Tuesday is a busy day on the celestial calendar. Before sunrise, one of the most prolific displays of "shooting stars" will take place. For skywatchers in Europe and parts of Africa and Western Asia, another great sky show awaits: a partial eclipse of the sun.
To catch the best views of these two sky shows — the first major skywatching events of 2011 — it's best to be prepared, and dress warmly. Here's a look at the skywatching bonanza, starting with the Quadrantid meteor shower.
Quadrantid meteor shower returns
Early each January, the Quadrantid meteor stream provides one of the most intense annual meteor displays, with a brief, sharp maximum lasting only a few hours.
This Quadrantid meteor shower skywatching guide shows where and how to look in the northeastern sky to spot the shooting star display.
The meteors actually radiate from the northeast corner of the constellation of Bootes, the Herdsman, so we might expect them to be called the "Bootids."
But back in the late 18th century there was a constellation here called Quadrans Muralis, the "Mural or Wall Quadrant" (an astronomical instrument). It is long-obsolete star pattern, invented in 1795 by J.J. Lalande to commemorate the instrument used to observe the stars in his catalog.
Adolphe Quetelet of Brussels Observatory discovered the shower in the 1830s, and shortly afterward it was noted by several astronomers in Europe and America. So they were christened "Quadrantids" — and even though the constellation from which these meteors appear to radiate no longer exists, the shower's original moniker continues to this day.
Crumbs of a dead comet?
At greatest activity, probably 50 to 100 Quadrantid meteors per hour should be seen. However, the Quadrantid influx is sharply peaked: Six hours before and after maximum, these blue meteors appear at only a quarter of their highest rates.
This means that the stream of particles is a narrow one, possibly derived relatively recently from a small comet.
In fact, in 2003, astronomer Peter Jenniskens of NASA found a near-Earth asteroid (2003 EH1) that seemed as if it was on the right orbit to be the source of the Quadrantid meteor shower. Some astronomers think that this asteroid is really a piece of an old, "extinct" comet; perhaps a comet that was recorded by Chinese, Korean, and Japanese observers during the years 1490-91.
According to that theory, the comet broke apart, and some of the pieces became the meteoroids that make up the Quadrantid stream.
When and where to look
This year, a strong display of Quadrantid meteors is likely for Europe and points east to central Asia.
Maximum activity is expected at around 0100 GMT on Tuesday, when the radiant of this shower from where the meteors appear to emanate is ascending the dark northeastern sky. With no moonlight to interfere, this might turn out to be one of the best meteor displays of the year. Morning twilight will not interfere until about 6 a.m. local time.
What about for North America? At the time the shower is reaching its peak, it will be Monday evening on the other side of the Atlantic: 8 p.m. ET in the East and 5 p.m. PT (still twilight) in the West. The radiant will be positioned low near the north-northwest horizon.
As a consequence of the low altitude, only a fraction of the 50 to 100 Quadrantids will likely be seen.
But those "Quads" that are seen will likely be spectacular "earthgrazers" that skim across our upper atmosphere on long, majestic paths. By 1 a.m. ET (0600 GMT), the radiant will be climbing in the northeast sky, but the meteor rates will be rapidly declining.
East of the Mississippi, you might still count a respectable 20 or 25 per hour; west of the Mississippi, perhaps more like 5 to 15 per hour.
And who knows? As meteor expert Allistair McBeath has noted, some Quadrantid outbursts in the past have been several hours early or late. If the latter happens this year, it could lead to higher hourly rates for North America.
If you do head out to look for meteors, remember to bundle up with blankets and a comfortable chair! The same rules we laid out last month for the December Geminid meteor shower apply to the Quadrantids as well.
Partial solar eclipse
After viewing the spectacle of a fine meteor shower on Tuesday morning, skywatchers over Europe, the northern half of Africa and western Asia will then be treated to a bonus. Weather permitting, they'll enjoy the spectacle of a partial eclipse of the sun.
The moon's outer shadow, called the penumbra, will scrape the northern part of the Earth.
First, a note of caution: Be very, very careful about the precautions for eclipse viewing! Never look at even a tiny bit of the sun's disk without proper light filter.
The safest way to view a solar eclipse is to project the sun's image either through a pinhole or through binoculars or a telescope. (But at no time should you look through the pinhole or binoculars or telescope at the sun!)
You'll get useful solar eclipse viewing safety tips here. Be sure to observe them!
Tuesday's partial solar eclipse will first appear in Algeria, the second-largest country on the African continent. The first contact of the penumbral shadow (where the sun rises with a barely perceptible nick in its southern edge) coincides with local sunrise a few hundred kilometers northeast of In Salah, an oasis town in central Algeria, at the heart of the Sahara Desert region of northern Africa.
Ultimately, the penumbral shadow will fall on nearly all of Europe, the northern half of Africa, the Middle East, and southern Asia.
Sweden has the best show
The region of greatest eclipse, where the moon will hide 80 percent of the sun's disk, occurs at sunrise over northeastern Sweden, along the Gulf of Bothnia, near the city of Skellefte. There, the early winter sun should appear to barely rise along the southern horizon, its top and center blocked at 9:51 a.m. local time by the moon. [Photos: The Total Solar Eclipse of 2010]
From this spot on Earth, looking along the brow of our planet toward this U-shaped sun might convey to some a sensation of the moon's tubular shadow hurtling overhead and onward into space.
Cities in Western Europe will also enjoy a sunrise eclipse, with the striking spectacle of a partially eclipsed sun emerging into view from beyond the east-southeast horizon. London will see 66.7 percent coverage at 8:12 a.m. local time; Madrid, 46.8 percent coverage at 8:52 a.m.; Paris, 64.9 percent coverage at 9:09 a.m.; and Oslo, 77.9 percent coverage at 9:35 a.m. local time in Norway.
All times given here are for local standard time. It should be pointed out that we are providing values pertaining to the obscuration of the sun by the moon, which refers to the total area of the sun's disk that is being covered.
This is not to be confused with the magnitude of the eclipse, which refers to the fraction of the sun's diameter that is covered.
NASA astronomer Fred Espenak has calculated the GMT/UT observation conditons for 65 selected cities in Europe, Africa and Asia, which includes both the obscuration and magnitude values. You can see the entire city list by clicking here.
The shadow sweeps eastward and leaves Earth's surface in the Eurasian country of Kazakhstan, to the north of Lake Balkhash — about 4 hours and 21 minutes after it first touched down in Algeria.
Good viewing to you, and no frustrating cloud cover!
- Solar Eclipse and Meteor Shower to Launch 2011 Skywatching Season
- Video Meteor Shower, Solar Eclipse of January 2011
- Photos: The Total Solar Eclipse of 2010
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.