Tonight the public forecast calls for "partly cloudy," and the Clear Sky
Chart suggests not entirely transparent skies, but steady seeing. I'm
going to anticipate a good viewing evening from the corner of Myrtle &
Lime and try setting up a telescope.
Sunset is at 7:03, and we'll try to be there from 7:00 - 9:00 p.m.
We'll have a lovely gibbous moon, and Jupiter near opposition. With a
good seeing forecast, I'm going to plan to bring out the giant 7-inch
refractor -- a special treat.
It should be pleasant weather, a little chilly, light winds.
No sidewalk astronomy in Monrovia tonight.
It's not raining, but it's very unsettled in advance of the next storm.
Monrovia is pretty well clouded out right now.
We may try again next weekend, and may try for a special event on a
Monday evening soon. We'll let you know!
March 8 is Jupiter Opposition - when Jupiter is on the opposite side of
Earth from the sun, rising at sunset, setting at dawn and closest to
Earth in its orbit. It will be a little brighter and a little closer to
Earth before, during and after March 8. So don't worry if it is cloudy,
you have several more months of excellent Jupiter viewing opportunities.
The planet, with all its cloud patterns above and below the equator show
well, even in the smallest telescope, and even with steady binoculars.
The four Galilean moons Io, Europa, Callisto and Ganymede are also easy
to see through steadily held binoculars, but much more easily seen in
telescopes of all sizes -- except when they are passing behind the
planet -- or in front.
Near opposition, as a moon passes in front of Jupiter the sun, the
moon's shadow appears against the clouds of Jupiter. Astrophotographers
are capturing images showing the pearly spheres of Io and Europa and
their shadows marching across the face of Jupiter all month long.
There are 11 of these double shadow transits in March, and three of them
are visible from the US. Unfortunately, they are all on Monday nights
and end between 9:30 p.m. and 1:25 a.m.
I doubt we'll get telescopes out after work, but we'll let you know if
someone is available. In the meantime, make friends with that neighbor
with a telescope!
Dates and times
March 15 02:22 UTC March 14 7:22 p.m. - 9:34 p.m. PDT (Pacific
March 22 04:23 UTC March 21 9:23 p.m. - 11:23 p.m. PDT
March 29 07:00 UTC March 28, 12:00 a.m. - 1:25 a.m. PDT
of the three, March 14/15 had the added bonus of volcanic Io overtaking
Europa at the end of the transit.
We animated both the shadow transits and a depiction of the view from
above Jupiter and from Earth in my March What's Up Video
If you have trouble with YouTube, here's the JPL version
We're hoping to do sidewalk astronomy in Monrovia, weather and schedules
permitting on either March 12 or 19th, maybe both.
Jane and the Old Town Sidewalk Astronomers
Jane Houston Jones
What's Up March 2016: Jupiter, its moons, their shadows