Camelopardalid meteor shower targets the moon too – watch for impact flashes

To monitor the moon for possible impacts from the Camelopardalid meteor shower, focus your attention on the speckled area in the darkened upper half of the moon Saturday morning. Impacts may flare to magnitude +8-9. Credit: Bill Cooke

Our favorite orbital partner the moon will join us for the hoped-for Camelopardalid meteor shower Friday night-Saturday morning May 23-24. While any shards of comet debris will flash to incandescence in Earth’s atmosphere, particles striking the airless moon will appear as faint flashes of light when they smack the lunar rocks and vaporize.

Bill Cooke of NASA’s Meteoroid Environment Office suggests that anyone with a telescope should monitor the moon until dawn. The meteor shower is expected to peak in Earth’s skies around 2 a.m. CDT (3 a.m. Eastern, 1 a.m. Mountain and midnight Pacific). On the moon, activity is possible between 9:30 p.m. CDT Friday night through 6 a.m. Saturday morning (2:30-11 a.m. Greenwich Time) with a peak from 1-3 a.m. CDT (6-8 a.m. Greenwich).

The crescent moon and Venus in the eastern sky Saturday morning May 24 around 4 a.m. local time. Stellarium

East Coast skywatchers are favored as the moon is up in the eastern sky around the time of maximum. But the time spread means that anyone from Western Europe across the U.S. could potentially spot a flash. You’ll need a 4-inch or larger telescope magnifying between 40-100x. Higher powers aren’t necessary as they restrict the field of view.

I can’t say how easy it would be to catch one but it will take patience and attention. That’s why the favored method for capturing views of lunar impacts is a video camera hooked up to a telescope set to automatically track the moon. That way you can kick back and examine your results later in the light of day. Seeing a meteor hit live would truly be the experience of a lifetime.

Video frame grab of an earlier meteorite impact on the moon. Impacts look like stars that flash and then quickly disappear. Credit: NASA

As a crescent, much of the moon will be in shadow – perfect for checking for flashes which would otherwise impossible to spot on the brilliant, sunlit crescent. Earthlight will faintly illuminate the remaining 2/3 of the moon, making for a nice dark backdrop against which to see any meteorite strikes.

If you’re into photography and plan to shoot stills or video of the meteor shower and lunar impacts, Brook Brooke Boen (sydney.b.boen@nasa.gov) at NASA’s Marshall Space Flight Center would love to hear from you. Please send any images or video to her e-mail. Your observations will help astronomers better understand the birth and evolution of this brand new meteor shower.

The sky is falling! Surprise meteor shower may strike Saturday morning

A brand new meteor shower shooting 100 and potentially as many as 400 meteors an hour may radiate from the dim constellation Camelopardalis below the North Star Saturday morning May 24. This map shows the sky facing north around 2 a.m. from the central U.S. Saturday.  Stellarium

Get ready for what could be the most awesome meteor shower of the year. On Saturday morning May 24 between 1 and 4 a.m. skywatchers across much of North America are in prime position to witness the birth of a brand new meteor shower – the Camelopardalids. At least 100 meteors per hour and possibly as many as 400 meteors per hour are expected with a peak viewing time around 2 a.m. Central Daylight Time. Short but sweet!

If predictions by meteor experts Peter Jenniskens of the SETI Institute and Esko Lyyttinen of Finland hold true, that morning, Earth will pass through multiple filaments of sand and pebble-sized debris trails boiled off comet 209P/LINEAR during previous passages near the sun during the 19th and early 20th centuries.

The comet was only discovered in 2004 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) automated sky survey. Unlike Comet Hale-Bopp and the late Comet ISON that swing by the sun once every few thousand years or million years, this one drops by every 5.1 years.

When closest at perihelion, 209P/LINEAR passes some 90 million miles from the sun. At the far end of its orbit it’s about Jupiter’s distance from the sun. In 2012, during a relatively close pass of that planet, Jupiter perturbed its orbit, bringing the comet and its debris trails to within 280,000 miles (450,000 km) of Earth’s orbit, close enough to spark a meteor shower.

When a comet nears the sun, heat vaporizes dust-laden ices from the comet’s nucleus. The solar wind ‘blows’ the dust particles into a tail which spread out along the comet’s orbit. Under the right circumstances, as with returning comet 209P/LINEAR, Earth can pass through the debris stream and we see a meteor shower as comet grit burns up in the atmosphere.

This time around, the comet itself will fly just 5 million miles from Earth on May 29 a little more than 3 weeks after perihelion, making it the 9th closest comet encounter ever observed.

You’d think this close pass would make 209P a bright sight, but it’s only predicted to reach magnitude +11, faint enough to require an 8-inch or larger telescope to see. Most likely the comet is either very small or producing dust at a very low rate or both.

Next week I’ll post maps here on how to find it. For the moment, 209P/LINEAR glows dimly at around magnitude +14 and visible in large amateur telescopes. As it speeds from the Big Dipper south to Crater the Cup over the next couple weeks, we’ll be watching it closely. Check here for updates if the comet experiences any hiccups.

The shaded area shows where the shower will be visible on May 23-24. North of the red line, the moon (a thick crescent) will be up during shower maximum around 2 a.m. CDT May 24. Click for more details. Credit: Mikhail Maslov

Meteors from 209P/LINEAR are expected to be bright and slow with speeds around 40,000 mph compared to an average of 130,000 mph for the Perseids. Most shower meteoroids are minute specks of rock, but the Camelopardalids (Cam-el-o-PAR-duh-lids) – let’s just call them ‘Cams’ –  contain a significant number of particles larger than 1mm, big enough to flare as fireballs.

Viewers in the northern half of the U.S. and southern Canada have the best seats for watching the potential shower because the radiant is midway up in the northern sky during peak viewing time Saturday morning. For points farther north, all-night twilight will blot out the fainter meteors. For observers in the far southern U.S. the radiant will be low in the northern sky, reducing meteor counts.

There’s always the chance the shower won’t materialize, so prepare yourself for that possibility. At worst we may see zero meteors, but even the most conservative estimates predict a show at least as good as the Perseids and Geminids, two of the strongest showers of the year.

But if you’re an optimist – and what skywatcher can’t afford not to be? – plan to be out before the peak and face north in a comfortable lawn chair. Bring a friend and share a cup of your favorite hot drink while you watch this ultimate wild card event.

Shower observing times across Canada and U.S.:

* Eastern Daylight Time 1:30-5 a.m. with the peak around 3 a.m.

* Central Daylight Time 12:30-4 a.m. with a 2 a.m. peak

* Mountain Daylight Time 11:30-3 a.m. with a 1 a.m. peak

* Pacific Daylight Time 10:30-2 a.m. with a peak at midnight

The dark “finger” represents streams of dust and rocks left behind by 209P/LINEAR during passes made from 1803 to 1924. Earth is shown intersecting the debris on May 23-24, 2014. Click for more details. Credit: Dr. Jeremie Vaubaillon

If it’s cloudy or you’re not in the sweet zone for viewing, the SLOOH will cover comet 209P/LINEAR live on the Web with its telescopes on the Canary Islands starting at 5 p.m. CDT (6 p.m. EDT, 4 p.m. MDT and 3 p.m. PDT) May 23 Follow-up live coverage of the new meteor shower starts at 10 p.m. CDT. The broadcast will feature astronomer Bob Berman of Astronomy Magazine; viewers can ask questions during the comet show by using hashtag #slooh.

Astrophysicist Gianluca Masi will also have a live feed of the comet at the Virtual Telescope Project website scheduled to begin at 3 p.m. CDT (8 p.m. Greenwich Time) May 22. A second meteor shower live feed will start at 12:30 a.m. CDT (5:30 a.m. Greenwich Time) Friday night/Saturday morning May 24.

No matter what, you’re covered. Later this week I’ll update with a forecast and fresh comet photos and observations. Cross your fingers!

May’s Eta Aquarid meteor shower hails from Halley’s Comet

The Eta Aquarid meteor shower is active in early May and peaks before dawn on Tuesday and Wednesday May 6-7 this year. Watch for it before the start of morning twilight in the eastern sky. Created with Stellarium

Active right now but peaking on Tuesday and Wednesday mornings May 6-7, the annual Eta Aquarid meteor shower likewise peaks our interest in its origin. Most showers trace their parentage to a particular comet. The Perseids of August originate from dust strewn along the orbit of comet 109P/Swift-Tuttle, which drops by the inner solar system every 133 years after “wintering” for decades just beyond the orbit of Pluto.

Halley’s Comet photographed in May 1986 during its last go-round the sun. Dust particles boiled off the comet when near the sun are left behind in its orbit. Every May, Earth encounters the stream and we see the Eta Aquarid meteor shower. Halley’s next approach to Earth happens in the summer of 2061. Credit: Bob King

The upcoming Eta Aquarids (AY-tuh ah-QWAR-ids) have the best known and arguably most famous parent of all: Halley’s Comet. Twice each year, Earth’s orbital path intersects dust and minute rock particles strewn by Halley during its cyclic 76-year journey from just beyond Uranus to within the orbit of Venus.

Our first pass through Halley’s remains happens this week, the second in late October during  the Orionid meteor shower. Like bugs hitting a windshield, the grains meet their demise when they smack the atmosphere at 42 miles per second (68 km/sec) and fire up for a brief moment as meteors.

The farther south you live, the higher the shower radiant will appear in the sky and the more meteors you’ll see. For southern hemisphere observers this is one of the better showers of the year with rates around 30-40 meteors per hour. No moon mars the view, making conditions ideal.

Vintage painting of a fireball meteor flashing across the sky. While the Eta Aquarids aren’t known for their fireballs, the meteors are swift and white.

From mid-northern latitudes the radiant or point in the sky from which the meteors will appear to originate is low in the southeast before dawn. At latitude 50 degrees north the viewing window lasts about 1 1/2 hours; at 40 degrees north, it’s a little more than 2 hours. If you live in the southern U.S. you’ll have nearly 3 hours of viewing time with the radiant 35 degrees high.

Expect to see 5-10 meteors per hour during the hour or two before the start of dawn Wednesday May 7. Face east for the best view and relax in a reclining chair. An added bonus this spring season will be hearing the first birdsong as the sky brightens toward the end of your viewing session.

A modern photographic depiction of Eta Aquarid meteors from May 2012. Credit: John Chumack

Meteor shower members can appear in any part of the sky, but if you trace their paths in reverse, they’ll all point back to the radiant. Other random meteors you might see are called sporadics and not related to the Eta Aquarids. Meteor showers take on the name of the constellation from which they originate.

Aquarius sports at least two showers. This one’s called the Eta Aquarids because it emanates from near the star Eta Aquarii. An unrelated shower, the Delta Aquarids, is active in July and early August.

Happy viewing and clear skies!

Lyrid meteor shower graces the planet on Earth Day

A bright Lyrid meteor streaks across the northwestern sky in this photo taken during the last peak on April 22, 2013. Credit: John Chumack

We celebrate Earth Day this upcoming Tuesday, a time to reflect on how each of us can better our environment. It also happens to be the peak of the annual Lyrid meteor shower.

The Lyrids reliably shoot from the sky every mid to late April, peaking overnight April 21-22 this year. I’ve seen the Lyrids on a couple occasions and can vouch that it’s a reliable though not particularly rich meteor shower. Normal rates are 10 to 20 meteors per hour, but light from the last quarter moon will reduce this year’s count to 5-10 per hour.

This map shows the sky facing east around 12:30 a.m. Tuesday morning April 22 when the radiant will be lower but still up before moonrise. Stellarium

The greatest number of meteors are seen when the radiant, the point in the sky from which they appear to stream, is highest. That occurs just before dawn Tuesday morning. But because the moon doesn’t rise until 2-2:30 a.m., you might do just as well catching the Lyrids from midnight till 2. The radiant will be moderately high in the east and the sky still dark.

The Lyrid radiant is much higher around 4 a.m. when the moon will also be up. Skywatchers take note! The moon will be very close to the third magnitude star Beta Capricorni. Those living in the western half of the U.S. will see it covered up or occulted by the moon around 4:30 a.m. MDT / 3:30 a.m. PDT. The event will be visible in 10x binoculars and small telescopes. Stellarium

While the Lyrids implies an association with the constellation Lyra, home to the brilliant star Vega, the meteors shoot from a location in eastern Hercules 7 degrees southwest of Vega. Each one you see is small bit of dust or rock left behind by Comet Thatcher which last appeared in 1861 and won’t again until 2276.

Voyager 1, which has crossed into interstellar space, is traveling at 38,000 miles an hour or about 1/3 the speed of a Lyrid meteor. Credit: NASA

Each April, Earth passes through Thatcher’s stream of debris and we see the pieces flare as meteors when they strike the air overhead.

Their average speed is 105,000 mph (169,000 km/hr). That’s almost 3 times faster than the current fastest moving spacecraft in the solar system, Voyager 1, at 38,000 mph (61,000 km/hr).

Not a major shower, the Lyrids still occasionally surprise with fireballs and rich outbursts of meteors. Counts were much higher than normal in 1803, 1849, 1850, 1884, 1922, 1945, and 1982. Both Ludwig von Beethoven and famous astronomer William Herschel were around for the 1803 Lyrids which topped out at more than 500 per hour!

NASA’s All Sky Fireball Network detected more than 30 Lyrids as bright as Venus on the nights around the shower’s peak last April 22. Their orbits, shown here in green, neatly intersect the Earth (red splat). “The purple ellipse is the orbit of Comet Thatcher,” adds Bill Cooke, lead scientist for the Office. “The orbits of the comet and the meteoroids match up nicely.” Credit: NASA

To watch the shower, either take the ‘early shift’ from midnight-2:30 a.m. and face east or dare to challenge the moon between 2 and dawn when Hercules and Vega are high in southern sky. I usually spice up my meteor watching with a look through the telescope at the bright planets. Mars shines due south now around midnight with Saturn further off to the southeast.

One final note. The moon will be very close to the star Beta in Capricornus Tuesday morning. Take a look at it in binoculars. If you live in the western half of the U.S., Beta will be occulted by the moon around 4:30 a.m. Mountain time, 3:30 a.m. Pacific. Midwesterners might still see it in bright twilight around 5:30 a.m. with a small telescope. Look immediately to the left of east of the moon’s bright edge.

Invite a friend to join you, boil up some tea and relax under the stars. Every meteor you see is a gift.

Catch some Quadrantids! Year’s first meteor shower peaks tomorrow morning

Watch for the Quads to radiant from a point in northern Bootes below the handle of the Big Dipper tomorrow morning. Stellariu

Tomorrow morning before dawn will be the best time to catch the very first meteor shower of the new year. The Quadrantids, named for the one-time constellation Quadrans Muralis, located below the handle of the Big Dipper, is one the most reliable showers of 2014. While the constellation’s now obsolete and erased from modern sky maps, its name lives on in fiery sparks of meteoric light. Pity the shower rains down at the coldest time of the year.

Ideally, you might see from 60-200 “Quads” per hour, when the shower’s very sharp peak coincides with the radiant being high in the northeastern sky for your location. This year the peak happens around 1:30 p.m. January 3, not exactly ideal for North and South American observers but perfect for folks living in the Middle East and Russia. Numbers will probably be less than half that for western hemisphere skywatchers.

Quadrans Muralis represents the wall quadrant, a instrument once used to measure star positions. Credit: Johann Bode atlas

Don’t let it bring you down. We’ll still see a good show tomorrow morning between the hours of 2 and 6 a.m as meteors emanate from the shower radiant located about a fist below the end of the Big Dipper’s handle in the northeastern sky. No moon will cast its glare to compromise the view. I’d suggest dressing warmly and relaxing in a sleeping bag on a reclining chair. Face to the east or north for the best view. The later you’re up, the more Quads you’ll see as the clock ticks closer to the daytime shower maximum.

A beautiful Quadrantid meteor captured over Duluth near the Big Dipper (partly outlined) a couple years back. Credit: Stephen Bockhold

Quadrantids are slower than other major showers like the August Perseids and December Geminids with speeds around 25 miles per second (41 km/sec). You’ll know you’re seeing a Quad if you can trace its trail back to the northeastern sky below the Dipper.

Peter Jenniskens, senior research scientist at NASA’s SETI Institute, traces the Quads’ origin to the asteroid 2003 EH1, a likely extinct or occasionally active comet. Its orbital characteristics agree well with the paths of our cold weather friends.

Bundle up! Geminid meteor shower peaks this Friday night

The annual Geminid meteor shower will peak Friday night – Saturday morning Dec. 13-14. Geminids can appear anywhere in the sky but if trace their trails backwards they’ll lead back to one point in the sky in Gemini called the radiant. Random meteors not connected with the shower are called sporadics. Stellariumf

This past week we touched on the resurgence of the Andromedid meteor shower and learned that Comet ISON may even gift us with dusty sprinkles next month. These one-off meteor blasts are certainly worth following, but if it’s reliability and numbers you’re looking for, the Geminids are your shower. No speculating here. No maybes. From a dark sky, anywhere from 60-120 Geminids an hour will zip past starting Friday night through dawn Saturday.

Composite photo of many Geminids plus a few sporadic meteors from Dec. 13-14, 2010. Credit: John Chumack

Every year in mid-December, Earth’s orbital path crosses that of 3200 Phaethon (FAY-eh-thon), a 3.2 mile diameter (5.1 km)  asteroid with an orbit takes it only 13 million miles from the sun every 1.4 years – almost three times closer than Mercury. That has consequences as we’ll soon see.

Most meteor showers are the offspring of comets, which drop dust and small rocks along their orbits after getting roasted by the sun. Phaethon’s sometimes referred to as a “rock comet”. Normally a quiet, well-behaved asteroid, Phaethon brightened by a factor of two and was caught spewing jets of dust when nearest the sun in 2009, 2010 and 2012. Apparently the intense heat of the sun either fractured the surface or heated rocks to the point of desiccation, creating enough dust to form temporary tails like a comet.

While it may look like an asteroid most of the time, Phaethon may really be a comet that’s still occasionally active. Either way, this originator of the Geminids produces a reliable meteor shower.

While many will opt to view the Geminids during more convenient evening hours Friday, others will want the darkest skies possible. This map shows the sky facing west around 5 a.m. Saturday Dec. 14 after moonset. Stellarium

This year the Geminids will be at their best overnight Dec. 13-14 with maximum activity forecast for around 8 p.m. CST (2 a.m. Greenwich time Dec. 14) Friday night. At that time, the radiant will be low or will not have risen for western hemisphere skywatchers, but that shouldn’t be a problem – the shower’s active all night. The later it gets, the more meteors you’ll see as the radiant rises ever higher in the sky.

There are two times for viewing the Geminids. You can go out around 9 or 10 Friday evening and face east toward brilliant Jupiter in Gemini, which by good fortune shines close to the shower radiant. Because the bright, waxing gibbous moon will be out, its light will cut the number of meteors you’ll see about in half. That’s why it’s a good idea to hide the moon from view if you can, so its glare isn’t a bother.

If you want to see more Geminids, you can set your alarm for just before 5 a.m. That’s when the moon sets and leaves about an hour of dark sky before the start of morning twilight. Because of the much later hour, the Earth will have “rotated” Gemini and Jupiter into the western sky. Just take that lawn chair and turn it to face the south-southwest for the best view.

Video still of a train or trail left by a bright meteor from the video “Left by a Fireball”. The Big Dipper is seen at left. Credit: Babak Tafreshi

The Geminids are medium-speed meteors, hitting the atmosphere at 70 miles overhead at 35 km/sec and often leave chalky-white “trains” or streaks of what looks like glowing smoke when they burn up. If you get one that lingers a while, consider examining it with binoculars. Sometimes you’ll see swirls and loops in the fading train.

The Geminids are now the richest annual meteor shower, even beating out the August Perseids. Their only drawback? They happen at the coldest time of year. So layer up, heat up the coffee and don’t let the cold rob you of what should be one of 2013′s astronomical highlights.

Comet ISON update Dec. 10 – Meteor shower in the offing?

One of the last spacecraft photos of Comet ISON. It was taken with NASA’s STEREO-A probe on Dec. 6, 2013. This image was compiled using 11 photos stacked atop each other to improve the comet’s visibility. Click to enlarge. Credit: NASA / Toni Scarmato

Comet ISON has left the eyes of spacecraft for the moment and now challenges amateur and professional astronomers from the ground. To date, there has been only one positive observation by an amateur astronomer in Spain and a couple “maybes”. Many have tried to see and photograph the comet’s faint remains, but none have been successful.

The sky facing east 1 1/2 to 1 3/4 hours before sunrise for mid-northern latitude skywatchers. The comet’s position is shown daily and marked every 3 days. Stars plotted to mag. 6. Guide stars are labeled: Oph = Ophiuchus, Her = Hercules, Ser = Serpens and CrB = Corona Borealis. Click for a large version. Created with Chris Marriott’s SkyMap software

Tomorrow morning, ISON climbs to 15 degrees altitude in the morning sky before the onset of twilight. That’s high enough for someone with a fast telephoto lens or fast, wide-field telescope to make a long time exposure without haze and dawn interfering. Photos taken with typical narrower fields of view through telescopes haven’t shown the faintest trace of a nucleus or condensation at the location of ISON’s core. Wide fields might still succeed.

Frame grab from solarsystemcope.com/ison shows Comet ISON (now a debris cloud) later this month when making its closest approach to Earth of 40 million miles. It’s orbit is inclined 62 degrees to the horizontal, taking it high above Earth’s plane.

I’ve been asked whether Earth will get dusted by ISON’s dusty cloud of debris as it passes our planet on the outbound leg of its journey. The answer is almost certainly “no”. There are several reasons why. First, the debris passes far above the Earth’s orbit even at its closest approach on Dec. 26, when what’s left of the comet will be nearly directly above our planet and 40 million miles away. That’s farther than Venus and even farther than Mars during its closest approaches. I’ve read catastrophic talk ISON raining hell fire on Earth. Not gonna happen. Not even meteor fire – at least from the breakup.

Second, while the debris cloud will certainly expand and enlarge, the comet leftovers will continue to travel along the same general path as ISON. They won’t suddenly veer off and make a beeline for Earth. They carry much of the original momentum and direction as the comet that created them.

Comet ISON photographed from the International Space Station on Nov. 23. You can see the twilight glow along the Earth’s limb at bottom and part of the spacecraft in the foreground. Credit: NASA

We also have to consider that as the cloud continues to expand it will rapidly thin. While it’s true a comet’s coma (not the “hard” inner nucleus) can expand to the size of the sun and tails can reach 300 million miles (500 million km) or longer, the amount of material involved spread over those distances is vanishingly small. We’ve passed through at least one comet’s tail (Halley in 1910) with no meteor shower or other ill effects to show for it.

Comets can be powder puffs though, that’s for sure. Even as long ago as January, when ISON was at Jupiter’s distance from the sun, NASA’s Swift spacecraft found it spewing dust at 112,000 lbs. a minute. While our planet’s highly unlikely to get an outbound meteor shower, we may encounter some of ISON’s inbound flotsam and jetsam come mid- January.

Illustration showing Earth encountering Comet ISON dust in mid-January 2014. Credit and copyright: Paul Wiegert

Meteor researcher Paul Wiegert of the University of Western Ontario has been using a computer to model the trajectory of dust ejected by Comet ISON and predicts that starting about January 12 and continuing for several evenings, we stand a chance of a meteor shower from material released well before perihelion.

The dust particles will strike Earth’s atmosphere at around 125,000 mph (56 km/sec), but because they’ll be so tiny, it’s unlikely we’ll actually see anything.

Illustration showing Earth passing through dual debris streams left in the path of Comet ISON in January. Credit: Paul Wiegert / NASA

“Instead of burning up in a flash of light, they will drift gently down to the Earth below,” said Wiegert. In a fascinating twist, Earth will encounter not one but two dust streams from Comet ISON. Dust released by the comet and headed in toward the sun will pepper one side of Earth, while a second stream, blown back from the comet’s former head by sunlight, will pelt the other side.

ISON dust settling into the upper atmosphere may even serve as sites for water vapor to condense and form high-altitude, blue-colored noctilucent clouds.

As we approach the potential shower date, I’ll provide additional information. A possible radiant for the shower is in the Bootes-Draco part of the sky, which in January rises in the northeast not long after midnight. Sure, we may see nothing, but wouldn’t it be cool if ISON made its final appearance as daggers of light right here so close to home?

Fireball in a paperclip? Why Perseids pack a punch

A bright Perseid meteor caught by video over Ohio Sunday morning Aug. 4. Credit: John Chumack

Thought I’d tease you with a recent photo of a bright Perseid meteor. It was taken at dawn on Aug. 4 at Chumack Observatory using a video camera. Click HERE to see a movie of highlights from the video feed. You might be surprised at how little it takes to make a spectacle when it comes to meteors.

The Perseid meteor shower, which peaks on the the mornings of August 12 and 13, produces meteors ranging in brightness from telescopic to brighter than Venus. Traveling at 41 miles per second (66 km) guarantees a lot of bang for your buck. At that speed even a small grain can create a brilliant streak of light when it slams into the atmosphere.

To give you an idea, here’s a table comparing meteoroid size and brightness for Perseid meteor shower members (source M. Campbell-Brown, P. Brown). The brightness estimates are for meteors hitting the atmosphere directly overhead at an altitude of 62 miles (100 km). Weights are in grams; one ounce weighs 28.3 grams:

* 1/1,000 gram (weight of the smallest snowflake or seven grains of fine sand) = magnitude 3 or one brightness level fainter than the Big Dipper stars
* 1/100 gram (four grains uncooked rice) = magnitude 0.5 or similar to the bright star Vega
* 1/10 gram (a toothpick) =  -2 magnitude or a little fainter than Jupiter
* 1 gram (the cap of a pen, metal paperclip) = -4 magnitude and similar to Venus
* 10 grams (a pencil or two nickels) = -7 magnitude and bright as the thick crescent moon

Vintage lithograph of a meteor flaring over the countryside. Entering Perseids meteoroids that reach fireball status can weigh as little as a gram.

Perseids are zippy. Slower meteors like the Geminids that light up December nights  are breeze in at a mere 22 miles per second (35 km). A 1/10 gram Geminid meteoroid shines weakly at 3rd magnitude compared to a similar-sized Perseid. That’s at least part of the reason why the Perseids are famous for their fireballs - meteors the equal of Venus or brighter.

Speedy motion (kinetic energy) is transformed into the energy that creates the light streak and vaporizes the cookie-crumb meteoroid. Faster-moving meteoroids possess more kinetic energy and flare more brightly. Now you can see why even the small and meek can wow us skywatchers.

Comet Lemmon passes near the star Beta Cephei on August 6. While it has faded over the summer, Lemmon remains the current brightest comet visible from the northern hemisphere. Click for full size. Credit: Rolando Ligustri

While we’re on meteors, it’s good to remember that most originate as dust boiled off comets by the sun. The Perseids originate from Comet 109P/Swift-Tuttle which swings around the sun every 133 years. Each August, Earth passes through the comet’s orbit; any bits of Swift-Tuttle in our path get fried by our atmosphere.

No bright comet currently graces the August sky. Comet C/2012 F6 Lemmon remains the best of the bunch, still shining at a respectable 10.5 magnitude; it looks like a fuzzy blob with a short southward-pointing tail in 8-inch and larger telescopes.

Amateur astronomer Rolando Ligustri recently took a beautiful portrait of Lemmon as it passed near the star Beta in Cepheus the King. The image reminds us of the dynamic process that cycles meteors to Earth’s skies by way of dust shed from comet tails.

June Arietids – the invisible meteor shower you just might see

You might just see a few meteors from the combined Arietids and Zeta Perseid showers that peak Friday and Saturday mornings. This map shows the sky facing northeast at dawn for the mid-section of the U.S. Created with Stellarium

I’ve never seen an Arietid meteor and chances are you haven’t either. Peaking on June 7-8, the Arietid (AIR-ee-uh-tid) meteor shower is one of the strongest of the year with a maximum rate of 50-80 per hour. But there’s a rub. The shower radiant, the point in the sky from which the meteors appear to radiate, is near the sun and best seen during daylight hours. When was the last time you saw meteors in daylight?

Early scientific exploration of the sky in radio waves at Jodrell Bank Observatory in 1945. Credit: Jodrell Bank, University of Manchester

If you’re wondering how anyone could discover a meteor shower when the sun is out, it’s impossible unless your eyes can see radio waves. The Arietids were first “seen” in 1947 by operators of radio equipment at Jodrell Bank Observatory in England. Meteors leave trails of ionized gases when they rip through our upper atmosphere at tens of thousands of miles per hour and briefly make ideal reflectors of radio waves.

You can even hear them yourself by tuning to a “blank” spot between stations on an FM radio and listening for sudden bursts of talk or music when the meteor trail boosts a neighboring station into audibility. Click HERE for simple instructions if you’d like to give it a try.

The Arietids are joined by a second daytime shower at the same time by the Zeta Perseids, a smaller shower, to guarantee a couple busy days of meteor-listening — and potential meteor-watching —  on and around June 7-8. Most meteor showers are tied to a particular comet, since they’re swarms of dusty detritus left behind in a comet’s wake as it travels ’round the sun. When Earth intersects the stream, tiny comet bits slam into the atmosphere, heat up to 3,000 F or more and self-immolate in glowing streaks we call meteors. Occasionally a shower’s parent can be an asteroid as in the case of the January Quadrantid meteor shower. It’s suspected that the asteroid 2003 EH1 may be a extinct comet.

Most meteors are comet dust striking at the atmosphere at speeds so high, they vaporiz in a blaze of light. This is a meteor from the Leonid shower in 2001. Photo: Bob King

No one’s certain of the Arietids’ parentage. Likely candidates include the near-Earth asteroid 1566 Icarus and Comet 96P/Machholz, both of which have orbits that resemble the shower’s.

After ignoring May’s Eta Aquarid meteor shower for years because of its very low radiant at dawn, I was pleasantly surprised by the many meteors I saw when I happened to catch the shower at maximum on May 6 this year. Circumstances are only slightly worse for the Arietids. That’s why I think it’s worth your while to check out this shower tomorrow (Friday) and Saturday morning(June 7-8). Face east and start watching an hour or two before the start of dawn and continue your vigil until the sky brightens in the east.

The lesser Zeta Perseids are also active, adding to the fun. Since the two shower radiants are close to each other in the sky, it may be hard to tell which you’re seeing. No matter. Any fiery streaks you can trace back toward the east-northeast horizon will likely be one or the other.

Earth-grazing meteor photographed by Manuel Conde of Barcelona, Spain.

Whenever a radiant is near the horizon, many of the meteors approaching us do so at a very shallow angle almost horizontal to the Earth’s atmosphere. From our perspective they travel slowly and last a much longer time than do meteors striking the air at a steeper angle, typical for radiants that are higher in the sky.

Astronomers use the poetic “Earth-grazers” to describe them. Having seen a handful of these unique beauties during the May Aquarid shower, I’m hungry for more. Since the Arietids / Zeta Perseids also originate low in the sky, we should expect similar sights Friday and Saturday mornings.

Eta Aquarid meteor shower from Halley’s Comet peaks this weekend

The Eta Aquarid meteor shower peaks tomorrow morning May 5. This map shows the sky facing east at dawn for mid-northern latitudes. The shower radiant (red) is near the star Eta in the constellation Aquarius to the right of the Great Square of Pegasus. The crescent moon and Comet Lemmon, visible in binoculars, will also join the scene tommorow. Stellarium

Up for another early morning meteor shower? Then get ready for the Eta Aquarids (AY-tuh ah-QWAR-ids) which peak tomorrow in the quiet hours before dawn. This is a fairly big event for southern hemisphere observers who might see up to one meteor a minute during tomorrow morning’s maximum. The radiant or point in the sky from which the meteors will appear to originate is much higher for southern latitudes. Morning twilight also begins later allowing for more viewing time.

The higher the radiant, the more meteors. A low radiant means most of a shower’s meteors are out of view, streaking away below the horizon. At latitude 50 degrees north the viewing window lasts 1 1/2 hours with the radiant low in the southeastern sky; at 40 degrees north, it’s a little more than 2 hours. If you live in the southern U.S. you’ll have nearly 3 hours of viewing time with the radiant 35 degrees high.

Shower meteors are typically small bits of rock or dust left behind by a comet. When the material hits the atmosphere, it heats the air to glow and we see a meteor.

Across the middle north latitudes expect to see about 10 very fast meteors an hour. Eta Aquarids, which are the dusty remains of numerous visits of Halley’s Comet to the inner solar system, tear across the sky at over 147,000 mph (237,000 km/hr). Slower meteors are often yellow or orange; these will flare white as they’re incinerated by the atmosphere.

Earth crosses Halley’s orbit twice a year. Each time, bits of the comet collide with our atmosphere and burn up. In mid-October we’ll encounter Halley’s orbit again and re-visit the comet’s dust trail as the Orionid meteor shower.

Tomorrow morning the crescent moon will also be out – it eases up over the tree line about the time dawn begins – and a special guest, Comet Lemmon, located about one “fist” to the moon’s left. While visible in binoculars as a dim, fuzzy patch of light, a telescope should show the comet’s bright head and diffuse tail. The radiant is located near the star Eta Aquarii well to the right of the familiar Great Square of Pegasus.

Halley’s Comet – source or parent of both the Eta Aquarid and Orionid meteor showers. Credit: NASA

Meteor shower members can appear in any part of the sky, but if you trace their paths in reverse, they’ll all point back to the radiant. Other random meteors you might see are called sporadics and not related to the Eta Aquarids.

For most mid-northern sky watchers, the best time to watch will be about 2 1/2-3 hours before sunrise. (Find your sunrise time HERE). Even if Aquarius is very low or hasn’t risen yet, you can still catch a few meteors before twilight brightens the sky. You might even get lucky and spot an Earth-grazer, a slow-moving meteor skimming the upper atmosphere nearly parallel to the ground. They’re best seen around the time the radiant rises. Keep an eye out for them.

The Eta Aquarid shower has a broad peak, so if it’s cloudy tomorrow, try again on Monday or Tuesday. You’re likely to catch at least a few. All you need for equipment are your eyes, a comfy lawnchair and a reasonably dark sky. Face east or south for the best view. Good luck!