It's been a disappointing fall for meteor watchers. October's Orionids made a more modest showing than many observers hoped, and November's Leonids were even harder to spot.
If you spent any significant amount of time in your yard, neck craned towards the sky in the hopes of seeing those meteor showers, redemption may be on its way later this week.
The final meteor shower of the year is the Geminids, expected to peak on the night of Dec. 13 into Dec. 14, and no less an authority than Astronomy Magazine says it should be the best display of the year.
Rates of up to an astonishing 120 meteors per hour ― or about two every minute ― mean that even if other recent meteor showers have left you unimpressed, the Geminids are worth a look.
A possible 'mystery' meteor shower
What makes this week even more intriguing is that the Geminids may not be the only meteor shower on the schedule.
NASA's "Watch the Skies" blog reported that according to some computer models, a brand new, as yet unnamed meteor shower may make its debut this week.
If both showers materialize, the night sky during the second half of this week could provide anyone with a clear view of dark sky with an unprecedented show of up to 150 meteors each hour.
Conditions should be close to ideal: Not only does the forecast for southeastern Pennsylvania call for clear skies, but it's also a New Moon (the phase of the Moon when the Moon is not visible at all). The absence of the Moon's light means that more and smaller meteors should be visible in the darkness.
How and when to watch
The Geminids are so named because they appear to come from the general direction of the constellation Gemini, which will rise around 6:30 p.m. Try to find Gemini in the eastern sky at about 10:00 p.m., to the left of the more famous constellation, Orion. Look for Gemini's two brightest stars, Castor and Pollux. At 10:00 p.m. on Thursday, Castor will be "above" Pollux in the eastern sky.
At the same time, the "mystery" meteor shower is expected to come from the general direction of the constellation Pisces. At 10:00 p.m., Pisces will be on almost the opposite side of the sky, heading towards the western horizon. Pisces doesn't have any very bright, easily identifiable stars, but that's okay. You're not looking for the constellation, just the meteors that may come from that direction.
Temperatures are expected to be close to freezing, so get yourself a thermos full of cocoa and bundle up! Turn off any exterior lights and consider asking your neighbors to do the same. Give your eyes at least 10 to 15 minutes to adjust to the darkness. If you want to go the extra step, drive to a viewing site that's at least 40 miles away from Philadelphia or any other major cities.
The "mystery" shower will be the opening act, and any meteors from that direction should be visible as soon as dusk turns to night on Thursday. The Geminids are the main attraction, though. They peak at midnight on Thursday night, but should be visible all night long. Indeed, if you've seen any shooting stars in the past week, you've likely already seen an early Geminid.
What does a meteor look like?
If you've seen a "shooting star," you've seen a meteor. The vast majority of meteors are tiny particles of ice and dust, no bigger than a grain of sand. They're incinerated as they hit our upper atmosphere, more than 50 miles over our heads, at several miles per second. You'll see a streak of light ― blink and you'll miss it! ― that will usually last less than a second.
This video of the Perseid meteor shower in 2009 should give you some idea of what to expect. (Watch it in full screen mode.)
The most spectacular meteors might last up to two or even three seconds, and leave a ghostly trail behind them that lingers for a few seconds more. We might get some of those Thursday.
If you see one, don't feel silly if you let loose with an involuntary "Wow!"
That's the point. Enjoy.