It's a clear and slightly chilly night expected in Monrovia. The
crescent moon will be out early, and later Jupiter might clear the trees
to the east.
While tonight's sky is expected to be very transparent (dark), the other
atmospheric feature that affects astronomy is scintillation, a measure
of how turbulent the air is. Astronomers have a technical term for this:
"seeing." The seeing tonight is not expected to be very good, because of
different layers of air temperature and upper level winds.
That's what gives the slightly watery effect you notice when you view
the moon or planets through a telescope, and it gives stars more of a
twinkle when you look up at the night sky.
Notice the brightest star Sirius tonight due south, and see how it
flashes and changes color as its light passes through the turbulent air.
It's a little like looking up at the sky from the bottom of a deep
But "seeing" is highly variable! If you look for a while, you will have
moments when you're looking through air that isn't turbulent, and you
can see fine detail: mountain peaks and lava tubes on the moon, cloud
belts and swirls on Jupiter.
Come take a look if you can.
Jane and I have a family engagement tonight so we won't be there, but
Todd and Dave and maybe some others are planning to set up from about
6:00 'til 8:00.
Mojo and I were talking last night while observing a fairly bright
comet, which is visible near the familiar constellation Orion.
So we thought we should take telescopes out Saturday night. But this
morning we looked at the weather forecast, and sadly we are expecting
clouds and even a chance of rain this weekend. If that changes, we'll
let you know, with short notice, probably on Saturday afternoon.
Meanwhile, if it's clear where you live, definitely step outside with
your binoculars and you too can aim your binos at C/2014 Q2 Lovejoy. Its
color is unmistakeable. It will appear as a ghostly faint fuzzy
blue-green patch much bigger than a star in your binoculars. If you can
Identify Orion, the comet is moving North, from parallel to Orion's
knee, Rigel. It's now close to the Belt stars, and in a week will be
near the Pleiades. I've seen it every night from my front door using 7 x
50 binoculars Here is where to look all month long (for both northern
and southern hemispheres)
In two weeks, three of Jupiter's moons will scoot across the visible
disk of Jupiter, preceded by their shadows - a triple shadow transit!
It's a telescopic viewing opportunity (maybe you'll spot one of the
shadows through good binoculars) and our Monrovia Corner isn't well
suited for this event since it goes on until 11 p.m. on Friday the 23rd
of January. Jupiter won't rise above the buildings until 9 p.m. or so.
Jupiter is the sole topic of my January What's Up video, you can enjoy
it here, and marvel at the images of moons, shadows, eclipse and
occultations, all contributed by amateur astronomers around the world,
and this month, from one of our local sidewalk astronomers, Jon
Philpott! His images appear at 45 seconds into the video and one
features a backyard telescope view of Jupiter and the other showing the
4 galilean moons, two right next to each other, with an overexposed
Jupiter to see the moons better. Here's the YouTube ink
https://www.youtube.com/watch?v=YWlYTppifhI, and more video formats are
There are lots of other naked eye planets to view this month. That's
Venus shining brightly in the west at sunset, with faint Mercury nearby,
and Mars above. Jupiter is king this month, visible all month long. You
can see Saturn at dawn, too!
Thanks all for this month from Jane
Jane Houston Jones
Senior Outreach Specialist, Cassini & InSight Missions
@jhjones @CassiniSaturn @NASAInsight
What's Up For January? Jupiter