New bright nova sparkles in Sagittarius

New Nova Sagittarii 2012 #4 is located just above the star Delta in the “spout” of the Teapot constellation of Sagittarius. Sagittarius is east or left of the Scorpion with its bright fiery star Antares. The map shows the sky facing south around 11:15 p.m. Maps created with Stellarium.

Novas are popping up like daisies in the constellation Sagittarius this year. To date, four “new stars” have been discovered in the Teapot, enough to keep its contents at a steady boil.

Earlier yesterday (July 7) Koichi Nishiyama and Fujio Kabashima of Japan found the most recent nova – Nova Sagittarii 2012 #4 – on exposures made with a camera and 105 mm lens. Shining at magnitude 7.7 at the time of discovery, the nova was bright enough to see in binoculars and small telescopes. It still is. Last night I saw it from my driveway at the identical brightness through my 8x40s.

Use this zoomed-in map with a pair of binoculars or small telescope to hunt down the new nova. Center your scope on the naked-eye star Delta in Sagittarius, then move about 1 degree north to find a bright triangle of 6th magnitude stars. Nova Sgr #4 is about 1/2 further north just south of the magnitude 7.2 star.

Typical 40mm and larger binoculars can reach 8th magnitude or fainter; with a good locator map, you should be able to see the nova for yourself in the coming nights, especially since the moon is rapidly departing the evening sky.

As we learned a few days ago in the case of Nova Persei, novas occur in close binary stars, where a small but extremely dense and massive (for its size) white dwarf grabs hydrogen gas from its closely orbiting companion. The gas swirls down to the dwarf’s 150,000 degree F surface, where it’s compacted by the gravity and heated until detonating like a gazillion thermonuclear bombs. Suddenly, a faint star that wasn’t on anyone’s radar vaults a dozen magnitudes to become a standout “new star”, one bright enough for a pair of Japanese amateurs to snag it in a 40-second exposure.

Model of a nova in the making. A white dwarf star pulls matter from its bloated red giant companion into a whirling disk. Material funnels to the surface where it later explodes. Credit: NASA/CXC/M. Weiss

Novae can rise in brightness from 7 to 16 magnitudes, the equivalent of 50,000 to 100,000 times brighter than the sun, in just a few days. Meanwhile the gas they expel in the blast travels away from the binary at up to 2,000 miles per second. This is one big firecracker!

Depending on the particulars of the explosion, including distance and whether or not there’s a significant amount cosmic dust between us and the star, novae can be bright or faint.

Some, like  Nova Cygni 1975 (in the Northern Cross) reached magnitude 1.7  in late August that year. I remember how its presence “distorted” the outline of that familiar constellation. Other novae are too faint for small instruments or brighten and fade so quickly, if there’s a cloudy spell, you might miss it.

An imaginary view of a nova explosive seen close up. The blast is not powerful enough to eject the companion star. Credit: Emanuele Feronato, Bob King

Sagittarius – and nearby Scorpius and Ophiuchus also – are familiar discovery grounds for novae because that’s where most of the stars of the Milky Way are concentrated. Why? Because we’re facing the center of the galaxy when we direct our gaze toward these star groups. The more stars in your line of sight, the better the chance that one of the many billions will flare into nova-hood.

The best time to see Nova Sgr 2012 #4 is between about 10:30 p.m. and 3 a.m. Optimum time is around midnight when Sagittarius, always low in the southern sky from northern latitudes, reaches its highest point above the horizon. Use the maps to star-step your way to the nova. For those familiar with celestial coordinates, its exact position is: R.A. 18 h 20′ 27.3″, Dec. -27 degrees 44′ 26″.

You can also get a nice printable chart at the American Association of Variable Star Observers (AAVSO) website. In the Star Finder box, type in PNV J18202726-2744263, the temporary name for the new nova, and click the Create a finder chart link. Your chart will have north at top. If you want to print out a different orientation or a more customized version, just click the blue Return and Replot link.

How bright the nova will be tonight is anybody’s guess. Maybe the same as last night, but it could also be fainter or brighter. Good luck spotting one of nature’s more explosive creatures!

Double star in Poniatowski’s bull simply gorgeous

Though now obsolete, the sky’s other bull, Taurus Poniatowski, once grazed to the left or east of the Ophiuchus the Serpent Bearer.

In 1777 a Polish-Lithuanian astronomer Marcin Poczobutt chose to honor the Polish king Stanislaus Poniatowski by creating a small constellation in his honor named Taurus Poniatovii (Poniatowski’s bull). The little figure was scraped together from stars alongside the much larger Ophiuchus the Serpent Bearer.

Like a lot of small, faint groups created by 18th century astronomers, the bull never survived except in the history books. One of a dozen or more obsolete constellations, the stars of Poniatowski’s bull eventually were parted out to Ophiuchus and Aquila the Eagle.

The southern sky around 10:30 p.m. in early to mid-July. Ophiuchus is a large constellation above Scorpius and its bright, red star Antares. Our featured double star, 70 Oph, lies just to the left or east of Beta Oph. Maps created with Stellarium

The face of the bull is a stellar “V”outlined by the 4th magnitude stars 67, 68 and 70 Ophiuchi. Fainter stars extend the V further north. In binoculars they resemble a dimmer version of the Hyades in the real Taurus the Bull. From suburban areas and the countryside, it’s easy to see the group about halfway up in the southern sky at nightfall around 10:30 p.m.

Close up of 70 Oph located about 4 degrees to the left or east of the easily visible Beta Ophiuchi.

You’re welcome to seek out the obsolete bull for its own sake, but if you own a telescope, point it at 70 Ophiuchi (Oph) the next clear night. This unassuming star is one of the sky’s most colorful doubles.

Located just 16 light years away, the stars of 70 Oph revolve about their common center of gravity in just 88 years.

That’s short enough to watch them through at least half an orbit during your lifetime. Most doubles show no noticeable change over hundreds or even thousands of years because of greater separation and distance.

This diagram shows the dimmer 6th magnitude companion of 70 Oph in orbit about the brighter one (on crosshairs). The two are about 6 arc seconds apart and easily splittable in a small telescope. South is up and east to the right in the diagram. Credit and copyright: Richard Dibon-Smith

Their average separation of the two stars is nearly the same as the distance of Uranus from the sun. When closest back in 1989, they were a little more than a billion miles apart or Saturn’s distance from the sun. The duo reaches maximum separation in 2028 at 3.2 billion miles, similar to Pluto’s average distance.

Currently they’re easily divisible with a small telescope using a magnification of 50x or higher. The fainter companion lies to the southeast or upper right of the brighter as seen in a typical reflecting telescope.

How 70 Oph looked to my eye last night at 76x in a 10-inch telescope. Illustration: Bob King

Classified as orange dwarfs, both stars are smaller, cooler and less luminous than the sun. These characteristics make 70 Oph one of the most colorful pairs in the sky as I found out last night when viewing it through my 10-inch scope.

The brighter star is yellow orange; its fainter companion shines a rich red. Strongly colored stars so close together make a thrilling sight in any telescope. Take a look for yourself and see what you think.

While you’re in the area, make a second stop above the top of Ophiuchus at Alpha Herculis, the brightest star in Hercules the Strongman. This is another colorful double star with a bright red-orange supergiant orbited by a fainter greenish companion separated by about 5 arc seconds.

It’s estimated that at least half of the stars in the Milky Way galaxy are double or multiple. You could easily spend all night hopping from one to the next and barely scratch the surface. To help you in that quest, here’s a list of 100 of the best.

Binocular vision? Go trinocular with Mars!

Mars, Saturn and the star Spica are the apexes of a right triangle (one containing a 90-degree angle) visible in the west last night. The trio will be visible all month in the southwestern sky at dark. Photo: Bob King

Triangles abound in the night sky. You can take any three stars and connect them to make a variety of triangles. Amateur astronomers often navigate to a deep sky object by creating instant triangles, squares and other figures to help them negotiate a busy star field. There are even two official triangular constellations: Triangulum and Triangulum Australe, the Southern Triangle.

Binocular vision may be characteristic of more advanced life forms, but I’m advocating we take the next step: trinocular vision. Trinocular refers to the three eyepieces used for viewing and photography in a trinocular microscope; for this article we use it in the spirit of fun.

Let’s take a look at a fresh new triangle in the heavens this month comprised of Mars, Saturn and Spica. These three apexes all shine brightly at 1st magnitude and span the southwestern sky at nightfall. As you’d expect, any triangle involving planets never remains the same thanks to their tireless orbiting of the sun. A month from tonight, the three will be gathered into a much more compact equilateral triangle (all three sides of equal length).

Mars heads quickly toward Saturn and Spica in the coming month. Around the 7th and 8th of August it forms an equilateral triangle with Saturn and Spica, then slips between them on the 13th. Created with Stellarium

Mars is much closer to the Earth and sun and moves more rapidly across the sky while Saturn, nearly a billion miles distant, appears to barely move at all. Spica is so much farther than either planet and essentially stays put for thousands of human generations.

Opportunity has spent the past four months at Greeley Haven, named after Ronald Greeley, a former member of the mission team. The colors have been exaggerated to better show differences in materials across the landscape. Click the photo to see a larger version. Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.

The Mars rover Opportunity completed its 3,000th Martian day this past Monday July 2. The milestone marks NASA’s more than 15 continuous years of robotic presence on the Red Planet starting with the Mars Pathfinder rover in 1997 and followed by the Mars Global Surveyor orbiter, Mars Odyssey orbiter and Opportunity, the last two of which are still in service. At the same time the agency released a brand new panorama of “Greeley Haven” on the rim of Endeavour Crater, where Opportunity spent its most recent winter. The crater’s interior can be seen in the lower right of the photo below the horizon.

817 separate photos taken  taken between Dec. 21, 2011, and May 8, 2012 were used to create the image showing the terrain around the rover where it was stationery for four months. Sunlight isn’t strong enough during the Martian winter to fully power Opportunity’s solar panels, so mission controllers park it in a protected spot in low-power mode until the sun is high enough to give the rover its get-up-and-go.

You’ll find more information about the panorama HERE, and if you willing to take the risk of downloading a 124MB file of the scene, have at it.

Could the sun back off a bit, please? Tune in tonight to learn about light pollution

Earth’s distance from the sun varies because its orbit is an ellipse or oval with the sun slightly off to one side. When closest, our planet is at perihelion; when farthest, aphelion. As distance varies, so does Earth’s speed. Illustration: Bob King

Yesterday July 4 Earth reached aphelion (AP-hee-lee-un) or its farthest point from the sun this year. The difference between closest and farthest points in our orbit amounts to about 3 million miles. How I wish that would translate into cooler temperatures. Not gonna happen. While 3 million sounds like a big number, our orbit is so big we’re only about 3% farther today compared to perihelion in January.

Aphelion also occurs during the year’s warmest season, so any slight effects introduced by a closer, bigger sun are lost in summer’s heat. You be tempted to think that in the southern hemisphere, where it’s now winter, the extra distance would add a extra shiver to the air, but the vast expanse of southern oceans moderate the temperature.

Sunspot region 1515 at 11:30 a.m. (CDT) today photographed with NASA’s Solar Dynamics Observatory. The group harbors the potential for the most powerful variety of flares called X-class. Credit: NASA

The sun has been trying to kick up a storm all the same. Sunspot region 1515, which has grown to more than 8 times Earth’s diameter, is now easily visible with the naked eye through a safe solar filter. If you bought one for the Venus transit, dust it off and give the sun a look today. The spot group is located to the lower right of the sun’s center and look like a small piece of “dirt” on the otherwise smooth disk.  1515 has been going bananas with M-class flares (big, high-energy variety); sky watchers in the northern U.S., northern Europe and Canada should be watchful for northern lights starting tomorrow night July 6 through the morning hours of July 7.

Check your local listing for tonight’s PBS show on light pollution titled “The City Dark”. Credit: Wicked Delicate Films LLC

Tonight PBS will air a POV documentary on the growth of artificial light and the effects of light pollution on the skies, our psyche and our health. Titled “The City Dark” you can watch it in Duluth, Minn. on Channel 8 starting at 9 p.m. Click HERE to check your local schedule.

While many of us love “the city lights”, we sometimes forget the price we pay in the loss of the night sky. Comfortable in our cocoons of light, we’re blinded to the stars and a visceral connection to the cosmos. Many city dwellers have no idea what constellations look like let alone the Milky Way.

Astrophysicist and director of New York’s Hayden Planetarium Neil deGrasse Tyson said it best: “When you look at the night sky, you realize how small we are within the cosmos. It’s kind of a resetting of your ego. To deny yourself of that state of mind, either willingly or unwittingly, is to not live to the full extent of what it is to be human.”

Fireworks in the sky and in the lab – elusive Higgs boson finally found!

Royal fireworks display on the Thames River in England in 1749 to celebrate an important treaty signing by King George II.

Fireworks are on the menu today in thousands of U.S. cities as we celebrate the July 4th Independence Day. The invention of fireworks takes us back to the time of the ancient empires.

The Chinese stumbled onto the first proto-firecrackers around 200 B.C. when someone threw green bamboo rods into a fire. Air and sap inside the reeds heated up until bursting through the wood in a loud bang. The noise was thought to ward off evil spirits.

Sometime between 600 and 900 A.D. a precursor to gunpowder was invented that burned bright and hot when exposed to flame. Packed inside a bamboo tube and lit on fire, the gas created when the mixture burned under pressure blew the tube apart. The firecracker was born! Rolled paper later replaced bamboo.

Nova Persei provided a fireworks show during an explosion in 1901 when it briefly became one of the brightest stars in the sky. Today the twin stars are surrounded by a colorful expanding shell of gas reminiscent of  an aerial burst. Credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona

Firecrackers were introduced to the West by none other than Marco Polo when he returned to Italy with a sackful from his trip to the Orient in 1292. Before any of these seminal events, the universe had been playing with fire since time began. One of its grandest creations still lighting up galaxies to this day is the exploding star or supernova. Lesser but equally picturesque fireworks happen all the time in the Milky Way.

Thomas Anderson

Like many an amateur astronomer, Scottish clergyman Thomas Anderson made a last naked eye sweep of the sky while walking to his home late on the evening of February 21, 1901. He gaze suddenly stopped at a brand new 3rd magnitude star in the constellation Perseus the Hero. Anderson reported his observation to the Greenwich Observatory thinking that something so bright must have been seen by others. He soon learned he was the first discoverer of a new nova.

Nova Persei brightened over the next two days to magnitude 0.2, rivaling Vega in brilliance. While astronomers at the time realized they were witnessing a stellar explosion, they didn’t know its nature.

The tiny white dwarf in Nova Persei (right) sucks gas from its companion into a whirling disk. Material lands on the dwarf’s surface where it’s heated explosively. Credit: NASA/CXC/M.Weiss

Novas or novae (NO-vee) occur in tight binary star system where a larger, bloated star – typically a red giant – orbits an Earth-sized but extremely dense star called a white dwarf.

In a scene straight out of David-and-Goliath, the dwarf’s strong gravity pulls hydrogen gas from the giant into a swirling disk, where it funnels down to the surface of the star to accumulate as an ocean of  gas.

Heated to millions of degrees, the hydrogen suddenly ignites in a thermonuclear explosion. Sort of like bamboo in a fire but kicked it up a few billion notches. Remnants of the blast form a halo of fireworks around the binary.

A once-obscure star can brighten to the naked eye visibility in a matter of days. We call the star a “nova”, the Latin word for new, but of course it’s been there all along, lost in obscurity until its sudden rise to fame. Nova Persei is still around but renamed GK Persei. While it typically shines at a dim 13th magnitude, the star shows occasional smaller flare-ups.

A high-speed collision of two protons in the LHC shows the characteristics expected from the decay of a Higgs boson. The LHC is located in Switzerland. Credit: CERN

In other explosive news, scientists using CERN’s Large Hadron Collider (LHC) announced the discovery today of the “holy grail” of subatomic particles, a Higgs-like boson. British physicist Peter Higgs, after whom it’s named, was one of six physicists who predicted the particle’s existence in the 1960s.

The Higgs boson is a physical sign of the Higgs field, an invisible force field that pervades the universe and gives all elementary particles – every neutron, proton and electron comprising the atoms of which we’re made – their most basic quality: mass. Were it not for the Higgs field and its particle manifestation, the Higgs boson, matter as we know it would not exist. Our universe would be little more than radiation zipping about at the speed of light. The various particles acquire their unique masses as they “swim” through the field.

Since the Higgs boson is a heavy particle, you need a lot of energy to create one. Remember what we learned from Einstein – mass or stuff is a super compact form of energy. Scientists used the LHC to fling millions of protons at one another at 99.99% the speed of light to detect the presence of the Higgs. To read more about the seminal discovery, check out this Reuters story . The London Telegraph has a video and live coverage.

It’s certainly going to be a happy Fourth of July in Switzerland today. Fireworks all around!

Full Thunder Moon goes boom-boom tonight

Tonight’s the full Strawberry Moon. Pick a place with a wide open view to the southeast to watch it rise around sunset in the southeast. Photo: Bob King

Tonight the Full Thunder Moon (also called the Full Buck Moon) will rise around sunset in the southeast in the constellation Sagittarius. In Duluth watch for it to breach the horizon at 8:55 p.m. For moonrise times for your town, click HERE and add an hour for daylight saving time.

Early summer is when velvety antlers grow from the foreheads of buck deer, hence the traditional name. July’s full moon is also known as the Full Thunder Moon, since thunderstorms are common this month. One blasted through my town only last night.

Like the sun, the moon is colored a deep orange when rising or setting. That’s because we see we look horizontally through the thickest (lowest) part of the atmosphere at those times. The shorter wavelength greens, blues and purples are scattered away by the dense air leaving the yellows, oranges and reds to shine through.

The moon takes on a rich orange color near moonset last week. Our atmosphere acts to remove the shorter wavelengths of light (blues and greens), but the longer-wavelength red rays are able to penetrate the air to your eye. Photo: Bob King

All full moons are directly opposite the sun in the sky. Since the sun’s highest in the summer, the full moon occupies the place directly opposite that spot in the lowest part of the sky. The sun will occupy the spot the moon is in tonight later come this December.

For sky watchers living at mid-northern latitudes, the low-riding moon remains orange to yellow hued for much of the night, since it never climbs high enough to be seen through the thinner air overhead. That’s OK by me. I’ve always enjoyed seeing the yellow moons of June and July. The color is a perfect fit for the warmest season of the year.

Which asteroid will humans first set foot upon? Ask NHATS

Sometime in the mid to late 2020s, NASA plans to send a manned mission to explore a near-Earth asteroid. Here an astronaut uses rope or cable to climb about a small asteroid. Credit: NASA/JPL

NHATS? The letters hold a mouthful but let’s have a go at it: Near-Earth Object Human Space Flight Accessible Targets Study. It’s NASA’s short list of near-Earth asteroids (NEAs) that would take a robotic or manned expedition a minimum of fuel and time to reach, explore and then return to Earth. The current Presidential administration directed NASA to include NEAs as destinations for future human exploration with plans for a mission in the mid-2020s.

The goal of the program is to identify asteroids that are the most easily accessible. Important factors include:

* An orbit similar to Earth’s that’s nearly circular (comets with cigar-shaped orbits need not apply!)
* An orbit that is nearly flat (low inclination). Extra fuel and time are required to put a spacecraft into a tipped orbit.
* Minimum change in the velocity or speed of the spacecraft to conserve fuel and time. Fuel is needed to leave Earth orbit, enter orbit around the asteroid, depart the asteroid and to slow reentry on return to Earth.
* Planned for missions would last 450 days or less, meaning the asteroid must be within about 9.3 million miles (37 lunar distances) of Earth.

In all the time spent coming and going, astronauts would spend just 8 days exploring the asteroid. NEAs make ideal targets – they’re diverse and extremely ancient, having formed in the early history of the solar system, and much closer than and less demanding time and fuel-wise than say, a mission to Mars.

The huge Arecibo radio telescope is built into a large sinkhole in Puerto Rico. It’s contains the largest curved focusing dish on Earth and often used to study close-approaching asteroids. Credit: H. Schweiker/WIYN and NOAO/AURA/NSF

As plans are being made, observatories like the big 1000-foot radio dish at Arecibo in Puerto Rico are gearing up to track likely candidates to further nail down their orbits, sizes and physical characteristics.

Radio telescopes ping an asteroid with radio waves to take a rough picture of its shape and surface by measuring the returned signal. Surveying the NHATS list of potential targets, I see that 2012 MD7, estimated at between 88 and 394 feet wide, will be in Arecibo’s crosshairs this month. The asteroid does not pose a threat to Earth.

Asteroid 2005 YU55, captured by reflected “radio light” in 2011 by the Arecibo Observatory, is about 1300 feet across. Credit: NASA

Let’s hope the U.S. has the desire and determination to set aside a few tax dollars toward a manned asteroid exploration. What a stimulus it could become for both the space industry and science.

In honor of the fine work Bruce Willis did in the 1998 movie Armageddon, we might consider nicknaming the first asteroid we set foot upon “Bruce”.

“Fireworks moon” sure to delight this 4th of July

Fireworks at Fourth Fest at Bayfront Park in Duluth in 2010. This year the nearly full moon will share the scene. Photo: Bob King

No auroras around here last night though I suspect there would have been a green glow in the north were it not for moonlight. There’s still a chance for magnetic storms and potentially more auroras this evening through July 3. Take a minute to scan the northern sky before going to bed the next few nights just in case.

The kids in my township love setting off firecrackers and bottle rockets well before the 4th of July. Last night a large explosion echoed loudly through the neighborhood under a tranquil moon and the silent strutting of fireflies. Thanks for the reminder guys (they’re always guys).

Simulated view looking southeast around 9:45 p.m. July 4. For the exact moonrise time for your town, click the photo. Remember to add an hour for daylight saving time to the times shown. Illustration: Bob King

This July 4 will be special because it happens just one day past full moon. While you relax on a blanket or get comfy in that lawn chair, the big orange eye of the moon will rise in the east around 9:30 p.m. local time about the time many cities start their fireworks shows. Bangs and showers of colored fire will rivet your attention, but the grand finale of it all may be the quiet moon taking center stage in the east.

If you have kids (or even if you don’t), use the  opportunity to point out the face of the “man in the moon”, explaining that the lighter-colored areas were once molten lunar crust that was later bombarded by meteorites, leaving it riddled with millions of craters like Swiss cheese on steroids.

The light-colored areas are ancient, now-solidified lunar crust. The dark spots are named “seas” because of their smoother appearance. Seas are named after moods and weather. Illustration: Bob King

The dark patches that form the eyes, nose and mouth are really huge holes blasted out by asteroids more than 3 billion years ago that later filled with dark-colored lavas.

The moon’s pretty quiet now, except for the occasional moonquake or meteorite hit, but the fireworks of bombardment during its youth was a grand finale that lasted some 300 million years. Scientists term the period of intense cratering that affected not only the moon but Earth, Mars and Venus, the Late Heavy Bombardment or LHB.

The reshuffling of the outer giant planets flung millions of comets and asteroids into the inner solar system bombarding the moon, Earth, Venus and Mars. Credit and copyright: Julian Baum

The LHB occurred 4.1-3.8 billion years ago (some say 4.1 to 2.5 billion) 700 million years after the planets had formed. Jupiter, Saturn, Uranus and Neptune were rapidly migrating at that time to different positions in the outer solar system. Their movements stirred up millions of comets and asteroids, sending them into the inner solar system to wreak havoc on the rocky planets and their moons. Once the giants reached stable orbits, the neighborhood became a calmer place, and the moon was left with enough scars to arouse the curiosity of humans who would evolve several billion years later.

A team of scientists estimates that 3 billion years ago a small asteroid slammed into what is now Greenland to gouge the oldest crater found to date on Earth. Credit: Carsten Egestal Thuesen / GEUS

Earth also took its hits during the LHB. Just this week a team of scientists from Cardiff, the Geological Survey of Denmark and Greenland, Lund University in Sweden and the Institute of Planetary Science in Moscow announced the discovery of the oldest impact crater yet found on Earth – a 3-billion year old giant near the town of Maniitsoq in southwestern Greenland.

While the crater bowl has long since been eroded, scientists found evidence of shocked rocks, pulverized granite and deposits of nickel and platinum, elements often found in meteorites. The estimated19-mile-wide asteroid blasted out a crater that was originally 373 miles across and over 15 miles deep. After billions of years of erosion, only a 62-mile-wide remnant survives.

Space rocks still fling about the sun creating concerns for the future, but it’s nothing compared to the LHB. While you’re out watching things blow up on the 4th, let your imagination wander to those earlier days when the fireworks never seemed to end.

Watch for auroras on this last night of June

Posers! Cirrus clouds catching twilight’s bright western glow and perhaps a bit of moonlight resemble noctilucent or night-shining clouds. Hints of pink and a more fibrous form gave them away. The REAL noctilucents were much lower in the sky. Photo: Bob King

Since about 4 a.m. this morning, the Kp index, an indicator of geomagnetic activity and aurora borealis, has been pinned at “4″ or just below the minor storm level. The gusty solar wind we talked about yesterday is already rattling its cage, making auroras a possibility for the northern states and Canada tonight. Members of our local Arrowhead Astronomical Society spotted the lights very early this morning from Duluth’s Canal Park. Again, one caveat – the moon is 3/4 full, bright and sets late. Its light may well swamp the aurora’s unless the display is relatively bright.

Close up of true noctilucent clouds glowing pale blue very low in the northern sky last night June 29. At 50 miles high and composed of ice crystals, they’re Earth’s loftiest clouds. Photo: Bob King

Last night, patchy cirrus clouds did an excellent job pretending to be noctilucent clouds. They glowed white well into twilight and had a fibrous texture, but there was something not right about their ever-so-faint pink tinge and lack of “waviness” so prevalent in true noctilucents. By 10:45 p.m. (about 1 3/4 hours after sunset) the cirrus were exposed as impostors when I finally noticed the real item much lower in the northern sky.

Jupiter (top) and Venus shine in the eastern sky over Lake Superior during morning twilight June 30. The two were about 6 degrees apart. In the coming weeks they’ll draw closer together and be joined by the crescent moon. Photo: Bob King

Have you felt the pull of Venus and Jupiter yet? I finally gave in this morning and arose at dawn for a face-to-face with the two luminaries.  They made a most tranquil sight over the big lake around 4 a.m.

Jupiter through a 14-inch telescope on June 20 photographed by Philippines amateur Christopher Go. The wide appearance of the North belt (top) I saw was a combination of the NEB and the further north, narrower belt called the North Temperate Belt.

Back at home, I looked at each in the telescope. Venus was again a crescent but with its horns pointed west, opposite of how we saw it last in the evening sky. Jupiter fluttered about in turbulent air making it difficult to see much detail. I managed the South Equatorial Belt (SEB) –  a dark, easy-to-see stripe – and noticed the odd appearance of the North Equatorial Belt (NEB), which looked pale and unusually wide.

Jupiter’s northern hemisphere has been in meteorological upheaval since the planet’s returned to view in the morning sky.

July begins tomorrow. Mark your calendar for a grand conjunction of the two planets and crescent moon on the morning of the 15th.

Invisible portals let sun’s wind blow through Earth’s hair

A coronal hole shows up as huge dark patch in this photo taken this morning in ultraviolet light by NASA’s Solar Dynamics Observatory. Holes are places where the sun’s magnetic field opens up and allows pent up solar wind to escape. Electrons and protons in the wind can cook up auroras in Earth’s upper atmosphere. Credit: NASA

The sun giveth in so many ways. A high speed wind of particles from a large hole in its outer atmosphere is streaming toward Earth right now and will put the squeeze on our planet’s protective magnetic bubble wrap tomorrow June 30 and Sunday.

Flaring sunspot groups currently crossing the sun will also contribute to the disturbance.

That puts at least minor auroral storms back in the forecast, so be on the lookout. One downer. A bright moon could dilute their visibility.

A NASA-funded researcher has been studying a recently discovered phenomenon called “portals” that connect the sun’s magnetic field with Earth’s, allowing the solar wind direct entry to our upper atmosphere, where it can spark auroras and other geomagnetic storm effects.

Earth’s magnetic field lines (pink) tie in directly with the sun’s (yellow) at portals located in the sun-facing side of our planet’s magnetic bubble. The resulting connection sends solar wind particles straight into the upper atmosphere. Credit: NASA

The sun’s magnetic field, which is bundled with the solar wind’s blizzard of electrons and protons, hooks up with Earth’s at so-called X-points, creating an uninterrupted path between our planet and the sun’s atmosphere. Portals are cylinder-shaped and located about 20,000 miles from Earth toward the sun. Approximately every 8 minutes a portal open up and the two fields connect, allowing particles access to Earth. Most X points are small and come and go quickly, but some are as big as the Earth and long-lived.

When Earth’s and the sun’s fields cross at the X point (right) material can follow our planet’s magnetic lines of force (blue) down into the polar atmosphere to create auroras. Credit: NASA

Earth’s magnetosphere staves off much of the sun’s solar wind, but like a mole in the CIA, a portal allows the wind to get in through the front door. Don’t get too alarmed about them – the sun’s wind’s been blowing for billions of years. No matter how it ultimately enters Earth’s inner sanctum to bless and curse us with geomagnetic storms, we’re still protected by our atmosphere from any direct particle hits.

Photograph of the northern auroral oval during an active geomagnetic storm, when Earth’s magnetic field is energized by particles flowing in the solar wind. Credit: NASA

NASA plans to study the portals in detail when the agency with a series of four satellite due to launch in 2014. Called the Magnetospheric Multiscale Mission (MMS), the probes will fan out and hunt for portals using particle detectors and magnetic sensors.

Scientists are coming to understand that the auroras we so enjoy are stoked by more often by the solar wind popping through portals then trickling around the edges of Earth’s magnetosphere. To learn more, take a look at NASA’s video on the topic.