Friday, March 18, 2011

Super Moon tomorrow night!

From the NASA Science website:

On March 19th, a full Moon of rare size and beauty will rise in the east at sunset. It's a super "perigee moon"--the biggest in almost 20 years.

Full Moons vary in size because of the oval shape of the Moon's orbit. It is an ellipse with one side (perigee) about 50,000 km closer to Earth than the other (apogee): diagram. Nearby perigee moons are about 14% bigger and 30% brighter than lesser moons that occur on the apogee side of the Moon's orbit.

Super Full Moon (movie strip, 550px)
Above: Perigee moons are as much as 14% wider and 30% brighter than lesser full Moons. [video]

"The full Moon of March 19th occurs less than one hour away from perigee--a near-perfect coincidence1 that happens only 18 years or so,

"A perigee full Moon brings with it extra-high "perigean tides," but this is nothing to worry about, according to NOAA. In most places, lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 15 centimeters (six inches)--not exactly a great flood.

Super Full Moon (moon illusion, 200px)
The Moon looks extra-big when it is beaming through foreground objects--a.k.a. "the Moon illusion."

Indeed, contrary to some reports circulating the Internet, perigee Moons do not trigger natural disasters. The "super moon" of March 1983, for instance, passed without incident. And an almost-super Moon in Dec. 2008 also proved harmless.

Okay, the Moon is 14% bigger than usual, but can you really tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon can seem much like any other.

The best time to look is when the Moon is near the horizon. That is when illusion mixes with reality to produce a truly stunning view. For reasons not fully understood by astronomers or psychologists, low-hanging Moons look unnaturally large when they beam through trees, buildings and other foreground objects. On March 19th, why not let the "Moon illusion" amplify a full Moon that's extra-big to begin with? The swollen orb rising in the east at sunset may seem so nearby, you can almost reach out and touch it.

Don't bother. Even a super perigee Moon is still 356,577 km away. That is, it turns out, a distance of rare beauty.

PS from Marie

The moon rises tomorrow at 7:27 Daylight Savings Time. You should be seeing the planet Saturn quite close to the moon shortly after moonrise. Also nearby, the bright star Regulus from the constellation Leo.

Central Park's Belvedere Castle would be a perfect place to watch this spectacular show.

Wednesday, March 16, 2011

What's in a name

Pale Male in Central Park - fall 2009

With Pale Male and his new mate making love in plain sight on rooftops near the nest building [ 5th Ave and 74th Street] the hawkwatching season of 2011 has joyfully begun. There will be eggs in the nest any day now; the clock will start ticking for the 28-32 day incubation period. It is high time to settle on a name for the handsome female red-tailed hawk Pale Male has paired up with this year.

Why name these hawks at all? Obviously it doesn't matter to the hawks themselves; it is entirely for the hawkwatchers' convenience. In November, 1991, when a light-colored red-tailed hawk began to hang around Central Park's Ramble, the park's birdwatchers took notice; hawks of any species were rare visitors to the park then. Soon, however, it became cumbersome to keep referring to the bird as "the light-colored male red-tailed hawk." When someone simplified things by referring to the bird as Pale Male, the name stuck. A perfect name, focusing as it did on a physical attribute of the bird -- his unusually light color. And by choosing a descriptive name rather than a "people name" such as Henry or Robert , the hawkwatchers avoided being scorned for anthropomorphism, the much reviled attribution of human characteristics to things or animals.

Central Park hawkwatchers have continued to avoid anthropomorphism in the names they've assigned subsequent females at the Fifth Avenue nest, by using a physical attribute [Chocolate, Blue] or a time reference [First Love] for each of Pale Male's mates. Even the seemingly non-descriptive name of Lola, the reigning female at the nest from 2002 to 2010, has an explanation. When Lola first showed up in Central Park she still had some juvenile plumage. This suggested that she might be too young for breeding: hence she was called Lolita [after Nabokov's underaged heroine]. She soon proved to be old enough. As she matured the name was shortened to Lola.

We need a name for the new female Pale Male has been courting so conspicuously on the rooftops and TV antennas of Fifth Avenue. But assigning her an arbitrary human name [like Paula] is not in keeping with the historic naming patterns Central Park hawkwatchers have always followed.

We need another descriptive name. Since Pale Male's new mate [see, it's too long to keep saying!] is notably light in color - -as light, indeed, as Pale Male himself -- I once suggested Pale Beauty--it also happens to be the name of a beautiful moth. But lots of other names denoting lightness in color fall more trippingly on the tongue: Blanche, Pearl, Honey, Lily, Snow White -- that's off the top of my head. There's a better name somewhere, I'm sure of it.

Any ideas, anyone?

Monday, March 14, 2011


Eastern Phoebe in Central Park 3/30/09

Yesterday [3/13] birder Sharon Berlan wrote to eBirds:

an Eastern Phoebe was seen in Central Park behind the Tupelo tree, this morning. Also a yellow rumped/Myrtle warbler (strawberry field area) - along w/the usual suspects.

Today Tom Fiore noted the Phoebe arrivals and added other signs of spring:

Hi Marie,

In case you have not seen or heard about them, Eastern Phoebes have arrived in Central Park. There were several in as of Sunday, including one or more in the Ramble. They also turned up near Sheep Meadow and in the north woods. Other signs of spring are about, and on Saturday all of the ponds and lakes in the park had sunning turtles - many, many turtles. Of rare and uncommon birds, the Varied Thrush was still there Sunday, and the Red-headed Woodpecker as well, each in the same areas where they had been much of the winter, the maintenance field area & the trees south of Sheep Meadow, respectively. A number of other signs of the season include many more birds singing, among these: small numbers of Fox Sparrows. The willows are gaining in color and the maples are showing their reds; blooms on some other trees are almost out and likely will be soon.