Astroblog: 31 May, Moonight, Mars and Meteors from 73P?

Tuesday, May 30, 2006

31 May, Moonight, Mars and Meteors from 73P?

(Click to enlarge) Approximate radiant of T-taurids marked with a circle. The view of the Northern horizon at 22:55 pm ACST, similar views will be seeen at similar local times elswhere in the southern hemisphere)

As noted by Tom, the night of Wednesday May 31 is the time of closest apporach of the largest fragment of 73P. The t-Herculid meteor shower is associated with comet 73P, so will we get a decent meteor shower from it? Probably not. Because the comet is relatively so far away (around 0.4 au) it is very unlikely we will see much at all, perhaps 1-2 meteors per hour. In the Southern hemisphere, the radiant (which is near the fouth magnitude star delta Bootis (cirlced in the image above)) never gets very far above the horizon (around 25 deg at Adelaides latitude), so we are likely to see even fewer meteors. Then again, we have been surprised before, so why not take a look. While the radiant isn't high in the Southen hemisphere, in Australia at around 11 pm AEST the comet will pass through earths orbital plane, so this should be the time of maximum meteors (the Americas and Europe miss out on the plane crossing to a large extent). See this interesting paper on the t-Herculids. The best times for meteor showers for 73P is 2022 and 2049. Here's a nice image of 73P from earlier in the month.

(Click to enlarge: northwestern horizon at 6:00 pm ACST, similar views will be seen at similar local times elsewhere in the Southern Hemisphere) 73P meteors aren't the only reason to go out on Wednesday May 31. In the early evening, Mars is close to the crescent Moon. With Saturn nearby, and Castor and Pollux below, this will be an attractive (and photogenic) time to view the sky. Saturn is on the border of the Beehive cluster, and looks very attractive in binoculars. This is the furst step in an array of planetary alignments that I will write about tomorrow.

# posted by Ian Musgrave @ 11:21 pm