As If Things Weren’t’ Bad Enough

The meteor shower that brought Tunguska is due in June

That disastrous rock may now looks to have been a Beta Taurid passenge

  • Analysis of the Tunguska tree-fall patters suggests a familiar source for the asteroid that caused it
  • Its timing also fits perfectly with a late June annual meteor shower
  • Nonetheless, it’s more interesting than dangerous. Put down that helmet.

It’s just after seven in the morning on June 30, 1908 as a man sits on the front porch of a trading post in Vanavara, Siberia. That is, until a sudden blast of heat at 7:17 hurls him from his seat. It comes from a huge asteroid exploding about 28,000 feet above the Podkamennaya Tunguska River 40 miles away.

Suddenly in the north sky… the sky was split in two, and high above the forest the whole northern part of the sky appeared covered with fire… At that moment there was a bang in the sky and a mighty crash… The crash was followed by a noise like stones falling from the sky, or of guns firing. The earth trembled.

Such asteroids are not that rare — scientists estimate they happen about every 300 years. There was one over the Russian city of Chelyabinsk in 2013, and though smaller at 11,000 tons than the Tunguska rock, it nonetheless injured 1,200 people and caused damage to buildings up to 58 miles away.

It seems like we now know how the Tunguska asteroid got here. Physicist Mark Bosloughof Los Alamos National Laboratory recently presented, at the American Geophysical Union fall meeting, a new analysis of the tree-fall pattern in the Tunguska area. It suggests that the rock may have arrived during the annual Beta Taurid meteor shower. The next one’s in June 2019. (There’s another Taurid shower each October.) A quote from the presentation: “If the Tunguska object was a member of a Beta Taurid stream … then the last week of June 2019 will be the next occasion with a high probability for Tunguska-like collisions or near misses.”

The Tunguska event


The Tugnuska asteroid , a 220-million-pound space rock, is believed to have been traveling at about 33,500 miles per hour, heating the air around it to 44,500° Fahrenheit before it exploded, flattening trees for about 800 square miles. As NASA puts it: “Eighty million trees were on their sides, lying in a radial pattern.” The timing for being a Beat Taurid is about right, too, since it arrived in their typical late-June window.

The first scientific investigation occurred 19 years after the event, led by Leonid Kulik of the St. Petersburg Museum. Don Yeomans, of NASA’s Near-Earth Object Office describes what Kulik found when he arrived in the area: “At first, the locals were reluctant to tell Kulik about the event. They believed the blast was a visitation by the god Ogdy, who had cursed the area by smashing trees and killing animals.” Kulik was able to follow the flattened trees to identify “ground zero. “Those trees,” according to Yeomans, “acted as markers, pointing directly away from the blast’s epicenter.” And eventually, “when the team arrived at ground zero, they found the trees there standing upright — but their limbs and bark had been stripped away. They looked like a forest of telephone poles.”

The Taurus

(Big Think/NASA)

The Taurus’ elliptical orbit

The Earth encounters the Taurids twice a year due to the belt’s odd orbit, which is roughly on the same plane as ours. We pass through it twice a year, as the belt carries Taurid materials toward the sun in October, and away from the sun in June. It’s also a very elliptical orbit that gets as close to the sun as Mercury, but also stretches far beyond Earth’s orbit.

The October encounter is visible in our autumn night skies, but the June visit occurs during daylight so it’s not as visible. Its passengers are primarily spotted via radar.

Some years we encounter denser regions of the Taurid stream than others, and 2019 is one of those years, with scientists saying we’ll be seeing more incoming material than any year since 1976. That year, Apollo-mission seismometers installed on the moon’s surface recorded an unusually high number of Taurid impacts.

The odds of another Tunguska blast early this summer


Neither Bosloughof of anyone else predicts a Tunguska-style event in June, but if the new calculations are correct, it’s just the meteor shower in which it probably arrived back in 1908. According to physicist Peter Brown, who presented the new analysis with Bosloughof, “This is not something that should be keeping you up at night.” Paul Chodas, of the Center for Near Earth Object Studies, says, “There are no objects in our catalogue that have any significant impact probability in the next 100 years.”

In fact, if there are any near misses this summer, as Bosloughof says, our best odds of finding out if the Beta Tarids did, in fact, carry any Tunguska-sized asteroids would be to spot them in telescopes them as they streak away through space from a much-relieved Earth.


Eyes Open for Comets

EARTH IS CROSSING TWO COMET DEBRIS STREAMS: The Canadian Meteor Orbit Radar (CMOR) is scanning the skies above North America for echoes from disintegrating meteoroids. There are plenty of echoes to detect. The latest CMOR sky map shows two active radiants in the night sky–one associated with the Perseid meteor shower (PER) and another with the Southern Delta Aquarids (SDA):

Perseids come from 109P/Swift-Tuttle, a large comet with a rich debris stream. The shower is expected to peak this year on August 12-13 with as many as 100+ meteors per hour. Of all the meteor showers of the year, the Perseids produce the most fireballs.

While we are waiting for the Perseids to peak, the Southern Delta Aquarid meteor shower is making its own contribution. Caused by debris from an ancient sungrazing comet, this shower produces 10 to 20 meteors per hour every year in late July and early August.

Earth’s simultaneous interaction with these two debris streams should keep the meteor rate elevated for the entire week ahead. Be alert for flashes of light in the night sky


Geminid Meteor Shower Peaks 12/14

GEMINID METEOR SHOWER: Mark your calendar: The annual Geminid meteor shower peaks this year on Dec. 14th when dark-sky observers around the world could see as many as 120 meteors per hour. The source of the display is “rock comet” 3200 Phaethon. As November comes to a close, Earth is entering the outskirts of 3200 Phaethon’s debris stream, and this is causing some Geminids to appear weeks ahead of peak night. The first Geminid fireball of the season was detected on Nov. 26th by NASA’s network of all-sky meteor cameras.

from:    spaceweather .com

Camelopardalid Meteor Shower Tonight 5/23-24

ANTICIPATION BUILDS FOR TONIGHT’S METEOR SHOWER: This weekend, Earth will pass through a stream of debris from Comet 209P/LINEAR. If forecasters are correct, the encounter could produce an outburst of bright meteors numbering more than 200 per hour.  Most models agree that peak rates should occur between the hours of 0600 UT and 0800 UT (2 a.m. and 4 a.m. EDT) on Saturday morning, May 24th, a time frame that favors observers in North America.  It is worth noting, however, that Earth has never encountered this stream of debris before, so forecasters cannot be certain of their predictions.  The display could be a complete dud, a fantastic “meteor storm,” or anything in between. Whatever happens, NASA plans to chat about it.

It is often said that this is a new shower, and no one has ever seen a Camelopardalid meteor before. Well…maybe just one. “We searched through our database of several thousand bright meteors and found a likely candidate,” reports Bill Cooke of NASA’s Meteoroid Environment Office. “Back on May 9th of 2012, one of our all-sky cameras caught it burning up at an altitude of 66 kilometers.” This is what it looked like:

“Peaking at a magnitude of -2 (Mars brightness), our now-extinct visitor was about 3.3 cm in diameter – a little smaller than a ping pong ball,” continues Cooke. “We believe it was a May Camelopardalid because it had an orbit that greatly resembles that of parent Comet 209P/LINEAR.” The diagram, below, shows the match:

“So why is this good?” asks Cooke. “Looking back to 2012, our computer models show very little comet debris near Earth. We predicted nothing, yet got one meteor. Does this mean that a legion of his siblings will show up this year, when the models suggest the potential of a full-fledged meteor outburst? I’m getting excited about Friday night/Saturday morning.”

Earth won’t be the only body passing through the debris zone. The Moon will be, too. Meteoroids hitting the lunar surface could produce explosions visible through backyard telescopes on Earth. The inset in this picture of an actual lunar meteor shows the region of the crescent Moon on May 24th that could be pelted by May Camelopardalids:

According to NASA’s Meteoroid Environment Office, the best time for amateur astronomers to scan the Moon for lunar meteors is after 0800 UT (4 a.m. EDT) on May 24th.

There is much uncertainty about the strength of this shower, both on Earth and on the Moon. As far as we know, our planet has never passed directly through a debris stream from Comet 209P/LINEAR, so no one knows exactly how much comet dust lies ahead. A magnificent meteor shower could erupt, with streaks of light in terrestrial skies and sparkling explosions on the Moon–or it could be a complete dud


Lyrid Meteor Shower 4/22

EARTH DAY METEOR SHOWER: Earth is passing through a stream of debris from ancient Comet Thatcher, source of the annual Lyrid meteor shower. Prof. Peter Brown of the Universiy of Western Ontario reports that “the Canadian Meteor Orbit Radar (CMOR) just finished processing orbital data from last night and the Lyrids are showing up quite nicely. The meteor rate is near 15 per hour so visual observers should have had a good view early this morning and should be able to easily detect the shower tonight.”

Click to view an all-sky map of CMOR meteor radar echoes on April 22nd:

The bright pink blob pinpoints the Lyrid radiant in the constellation Lyra. Other lesser showers are active, too, but they are much weaker. If you see a meteor tonight, it is probably a Lyrid.

Usually the Lyrid meteor shower is mild (10-20 meteors per hour), but unmapped filaments of dust in the comet’s tail sometimes trigger outbursts ten times stronger. So far this year’s shower is trending toward the usual. “The shower is comparable in strength to what was seen last year – so far no surprises,” says Brown.

Forecasters expect the shower to peak on April 22nd between the hours of 10:00 UT and 21:00 UT.


Lyrid Meteor Shower 4/22-23

The Lyrid Meteor Shower
Global Notes: This is a northern hemisphere shower.


Every year in late April Earth passes through the dusty tail of Comet Thatcher (C/1861 G1), and the encounter causes a meteor shower–the Lyrids. This year the shower peaks on Tuesday, April 22nd. Forecasters expect 10 to 20 meteors per hour, although outbursts as high as 100 meteors per hour are possible.

Lyrid meteors appear to stream from the bright star Vega in the constellation Lyra:

In fact, Lyrids have nothing to do with Vega. The true source of the shower is Comet Thatcher. Every year in April, Earth plows through Thatcher’s dusty tail. Flakes of comet dust, most no bigger than grains of sand, strike Earth’s atmosphere traveling 49 km/s (110,000 mph) and disintegrate as streaks of light.

Lyrid meteors are typically as bright as the stars in the Big Dipper, which is to say of middling brightness. But some are more intense, even brighter than Venus. These “Lyrid fireballs” cast shadows for a split second and leave behind smokey debris trails that linger for minutes.

Occasionally, the shower intensifies. Most years in April there are no more than 5 to 20 meteors per hour during the shower’s peak. But sometimes, when Earth glides through an unusually dense clump of comet debris, the rate increases. Sky watchers in 1982, for instance, counted 90 Lyrids per hour. An even more impressive outburst was documented in 1803 by a journalist in Richmond, Virginia, who wrote:

“Shooting stars. This electrical [sic] phenomenon was observed on Wednesday morning last at Richmond and its vicinity, in a manner that alarmed many, and astonished every person that beheld it. From one until three in the morning, those starry meteors seemed to fall from every point in the heavens, in such numbers as to resemble a shower of sky rockets…” [ref]

What will the Lyrids do this year? The only way to know for sure is to go outside and look.

Experienced meteor watchers suggest the following viewing strategy: Dress warmly. Bring a reclining chair, or spread a thick blanket over a flat spot of ground. Lie down and look up somewhat toward the east. Meteors can appear in any part of the sky, although their trails will tend to point back toward the radiant–i.e., toward Vega.

Vega is a brilliant blue-white star about three times wider than our Sun and 25 light years away. You might have seen Vega in Carl Sagan’s movie Contact. It was the source of alien radio transmissions to Earth.



Perseid Meteors Arriving Now

FIRST PERSEIDS OF 2013: Earth is entering a broad stream of debris from comet 109P/Swift-Tuttle, source of the annual Perseid meteor shower. Although the shower won’t peak until August 12-13, when Earth hits the densest part of the stream, the first Perseids are already arriving. “Despite poor weather over our network of meteor cameras, we detected three Perseid fireballs on July 30-31,” reports Bill Cooke, head of NASA’s Meteoroid Environment Office. He made this plot showing the orbits of the meteoroids:

In the diagram, the green lines trace the orbits of Perseid meteoroids. All three intersect Earth (the blue dot). The orbit of the parent comet is color-coded purple. An inset shows one of the fireballs shining almost as brightly as the Moon: video.

The shower is just getting started. Rates should remain low for the next week as Earth penetrates the sparse outskirts of the debris stream, then skyrocket to ~100 meteors per hour as the calendar turns to the second week of August.


06/11 Meteor Shower

ETEOR ALERT: Sky watchers in North America might see an outburst of meteors during the early hours of June 11th when Earth passes through a stream of cometary debris last seen in 1930. Forecasters Peter Jenniskens (SETI Institute) and Esko Lyytinen (Helsinki, Finland) predict the return of the gamma Delphinid meteor shower this Tuesday morning around 08:30 UT (04:30 am EDT). The shower is expected to last no more than about 30 minutes with an unknown number of bright, fast meteors.


December 13/14 —- Geminid Meteors

December 13/14, 2012, late night December 13 until dawn December 14 Geminids
The final major meteor shower of every year (unless one surprises us!) is always the December Geminid shower, often producing 50 or more meteors per hour. It is a beloved shower, because, as a general rule, it’s either the August Perseids or the December Geminids that give us the most prolific display of the year. Best of all, the new moon guarantees a dark sky on the peak night of the Geminid shower (mid-evening December 13 until dawn December 14). But the nights on either side of the peak date should be good as well. Unlike many meteor showers, you can start watching the Geminids by 9 or 10 p.m. local time. The peak might be around 2 a.m. local time on these nights, because that’s when the shower’s radiant point is highest in the sky as seen around the world. With no moon to ruin the show, 2012 presents a most favorable year for watching the grand finale of the meteor showers. Best viewing of the Geminids will probably be from about 1 a.m. to 3 a.m. on December 14.



Orionid Meteor Showers

The Orionid Meteor Shower

Oct. 12, 2012:  Usually, waking up before sunrise is a good way to get a head start on the day. On Oct. 21st, waking up early could stop you in your tracks.

Blame Halley’s Comet.  Every year in mid-to-late October, Earth passes through a stream of dusty debris from Comet Halley, and the pre-dawn sky lights up with a pretty display of shooting stars.

“We expect to see about 25 meteors per hour when the shower peaks on Sunday morning, Oct 21st,” says Bill Cooke, the head of NASA’s Meteoroid Environment Office.  “With no Moon to spoil the show, observing conditions should be ideal.”

Orionids (splash)

A new ScienceCast video explores the Orionid meteor shower. Play it

Because these meteors streak out of the constellation Orion, astronomers call them “Orionids.”

“The Orionid meteor shower isn’t the strongest, but it is one of the most beautiful showers of the year,” notes Cooke.

The reason is its setting: The shower is framed by some of the brightest stars and planets in the heavens. Constellations such as Taurus, Gemini and Orion provide a glittering backdrop for the display. But that’s not all.  This year, Venus and Jupiter have moved into position with Sirius, the Dog Star, to form a bright triangle in the eastern pre-dawn sky.  On the morning of Oct 21st, blazing pieces of Halley’s Comet will cut straight through the heart of this celestial triad.

To see the show, Cooke suggests going outside one to two hours before sunrise when the sky is dark and the constellation Orion is high overhead. Lie down on a blanket with a broad view of the heavens.  Although Orionids emerge from a small area near the shoulder of Orion, they will spray across the entire sky.

“Be prepared for speed,” he adds.  “Meteoroids from Halley’s Comet strike Earth’s atmosphere traveling 148,000 mph.  Only the November Leonids are faster.”

Speed is important because fast meteors have a tendency to explode.  Occasionally, Orionid fireballs will leave incandescent streams of debris in their wake that linger for minutes. Such filaments of meteor smoke twisted by upper atmospheric winds into convoluted shapes can be even prettier than the meteors themselves.

“It really is a wonderful morning to be awake,” says Cooke.  “Just don’t plan on going anywhere in a hurry.”