DECEMBER has already provided those looking skyward with a spectacular ‘Cold Moon‘.
But there’s another treat in store for budding astronomers: the Geminids meteor shower, one of the more active showers on the celestial calendar.
We’ll also be getting a close brush with the meteors’ asteroid source.
What are the Geminids?
The Geminids occur when the Earth flies through a cloud of cosmic debris, particles from which burn up brightly as they enter our planet’s atmosphere.
Unlike most meteor showers however, the Geminids do not originate from the dust trail of a comet.
The shower takes place when our planet passes through the debris trail of the asteroid ‘3200 Phaethon’, so the meteors have a more rocky composition, making them slightly easier to observe in comparison to others.
They are so-called because they appear to radiate from the constellation of Gemini, although they can appear almost anywhere in the night sky.
They appear as fast-moving streaks of light as the small particles – some just the size of a grain of sand – enter the Earth’s atmosphere at 130,000mph.
This year, the Earth will also be getting a close flyby from Phaethon itself, as it passes just 0.069 astronomical units (don’t worry, that’s still 6.4 million miles) past the Earth late on 16 December, making it a viable target for small telescopes.
When can I see them?
The meteor shower actually takes place across about nine days, from 8 to 17 December.
But this year’s peak comes on the evening of Thursday 14 December. That’s when you’ll really want to cross your fingers for clear skies.
The Geminids are thought to be intensifying every year, and recent showers have seen 120–160 meteors per hour.
Night owls will have a better chance, with optimal conditions coming between 2 and 3am, but meteors should be visible as soon as it gets dark enough.
What do I need to see them?
All of the major meteor showers can be seen with the naked eye, so there is no need for any sort of specialist equipment.
You will need to wrap up warm if you intend to venture out into the cold night though, and with December skies often unsettled, it would be advisable to keep the waterproofs handy.
Astronomers also advise you give yourself around an hour of observing time as the meteors can appear in spurts and are interspersed with lulls.
When is the next meteor shower?
If you miss the Geminids, you won’t have too long to wait until the next shower.
The Ursids meteor shower, the final one of the year, takes place following the winter solstice from 22 to 23 December.
Derived from the name Ursa Minor, the Ursids will appear to come from the constellation colloquially known as the Little Bear.
Unlike the Geminid Meteor Shower, Ursids might be a bit more difficult to see, but should still be visible with the naked eye when they do appear.