biblical term “-dom” is open to interpretation, and the researchers chose the Hebrew “to become dark” instead of the King James translation of “to stand still,” or “stationary”.
If this Bible verse sounds familiar, that’s because it turns up in astronomical history again in medieval Europe, when Church proponents used it as supposed proof of geocentricism.
It’s tough to predict eclipses in distant time. The rotation of the Earth is not entirely smooth, and the minute change in the length of the day (known as Delta T) accumulates to the point that a leap second must be inserted on occasion to keep observed time in sync with reckoned terrestrial time. Braking action by the Sun and Moon, tectonic activity, and even global warming all cause small changes in the Earth’s rotation that slowly build up over time. This means that it’s tough to predict eclipses more than a few thousand years out, where at best we can only judge which continent they might have or will fall on.
“Not everyone likes the idea of using physics to prove things from the Bible,” said researcher Hezi Yitzhak to the Israeli news site Haaretz. “We do not claim that everything written in the Bible is true or took place… but there is also a grain of historical truth that has archaeological evidence behind it.”
The eclipse in question occurred on October 30th, 1206 BC. This was an annular eclipse, crossing the Atlantic and the Mediterranean and ending over Israel and Jordan at sunset. Researchers pegged this suspect eclipse because of its fit for historical context and visibility. Annularity for the eclipse was 86% obscuration and started at an altitude of nine degrees above the western horizon, and would have still been in progress during its final phases at sunset.
Lots of eclipses turn up in history. A partial lunar eclipse preceded the fall of Constantinople in 1453, seeming to fulfill prophecy. Solar and lunar eclipses made a showing at lots of battles, including the Second Battle of Syracuse on August 28th, 412 BC and during the Zulu War on January 22nd, 1879. A solar eclipse on June 15th, 762 BC mentioned in Assyrian texts pinpoints a crucial time in ancient history, giving us a benchmark for later dates. It’s worth noting that prior to modern times, it seems that battles were the only thing worth writing down…
Still, it’s interesting to imagine the scene as ancient armies clash, only to stop and gaze at the wondrous sight on the horizon: a pair of glowing horns, hanging low in the pre-dusk sky. We caught the 1994 annular eclipse from the Sandusky, Ohio on the shores of Lake Erie and can attest that even a 98% eclipsed Sun is still pretty bright, giving even a clear day a deep steely blue tint. Lower to the horizon though, an annular eclipse is more readily visible to the unaided eye.
You have to be careful when attempting to read ancient texts as astronomical guide books. Great minds, including Kepler and Newton, expended lots of mental juice on attempting to link biblical accounts such as Ezekiel’s Wheel and the Star of Bethlehem with actual astronomical events. We’ll probably never know for sure if a coincidental conjunction graced the sky over the manger in Bethlehem, or if Ezekiel saw the breakup of a brilliant comet, but it’s always fun to imagine and wonder. Then, there’s the inevitable embellishment that accompanies stories that may have been first sparked by meteor showers or sundogs, centuries ago. We don’t, for example, see flaming swords or banners emblazoned with Latin inscriptions across the sky today, though if you can believe medieval accounts, they seemed common back in the day.
And don’t forget: we’ve got our very own history making eclipse (hopefully sans battlefields) this coming August 21st, 2017 crossing the United States from coast-to-coast.
Though far from conclusive, the results of the study concerning Joshua’s eclipse and the battle of Gideon are interesting to consider. Most likely we’ll never truly know what happened that ancient afternoon, unless, of course, we perfect time travel. What other events remain hidden and lost to time, ready for some historical astro-sleuth to uncover them?
-Can’t get enough of eclipses, historical or otherwise? Check out our original eclipse-fueled sci-fi tales Exeligmos, Peak Season and Class Field Trip.
Imagine if you will, that you are a human being living in prehistoric times. You look up at the sky and see the Sun slowly being blocked out, becoming a ominous black sphere that glows around the edges. Could you really be faulted for thinking that this was some sort of supernatural event, or that the end of the world was nigh?
Of course not. Which is why for thousands of years, human beings believed that solar eclipses were just that – a sign of death or a bad omen. But in fact, an eclipse is merely what happens when one stellar object passes in front of another and obscures it. In astronomy, this happens all the time; and between the Sun, the Moon, and the Earth, total eclipses have been witnessed countless times throughout history.
The general term for when one body passes in front of another in a solar system is transit. This term accurately describes how, depending on your vantage point, stellar bodies pass in front of each other on a regular basis, thus causing the reflected light from that body to be temporarily obscured.
However, when we are talking about how the Moon can pass between the Earth and the Sun, and how the Earth can pass between the Sun and the Moon, we use the term eclipse. This is also known as a syzygy, an astronomical term derived from ancient Greek (meaning “yoked together”) that describes a straight-line configuration between three celestial bodies.
When the Moon passes between the Sun and the Earth, and the Moon fully occults (blocks) the Sun, it is known as the solar eclipse. The type of solar eclipse – total or partial – depends on the distance of the Moon from the Earth during the event.
During an eclipse of the Sun, only a thin path on the surface of the Earth is actually able to experience a total eclipse – which is called the path of totality. People on either side of that path see a partial eclipse, where the Sun is only partly obscured by the Moon, relative to those who are standing in the center and witnessing the maximum point of eclipse.
A total solar eclipse occurs when the Earth intersects the Moon’s umbra – i.e. the innermost and darkest part of its shadow. These are relatively brief events, generally lasting only a few minutes, and can only be viewed along a relatively narrow track (up to 250 km wide). The region where a partial eclipse can be observed is much larger.
During a solar eclipse, the Moon can sometimes perfectly cover the Sun because its size is nearly the same as the Sun’s when viewed from the Earth. This, of course, is an illusion brought on by the fact that the Moon is much closer to us than the Sun.
And since it is closer, it can block the light from the Sun and cast a shadow on the surface of the Earth. If you’re standing within that shadow, the Sun and the Moon appear to line up perfectly, so that the Moon is completely darkened.
After a solar eclipse reaches totality, the Moon will continue to move past the Sun, obscuring smaller and smaller portions of it and allowing more and more light to pass.
A total eclipse of the Moon is a different story. In this situation, the entire Moon passes into the Earth’s shadow, darkening it fully. A partial lunar eclipse occurs when the shadow of the Earth doesn’t fully cover the Moon, so only part of the Moon is darkened.
Unlike a solar eclipse, a lunar eclipse can be observed from nearly anywhere in an entire hemisphere. In other words, observers all across planet Earth can see this darkening and it appears the same to all. For this reason, total lunar eclipses are much more common and easier to observe from a given location. A lunar eclipse also lasts longer, taking several hours to complete, with totality itself usually averaging anywhere from about 30 minutes to over an hour.
There are three types of lunar eclipses. There’s a penumbral eclipse, when the Moon crosses only the Earth’s penumbra (the region in which only a portion of light is obscured); followed by a partial, when the Moon crosses partially into the Earth’s umbra (where the light is completely blocked).
Last, there is a total eclipse, when the Moon crosses entirely into the Earth’s umbra. A total lunar eclipse involves the Moon passing through all three phases, then gradually passing out of the Earth’s shadow and becoming bright again. Even during a total lunar eclipse, however, the Moon is not completely dark.
Sunlight is still refracted through the Earth’s atmosphere and enters the umbra to provide faint illumination. Similar to what happens during a sunset, the atmosphere scatters shorter wavelength light, causing it to take on a red hue. This is where the phrase ‘Blood Moon‘ comes from.
Since the Moon orbits the Earth, you would expect to see an eclipse of the Sun and the Moon once a lunar month. However, this does not happen simply because the Moon’s orbit isn’t lined up with the Sun. In fact, the Moon’s orbit is tilted by a few degrees – 1.543º between the angle of the ecliptic and the lunar equator, to be exact.
This means that three objects only have the opportunity to line up and cause an eclipse a few times a year. It’s possible for a total of 7 solar and lunar eclipses every year, but that only happens a few times every century.
The term eclipse is most often used to describe a conjunction between the Earth, Sun and Moon. However, it can also refer to such events beyond the Earth–Moon system. For example, a planet moving into the shadow of one of its moons, a moon passing into the shadow of its host planet, or a moon passing into the shadow of another moon.
For instance, during the Apollo 12 mission in 1969, the crew was able to observe the Sun being eclipsed by the Earth. In 2006, during its mission to study Saturn, the Cassini spacecraft was able to capture the image above, which shows the gas giant transiting between the probe and the Sun.
In July of 2015, when the New Horizons mission passed through the shadow of Pluto, it was able to capture a stunning image of the dwarf planet eclipsing the Sun. The image was taken at a distance of about 2 million km (1.25 million miles), which provided the necessary vantage point to see the disc of the Sun become fully obscured.
On top of that, many other bodies in the Solar System can experience eclipses as well. These include the four gas giants, all of which have major moons that periodically transit between the planet and either Earth-based or space-based observatories.
The most impressive and common of these involve Jupiter and its four largest moons (Io, Europa, Ganymede and Callisto). Given the size and low axial tilt of these moons, they often experience eclipses with Jupiter as a result of transits, relative to our instruments.
A well-known example occurred in April of 2014, when the Hubble Space Telescope caught an image of Ganymede passing in front at of Jupiter. At the time the image was taken, Ganymede was casting its shadow within Jupiter’s Great Red Spot, which lent the planet a cyclops-like appearance (see below).
The other three gas giants are known to experiences eclipses as well. However, these only occur at certain periods the planet’s orbit of the Sun, due to their higher inclination between the orbits of their moons and the orbital plane of the planets. For instance, Saturn’s largest moon Titan has been known to only occult the ringed gas giant once about every 15 years.
Pluto has also been known to experience eclipses with is largest moon (and co-orbiting body) Charon. However, in all of these cases, the eclipses are never total, as they do not have the size to obscure the much larger gas giant. Instead, the passage of the moons in front of the larger celestial bodies either cast small shadows on the cloud tops of the gas giants, or lead to an annular eclipse at most.
Similarly, on Mars, only partial solar eclipses are ever possible. This is because Phobos or Deimos are not large enough (or distant enough in their orbits) to cover the Sun’s disc, as seen from the surface of the planet. Phobos and Deimos have also been known to experience lunar eclipses as they slip into the shadow of Mars.
Martian eclipses have been photographed numerous times from both the surface and from orbit. For example, in 2010, the Spirit rover captured images of a Martian lunar eclipse as Phobos, the larger of the two martian moons, was photographed while slipping into the shadow of Mars.
Also, between Nov. 4 and Nov. 5, 2010, the Opportunity rover captured several images (later turned into movies) of a Martian sunset. In the course of imaging the Sun for a total of 17 minutes, Opportunity captured stills of the Sun experiencing a solar eclipse. And on September 13th, 2012 – during the 37th day of its mission (Sol 27) – the Curiosity rover captured an image of Phobos transiting the Sun.
As far as astronomical events go, total eclipses (Lunar and Solar) are not uncommon occurrences. If you ever want to witness a one, all you need to do is keep track of when one will be visible from your part of the world. Some good resources for this are NASA’s Eclipse Website and timeanddate.com.
Or, if you’re the really adventurous type, you can find out where on Earth the next path of totality is going to be, and then book a vacation to go there. Get to the right spot at the right time, and you should be getting the view of a lifetime!
We have written many articles about the eclipse for Universe Today. Here’s a list of articles about specific times when a total Lunar Eclipse took place, and here’s a list of Solar Eclipse articles. And be sure to check out this article and video of an Annular Eclipse.
If you’d like more info about the Eclipse, check out NASA Homepage, and here’s a link to NASA’s Solar System Simulator.
We’ve also recorded related episodes of Astronomy Cast about Eclipses. Listen here, Episode 160: Eclipses.
Sources:
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 1st, 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.
Tales of the Saros
This eclipse is member 39 of 71 solar eclipses for saros 135, which runs from July 5th, 1331 to August 17th, 2593. This series finally produces its first total solar eclipse on March 29, 2359.
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.
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 16th, 2016, and then the next solar eclipse is another annular favoring Argentina, Chile and the west coast of southern Africa on February 26th, 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.
