The next meteor shower is the Quadrantid meteor shower, peaking on the morning of January 3, 2013.
The annual Quadrantid meteor shower will peak on the morning of January 3, 2013. It is themorning of January 3, not that evening. This shower has a notoriously narrow peak, lasting only a few hours. This year the waning gibbous moon will be in the sky during the best hours for meteor-watching, but some of the meteors will be bright. You might see some, skimming along in bright moonlight, if you look.
This Quadrantid meteor, seen in 2009, was bright enough to be seen in twilight. The meteor is the streak on the right side of the image. Image by Mila Zinkova.
False-color image of a rare early Quadrantid, captured by a NASA meteor camera in 2010. Image Credit: NASA/MSFC/MEO/B. Cooke
The radiant point for the Quadrantid meteor shower is near the Big Dipper and bright star Arcturus in the constellation Bootes. The radiant is far to the north in our sky, in other words. That’s why this shower is best for Northern Hemisphere observers.
Unlike some meteor showers, whose peak can last a day or two, and whose meteors can fly in lesser numbers for weeks, the Quadrantids’ peak is very narrow, lasting only a few hours. So you have to be in the right place on Earth’s globe to observe the meteor shower’s peak, but, if you are, you might see 100 or even 200 Quadrantid meteors in an hour. Woot?! Yes, in some years. But the moon is in the way for the Quadrantids this year, no matter where you are on Earth.
Most meteor showers are named for the constellations from which they appear to radiate. So it is with the Quadrantids. But the Quadrantids’ constellation no longer exists. The name Quadrantids comes from the constellation Quadrans Muralis (mural quadrant), created by the French astronomer Jerome Lalande in 1795, and representing an early astronomical instrument used to observe and plot stars. This constellation was located between the constellations of Bootes the Herdsman and Draco the Dragon. Where did it go? When the International Astronomical Union made its list of 88 “official” constellations in the 1930s, Quadrans Muralis did not make the list. The meteor shower was first seen in 1825, though, and still retains the name of this now-extinct constellation.
Today the radiant point for the Quadrantids is at the northern tip of Bootes, near the Big Dipper asterism in our sky, not far from Bootes’ brightest star Arcturus. It is very far north on the sky’s dome, which is why Southern Hemisphere observers probably won’t see many (if any) Quadrantid meteors. The meteors simply won’t make it above the horizon for Southern Hemisphere skywatchers.
In 2003, Peter Jenniskens proposed that this object, 2003 EH1, is the parent body of the Quadrantid meteor shower.
In 2003, astronomer Peter Jenniskens tentatively identified the parent body of the Quadrantids as the asteroid 2003 EH1. If indeed this body is the Quadrantids parent, then the Quadrantids, like the Geminid meteors, come from a rocky body – not an icy comet. In turn, though, 2003 EH1 might be the same object as the comet C/1490 Y1, which was observed by Chinese, Japanese and Korean astronomers 500 years ago. Our nomenclature for these space bodies – asteroid, comet – are just words, after all. They’re a net of language thrown over Nature, which operates by its own subtle rules.
Whatever their origin, the bits of asteroidal or cometary debris that become Quadrantid meteors enter our atmosphere at 250 miles per second! They typically vaporize about 50 miles above Earth’s surface, creating the streaks of light we see as a meteor shower. If you’re in the Northern Hemisphere on the morning on January 3, 2013, check out the Quadrantid meteors. Try watching from midnight until dawn, and remember … the moon is in the way.
A reader asked, When can I see the Southern Cross in Hawaii? The answer is now, but you’ll have to look for it at just the right place and time. Each year in late December and early January, Hawaiians – or those at the latitude of Hawaii – can see the Southern Cross in the southern sky briefly before dawn. The Southern Cross, aka the constellation Crux, stands close to upright, but quite low in the sky for the latitude of Honolulu. Notice the two nearby stars, Rigel Kentaurus and Hadar, in the constellation Centaurus. Rigel Kentaurus is also known as Alpha Centauri, the star system nearest to Earth, at a little more than four light-years away. It and Hadar point to the Southern Cross.
Hawaii is at 21 degrees N. latitude. Other cities at about this same latitude include Mecca in Saudi Arabia, Leon and Guanajuato in Mexico, and Hanoi in Vietnam. All of you at this latitude will be able to see the Southern Cross before dawn for at least another month.
Are you south of Hawaii’s latitude? Then you can see the Southern Cross, Rigel Kentaurus and Hadar all higher in the sky before dawn now. From Australia or New Zealand now – or South America or South Africa – Crux is circumpolar. That is, it circles around the sky’s southern pole and appears for most, if not all, of the night.
Here is the Southern Cross as seen from Manila – latitude 14 degrees N. of the equator – on an April evening in 2012. The photo is from EarthSky Facebook friend Jv Noriega. Thank you, Jv! Make larger.
If you can see the constellation Cassiopeia in your northern sky, then the Southern Cross is below your horizon. Cassiopeia is shaped like the letter M or W.
How can I know if the Southern Cross is visible in my sky? If you know a bit about the sky, then there is one surefire way to know if the Southern Cross is visible in your sky. When the easy-to-find constellation Cassiopeia the Queen is visible in your sky, the Southern Cross is below your horizon. So, for example, Cassiopeia lights up Hawaiian skies on winter evenings, but it sets beneath Hawaii’s northern horizon several hours before sunrise. As Cassiopeia sets, the Southern Cross rises.
Meanwhile, for latitudes north of Hawaii (for example, the southernmost continental U.S.), Cassiopeia is circumpolar. It circles endlessly around the sky’s north pole and never sets. Therefore, the Southern Cross never rises as seen from northerly latitudes.
The Southern Cross marks the southern terminus of the glowing band of stars that we call the Milky Way – really the edgewise view into our own Milky Way galaxy. Meanwhile, Cassiopeia lodges at the Milky Way’s northern terminus in our sky.
This U.S. Naval Observatory page tells you the rise and set times for the Crux star Mimosa, and the stars Hadar and Rigel Kentaurus.
Taking into consideration its size, an ancient relative of piranhas weighing about 20 pounds delivered a bite with a force more fierce than prehistoric whale-eating sharks, the four-ton ocean-dwelling Dunkleosteus terrelli and – even – Tyrannosaurus rex.
Besides the force of the bite, Megapiranha paranensis appears to have had teeth capable of shearing through soft tissue the way today’s piranhas do, while also being able to pierce thick shells and crack armoring and bones, according to Stephanie Crofts, a University of Washington doctoral student in biology.
Bite force quotients – considering both bite force and body size – compare the powerful bites of black piranha (S. rhombeus) and now-extinct Megapiranha (M. paranensis) with barracuda, blacktip shark (C. limbatus), bull shark (C. leucas), hammerhead shark (S. mokarran), the extinct 4-ton Dunkleosteus terrelli, great white shark (C caracharias) and the extinct whale-eating Carcharodon megalodon. Image credit: University of Washington
“If our calculations are correct, Megapiranha was probably a bone-crushing predator taking bites of anything and everything,” she said. Crofts is co-author of “Mega-Bites: Extreme jaw forces of living and extinct piranhas,” published Dec. 20 in the online journal Scientific Reports.
The bite force of Megapiranha, which lived 10 million years ago, was extrapolated from the first field measurements of the biting force of Earth’s largest piranha today, Serrasalmus rhombeus or black piranha. One 2 ½ pound fish delivered a bite with a force of 320 newtons, or about 72 pounds, which is 30 times its body weight. The force is nearly three times greater than the bite force of an equivalent size American alligator.
Based on the 2 ½ pound piranha and other specimens tested in the wild, the scientists calculate that Megapiranha paranensis, which weighed approximately 22 pounds, could have had a bite force anywhere from 1,240 to 4,750 newtons – or 280 to 1,070 pounds – and possibly more.
Other scientists have previously estimated that T. rex slammed its jaws shut with 13,400 newtons, or 3,000 pounds of force, but that’s nowhere near 30 times its body weight.
Pound for pound, Megapiranha and black piranha have the most powerful bites among carnivorous fishes, living or extinct, the paper said. “For its relatively diminutive size, Megapiranha paranensis’ bite dwarfs other extinct mega-predators” including the enormous whale-eating Carcharodon megalodon and the monstrous Dunkleosteus terrelli, a four-ton armored fish.
The same was true when the scientists corrected for body size and made comparisons with today’s barracudas, hammerhead sharks and great white sharks.
“We were surprised that in spite of their long history and infamous reputations that no one had ever measured their bite forces,” said Justin Grubich, with the American University in Cairo, Egypt, and lead author of the paper. “When we finally started to get the data, we were blown away at how tremendously strong the bites were for these relatively little fish.”
As the paper says, “While anecdotes of piranha-infested waters skeletonizing hapless victims are generally hyperbole, the effectiveness of their bite is not.”
Just how does one measure the bite force of a piranha living in the wild? Well, you get out your rod and reel and go fishing. Land a specimen, then hang tight to the tail with one hand and use your other hand to support its belly while offering the fish a chance to bite the plates of a customized force gauge.
“Piranhas are ornery little fish so they bit down as hard as they could,” Crofts said based on what she was told by those on the fishing expedition along tributaries of the Amazon River.
The black piranha’s bite is so powerful in part because of its massive jaw muscles and rope-like tendons that together account for 2 percent of the fish’s overall weight, the scientists found. Further the shape of their jaw has evolved into a powerful lever, “one of the highest jaw-closing mechanical advantages ever identified in fishes,” the paper said.
Crofts’ main contribution involved analysis of how Megapiranha teeth handled stresses and how breakable the teeth might have been. The scientists were particularly interested because Megapiranha’s unusual teeth appear to do two things at the same time, one the piranha-like ability to shear soft tissues and the other an ability to bite like the nut-crushing pacu, piranha’s close relative.
Based on a fossilized jaw and three teeth, Crofts conducted a computer generated “finite element analysis” for the team.
“We found the Megapiranha teeth had the same maximum strength like you saw in regular piranha, but then the patterns of stress distribution within the tooth was also similar to fish able to eat hard-prey,” she said.
The actual diet remains a mystery, but during the time when Megapiranha lived a lot of potential prey species were gigantic.
“Thus it is reasonable to assume the food resources available to Megapiranha would likely have required jaw forces and dental weaponry capable of capturing and processing very large prey,” the paper says.
Other co-authors on the paper are Steve Huskey with Western Kentucky University, Guillermo Orti with George Washington University and Jorge Porto with the Instituto Nacional de Pesquisas da Amazônia.
Funding came from the National Geographic and the Field Museum of Natural History.
Night sky watcher David Kingham took this photo of the Perseid meteor shower from Snowy Range in Wyoming on August 12, 2012. CREDIT: David Kingham/DavidKinghamPhotography
As 2012 comes to a close, some might wonder what is looming sky-wise for 2013.What celestial events might we look forward to seeing?
I’ve selected what I consider the top 13"skylights" (get it?) for the coming year, and have listed them in chronological order. Not all thesenight sky events will be visible from any one locality (you may have to travel to catch all the eclipses), but you can observe many of them from the comfort of your backyard, weather permitting.
The next year also promises two potentially bright comets: PANSTARRS and ISON. As any astronomer can tell you, comets are notoriously capricious; we can only guess at how bright they will get and how long their respective tails will be. We’ll just have to wait and see.
For North Americans, this is a real head-turner, one easily visible even from brightly lit cities. A waxing gibbous moon, 78-percent illuminated, will pass within less than a degree to the south of Jupiter, the largest planet in our solar system. (For reference, your closed fist held out at arm's length covers 10 degrees of the sky.)
These two bright luminaries will make their closest approach high in the evening sky for all to see. What’s even more interesting is that this will be the closest moon-Jupiter conjunction until the year 2026! [Amazing Photos: Jupiter and the Moon]
Jupiter shines bright near a halo-wrapped moon in this amazing photo by stargazer Hunter Davis of Durango, Colo., on Dec. 25, 2012. CREDIT: Hunter Davis
Mercury, the "elusive" innermost planet, will travel far enough from the glare of the sun to be readily visible in the western sky, soon after sunset. On the evening of Feb. 8, Mercury will skim within less than 0.4 degrees of the much-fainter planet, Mars.
Mercury will arrive at its greatest elongation from the sun on Feb.16. It will be quite bright (-1.2 to -0.6 magnitude) before this date and will fade rapidly to +1.2 magnitude thereafter.(Astronomers measure the brightness of sky objects using magnitude, a reverse scale in which lower numbers correspond to brighter objects. Negative magnitudes denote exceptional brightness.)
Discovery image of the newfound comet C/2011 L4 (PANSTARRS), taken by Hawaii's Pan-STARRS 1 telescope. CREDIT: Institute for Astronomy/University of Hawaii/Pan-STARRS
Comet PANSTARRS, discovered in June 2011 using the Pan-STARRS 1 Telescope at Haleakala, Hawaii, is expected to put on its best show during this two-week period. During this time, the comet will also be near its closest approaches to the sun (28 million miles, or 45 million kilometers) and Earth (102 million miles, or 164 million km).
While Comet PANSTARRS was a very dim and distant object at the time of its discovery, it has brightened steadily since then. It still appears on target to reach at least first magnitude and should be visible low in the west-northwest sky shortly after sunset. On the evening of March 12, the comet will be situated 4 degrees to the right of an exceedingly thin crescent moon.
April 25: Partial Lunar Eclipse
This will be a very minor partial lunar eclipse, with the moon's uppermost limb merely grazing the Earth's dark, umbral shadow. At mid-eclipse, less than 2 percent of the moon's diameter will be inside the dark shadow. The Eastern Hemisphere (Europe, Africa, Australia and most of Asia) will have the best view.
This lunar eclipse will not be visible from North America.
May 9: Annular Eclipse of the Sun
During annular solar eclipse (also known as a "Ring of Fire" eclipse), the long, umbral shadow cone of the moon is too short to reach the Earth. In angular size, the moon's disk appears about 4.5 percent smaller than the disk of the sun. So, the effect is like placing a penny atop a nickel: a ring of sunlight remains visible surrounding the moon.
The shadow path from where the ring can be seen runs for thousands of miles, but will get no wider than 107 miles (172 km) at the point of greatest eclipse. Much of the path falls over the Pacific Ocean, but at or soon after local sunrise, it will slice across a part of northern Australia (where it will be the morning of May 10) and the extreme eastern tip of Papua New Guinea, along with some of the nearby Solomon Islands.
At the point of greatest eclipse, the ring phase will last 6 minutes, 4 seconds. Hawaiians will see a partial eclipse when, at 3:48 p.m. Hawaii time, the moon will obscure about 32 percent of the sun's disk.
May 24 to 30: Dance of the Planets
Mercury, Venus and Jupiter will provide a fascinating show low in the west-northwest twilight sky soon after sunset. They will seemingly shuffle around each other, changing their positions noticeably from one evening to the next. The two brightest planets, Venus and Jupiter,will be separated by just over 1 degree on May 28, with Venus passing to the northwest (upper right) of Jupiter and shining more than six times brighter than Jupiter.
June 23: Biggest Full Moon of 2013
On June 23, the moon turns full at 7:32 a.m. EDT(1132 GMT),and just 32 minutes earlier it will arrive at its closest point to the Earth in 2013 at a distance of 221,824 miles (356,991 km), making it a so-calledsupermoon.Expect a large range in ocean tides (exceptionally low to exceptionally high) for the next few days.
Aug. 12: The Perseid Meteor Shower
The annual Perseid meteor shower is considered among the best of the annual displays thanks to its high rates of up to 90-meteors-per-hour for a single observer, as well as its reliability. The shower is beloved by summer campers and often discovered by city dwellers who might be spending time in the country under dark, starry skies.
This past summer, the moon was a fat waning crescent and presented a minor nuisance during themeteor shower. But in 2013, the moon will be a couple of days before first quarter and will set during the evening hours, leaving the rest of the night dark for prospective observers.
Photographer Jeff Rose captured this amazing photo of a Perseid meteor and the bright moon just after 1 a.m. on Aug. 11 during the 2012 from Cave City, Arkansas, during the 2012 Perseid meteor shower peak. CREDIT: Jeff Rose/Jeka Photography
Oct. 18: Penumbral Eclipse of the Moon
The moon slides through the northern part of the Earth's penumbral shadow during this lunar eclipse event.
At mid-eclipse, 76 percent of the moon's diameter will be immersed in the penumbra, probably deep enough to cause a faint, yet discernible darkening of the moon's lower limb. The region of visibility includes much of Asia, Europe and Africa. The central and eastern portion of North America will get a view of the slightly darkened Hunters' Moon during the early evening hours.
Nov. 3: Hybrid Eclipse of the Sun
This is a rather unusual solar eclipse in that, along its track, which runs for 8,450 miles (13,600 km) across the Earth's surface, the eclipse quickly morphs from annular to total; it is therefore known to astronomers as a "hybrid eclipse."
Truth be told, along most of the track, the eclipse appears as a total, with a very thin annulus (or ring) of sunlight visible near the very beginning of the track. The track of the central line of this eclipse begins in the Atlantic about 545 miles (875 km)southwest of Bermuda. So, along North America's Atlantic Coast, interested viewers (using proper viewing devices, such as pinhole projection or #14 welders glass) will only see the dark disk of the moon exiting the sun's face at sunrise.
The eclipse track will pass south of the Cape Verde Islands, then curve southeastward parallel to the African coastline. The greatest eclipse, with 100 seconds of totality and the path width reaching a maximum of just 36 miles (58 km), occurs approximately 250 miles (402 km) off the coast of Liberia. The shadow track will then sweep across central Africa, passing over sections of Gabon, Congo, Democratic Republic of the Congo, Uganda and Kenya, before ending at sunset at the Ethiopia-Somalia border.
This image shows the newfound comet C/2012 (ISON) as seen by the Remanzacco Observatory in Italy. The image, taken by amateur astronomers Ernesto Guido, Giovanni Sostero and Nick Howes, is a confirmation view of the comet, which was first discovered by Vitali Nevski (Vitebsk, Belarus) and Artyom Novichonok (Kondopoga, Russia). Image released Sept. 24, 2012. CREDIT: Remanzacco Observatory/Ernesto Guido, Giovanni Sostero & Nick Howes
On Sep. 21, 2012, two amateur astronomers (Vitali Nevski of Belarus and Artyom Novichonok of Russia)used a telescope owned by the International Scientific Optical Network to discover a new comet that was christened using the acronym of the instrument used to find it: Comet ISON.
Orbital calculations indicate that comet ISON will travel closest to the sun, less than 750,000 miles (1.2 million km) above the sun's surface, making it a true "sungrazer," on Nov. 28 (Thanksgiving Day in the United States).
The comet could eventually be bright enough to be visible in broad daylight around the time of its nearest approach to the sun. It will then travel toward Earth, passing within 40 million miles (64 million km) of our planet a month later.
Since comet ISON will become very well placed for viewing in the morning and evening sky from the Northern Hemisphere during the following weeks, it could become one of the most watched comets of all time.
December (all month): Dazzling Venus
Venus, the brightest of all the planets, puts on a holiday show all month long, and what a spectacular one it is! Venus is the showiest it will be for all of 2013 and 2014 either in the evening or morning sky. It adorns the southwestern evening sky as much as three hours after sundown at the beginning of the month, and 1.5 hours after sundown by New Year's Eve. A lovely, crescent moon passes well above and to the right of the planeton Dec. 5, and the next night Venus will reach the pinnacle of its brilliance; Venus won’t be as bright an "evening star" again until 2021.
Dec. 13 to 14: Geminid Meteor Shower
If there is one meteor display guaranteed to put on a very entertaining show, it is the Geminid meteor shower. Most meteor experts now place it at the top of the list, as it surpasses in brilliance and reliability even August's Perseids.
Unfortunately, in 2013, the moon will be several days before full phase and will light up the sky for much of the night, hiding many of the fainter meteors. But around 4:30 a.m. (your local time), the moon will have finally set, leaving the sky completely dark for about an hour. That will be your chance to make as many as two meteor sightings per minute, or 120 per hour!
Meteor Shower Quiz: How Well Do You Know 'Shooting ...
Meteor showers can be awesome night sky sights, but how well do you know your shooting star facts? Find out here and good luck!
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So stargazers mark your calendars: 2013 promises to be a great year for skywatching, and if you take an impressive photo of the night sky, let us know!
Editor's Note: If you snap an amazing night-sky photo and would like to share it with SPACE.com for a possible story or gallery, please send images and comments (including your name and the photo's location) to managing editor Tariq Malik at: spacephotos@space.com.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York. Follow SPACE.com on Twitter @Spacedotcom. We're also on Facebook & Google+.
