Tuesday, October 22, 2013

Double Shadow Transits on Jupiter - 23 Oct 2013

There will be another rare double shadow transit across Jupiter early tomorrow morning.

Date: Wednesday 23 October 2013
Time: 03:22am - 05:34am
Location of Jupiter: East North East (ENE)
Jupiter rising above horizon: 00:23am (23 Oct 2013)

The two shadows will be casted by the two moons of Jupiter - Io and Europa.

Europa Shadow Transit: 03:19am - 05:56am
Io Shadow Transit: 03:22am - 05:33am

Compared to the previous double shadow transit last Wednesday, Jupiter will be in a higher 56° altitude - displaying the shadow transits through thinner atmosphere for a clearer view.

Some double transits happens far apart - one about to disappear (egress) while the other just appeared (ingress). For tomorrow's transits, their ingress timings are very near to one another. They are only about 3 minutes apart. This means we can potentially observe or photograph these transits for a much longer time across the disc of Jupiter - 2 hours and 12 minutes!

Although there is a bright Moon tonight, if the sky is clear enough, you may even catch a meteor while looking at the the direction of Jupiter! The radiant point of Orionid Meteor shower is near the "club" of Orion which is near Jupiter. This meteor shower is expected to peak last night (21 Oct) and tonight is still pretty close to the peak night.

According to SpaceWeather.com officials -"Forecasters expect the shower to peak on Oct. 21 with about 20 meteors per hour. However, Halley's debris stream is broad, so Orionid activity could spill into Oct. 22nd.".

Do not have overly high expectation of catching it tonight because the meteor rate is low - about one every three minutes on average. Treat it as a bonus if you do, else continue to enjoy the shadow transits!

And if the sky is clear enough, there may be still a chance to catch the elusive Comet ISON below Mars!

So good luck, clear skies and try to stay awake the healthy non-caffeinated way - pure adrenaline rush from thinking about seeing these rare transits at more than 600,00,000km away from Singapore through telescopes!


  1. I wish I can see it on Singapore but I guess it very hard.
    Guys Outing

    1. No harm trying. If you want something bad enough, you will do whatever it takes to get it. :) My friends and I managed to see the first two of such transits in Singapore. Tomorrow early morning will be the last one for October 2013.