Astronomy

By John Harrod, Manager, Dupont Environmental Education Center
 
This past Thursday was a great fall day for an outing on the Christina River with a clear sky and a light breeze. On this day, the Delaware Nature Society led a late afternoon historic river cruise. Participants were treated to accounts of the river by Sally O’Byrne, DNS naturalist and co-author of Wilmington’s Waterfront.

 

Some happy boaters by John Harrod

Some happy boaters by John Harrod

Sally O’Byrne’s details of the waterfront’s history was extensive and informative, but as a summary,  it has a very rich industrial history that includes building the first iron hulled yacht to win the America’s Cup and making significant contributions to the navel efforts of WWII. 

Christina River ship building remnants by John Harrod

Christina River ship building remnants by John Harrod

Being on the water allowed us views not often seen riverfront including Swedes landing. I am going to let the photos do the rest of the talking. Enjoy the pictorial journey!
Swedes Landing by John Harrod

Swedes Landing by John Harrod

 

 

 

 

 

Christina landing by John Harrod

Christina landing by John Harrod

 

 

 

 

 

 

Boat at sunset by John Harrod

Boat at sunset by John Harrod

 

 

 

 

 

 

 

Justison landing at dusk by John Harrod

Justison landing at dusk by John Harrod

 

 

 

 

 

 

 

 

If you would like to spend some time on the  Christina River, DNS has a canoe trip this Saturday, October 31st that puts in the water near Churchman’s marsh and paddes down to the DuPont Environmental Education Center. For details visit: http://www.delawarenaturesociety.org/fp09_adult.html#deec.

by The Unknown Astronomer

I hope you all had unclouded views of the gorgeous conjunction of Venus, Jupiter, and the moon last weekend, and that you continue to observe Jupiter in decline and Venus ascendant.  Of course, the two planets are not really approaching and receding from one another in space.  What is actually going on is more a race than a dance.

Jupiter, Venus and Moon, Dec 1, 2008.  Image from Starry Night Pro Software

Jupiter, Venus and Moon, Dec 1, 2008. Image from Starry Night Pro Software

Picture a circular track with the sun in the center.  The innermost lane is occupied by the planet Mercury, whizzing around the track like Jimmie Johnson at Dover Downs, and completing its circuit in a mere 88 days.  Venus is in lane 2, making its journey in a zippy 243 days – not exactly NASCAR, but at least a turbo-charged Mustang.  Earth orbits in lane 3, getting once around in a respectable 365 days – the Mustang minus the turbocharger. By the time we get to lane 6, way out beyond Mars and the asteroids, it’s taking 12 years to complete one circuit.  That’s Jupiter – a Yugo driven by your grandmother.

So, what we have been observing over the last couple of weeks is a nightly snapshot of speedy Venus overtaking plodding Jupiter, from the perspective of lane 3.

Another effect of where we all are in space (or on that track) is the sometimes peculiar look of Venus through a telescope.  Right now it appears to be a tiny half-moon!  Indeed, like the moon, Venus (and Mercury) has phases, and for the same reason:  since it is inward toward the sun from our perspective on Earth (lane 2 as seen from lane 3), the planet will at times be only partially lit, appearing as full,  half, or crescent as it approaches and overtakes the Earth.

Now, how do you follow an act like a planetary conjunction?  WIth a meteor shower!  The Geminids, so named because they appear to radiate from the constellation Gemini, peak on the night/morning of Dec. 13 – 14.  These are bright, medium-fast meteors that can be colorful: In addition to the usual white, I have seen distinctly yellow and green ones, and they can also be blue or even red.  You can start looking a little north of east any time after 8:00 pm.  Gemini will have just cleared the horizon by then, so the best time to observe is realy after midnight, when Gemini is high in the sky.  There is one major problem with this year’s shower, however – we will be just one night removed from the largest, closest, brightest full moon of 2008, which will blot out all but the brightest meteors.  Ah, the moon – beloved of poets and romantics, bane of astronomers…

No matter which category you fit into, if it’s clear, brave the cold anyway – at it’s height,  this shower can produce a meteor a minute!

By:  The Unknown Astronomer

When naturalists look to the sky, it’s usually to spot birds.

For at least the next few evenings, though, I encourage you to look beyond the birds to watch a beautiful celestial event unfold.

If you look low in the southwest at dusk tonight you will see two bright planets:  Venus, blazing just above the handle of the “teapot” star group (sinking spout-first into the horizon) in the constellation Sagittarius; and Jupiter, a little higher than Venus and a bit less brilliant.

Over the next few days, Venus will creep closer and closer to Jupiter, joined in the chase by a very low, razor-thin crescent moon on 11/29.  On the following evening the two planets will be a mere 2 degrees apart and the moon will have closed to within a few degrees of the pair.  By 12/1, moon, Venus, and Jupiter will be at their closest to one another, forming a lovely, compact trio that should fit within many binocular fields.  Good binoculars held steady, or a small telescope, will also show you something unusual about the appearance of the planet Venus itself.  What do you see? 

Try to get out on subsequent evenings and watch as Venus s-l-o-w-l-y overtakes Jupiter, and the waxing moon leapfrogs across the sky, leaving both planets behind.

Are the moon and planets really performing this sweet celestial dance?  What is  unusual about Venus’s appearance?  Post the answer(s) if you know; otherwise, keep one eye on the sky and one eye out for the next appearance of the Unknown Astronomer.

Unknown Astronomer

Unknown Astronomer