Don’t let Comets PANSTARRS and Lemmon out of your sight … yet

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Comet L4 PANSTARRS on May 18. The anti-tail extends straight out from the comet’s coma to the left. Use the map below to find the comet. Click to enlarge. Credit: Michael Jaeger

What the heck have comets L4 PANSTARRS and Lemmon been up to anyway?  Well, they’re still visible in 50mm binoculars and small telescopes. You can see them both sans moonlight in the morning sky after moonset. PANSTARRS first shows at nightfall not far from the North Star Polaris, one reason why it’s easy to find.

Map showing Comet C/2011 L4 PANSTARRS’ location tonight through June 21. Positions are marked off every three nights. Stars are shown to about magnitude 8. Credit: created with Chris Marriott’s SkyMap software

Shining at around 8th magnitude it looks like a fuzzy spot in binoculars, a bigger fuzzy spot with a brighter head in a small scope and a twin-tailed wonder in large amateur telescopes. It sidles up the Little Dipper in the coming month passing near that constellations two brightest stars – Polaris and then Kochab (KO-kab). Moonlight will soon compromise evening viewing but morning skies are still dark just before dawn.

Comet C/2012 F6 Lemmon on May 17 showing its short, diffuse dust tail (left) and long gas tail. Credit: Damian Peach

Michael Jaeger’s amazing photo shows how drastically different PANSTARRS looks compared to a month ago. The principle dust tail (off to the right and fanning left) so bright in March and early April has shrunk and faded. Meanwhile, the anti-tail, formed by dust trailing in the comet’s orbit, stretches at least a full binocular field of view to the left. PANSTARRS never ceases to amaze.

This map shows the sky facing east around 3:30 a.m. or approximately 2 hours before sunrise near the start of morning twilight. Comet positions are shown every 3 days; stars plotted to about 7th magnitude. Lemmon travels from Pegasus into Andromeda over the next month. Credit: created with Chris Marriott’s SkyMap software

Comet C/2012 F6 Lemmon has finally risen high enough before dawn to clear the horizon haze and treeline. At 7th magnitude, you can see in binoculars a more compact fuzzy spot than PANSTARRS; a telescope will show a faint, short tail to the southwest. Time exposure photos reveal a soft, rounded dust tail and long, skinny gas or ion tail.

Watch as Venus, Jupiter and Mercury align after sunset

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The sky facing northwest this evening about 30-35 minutes after sundown. Venus and Jupiter should be relatively easy to spot provided you have an unobstructed view; Mercury might require binoculars. Stellarium

Hey, hey, hey. Three planets are now lining up in a neat row at dusk. Watch for the trio starting 30-35 minutes after sunset when they’ll be low in the northwestern sky.

The distance between Venus and Jupiter has shrunk over the past week and now stands at about 8 degrees or just shy of a fist held at arm’s length against the sky. Mercury finally joins the crew after emerging from the sun’s glare, though it will be the most challenging to see because of low elevation. As always when hunting planets in twilight, be a slacker and bring binoculars to make the job easy. Mercury will become easier to see by mid-week as it races up from the sun.

All three twilight planets appear close together near the sun in evening twilight is because they all lie in nearly the same line of sight (arrow) as seen from Earth. This view is a frame from a live orrery – click to watch the planets orbit the sun. Credit: dd.dynamicdiagrams.com

Venus is brightest at magnitude -3.4, while Jupiter and Mercury are near equals at -1.5 and -1.3 respectively. A week from now the three will all be clustered within a couple degrees of each other and form striking, triangle-shaped configurations that change night by night. I’ll have maps and times to look later this week. Get your cameras ready!

1998 QE2 asteroid flyby an opportunity for pros and amateurs alike

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Many separate telescopic images were combined to create this animation of asteroid 1998 QE2 moving through a star field this past week. Credit: Ernesto Guido and Nick Howes

An asteroid it would take an hour to walk across will speed past Earth on May 31 and provide radio astronomers a perfect opportunity to nab closeup views of its surface. 1998 QE2, discovered in 1998 by the Massachusetts Institute of Technology Lincoln Near Earth Asteroid Research (LINEAR) program,  will miss our planet by a healthy 3.6 million miles (5.8 million km) or 15 times the distance of the moon. Closest approach occurs at 3:59 p.m. Central time.

The asteroid’s large size combined with its relatively close approach makes it a great target for both the 230-foot (70-m) Goldstone radio dish and 1,000-foot (305-m) Arecibo dish in Puerto Rico. Lance Benner, the principal investigator for the Goldstone radar observations from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., will have all hands on deck for the flyby. By sending bursts of radio waves at 1998 QE2 and measuring the retured radar echoes, Benner expects the dishes to resolve surface features as small as 12 feet (3.75m) across on the 1.7-mile-long asteroid (2.7 km).

The orbit of asteroid 1998 QE2. Its May 31 flyby will be the closest it comes to Earth for at least the next 200 years. Its closest point to the sun is similar to Earth’s; when farthest it’s 353 million miles from the sun in the asteroid belt between Mars and Jupiter. Credit: NASA/JPL-Caltech

Through an ordinary optical telescope, even a large one, 1998 QE2 will appear as a point of light. Radar observations reveal far more including shape, size, rotation and a wide variety of surface features. Goldstone observations are scheduled from May 30 – June 9; those at Arecibo for several days around June 5.

Already optical telescopes in the southern hemisphere have this monster rock in their crosshairs. By measuring repeating highs and lows in the asteroid’s brightness as it spins on its axis, astronomers can determine its rotation rate. 1998 QE2′s composition is gleaned by how it reflects sunlight. Reflected sunbeams streaming back to Earth carry the imprint of particular minerals that absorb and reflect portions of the sun’s light in unique ways that nail down their identities.

“It is tremendously exciting to see detailed images of this asteroid for the first time,” said Benner. “With radar we can transform an object from a point of light into a small world with its own unique set of characteristics. In a real sense, radar imaging of near-Earth asteroids is a fundamental form of exploring a whole class of solar system objects.”

1998 QE2 looks like a point of light in this time exposure taken remotely with a telescope in Australia by the team of Ernesto Guido and Nick Howes. The asteroid is currently very faint and only visible in the southern hemisphere. Click for more on the asteroid in their blog.

I’m excited about the asteroid because it will be bright enough to be visible in small telescopes across both northern and southern hemispheres for several nights around the time of closest approach. Between May 30 and June 5 it will shine at 10.5-11.0 magnitude while chugging through the constellations Libra and Ophiuchus, both conveniently placed at nightfall. Its steady movement across the sky – 2/3 of a full moon diameter an hour – will be obvious through the telescope. Come the end of the month, I’ll create a map to help you find it.

Read more about 1998 QE2 HERE. Amateur astronomers needing orbital elements and ephemerides can check out the Goldstone planner.

Aurora alert tonight May 17-18, 2013

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This map created with satellite data for 11:30 p.m. CDT May 17 shows the extent of the northern auroral oval, one of two permanent caps of aurora centered on Earth’s north and south geomagnetic poles. Normally the oval is small and snugged up over Hudson Bay. Tonight it’s expanded southward and could produce auroras across the northern border of the U.S. Click to see current oval. Credit: NOAA

If it were clear here in Duluth, I’m sure we’d be seeing northern lights. The Kp index, an indicator of magnetic activity around the Earth, shot up to “5″ or minor storm level around 11 p.m. Central time this evening (Friday). From the satellite plot, it appears the auroral oval extends across southern Canada almost to the U.S. border.

Since the aurora is quite high – around 60-200 miles – it’s visible a fair distance to the south of that line. In other words, northern parts of Minnesota, Michigan, Wisconsin, N. Dakota, Montana and Washington may get treated to the sight of northern lights overnight.

Sunspot region 1748 still has the potential for more solar storms. Since the group’s now becoming more face-on to Earth, additional flares could send CMEs in our direction. Another flare on May 17 sent material expected to arrive on the 19th. Credit: NASA

Be sure to take a look at the northern sky tonight for arcs and rays of aurora. As you might guess, the cause for this show lies with the recent X-class flares sunspot region 1748 has been pounding out over the week. Our planet was expected to get a glancing brush from a coronal mass ejection (CME) overnight from one of the recent blasts. Let us know if you see anything. And get ready for May 19 – Sunday – when another blast could spark an even more auroras.

Space station spices up short May nights

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International Space Station Commander, Chris Hadfield, performs a revised version of David Bowies Space Oddity on board the station earlier this week. This is for real – enjoy!

The early bird is back! The International Space Station is once again making passes during morning twilight, putting in regular appearances for U.S. skywatchers. And I do mean early. With the sun now rising well before most of us are up and around, you’ll need to be out between about 3 and 5 a.m. to catch a look. Either that or party all night and wag your weary head skyward at dawn before crashing.

Log in to Heavens Above for viewing times and maps or go to Spaceweather’s Satellite Flybys page and type in your zip code.

Here’s when to watch for the Duluth, Minn. region. Brightness is given as magnitude. For reference, Jupiter is -2.5 magnitude, Venus -4.5 and the brightest star Sirius about -1.5. Altitude is in degrees; one fist held at arm’s length equals about 10 degrees.

* Sat. May 18 starting at 4:45 a.m. Low pass across the south-southeast. Max. brightness -1 magnitude, max altitude 20 degrees.
* Sun. May 19 at 3:57 a.m. low in the eastern sky. Mag. -1, altitude 13 degrees.
* Mon. May 20 at 4:43 a.m. Very nice pass across the south and east. Mag. -2.6, altitude 45 degrees
* Tues. May 21 at 3:55 a.m. visible low in the south to east. Mag. -2, altitude 28 degrees
* Weds. May 22 at 4:40 a.m. straight across the top of the sky. Mag. -3.3 (brilliant!) Altitude 86 degrees
* Thurs. May 23 at 3:51 a.m. high across the south and east. Mag. -3.2 (brilliant!) Altitude 60 degrees
* Fri. May 24 at 3:03 a.m. First appears in the southeast moving east. Mag. -2.6, altitude 38 degrees. Second pass at 4:36 a.m. across the northern sky. Mag. -2.5, altitude 50 degrees
* Sat. May 25 at  3:46 p.m. high in the northern sky. Mag. -3, altitude 69 degrees

Meteoroid hits moon, goes boom!

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Bright impact flash made by a 1-foot-wide rock that struck the moon on March 17, 2013. The moon was a crescent in the evening sky at the time. The impact occurred in the dark, earthlit part of the moon away from the sun-lit crescent. To see video, click photo and then click again to open video after download. Credit: NASA

Anyone looking at the moon at the right time on St. Patrick’s Day with a small telescope would have seen it. A pinpoint flash of light as bright as a 4th magnitude star suddenly appeared that evening in the lunar sea Mare Imbrium and faded away one second later.

The St. Pat’s Day meteoroid strike occurred near the prominent crater Copernicus in Mare Imbrium, the Sea of Showers. Photo: Bob King

“On March 17, 2013, an object about the size of a small boulder hit the lunar surface in Mare Imbrium,” says Bill Cooke of NASA’s Meteoroid Environment Office. “It exploded in a flash nearly 10 times as bright as anything we’ve ever seen before.”

Frames in false color taken from the original black and white video show the explosion in progress. Click to watch video. Credit: NASA

“It jumped right out at me, it was so bright,” said Ron Suggs, an analyst at the Marshall Space Flight Center. He was the first to notice the explosion in recordings made with a 14-inch telescope maintained by NASA’s lunar impact observation program. Observers there have been video monitoring the moon for the past 8 years looking for signs of explosions caused by meteoroids hitting the surface. Since 2005 the team has detected more than 300 strikes, but the St. Pat’s Day impact was the biggest and brightest to date.

Based on the flash brightness and duration, the space boulder measured between a 1 foot long and a foot and a half long (0.3-0.4 m) and hit the moon traveling at 56,000 mph with a force of 5 tons of TNT.

Artist view of the meteoroid impact last March as seen from the surface. Despite the blog’s title, no actual explosion would be heard because the moon has no atmosphere, however an astronaut would feel the impact through their feet if close enough. Credit: NASA

Remember, the moon has no atmosphere, so there’s nothing to slow down or break apart an incoming meteoroid as happens on Earth so even a small stone can dig a significant hole; its energy of motion transforms it into a powerful little bomb. NASA estimates the crater could be as wide as 65 feet (20 m) across. By the way, the flash of light comes from molten rock and white-hot dust vapor created at the moment of the strike.

NASA’s lunar monitoring program has detected hundreds of meteoroid impacts, nearly all of them on the dark, earthlit areas of the moon where they stand out against the darkened moonscape. You’ll also notice how few have been spotted in the white lunar highland regions. This is a selection effect: flashes stand out much better against black than white. Credit: NASA

That good news because the Lunar Reconnaissance Orbiter should have no trouble spotting the crater once it targets the impact region. Comparing the size of the crater to the brightness of the flash would give researchers a valuable “ground truth” measurement to validate lunar impact models.

A small, relatively fresh lunar impact crater 295 x 230 feet (90×70 m) in diameter photographed by NASA’s Lunar Reconnaissance Orbiter. Melted rock, now solidified, has pooled at the crater’s center. Click for large version. Credit: NASA

In an interesting twist, the very night the moon got smacked, all-sky cameras operated by NASA’s and the University of Western Ontario recorded several bright fireballs streaking through Earth’s skies from the same direction in space as the lunar meteoroid.

“My working hypothesis is that the two events are related, and that this constitutes a short duration cluster of material encountered by the Earth-Moon system,” says Cooke. Who knows. Maybe we’ll see a similar show next March.

 

Lizard Lemmon Comet loses tail, grows a new one

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Comet C/2012 F6 Lemmon photographed on May 15 showing its bluish, ion tail (bottom) beginning to peel away from the comet. The dust tail sticks out to the left. A wispy, new gas tail is already growing above the departing one. Credit: Damian Peach

Solar winds snapped off Comet Lemmon’s ponytail this week and sent it reeling into space. Not to worry. Comets possess the remarkable ability, shared by many species of lizards, to grow new ones. A lizard loses its tail to distract and escape a predator; a comet because its charged atoms – called ions – interact with the breezy blasts of charged particles from the sun called the solar wind.

Magnetic fields in the solar wind tore off Comet Lulin’s tail on Feb. 4, 2007. You can clearly see it falling away in the bottom frame. Credit: Joseph Brimacombe

One day Comet Lemmon was minding its own business and then on Wednesday morning, one of its two tails underwent a “disconnection event”. Comets frequently grow two tails when they orbit near the sun – a pale yellow one of fine dust and a blue one of ionized (electrically charged) gas. The blue color comes from ionized carbon monoxide which fluoresces blue when excited by ultraviolet light from the sun. The larger particles in a comet’s dust tail have no electric charge and aren’t affected by the solar wind; they get pushed away from the comet’s head by the pressure of sunlight.

Charged particles from the sun – electrons and protons – plow through the solar system and continuously interact with comets creating picturesque kinks and ripples in their ion tails. Wrapped up into this electrical mix are solar magnetic fields with north and south-directly poles similar to those on a horseshoe magnet.

 

Invisible magnetic field lines are made visible around a bar magnet when you sprinkle iron filings around it. The sun’s wind likewise has lines of magnetic force embedded within it created by moving charged (electric) particles.

Electricity and magnetism go hand in hand. A spinning magnet creates an electrical field and an electric current creates a magnetic field. Every time you turn on a lamp, the wires inside the cord are looped by invisible but very real magnetic fields.

Solar flare eruptions like the powerful X-class flares earlier this week can direct huge clouds of magnetized (and electrified) clouds of gas called coronal mass ejections or CMEs into space. When one smacks into a comet, it can rip its tail right off.

Magnetic field lines bound up in the sun’s wind pile up and drape around a comet’s nucleus to shape the blue ion tail. Notice the oppositely-directed fields on the comet’s backside. The top set points away from the comet; the bottom set toward. In strong wind gusts, the two can be squeezed together and reconnect, releasing energy that snaps off a comet’s tail. Credit: Tufts University

Comets present obstacles to the solar wind. The magnetic field carried by the sun’s constant wind gets pushed back by the comet’s electrified gases causing it to drape and flow around the comet’s head. That’s what forms the streamlined blue ion tail in the first place. But when an especially powerful blast of wind blows by, it can elbow its way around the backside of the comet and reconnect with itself, releasing a burst of energy that snaps off the tail.

Diagram showing how a CME slams into a comet (B) to create a tail disconnection event, known in the biz as a DE. Soon enough the comet grows a new one (D). Credit: NASA

In a very real sense, Comet Lemmon experienced a space weather event much like what happens when a powerful solar wind reconnects streams around Earth’s magnetic field and reconnects on the back or nightside of the planet. The energy released sends zillions of electrons and protons screaming down into our upper atmosphere where they stimulate the air molecules to produce auroras. One wonders whether comets might even have their own brief displays of northern lights.

As the solar wind flows away from the Sun, it creates a spiral-shaped interplanetary magnetic field (IMF). Two to four sectors – where the field is pointed toward or away from the sun – spin out every solar rotation (27 days). Each sector Credit: NASA

It’s unclear what pinched Lemmon’s tail since all four large flares from sunspot group 1748 and their associated CMEs weren’t directed at Comet Lemmon.

Maybe the comet crossed a sector boundary where the magnetic field carried across the solar system by sun’s steady breeze changed direction from south to north or north to south. When it sped across the older field wrapped around Lemmon, the two once may have linked up in a burst of energy.

When a lizard loses its tail, it may gain its life, but still suffer for the trouble. For a time, its sense of balance is compromised and important fat reserves stored in the tail aren’t available. Comet Lemmon will be no worse for the wear. As soon as the old tail drifts away, a new one sprouts in its place, cooked up by the ever-steady sun.

Read more about tail disconnections HERE; check out a map for finding Comet Lemmon HERE.

A 3rd X-class flare rocks the sun

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The latest X3.2 flare in far ultraviolet light at 8:16 p.m. CDT Monday evening May 13 (May 14 Universal Time) photographed by the Solar Dynamics Observatory. Credit: NASA

Solar activity’s been rising like nobody’s business. Two of the year’s most powerful flares fired off from the sun’s backside late Sunday and at least 8 spot groups speckle the sun’s white-hot surface today.

Another ultraviolet picture of the sun taken by NASA’s STEREO Behind spacecraft late on May 13. The flare looks like a giant spike because the brilliance of the explosion saturated the camera sensors. STEREO Behind orbits well behind Earth and sees a part of the sun’s backside not visible with Earth-based telescopes. Click to learn more about the STEREO probes. Credit: NASA

Now we can add a third strong X-ray class flare, an X3.2 that spewed a vast cloud of high-speed solar gases called a coronal mass ejection (CME). Lucky for Earth, it was directed – as the other flares were – away from our planet off the eastern edge of the sun’s disk.

The most energetic flare measured in the modern era occurred on November 4, 2003 during the last solar maximum. No one knows how truly strong it became since the sensors topped out at X28. But any flare in the X-category can affect everything from GPS satellites to radio communications, satellite electronics and even fry poorly-protected power grids.

The sun in normal white light late Monday with sunspot groups labeled. Region 1748 – site of the strong flares of the past few days –  is just coming into view at far left. Credit: NASA

Solar flares typically occur in sunspot groups where magnetic energy is concentrated. The  solar surface, which bubbles and churns like a monster pot of hot oatmeal, brings opposite magnetic fields (north and south poles) in contact with one another. When they reconnect, the sudden release of energy heats solar gases to many millions of degrees and blasts billions of solar electrons and protons into space as a CME.

The amount of energy from a big flare like the ones we’ve seen recently equals millions of thermonuclear (hydrogen) bombs.

A healthy CME (coronal mass ejection) in the wake of the most recent X3.2 flare late Monday. This photo was taken by the Solar and Heliospheric Observatory which uses a special mask to block out the bright sun to better photograph it outer atmosphere. Credit: NASA / ESA

The sunspot group responsible for all the current feistiness goes by the name of 1748; it’s just coming around to the sun’s front side. Though highly foreshortened because we’re peering at it along the extreme edge of the sun, you can tell it’s a big one. Let’s hope it kicks and sputters its way to a northern lights display without any serious damage to our favorite toys.

Sun cuts loose with the biggest flares of 2013

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Various spacecraft views of the flare eruption late Sunday evening

Late on Mother’s Day starting at 9:17 p.m. Central time, the sun unleashed an X1.7 class flare from its backside creating a spectacular display of hot gases. This was followed by an even more powerful X2.8 flare at 11:09 a.m. today. Both rate as the strongest solar blasts of 2013. Particles from the flare left the sun at 1,200 miles per second. Had they been directed toward Earth, power grids as well as satellites could have been affected; we’d also likely have all-night displays of northern lights.

High-speed electrons and protons propelled outward by the X1.7 solar flare expand into space behind the sun over an hour’s time. The particles were moving about 1,200 miles per second. Mercury is the bright object to the left – although it appears to be in the line of fire, it’s not. Credit: NASA/ ESA

This time around the energy and high-speed particles emitted in the flares “went the other way” as far as our planet is concerned. Not so two orbiting observatories. NASA says radiation from the latest flare may stream toward STEREO-B, a sun-watching probe, the Mercury MESSENGER spacecraft and Spitzer Space Telescope, which astronomers use to study the universe in infrared light. Engineers may decide at some point to put them all in safe mode to avoid damage to their sensitive electronics.

In a few days the sunspot region responsible for the flare will rotate onto the sun’s front side. Many are eager for a closeup look at this new bit of activity.

You’ll love this video of Lake Superior northern lights

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Opening screen of Shawn Malone’s “North Country Dreamland” video of auroras over Lake Superior. Click photo to watch. Credit and copyright: Shawn Malone / lakesuperiorphoto.com

Shawn Malone of Marquette, Mich. has created a masterpiece of video. She recently finished a year-long project shooting more than 10,000 pictures of the aurora borealis from 33 separate locations on many cold nights.

An eruption of magenta auroral rays from Malone’s video project. Credit: Shawn Malone

“It took a lot of coffee, a bit of tenacity and persistence to get this into a form of coherent electrified cosmic goodness,” writes Malone. Although I’ve never met Shawn, we’ve exchanged friendly e-mails and her work regularly appears on Spaceweather. I like to think of her covering the aurora from Lake Superior’s south shore while I keep vigil here along the north shore. Naturally, she has an advantage – the whole of Lake Superior is her reflecting pool for those awesome greens and reds captured so beautifully in the video.

A heron walks the beach during a time lapse sequence of the northern lights. Credit: Shawn Malone

Some of my favorite moments in the many time lapses include the heron walking along the beach, a magnificent eruption of deep red rays and the full moon fogbow beneath the aurora in the final sequence. I like that Malone spent time recording both the quieter side of the northern lights – those many low, green arcs – as well as its wild magic. Kudos for the nice soundtrack also.

Eagle Harbor lighthouse and the Milky Way. Credit: Shawn Malone

Click on the photo or go HERE to see the video. It’s in HD (high-definition) and will run slowly on some computers unless you wait a few minutes for it to load. You can also toggle the HD button to off for a real-time view. Either way it’s dynamite.

Be sure to read the comments Shawn included on the same page as the video. I hope you enjoy the show as much as I did.