When the moon is exactly lined up between sun and Earth, people in the narrow band of the moon’s central shadow (umbra) witness a total solar eclipse. Those living in the circle defined by the penumbra or outer shadow see a partial eclipse. Credit: Sagredo

If you’re in China tomorrow, I suggest you take a drive down to Shanghai to see the total eclipse of the sun. The moon will be in new phase tomorrow morning and people from India, China, southern Japan and anyone floating in a boat inside the hundred-plus-mile-wide path of totality as it crosses the Pacific will see a total eclipse of the sun.

This eclipse is special because it’s the longest one of the 21st century. Two factors conspire to make it so: the Earth is near its furthest point from the sun in July so the sun’s disk is just a wee bit smaller than usual and the moon happens to be near its closest point to Earth so it’s just a wee bit larger than usual. A smaller sun stays behind a bigger moon for a longer time creating an exceptional eclipse of more than six minutes.

During a total solar eclipse, it’s safe to look at the sun because the bright disk is completely covered by the moon. With the sun out of the way, its pearly, vibrant outer atmosphere called the corona is revealed, along with a rim of bright pink flame called the chromosphere. Credit: Luc Viatour

I saw a total eclipse in Baja California in 1991, when we basked under a black moon surrounded by the halo of the sun’s spectacular corona for almost seven minutes. As you can see from the diagram, the shadow the moon casts is very narrow. Only those living in the path directly beneath it will see a total eclipse. A much larger section of the eastern hemisphere will witness a partial eclipse, where only part of the moon covers the sun.

The path of totality, however narrow, doesn’t just sit in one spot but cuts a long swath across the planet because both the moon and Earth are in motion. In the animation (right) the black dot is the moon’s inner shadow or umbra while the larger circle shows the zone of partial eclipse. Because much of the path slices right through China, the world’s most populous country, this eclipse may be viewed by more people than ever before in history. Shanghai alone has 20 million people. That’s a lot of eyeballs.

Up until totality, you need a safe solar filter for viewing the sun otherwise your retina will be damaged by both ultraviolet and infrared (heat) radiation. Totality can be enjoyed without any filtration at all. I wish I could be there, but if you had to stay at home, our time is coming. Keep August 21, 2017 open because that’s when U.S. observers will be able to jump in a car and just drive to totality. The moon’s shadow will cut a path that morning from Oregon to South Carolina.

If you’d like to learn more about tomorrow’s eclipse, take a look at these two excellent websites:

* Shadow and Substance (lots of amazing maps and animations)
* NASA Science News

(Eclipse animation by A.T. Sinclair)

The new spot is at the "bottom" of the planet near the south pole. These images were taken by David Storey from the Isle of Man Observatory on July 20. Click here to see his full series of photos.

Australian amateur astronomer Anthony Wesley discovered a new black spot near Jupiter’s south pole this weekend that he thought might be the result of an impact of an asteroid or comet. Wesley was photographing the planet with his 14.5" reflecting telescope and first noticed the jet-black spot yesterday.

Jupiter is known for its spots, the most famous being the Great Red Spot which is more than twice the diameter of Earth. Other dark spots, which are localized weather systems or openings in the planet’s cloud deck, have been observed over the years. While astronomers first thought it likely was just a bit of Jovian weather, it now appears that Wesley’s suspicion might be correct. An astronomer with the Jet Propulsion Lab has photographed the spot with the NASA Infrared Telescope in Hawaii and found "high altitude particulates" confirming it’s the result of an impact. You can read more about the latest observations here and here.

Impact spots in the cloudtops of Jupiter made by fragments of Comet Shoemaker-Levy 9 that crashed into the planet in July 1994. Credit: Space Telescope Comet Team & NASA

It’s extremely rare to record an impact and a testament to the great work amateur astronomers can do. The last time anyone saw the planet get whacked was in 1994 when Jupiter’s gravity broke apart Comet Shoemaker-Levy 9. The resulting fragments rained down one after another into the planet’s atmosphere, creating fireballs followed by black, sooty spots big enough to see in a small telescope.
 

In this photo, south is at top and the arrow points to the black spot. The other black dot in the center is the shadow of Jupiter’s moon Io. Credit: Ian Sharp

Can you and I actually see this new spot for ourselves? Judging by the photos, the spot is very tiny and will require a moderate-sized telescope and steady air to see clearly. My best guess is that you’ll need at least a 6-inch or larger scope and high magnification. When to look? The spot is located at longitude 210 degrees and very close to the planet’s south pole. The best time to see it is when that longitude is centered on the planet’s face.
 
Fortunately, there’s a simple online utility created by Ole Nielsen of the Netherlands to help you identify good opportunites. Called the Jupiter Tool, it allows you to see where Jupiter’s moons are as well as what longitude is facing you at any time and from any location. You just enter the time (it uses a 24-hour clock), your location and up pops up an illustration of the planet and moons. In the lower right corner of the illustration, look for "CM System II". The number shown is the longitude facing you at the time you plan to observe. Play with the times and see when "CM System II" is around 210 degrees. That’s when to look for the black spot. The next opportunity occurs tomorrow morning around 2:30 Central time. If you see it, please let us know by using the Comments link below or sending me an e-mail at: rking@duluthnews.com

The view out the lunar module window on July 20, 1969 as the Apollo 11 astronauts began their descent to the surface of the moon. Their hearts must have been pounding. All photos credit: NASA

40 years ago today Neil Armstrong and Buzz Aldrin became the first men to walk on the moon. They set up scientific instruments on the lunar surface, recorded their impressions of the forbidding but beautiful landscape and brought back 22 precious kilos of moon rocks. Perhaps more important than any of those, they and their fellow Apollo astronauts showed us how finite and fragile Earth truly is through the photographs they took of our planet from afar. It really was "one giant leap for mankind" not just technologically but psychologically as well.

You look at these images and see how gorgeous and improbable our world looks in all that blackness. As we whirl around a star in a cosmos we struggle to comprehend, everything that we cherish most is right here in front of us. It feels right to commemorate this day by looking at some of the images that have helped raise our awareness of Earth’s uniqueness and our good fortune to be counted among its inhabitants.

This photo by Apollo 8 astronaut Frank Borman gave us a perspective on our planet never before seen. Apollo 8, launched in December 1968, was a test run to the moon and the first craft to escape the gravitational field of the Earth and orbit the moon. The contrast between the lifeless moon and blue Earth couldn’t be more vivid. 

Earth hovers above the rugged lunar landscape as the Apollo 11 lunar module heads for a landing in the Sea of Tranquillity.

The crescent Earth photographed by the Apollo 11 astronauts.

"Earthrise" as witnessed by the crew of Apollo 17.

Apollo 17 astronaut Gene Cernan poses with the flag and the faraway Earth in this picture shot by his crewmate Harrison Schmidt.

You can use this map to help navigate your way from Altair in the Summer Triangle to the constellations Delphinus, Sagitta (suh-JIT-uh)  and Brocchi’s Cluster. Only part of Aquila the Eagle is shown. The full constellation is shown in the map below. Maps created with Stellarium.

Sagitta the Arrow is one of those constellations few amateur astronomers pay much attention to. It’s dim, sparse and cowers in the radiance of the Summer Triangle, yet it’s shape is distinctive enough, like its neighbor Delphinus the Dolphin, that I thought it deserved spotlight treatment today.

The arrow goes back to Greek mythology and may have represented the one used by Zeus against a foe or perhaps by Heracles to kill a wayward eagle. It appears to be aimed right at Delphinus but I hardy think we want to spear the celestial dolphin. Let’s instead get familiar with Sagitta so that we can use it in the upcoming week to snag one of the brighter nebulas in the Milky Way.

This much wider map shows the entire southeastern sky at the end of twilight in late July, when the Summer Triangle dominates the view. Find Altair and then use the top map to make a beeline to Sagitta.

Sagitta is a small constellation like Delphinus, meaning you can completely cover it up with just three outstretched fingers. Go out around 10:30-11 p.m. and face southeast. Find Altair, the bottom-most star of the Summer Triangle, and look one fist to the left or east to spot Delphinus, which looks remarkably like a kite. Return to Altair and now look one fist above it to see the little arrow of four or five stars in a line. If you’re having trouble, bring out your binoculars for some optical enhancement.

Feel like going further? Take those binoculars and move one field above and a little to the right of the feathered end of the arrow. You’ll see one of the neatest asterisms in the sky called the "Coathanger" or Brocchi’s Cluster. Six stars form the bottom of the hanger while four others wrap around to make a hook. If the sky is really dark, you can even spot it with just your naked eye.

The Coathanger isn’t much use for hanging since it’s upside-down in the sky, and although it looks like a real star cluster, Brocchi’s just happens to be an attractive but chance alignment of stars.

No matter. We enjoy these gems whether they’re assembled properly or just thrown in the mix. Have at it.

The moon and Venus are reflected several times within the panes of my picture window this morning at dawn. Below is the correct moon with a fine display of Earthshine. Photos: Bob King

When I got up to see the moon, Venus and Mars this morning I was repaid in triplets for my efforts. After taking a few "normal" photos of the sky, I turned around and was surprised to see three moons and three Venuses reflected in my picture window. The multiple panes and internal reflections created a funhouse sky that was fun to play with in a photo.

It felt great to see a starry sky again, and the crescent floating above dark spruces and robin song was an inspiring way to start the day. I’ll have more to share with you later this afternoon about a pointy constellation you can look for tonight. In the meantime, if you got up at dawn this morning too, try to find time for a nap.

Moon and Venus in the eastern sky during twilight Sunday morning. Details: 150mm lens at f/2.8, 1-second exposure at ISO 400.

I tried twice to see this morning’s moon-planets rendevous but the clouds wouldn’t part. I hope you were more fortunate. Don’t forget that the show will continue tomorrow morning, when clear sky prospects look better for our region.

Clouds are good for contemplation and for me that always means a mental voyage through times past, present and future. While taking a walk in the woods yesterday I came across a spot my younger daughter and I had stopped to rest at many years ago. It was along a high ridge overlooking a creek. The shadow of a nearby red pine made it a very inviting place to sit down, relax and take in the view. We talked about a lot of small things that day, none of which I remember distinctly. When I saw the tree, the memory of the day instantly swept over me. A wave of reminiscence.
 
I’ll be honest and tell you I felt a little melancholy; those father-daughter moments are fewer now than back then. As my dog stayed put in the present tense, it occured to me how humans time-travel every day. We think about and plan for the future, wish at times that parts of the past would return and try to find our way in the present.

The asteroid Steins, named after Karlis Steins, a Latvian and Soviet astronomer, was photographed by the Rosetta spacecraft during a September 2008 flyby. The impact on top nearly tore the asteroid apart. Credits: ESA ©2008 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

The European Rosetta spacecraft has no such illusions about time. It began its 11-year journey to comet Churyumov-Gerasimenko in March 2004 and will arrive in November 2014. The trip includes three gravity assists at Earth in 2004, 2007 and 2009, one at Mars (2007) and two asteroid flybys of Steins (2008) and Lutetia in 2010. Last September it returned photos of the 3-mile-diameter, diamond-shaped Steins that showed one big crater and a string a tiny ones down the asteroid’s side.

Scientists have analyzed the photos and discovered that Steins got clobbered by another asteroid about 100 million years ago. That’s what gouged out the big crater and nearly cracked little Steins in two. The impact caused a fault or rupture along one side of the asteroid that gave rise to a string of smaller, collapse craters.

A selection of photos of some of the asteroids we’ve visited with spacecraft. Their sizes range from 21 miles for Eros to 1.3 miles for Braille. All of them are located in the asteroid belt between Mars and Jupiter. Credit: ESA/NASA with my own annotations. Composite created by ESA.

The U.S, Europe and Japan have sent spacecraft either to or near about a half dozen asteroids. What makes these floating islands of rock so interesting to scientists is that they were the precursors of the planets. Nearly five billion years ago, it was small bodies like the asteroids that served as the nuclei or beginnings of all of today’s familiar planets. The many thousands of asteroids still out there are like building blocks that never got assembled into larger orbs. The more we learn about them, the better we’ll understand our own planet’s origins.

In this illustration, Rosetta makes its final approach to comet Churyumov-Gerasimenko in the fall of 2014. The spacecraft will send a small lander, called Philae, to land on the comet to study it directly. The haze is dust and water vapor given off by the icy comet. To learn more about the mission, go to the ESA Rosetta website. Credit: Credits: ESA, image by AOES Medialab

That brings us back to time travel. By piecing together the past, we can discover what makes the present and what may lie ahead in the future. This principle applies as much on a personal level as it does to unraveling the great story of nature.

This photo of the Apollo 14 landing site was taken recently by the camera aboard the Lunar Reconnaissance Orbiter. To give you an idea of size, the landers measured 21 feet high by 14 feet in diameter. For a more expansive view, click here. Credit: NASA photos

It had to happen. Somebody would send a satellite into orbit around the moon with a camera sharp enough to photograph the Apollo landing sites. Just in time for the 40th anniversary, NASA released photographs today of five of the six Apollo sites taken by the Lunar Reconnaissance Orbiter (LRO). You might remember the LRO went into orbit just a couple weeks ago. It’s part of a larger mission to map and explore the moon in preparation for our eventual return.

Although the landers are tiny, you can see their shapes and shadows. The best image, shown above, even shows the tracks the astronauts made in the lunar soil almost 40 years ago. Simply amazing.

For the complete story and photos of all five landers, please click this link.

At right is the Apollo 11 lunar lander at peace in the Sea of Tranquillity. It was Neil Armstrong’s and Buzz Aldrin’s home for just under 22 hours back on July 20-21, 1969.

Tomorrow morning the 18th, the moon will be in conjunction with the planet Mars while at the same time hovering near the Seven Sisters star cluster (Pleiades), Venus and Aldebaran in Taurus the Bull. The chart shows the sky during early morning twilight as you look northeast. Created with Stellarium.

Are you morning skywatchers feeling ignored lately? I know there are a few of you who work an early shift or like to get up and run before the sun comes up. Good news. There’s a little something in store for you tomorrow and Sunday. Evening sky watchers can set their alarms for this one too, especially the star-starved folks of northern Minnesota. 

In early morning twilight, you can watch for a spectacular gathering of crescent moon, Mars, Venus, the bright star Aldebaran and the Pleiades. It’s not often that so many bright objects get corralled into one small piece of sky. I’m hoping for clear skies, but if the cloud party continues, there’ll be one more chance on Sunday morning the 19th as the thinning moon remains in the vicinity while sliding just to the left of Venus.

If you get up for the conjunction but get clouded out you still might get to see a pretty dawn sky like this one photographed by Lyle Anderson of Duluth earlier this week.

The space shuttle Endeavor will dock with the International Space Station at 12:55 p.m. today, and when they open their doors an hour later, the seven astronauts in the shuttle will meet the six astronauts in the station to make the biggest crowd of humans in orbit at one time. The two ships will remain docked for 11 days as the astronauts work on installing a new "outdoor" Japanese space laboratory.

Pieces of insulating foam break off the external fuel tank during the shuttle liftoff earlier this week. Some of them hit the heat-shield tiles on the shuttle (right), causing minor damage. Credit: NASA TV

NASA is studying why the foam insulation on the external fuel tank continues to break apart on liftoff. Although engineers are optimistic they’ll have a solution before the next shuttle liftoff in August, until they figure it out, NASA will not launch. For a more in-depth story, click here.

Remember the original, fuzzy Apollo 11 moon landing videos? With the help of a Hollywood film restoraton company, they’ve been restored to higher quality and are now available for viewing at this link. The videos are less grainy and show better detail. Gave me goosebumps all over again.

An earlier photo of the underside of one of the shuttles showing the mosaic of heat-shielding tiles that protect the craft and astronauts during extreme heat of re-entry. Some of the tiles on the belly of the shuttle Endeavor were hit by ice during liftoff yesterday. Credit: NASA

With the successful shuttle liftoff, we’ll now have the opportunity to watch it play catchup with the International Space Station. Tonight (Thursday) the shuttle Endeavor will make two low passes across the northern sky at 9:22 p.m. and again at 10:54 p.m. The ISS will make a similar northern pass — but higher and brighter — at 10:36 p.m. For times outside our region, click here, login and select your city. Endeavor will dock with the ISS on Friday. Meanwhile the crew will spend today inspecting the heat shield after pieces of either ice or insulation from the shuttle’s orange fuel tank struck the heat-shield tiles on the craft’s underside. No word yet on the severity of the damage.

We’ve had persistent clouds in Duluth the past few days but the forecast looks better for the weekend. My friend Rick from the state of Washington tells me he’s been watching those eerie noctilucent clouds this week. These 50-mile-high clouds glow a pale white-blue an hour to two hours after sunset (or before sunrise) when all other clouds have long since gone dark. You may want to keep a watch for them. Look very low in the northern sky long after sunset for wispy tendrils and wave forms.

You might remember we visited the constellations of Serpens and Ophiuchus in a blog last month. Guess what? They’re still there (as my wife would say) and very conveniently placed for viewing at the end of evening twilight. They’re also home to four diverse star clusters that are wonderful to see in a pair of binoculars (7×35 and 10×50 recommended) or very low power telescopes. Three of them are even visible with the naked eye under a dark sky. 

This map shows the sky around 10:30-11 p.m. in mid-July. If you look high in the southeast you’ll see the three bright stars that form the Summer Triangle. To give you an idea of how wide this map is, Vega is near the top of the sky. Extend lines from Vega southward and Altair to the west until they meet at Alpha — an easy naked-eye star – in Ophiuchus. Vega, Altair and Alpha form a nifty equilateral triangle of their own. Alpha is halfway up or about five stacked fists high in the south. You can also use last month’s blog maps to arrive at Alpha a different way. All maps created with Stellarium.

Found Alpha OK? Now take your binoculars and point them at Beta, just below and left of Alpha. If you look right above Beta, you’ll see a bright sprinkling of stars that’s two full moons across. That’s IC 4665. Now slide about two binocular fields to the left and above to find bright, little NGC 6633 and IC 4756, a sizeable misty ball studded with a smattering of brighter stars. Collinder 350 is the faintest and hardest of the four. You’ll need fairly dark skies to see it well.

IC 4665 is the biggest, brightest and easiest to find of the four. The name comes from a list of clusters and galaxies called the Index Catalog. Look for a loose, bright gathering of 20-30 stars that spans almost two full moons. You can’t miss it. Just south of the cluster, see if you can spot the much fainter but just as loosely grouped Collinder 350. I saw a sparse but obvious sprinkle of stars there about a full moon across.

IC 4665 and Collinder 350 (named after astronomer Per Collinder, a cluster researcher) just barely fit in one binocular field of view. Credit: DSS2 Survey/Wikisky

About two binocular fields to the east or left of IC4665 you’ll run into my favorite of the four, little NGC 6633 (the 6633rd entry in the New General Catalog). This one stands out right away because its several dozens of stars are bright and arranged in a tight group that reminds me of candies in a box. Keep moving east and drop downward to find the most mysterious-looking of our featured clusters, IC 4756. Binoculars show a couple dozens points of light against a misty backdrop of unresolved stars. It’s another large cluster, bigger than the full moon, and the richest in stars of the four. A small telescope at low power will enhance the binocular view manyfold with at least 100 stars visible.

The smallest of the four featured star clusters, NGC 6633. Credit: DSS2 Survey/Wikisky

When I looked at these gems last week it was just so much fun cruising back and forth with the binoculars to compare one with the other. All are between 1100 and 1600 light years from Earth, and all except Cr 350 are visible with the naked eye as subtle patches of light from a dark sky site.

(Noctilucent cloud photo: Bob King)  

 
The space shuttle Endeavor takes off right on time at 5:03 p.m. Central time Wednesday evening from NASA’s Kennedy Space Center in Florida. Credit: NASA/Jeffrey Marino 
 
After so many weather delays, it was a thrill to see the shuttle successfully liftoff this evening. Now we can watch Endeavor gradually approach the International Space Station (ISS) to dock. I wish I had pass times but nothing has been published just yet, so it’s possible the shuttle might be ahead or behind the space station tonight. Your best bet to see both spacecraft would be to go out and look a few minutes before the ISS arrives and hang around a few minutes after it passes. I can’t make any promises except to say that by tomorrow night, we’ll have times nailed down.