…by Anura Guruge
As I have pointed out in other posts meteor showers are caused when the Earth cut across the debris trail left by a comet. This is why we will in centuries to come still have a reminder of poor demised Comet ISON because there will be a Comet ISON (C/2012 S1) associated with the debris that was left behind on its one memorable trip past Earth.
This meteor STORM, with upwards of hundreds of meteors per hour, will be due to us crossing the debris trail left behind by a NOW periodic comet — 209P/LINEAR (where LINEAR stands for the automated Lincoln Near-Earth Asteroid Research sky survey).
This was a comet spotted in February 2004 — though precovery images were discovered going back to December 2003. Given that it now acts like a near-Earth, Jupiter-crosser asteroid with a perihelion of 0.97 AU (i.e., going just inside Earth’s orbit) and an aphelion of 5 AU (orbit of Jupiter), it was initially thought to be an asteroid since it did not exhibit a coma or tail. But, a month after its initial discovery ace-comet spotter, British Robert H. McNaught espied a tail.
That we only have images of it since December 2003 means NOTHING in terms of how long it has been in its current ‘near-Earth’ orbit or as to how many perihelion trips it might have made BEFORE it was gravitationally captured by Jupiter. We just don’t know. Like MOST comets it probably originated way, way, way, way out in the Oort Cloud — just like ISON. Over the last 4 billion years it might have made a number of visits to the Sun BEFORE it came to close to Jupiter on one of these trips — and YES it could have happened on its maiden voyage. But, we don’t know when this happened.
Astronomers now think that on May 23 – 24, 2014 we will cut across the debris trails left SINCE 1803. It now has a orbital period of 5.09 years. This too could have changed over the years.
So much of the hype in the media about this being a new comet and this being a NEW meteor shower/storm is WRONG.
We are just getting to know about it.
That doesn’t mean it hasn’t been around for longer.
Just because we didn’t spot it, when it comes to astronomy, does NOT mean it hadn’t already been there for millennia!
I will keep you posted.