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.
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.
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 Monday morning, 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.
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.
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.”
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.”
DRACONID METEOR SHOWER: The notoroiusly unpredictable Draconid meteor shower peaks this year on the night of Oct. 7-8. In most years, the Draconids come and go with a barely noticable peak of 10 or so meteors per hour. Occasionally, however, Earth passes through a dense clump of debris from parent comet 21P/Giacobini-Zinner and a meteor storm erupts. Just last year, Europeans witnessed a faint but furious outburst of 600 per hour. There is no reason to believe that 2012 is a “storm year.” Nevertheless, northern hemisphere sky watchers are encouraged to be alert for slow-moving Draconids on Sunday night
EARLY PERSEID METEORS: Earth is entering a broad stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Meteoroids in the outskirts of the stream are now hitting Earth’s atmosphere, producing as many as 10-15 meteors per hour according to worldwide counts from the International Meteor Organization. NASA’s network of all-sky meteor cameras captured 17 Perseid fireballs on the nights of July 28th through 30th. Here are their orbits:
The position of Earth is denoted by the red starburst; all of the meteoroid orbits intersect at that point. The purple line traces the orbit of the parent Comet Swift-Tuttle. Fortunately, the comet itself does not intersect Earth.
In the days ahead, Earth will plunge deeper into the meteoroid stream, and meteor rates will increase accordingly. Forecasters expect the shower to peak on August 12-13 with as many as 100+ meteors per hour visible from dark-sky sites.
July 28 and 29, 2012 Delta Aquarids
Like the Eta Aquarids, this shower favors the Southern Hemisphere, and the tropical latitudes in the Northern Hemisphere. Although the waxing gibbous moon won’t set till after midnight, the hours between moonset and dawn will probably offer the most Delta Aquarid meteors. (Click here to know when the moon sets in your sky.) The meteors appear to radiate from the southern part of the sky. From northern temperate latitudes, the maximum hourly rate may reach 15-20 meteors in a dark sky. Unlike many meteor showers, this one doesn’t have a very definite peak, despite the dates given above. Instead, these medium-speed meteors ramble along fairly steadily throughout late July and early August. An hour or two before dawn usually presents the most favorable view of the Delta Aquarids. Try watching in late July, in the hours between moonset and dawn.
As the year 2011 comes to a close, some might wonder what is looming sky-wise for 2012? What celestial events might we look forward to seeing?
I’ve selected what I consider to be the top 12 “skylights” for this coming year, and list them here in chronological order. Not all these events will be visible from any one locality … for the eclipses, for instance, you’ll probably have to do some traveling … but many can be observed from the comfort of your backyard.
Hopefully your local weather will cooperate on most, if not all, of these dates. Clear skies!
This meteor shower reaches its peak in the predawn hours of Jan. 4 for eastern North America. The Quadrantid meteor shower is a very short-lived meteor display, whose peak rates only last several hours. The phase of the moon is a bright waxing gibbous, normally prohibitive for viewing any meteor shower, but the moon will set by 3 a.m., leaving the sky dark for a few hours until the first light of dawn; that’s when you’ll have the best shot at seeing many of these bluish-hued meteors.
From the eastern half of North America, a single observer might count on seeing as many as 50-to-100 “Quads” in a single hour. From the western half of the continent the display will be on the wane by the time the moon sets, with hourly rates probably diminishing to around 25 to 50 meteors.
The first major meteor shower of 2012 takes place on the night of Tuesday, Jan. 3 and the morning of Wednesday, Jan. 4. It peaks at 2 a.m. EST (0700 GMT) on Jan. 4.
CREDIT: Starry Night Software
Feb. 20 to March 12: Best evening apparition of Mercury
In February and March, the “elusive” innermost planet Mercury moves far enough from the glare of the sun to be readily visible soon after sunset. Its appearance will be augmented by two other bright planets (Venus and Jupiter), which also will be visible in the western sky during this same time frame.
Mercury will arrive at its greatest elongation from the sun March 5. It will be quite bright (-1.3-to-0 magnitude) before this date and will fade rapidly to +1.6 magnitude thereafter. Astronomers measure the brightness of objects in terms of magnitude, with lower numbers corresponding to brighter objects.
March 3: Mars arrives at opposition
On March 3, the Earth will be passing Mars as the two planets wheel around the sun in their respective orbits. Because Mars reaches aphelion — its farthest point from the sun — on Feb. 15, this particular opposition will be an unfavorable one. In fact, two days after opposition, Mars will be closest to Earth at a distance of 62.6 million miles.
Compare this with the August 2003 opposition when Mars was only 34.6 million miles away. Nonetheless, even at this unfavorable opposition the fiery-hued Mars will be an imposing naked-eye sight, shining at magnitude -1.2, just a bit dimmer than Sirius, the brightest star, and will be visible in the sky all night long.
Astrophotographer Jeffrey Berkes of West Chester, Pa., snapped this stunning view of planet Venus and the crescent moon during a bright conjunction on Dec. 26, 2011.
CREDIT: Jeffrey Berkes
March 13: Brilliant “double planet”
The two brightest planets, Venus and Jupiter, team up to make for an eye-catching sight in the western sky soon after sunset. They will be separated by 3 degrees on this evening, Venus passing to the northwest (upper right) of Jupiter and shining nearly eight times brighter than “Big Jupe.” Although they will gradually go their separate ways after this date, on March 25 and 26, a crescent moon will pass by, adding additional beauty to this celestial scene.
May 5: Biggest full moon of 2012
The moon turns full at 11:35 p.m. Eastern Daylight Time and just 25 minutes later it will arrive at its closest point to the Earth in 2012, at a distance of 221,801 miles. Expect a large range in ocean tides (exceptionally low to exceptionally high) for the next few days.
May 20: Annular eclipse of the sun
The path of annularity for this eclipse starts over eastern China and sweeps northeast across southern and central Japan. The path continues northeast then east, passing just south of Alaska’s Aleutian Island chain. The path then turns to the southeast, making landfall in the western United States along the California-Oregon coast. It will pass over central Nevada, southern Utah, northern Arizona, the extreme southwest corner of Colorado and most of New Mexico before coming to an end over northern Texas.
Since the disk of the moon will appear smaller than the disk of the sun, it will create a “penny on nickel” effect, with a fiery ring of sunlight shining around the moon’s dark silhouette. Locations that will witness this eerie sight include Eureka and Reading, Calif.; Carson City, Reno and Ely, Nev.; Bryce Canyon in Utah; Arizona’s Grand Canyon; Albuquerque and Santa Fe in New Mexico and just prior to sunset for Lubbock, Tex.
A partial eclipse of the sun will be visible over a large swath of the United States and Canada, including Alaska and Hawaii, but no eclipse will be visible near and along the Atlantic Seaboard.
June 4: Partial eclipse of the moon
This partial lunar eclipse favors the Pacific Ocean; Hawaii sees it high in the sky during the middle of its night. Across North America the eclipse takes place between midnight and dawn. The farther east one goes, the closer the time of moonset coincides with the moment that the moon enters the Earth’s dark umbral shadow.
In fact, over the Northeastern United States and eastern Canada, the only evidence of this eclipse will be a slight shading on the moon’s left edge (the faint penumbral shadow) before moonset. Over the Canadian Maritimes, the moon will set before the eclipse begins. At maximum, more than one-third of the moon’s lower portion (37.6-percent) will be immersed in the umbra.
June 5: Rare transit of Venus across the sun
The passage of Venus in front of the sun is among the rarest of astronomical events, rarer even than the return of Halley’s Comet every 76 years. Only six transits of Venus are known to have been observed by humans before: in 1639, 1761, 1769, 1874, 1882 and, most recently, in 2004.
The next one will occur in the year 2117. When Venus is in transit across the solar disk, the planet appears as a distinct, albeit tiny, round black spot with a diameter just 1/32nd of the sun. This size is large enough to readily perceive with the naked eye. HOWEVER … prospective observers are warned to take special precautions (as with a solar eclipse) when attempting to view the silhouette of Venus against the blindingly brilliant solar disc.
The beginning of the transit will be visible from all of North America, Greenland, extreme northern and western portions of South America, Hawaii, northern and eastern portions of Asia including Japan, New Guinea, northern and eastern portions of Australia, and New Zealand. The end will be visible over Alaska, all of Asia and Indonesia, Australia, Eastern Europe, the eastern third of Africa, and the island nation of Madagascar.
Perseids composite, seen Aug. 12-13. Concentric circles are star trails.
Aug. 12: Perseid meteor shower
Considered to be among the best of the annual displays thanks to its high rates of up to 90 per hour for a single observer, as well as its reliability. Beloved by summer campers and often discovered by city dwellers who might be spending time in the country under dark starry skies. [10 Perseid Meteor Shower Facts]
Last summer a bright moon wrecked the shower by blotting out many of the fainter streaks, but in 2012 the moon will be three days past last quarter phase on this peak morning – a fat waning crescent presenting only a minor nuisance for prospective observers.
Nov. 13: Total eclipse of the sun
The first total solar eclipse since July 2010. Virtually the entire path of totality falls over water. At the very beginning, the track cuts through Australia’s Northern Territory just to the east of Darwin, then across the Gulf of Carpentaria, then through northern Queensland, passing over Cairns and Port Douglas before heading out to sea.
The rest of the eclipse path, including the point of the maximum duration of totality (4 minutes, 2 seconds) is, unfortunately, pretty much wasted by falling over the open waters of the Pacific Ocean.
Dec. 13-14: Geminid meteor shower
If there is one meteor display guaranteed to put on a very entertaining show it is the Geminid meteor shower. Now considered by most meteor experts to be at the top of the list, surpassing in brilliance and reliability even the August Perseids.
Bundle warmly against the winter chill; you can start observing as soon as darkness falls on the evening of Dec. 13 as Gemini starts coming up above the eastern horizon and continue through the rest of the night. Around 2 a.m. when Gemini is almost directly overhead, you might see as many as two meteor sightings per minute … 120 per hour! And the moon is new, meaning that it will not be a factor at all.
The first major meteor shower of 2012 is the Quadrantid shower, predicted to peak on the morning of January 4.
The next major meteor shower will be the Quadrantid shower, which is expected to peak after midnight on the morning of January 4, 2012. This shower favors northerly latitudes in the Northern Hemisphere. If the peak happens as predicted – at 7 to 8 hours Universal Time – that means eastern North America might be in a good position to watch the 2012 Quadrantid shower. Predicting the peak and the intensity of a meteor shower is always a tricky business, though. No matter where you live, the best time to watch is in the wee hours before dawn on January 4
Use the Big Dipper and the star Arcturus to locate the radiant of the Quadrantid shower
January 4, 2012 in the wee hours before dawn Quadrantids
When we say January 4, we mean in the wee hours before dawn, not that night. Although the waxing gibbous moon lights up most of the night and doesn’t set until roughly 3 a.m. local time, this is about the best time of night to watch for these meteors. Click here to know when the moon sets in your sky. Although the Quadrantids can produce over 100 meteors per hour, the sharp peak only lasts for a few hours, and doesn’t always come at an opportune time. In other words, you have to be in the right spot on Earth to view this meteor shower in all its splendor. If this year’s forecast proves correct, eastern North America, the North Atlantic Ocean and possibly western Europe will be in a fine position to watch this shower. However, meteor showers are notorious for defying predictions. This shower is worth a try at northerly latitudes all around the globe. Face the general direction of north-northeast, but take in as wide an expanse of sky as possible. Watch from about 2 a.m. until dawn.
Use the Big Dipper and the star Arcturus to locate the radiant of the Quadrantid shower