The 2015 Leonids meteor shower will begin on 6th November and peak on the 17/18th November. The shower will continue until the end of the month. A waxing crescent moon means that the sky will be dark enough to easily view the shower. The average meteor velocity is 71 km/s with an magnitude of 2.5 and Zenith hourly rate of 15 meteors per hour.The shower is called Leonids because its radiant or the point in the sky where the meteors seem to emerge, lies in the constellation Leo. The Leonids occur when the Earth passes through the debris left by the comet Tempel-Tuttle. The comet takes around 33 years to make one orbit around the Sun.
Live feed from the Exeter Observatory Meteor detectors.
( Updates every 30 secs )
See the latest meteor camera captures here: Meteor Camera Images
Data from The Spam Network: S.P.A.M. Network
Typical Meteor Strike
A -4.6 mag fireball was detected by the SPAM meteor network at 02.17.35 on the morning of 7th May 2013.
Here you can see what a typical meteor strike looks like. The trace starts high in frequency and rapidly drops to the radar carrier frequency as the meteor decelerates in the atmosphere, increasing in strength (ionisation) as it burns up. This creates this typical triangular shape you can see here. The width, height and shape tell us a lot about the strike. The blue is the baseline atmospheric noise.
When a meteor strikes Earth’s atmosphere it decelerates rapidly. The friction created by the air causes the meteor to burn up at extremely high temperatures creating the white “shooting star” that we are all familiar with. This process also ionises the air along the trail making it possible to reflect radio waves.
Utilising a high powered VHF radar signal sent into the sky, we are able to detect reflected waves from these ionisation trails. Because the meteor is moving, the reflected signal is shifted in frequency from the original, by an amount according to it’s speed. This shift is also heard as an audible ping by the station operator.
Our system translates the reflected wave into three main parameters –
You can see the output from our system above in real time (approximately 1 minute delay on the Internet). During a meteor shower this trace will be full of strike traces, but it is also surprising how many meteors are striking Earth’s atmosphere all of the time.