Tomorrow, the night of Sunday 13th December to Monday 14th December is the peak of the Geminids meteor shower.

This is the annual shower of “shooting stars” that appear to emanate from the constellation of Gemini (however, they are NOT stars, just fragments of dust and rock debris burning up in the Earth’s atmosphere and they are also completely unrelated to the stars we describe as Gemini).

Nevertheless, the Geminids is a sky event well worth making an effort for. You MAY see a wonderful display of streaks of light across your sky, if you are blessed with dark and clear skies where you are.

The peak is expected around 5am UT (that’s the same as Greenwich Mean Time), but it should be worthwhile for you to look to the sky in the early hours at your local time. The Geminids is often a broad maximum, so you may be surprised. Anything around one meteor per minute, is very good!

Here is a sky map of where to look.

December Geminids Meteor Shower Radiant (click for larger image)

Best of luck.

What is it?

This shower of meteors (often wrongly called “shooting stars”) occurs every year. It happens when the Earth on its orbit about the Sun, passes through dust and rock remnants, left behind in the past by the comet Tempel-Tuttle.

The brief, bright streaks of light we may see in the night sky, result when this material burns in the Earth’s upper atmosphere.

Why is this shower called the “Leonids”?

Because the meteor trails APPEAR to originate in the constellation of Leo (the Lion), if you trace back an imaginary straight line across the sky.. (But note, they have no true connection with the stars we see in the constellation, which are MUCH further away)

This apparent origin is illustrated by the sky map below. It shows the position of Leo and the meteor shower radiant point, rising above the Eastern horizon at 1.00UT during the night of 17 – 18 November.

Leonids Radiant Rising In East, 1.00 UT, 18 Nov, Lat 51 N, Long 0 E (click for larger)

Is it worth looking this year?

It should be – the conditions are extremely favorable.

With the new Moon on 16th November, there will be scarcely any moonlight to disrupt observation of meteors.

Also, some meteor specialists have suggested there may be a strong, even “storm force” shower this year, such as occured in the late 1990s and early 2000s.

When exactly should you look for meteors?

Various specialists use models to try to predict exactly when the shower peaks (both minor peaks and major peaks) will occur. But these are only predictions, so it should be worth looking over the 17th – 18th period.

It will be best to look when the radiant point (see map above) is above your local horizon. The further South you are, the earlier in the night Leo will rise above your local East horizon.

Summary

Wrap-up warmly if you are spending time outdoors and good luck!

Q. What are the Orionid meteors?

A. Each year in October as the Earth orbits about the Sun, it passes through an area of Space containing dust and rock fragments left behind by Halley’s comet. As these particles hit the Earth’s atmosphere they burn up, producing streaks of light we can see in the Night Sky. Occasionally, larger particles may burn up producing very bright “Fireballs” that can sometimes even be seen in daylight

Q. Why is this October meteor shower called the “Orionids”?

A. Because of the location of the Halley’s Comet debris in space, the meteors APPEAR to us on the Earth’s surface to originate from the constellation of Orion. This is nothing more than a “line of sight” effect however. The rock fragments which cause the meteors are actually very close to Earth – they have nothing to do with the distant star pattern we call Orion.

Here’s a graphic showing the apparent origin of Orionid meteor trails (the Radiant), located between the constellations of Orion and Gemini.

Orionids Meteor Shower Radiant, East Horizon, 21 Oct 2009 (Click For Larger Image)

Q. So will the meteors be seen only in the area of Orion?

A. No. The streaks of light may appear anywhere in our sky… But if you extend the traces backwards and continue the path, they will seem to have started in the area of Orion.

Q. When is the best time to look for the Orionid meteors?

A. The range of dates is expected as 16th – 27th October, with the peak meteor activity expected on 21st October 2009. In recent years, good numbers of meteors have been seen 1-2 days before and after the peak date, so it should be well worth observing over the period 18th-23rd October.

In some previous years, a double-peak of activity has been reported and this is an unusual feature of the Orionid shower. This may be because the orbit of Halley’s Comet brings it back to the Sun every 76 years, giving plenty of opportunity for depositing dust and debris.

Q. Will 2009 be a good year to observe the Orionid meteors?

A. It should be. Sometimes a bright Moon spoils the observing of meteor showers, but this time it’s very favorable. At the expected Orionid peak, the Moon will be just 2 days old. Therefore, it won’t be bright and it will set below the horizon, soon after sunset.

Q. How many meteors can I expect to see?

A. At the shower peak, something like 25 meteors per hour is predicted (this is called the ZHR – Zenithal Hourly Rate). Obviously, you will need dark, clear sky conditions to see the most meteors, and the number is just a prediction.. this makes it more fun to get outside and see for yourself, how many meteors appear!

Q. What equipment do I need to observe the meteors?

A. Good news… no equipment is really needed – just use your eyes (it will help if you allow 10-15 minutes for your eyes to become accustomed to the dark). If you like, you can try using binoculars too, but they may limit your view to a small area of the sky.

Q. Any other suggestions?

A. It’s getting cold in October, so make sure you wear warm clothing if you’re planning to spend an extended period outside, watching for meteors. Your observing session will also be more comfortable with a reclining garden chair, allowing you to lay back and look upwards. Some people like to put blankets or cushions on the ground, so they can lay flat and feel closer to the Universe, as they hopefully experience a memorable meteor display in the Night Sky.

Conclusion

Here’s wishing you the best of luck with your Orionids 2009 experience!

If you have questions or comments, please leave a reply below. I’ll do my best to answer each one personally (although I have to admit, the hundreds of questions on the Perseid meteor post, rather overwhelmed me!).

Every year in early August, we can observe the Perseid meteor shower (“the Perseids”) and it’s a fascinating sky event. This year 2011, the Perseid peak activity is expected on Saturday August 13th 2011.

Unfortunately, there is a full Moon on the same day and this will make observing difficult (but not impossible, so don’t give in until next year!)

Here’s a beginners’ guide to the Perseid meteor shower and how best to enjoy it. (Perhaps, impress your friends with these astronomy questions and answers!)

What are the Perseids and what is a meteor?

Every year in August, the Earth passes through rock and dust fragments left behind by the comet Swift-Tuttle, last time it came near the Sun. As these small particles collide with the Earth’s atmosphere, they burn-up, often creating a startling streak of light across the sky.

You can easily observe this and it can be a wonderous spectacle.

Why is it called the Perseid meteor shower?

The term “Perseid”, refers to the star constellation of Perseus.

View of Perseid meteor radiant point, above NE horizon after midnight

The meteors actually have nothing to do with the stars we see from Earth, as being part of Perseus. It just appears as though the meteors originate from Perseus.

In fact, the rock fragments are close to the Earth – that’s why they burn in our atmosphere.

They are very close, just a few hundred miles – not many, many light years distant like the stars.

But, if you trace-back the bright trails of meteors we see, they appear to originate from the stars of Perseus.

When can you see them?

The Perseid meteor shower actually starts in late July and runs to late August. However, the best time to view is around the peak.

It’s not precise, but the 2011 peak is expected on August 13th.

The predicted peak hours are during the European night and morning (01.00 – 13.00 GMT). So if you are in the US, the peak may be better placed in your night, whereas for those in Asia and the East, the predicted peak will be during daytime, so you should observe the night before and after.

But having said that, there is always uncertainty in these meteor shower predictions, so it may be very worthwhile to observe during the hours of darkness and indeed, other nights, before and after the expected peak.

This year the Moon will be a problem, as mentioned already. Full Moon and meteor observing, are not best friends.

What equipment do you need to observe the meteor shower?

The good news is none! Just use your eyes.

It will help your observation if you give your eyes some time (say 15 minutes), to become adapted to the darkness.

Binoculars may also help, but on the other hand, they may restrict your view to a small part of the sky.

The meteors originate in the region of Perseus, but they may appear in view just about anywhere in the sky. Although, if you were to track-back their trails, you would get to Perseus.

Can they be measured, at all?

Yes. Keen astronomers count how many appear in a fixed period of time, in a certain area of the sky. This is expressed as a Zenithal Hourly Rate (ZHR).

We may expect around 100 streaks of meteor light across the sky per hour, at or near the shower peak.

Do please look-up and be alert for Perseid meteors, on Saturday 13th August during hours of darkness and in the nights before and after.

Best of observing luck!