Observations

The Geminids are coming!

Geminid meteor shower 3 am Saturday 15 December 2007 as expected in the Southern Hemisphere, drawn by Nick Lomb

On Friday evening late until dawn on Saturday morning we expect one of the best meteor showers of the year – the Geminids.

What is a meteor shower?

As a comet approaches the Sun, the intensity of solar radiation blows off dusty particles from the surface of the dirty snowball at its centre. These particles form the head of the comet or coma as well as its long tail. Some of the particles disperse, but over many years some spread out over the path of the comet around the Sun. The Earth periodically runs into these meteor streams and as these burn up high in the atmosphere we see a meteor shower.

Why do the meteors appear to come from the one spot “the radiant” in the sky?

As the Earth passes through one of these streams all the particles appear to be moving in the same direction – a combination of the actual movement of the particles and that of the Earth. What we see in the sky is then like looking along a railway track with the different particles all appearing to come from the one spot in the sky.

From which comet do the Geminid meteors come?

Every rule has its exceptions and the Geminids is the exception in the case of meteor showers. The parent body for the dispersed dust particles is not a comet but an asteroid or space rock called 3200 Phaeton. Though some scientists speculate that 3200 Phaeton is the remnant of a dead comet, we will be unsure until future astronauts inspect it close-up.

How and when should you watch the Geminids?

Try to watch them from a dark spot as far from bright city lights as possible. You can start watching from late on Friday evening 14 December 2007 and continue until dawn on the Saturday morning 15 December 2007. This year we are fortunate that there will be no Moon visible to brighten the sky. Plus for those in Australia the predicted timing is good – the shower is expected to peak before dawn at about 3:45 am Eastern Australian summer time. Note that the meteors can appear anywhere in the sky, but if it is a Geminid, you should be able to mentally trace the path back to the radiant low in the north.

Clear skies and good viewing!

17 responses to “The Geminids are coming!

  • Hi Brandon
    Very sorry those comments had disappeared. I’ve had one of our experts (thanks Luke) diagnose the problem and fix it – so all the comments are back.
    Thanks for letting us know about the problem.

  • Hi Nick,

    Hope you’re well. 20 – 24 an hour or more were visible from Linden Observatory around midnight to 1 am on Friday night and Saturday morning. I managed to miss almost every one, but others were counting, and I’ve encouraged their reporting to you.

    Thanks. Alan.

  • I live in Kellyville in northwestern Sydney suburbia, and I actually had no knowledge of the Geminids shower until I’d been outside on both Thursday and Friday evening for only a couple of minutes at a time and observed meteors on each occasion. It was late Friday night when I looked up, saw a couple and thought “alright, what’s going on here?” and got on the net to see if there was anything happening. It was a total fluke not only that I’d found out in time to grab the sleeping bag and set up camp out back with the dog overnight but also that after so many consecutive nights marred by cloud cover that the skies would be perfectly clear throughout. I saw a southbound meteor at least every five minutes from about one until the pre-dawn, but it was after four and just as the light was beginning to show that things really picked up. Not in terms of frequency, but the duration of each meteor and the brilliant smoking trail that would follow them. I saw four such spectacular examples that lasted about 1.5 seconds as they flew southwards and passed me at close to 90 degrees, so awesome I caught myself gasping aloud. Each alone was worth fighting the mosquitoes off my face for several hours. I’m not sure but I guess at that time we’re moving headlong in to the comet debri along our orbital path. Having been somewhat disappointed by a lacking Orionids show several weeks ago I was totally impressed this time around and I can’t wait ’til the next December Geminids!

  • Like Luke, I also saw the SMH article and thought I’d put in my 2 cents…
    I was somewhat disappointed, but figured it was the Sydney light pollution that hampered the show. Observing from South Turramurra, I spotted my first Geminid at 12.10 – very bright, slow, visible tail, lasting maybe 1-2 seconds. It was very spectacular and I had high hopes. As it turned out, it was the best of the night!
    I was watching part-time until about 2.00AM, at which point I went full-time. The total tally being 39 as follows…
    12.10 (1), 12.50 (4), 1.00 (7), 1.40 (14), 2.10 (18), 2.50 (24), 3.30 (31), 4.05 (39)

    At least 4 of these were not Geminids, as they were travelling east to west. There were probably another 6 or so very very minor streaks that I may have imagined!

    Even though it was a little disappointing (and really freezing!), I would definitely do it again. Not sure if I could sell any tickets though!

  • Friday night (Sydney suburbs) was exceptionally clear and cool. I started at about 1.30 and finished at 3.30. I saw a number of fairly bright trails of light lasting perhaps 1 or 2 seconds and then extinguishing. They were travelling approximately north to south and did not appear to be moving all that fast. Also saw one in the Eastern sky falling to earth in a northerly direction.
    However in between, I saw several extremely fast and very dim streaks of light. They gave the impression of being a very rapidly moving search light spot that swept right across the sky overhead, faster than I could turn my head. Blink and you would literally miss them. They did appear to radiate away from a point source in the correct general direction so I assume they might have been part of the shower.

  • Maybe the meteor shower was not quite a fizzer. Here is a report from Chris:

    “After reading the report in the Herald today, I can confirm that I witnessed upwards of 75 meteors in the Australian skies on Friday night/Saturday morning!

    I was flying back from Thailand at 35,000 feet and saw a magnificent display!! Perhaps the light pollution from the city and surrounds meant that Sydneysiders didn’t get a good view!!”

  • I know it’s a bit late now, but after reading this SMH article ( http://www.smh.com.au/news/national/meteor-shower-very-cozzzzzzzmic/2007/12/17/1197740157937.html ) about it being a “fizzer”, I just thought I had to comment…

    On Friday night at from around 12:20am, I spent about 45 minutes with my partner up at Bilgola Lookout on the Northern Beaches of Sydney.

    We spotted around 15-20 meteors in this time, most were reasonably dim although we were treated with one very bright one going from the north-east to south-west and several reasonably bright ones along similar paths.

    It wasn’t the most spectacular sight I’ve seen but I didn’t feel it was disappointing either. My partner was quite happy as she had only seen 1 “shooting star” before (a few months ago up at Koolang Observatory) – she was overjoyed to see more than a dozen in one night.

    I think the media/press should avoid trying to overstate meteor showers. As most astronomers know, they can be a hit/miss affair (literally) – some years they can be great – others they can be dull. To me, Friday night/Saturday mornings shower was hyped-up by the media and even if it had have been a great meteor shower, I feel that most people reading the articles would have been disappointed unless they’ve experienced meteor showers before and know what to expect.

  • I spent time outside (Randwick) from 12:15 to 1:00 and 2:00 to 2:45. During this time I managed to spot 11 meteors including 1 going the wrong way! The 11 meteors included 2 very quick ones, 4 “medium” duration and 5 “longer” duration. I could tell it wasn’t going to get any better so gave up at 2:45. Clear Skies.

  • Thank you all for your comments. It is disappointing that more meteors could not be seen from Australia, especially from cities. The peak of the meteor shower did occur as predicted and reached a fairly high ZHR (the number of meteors seen by an experienced observer in a dark sky with the point of origin of the meteors directly overhead) of 140. As indicated on the International Meteor Organisation website http://www.imo.net/live/geminids2007/ the meteor shower was seen from around the world. The only Australian reports are from a team of three from country Victoria who reported sighting about one each four minutes or about 15 an hour.

    Mick also provided the following report under the Report your Sightings page of this blog:

    “Hi, this morning I watched the sky for several periods of up to ten minutes from 2.30am to 3.50 am. I sighted a total of around 6 or 7 meteors during this time. They were fast and not lengthy and were mostly travelling from north to south in the western sky. Some were low down and others 45 and 60 degrees high. I suspect they were associated with Geminids. I learned of this event on the radio as I travelled to work. All in all not as spectacular as I had hoped but nonetheless it was great to see the number I did. I was at Redfern and the city lights probably thwarted the sighting of many more.
    Cheers.”

  • So I managed to drag myself out of bed about 3:30am. I saw about 2 meteors over about 15-20 minutes. Both traveeling East. One was bright and short, the second was fainter and longer. I would not have said these where Geminids, they seemed to be well out of Gemini ( at least by the time I saw them).

    My trusty Sky Quality Meter gave a reading of 19.45, which indicates a level of ‘mild’ light pollution. Earlier in the night I had reading of 19.51

  • i looked up north of the sky every 15min since 1:45am … didnt c anything till around 3:45 …

    i can only see one or two meteor every 10~15min … small ones …

    then i went to sleep at around 4:30 … i think i saw a total of 6

  • Hello Josh. The article titled, “Meteor Shower Thursday night/Friday morning” was posted a year ago and relates to the expected timing last year. This year as stated above the prediction is for Friday night and Saturday morning as the most likely to be the best time to view the meteor shower.

  • Which day will the shower be most visible? The article titled, “Meteor Shower Thursday night/Friday morning” says just that, while this article states that Friday night/Saturday morning at 3:45am will be best. Please advise.

    Thanks,

    Josh

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