Journal of the Amateur Astronomers Association of New York

July 2015 Volume 64 Number 7; ISSN 0146-7662

Come Sail Away with Me: The Launch of the LightSail

By Stanley Fertig

On May 20, the Planetary Society’s LightSail success-

fully launched into orbit, and I was fortunate to be among

the Society’s guests attending that day at Cape Canaveral.

LightSail represents nothing less than a revolution in space

exploration. It is the first satellite financed entirely by the

public at large. The Society received donations directly and

through a crowdfunding campaign organized by Brooklyn’s

own Kickstarter. It blasted past its initial target in one day

and rapidly surpassed even the most fervent believers’ expec-

tations: over $500,000 donated by over 10,000 individuals in

less than a week!

LightSail also represents

an exciting alternative to con-

ventional chemical propulsion,

with a promise of faster,

cheaper space travel in the

future. It’s exactly what it

sounds like: a spacecraft with

a sail propelled by light from

the Sun. Think of the great

sailing ships of the 16th centu-

ry explorers that used wind to

tack their way across oceans

to discover new lands – now imagine sailing spaceships

pushed by the Sun across the Solar System to explore other

worlds. LightSail gives new meaning to solar wind.

“Although photons have no mass, they nevertheless can

impart a small bit of momentum to an object they strike,” ex-

plained Jason Davis of the Planetary Society. This surprising

property of light was first discovered by James Clark Maxwell

in 1865. While the push is extremely gentle – for LightSail

it’s about the weight of a fly sitting on your hand! – the force

is continuous. In frictionless space, with a large enough sail,

an object can accelerate gradually to great speeds. The main

advantage of solar sailing is that the Sun provides the fuel for

free. Of course, a huge amount of chemical fuel is still need-

ed for liftoff from the Earth’s surface by rocket, but a tradi-

tional spacecraft must carry additional propellant to be able to

accelerate out of orbit and make course changes on route to a

THIS MONTH: Observing at North-South Lake Jul 18/19 & Astronomy Night at the Intrepid Jul 24

FOR THE LOVE OF LIFTOFF

A Pluto Primer as New Horizons Homes in on the Icy Dwarf

By Amy Wagner

For the first time, hu-

mans will get a close-up view

of an icy dwarf planet in our

outer Solar System. When

NASA’s New Horizons space-

craft reaches Pluto this month,

after a 9 1/2-year and 2.8 bil-

lion-mile journey, we will final-

ly be able to study a type of

object never examined before.

“This is a very exciting time for

planetary science,” said AAA’s

Jaclyn Avidon, who presented

at a special Astro Answers event on May 8 entitled “New

Horizons: Exploring Pluto.” She likened New Horizons to

the Apollo 11 lunar landing in 1969 – a major “first” in the

exploration of our Solar System.

The celestial bodies found in our Solar System can be

divided into three groups fanning out from the Sun: rocky

planets (including asteroids and rocky dwarfs, like Ceres and

Vesta), gas giants, and icy dwarfs. In the 1960s and 1970s,

humans began exploring the first two groups, but up until

now, icy dwarfs have gone unexamined.

NASA and its university partner, Johns Hopkins Applied

Physics Laboratory, along with Southwest Research Institute,

hope to accomplish sev-

eral goals with the New

Horizons mission. They

seek to map Pluto’s sur-

face, understand its geol-

ogy and morphology,

study its atmosphere,

measure its temperature,

and image the moons of

the Pluto-Charon system.

Pluto and its largest

moon share a center of

gravity that lies between

the two bodies, so they

Astro Answers (cont’d on Page 6) LightSail Launch (cont’d on Page 5)

AAA ASTRO ANSWERS

NASA/James McDivitt

NASA celebrated 50 years of spacewalks on June 3. In 1965, Gemini 4 astronaut Ed White, seen here, became the first American to walk in space.

NASA/JPL

A highly pixilated image of Pluto from May taken by New Horizons from 50 million miles away.

NASA/JPL

A close-up of Jupiter’s Great Red Spot taken by Voyager 1 in 1979 from 5 million miles away. Scientists hope New Horizons will give us as detailed an image of Pluto.

Josh Spradling/The Planetary Society

Artist’s image of Lightsail in orbit.

2

July’s Evening Planets: Bight Venus and Jupiter can

be found under Leo the Lion until 10 PM, setting earlier eve-

ry night until 9 PM at the end of July. Neptune will be in

Aquarius the Water Bearer as of midnight, rising earlier eve-

ry night until 9PM at the end of the month. Uranus can be

found in Pisces, rising one hour after Neptune. Find Saturn

in Libra the Scales and dwarf planet Pluto in Sagittarius the

Archer all night.

July’s Evening Stars: Spot the Summer Triangle of

Vega in Lyra the Harp, Deneb in Cygnus the Swan, and Al-

tair in Aquila the Eagle all night. See Spica in Virgo the

Virgin, Antares in Scorpius the Scorpion, and Arcturus in

Boötes the Herdsman. Also find the stars of constellations

Cassiopeia, Cepheus, Draco, Virgo, Sagittarius, Libra, Her-

cules, Ophiuchus, and the two Dippers throughout the month.

July’s Morning Planets: Saturn is up between Scorpi-

us the Scorpion and Libra the Scales until 4 AM, setting ear-

lier each morning until 1 AM at the end of July. Uranus rises

in Pisces one hour after Neptune in Aquarius the Water

Bearer at 12 AM. Mars rises in Gemini the Twins at 5

AM every day with Mercury there in the first half of July.

Dwarf planet Pluto is in Sagittarius the Archer until sunrise.

July’s Morning Stars: Find the Summer Triangle of

Vega in Lyra the Harp, Deneb in Cygnus the Swan, and Al-

tair in Aquila the Eagle. Look for Capella in Auriga the

Charioteer, Aldebaran in Taurus the Bull, along with the stars

of constellations Lyra, Hercules, Sagittarius, Aquarius, Cap-

ricornus, Pisces, Aries, Draco, Pegasus, Cassiopeia, Cepheus,

Andromeda, Draco, and the two Dippers.

Jul 1 Full Moon at 10:20 PM

Jul 5 Moon at perigee (228,100 miles from Earth)

Jul 6 Earth at aphelion, farthest from Sun in 2015

Jul 8 Last Quarter Moon at 4:25 PM

Jul 15 New Moon at 9:25 PM

Jul 18 Venus 0.5° north of the Moon (sunset)

Jul 21 Moon at apogee (251,500 miles from Earth)

Jul 23 Venus stationary

Jul 24 First Quarter Moon at 12:05 AM

Jul 26 Saturn 2° north of the Moon (pre-dawn)

Jul 26 Uranus stationary

Jul 31 Full Moon at 6:20 AM

Times given in EDT.

WHAT’S UP IN THE SKY

July 2015

Naked-eye Stargazing in NYC

With so much to see in New York City, you may not realize

how much there is to see above it. Despite the glow of its

bright lights, there’s plenty to view in New York’s night sky

without the aid of equipment. On a clear night, you can find

20-30 objects shining above the Big Apple. Here is a list of

some of those objects you can see with the naked eye.

Big and Bright

The Moon: The

brightest object

in our night sky,

only tall build-

ings can hide it.

Planets: After

the Moon, Venus,

Jupiter, Mars,

and Mercury are the next brightest objects. Saturn is also

very bright with only a few stars more luminous. Planets are

often mistaken for stars, but you’ll notice they don’t twinkle.

Much closer to Earth, their lights shine steady without the

same interference of our atmosphere which distorts starlight.

Points of Light

Stars and Constellations: Sirius tops the list as the brightest

star viewed from Earth. Other bright stars include Arcturus,

Vega, Capella, Spica, Antares, Betelgeuse, Rigel, Deneb, and

Altair. In city skies, the shape-forming stars of constellations

Orion and Ursa Major (Big Dipper) can easily be seen.

Smudges and Spots

Galaxies: Our nearest neighbor, Andromeda, is 2.5 million

light-years away – a tiny bit of haze in only the darkest areas.

Nebulae: The Orion Nebula (M42) can be seen as misty spot

below Orion’s Belt in that constellation.

Star Clusters: The Pleiades cluster contains over a thousand

stars. It is a haze of light in our city sky, but in darker places

the brightest six of the “Seven Sisters” can be picked out.

On the Move

Comets: Halley and Hale-Bopp are large, nearby comets that

were visible to the naked eye when they appeared in the 80s

and 90s, but they won’t be back for a while.

Meteors and fireballs: In New York, shooting stars dart

across the sky. But city dwellers see barely a quarter of the

number spotted upstate during a meteor shower.

Satellites: Many of the thousands of artificial satellites that

orbit Earth are visible, like the International Space Station.

Slower than a meteor, it takes 5 minutes to cross the sky.

Now for some urban observing tips. Avoid lampposts.

Move even a few yards away, and there’s a drastic differ-

ence. Be patient. As your eyes get used to the dark, more

objects will appear. Head to the rivers. Get a wider view at

the city’s edges with the buildings out of the way. Observe

with AAA! Check the club’s calendar for stargazing sessions

at locations throughout the boroughs of NYC.

Follow veteran sky watcher Tony Faddoul each month, as he points our minds and our scopes toward the night sky.

AAA Observers’ Guide

By Tony Faddoul

July “Skylights”

3

July 2015

Seen In Space Spitzer Makes a Far Out Microlensing Discovery

In April, NASA’s Spitzer Space Telescope discovered

one of the farthest exoplanets from Earth in our galaxy at

13,000 light-years away. Less than 1% of the Milky

Way’s 1,852 confirmed exoplanets are that far, with the far-

thest about 25,000 light-years from Earth. Spitzer found the

new gas giant, with help from the ground-based Polish Opti-

cal Gravitational Lensing Experiment (OGLE), using the mi-

crolensing technique. When one star passes in front of anoth-

er, its gravity can act as a lens to magnify and intensify the

light of the star behind it. If the foreground star has a planet,

it will cause a blip in the light. OGLE is searching for planets

toward the center of our galaxy, where star crossing is more

common. Ground telescopes have found about 30 exoplanets

with microlensing, but their distances can’t be pinpointed.

When a space telescope observes the same microlensing event

from its vantage, then two sets of measurements can be used

to calculate the planet’s distance, or parallax. "Spitzer is the

first space telescope to make a microlens parallax measure-

ment for a planet," said lead author Jennifer Yee, "…ground-

based telescopes are not as effective at such great distances."

Spitzer is in Earth-trailing orbit around the Sun, drifting 1/10

AU behind each

year. It’s about

128 million miles

from Earth right

now. Spitzer saw

the microlensing

20 days before

OGLE. Usually,

the time-delay to

ready a second

telescope takes

too long to catch microlensing, because they are short-lived

events. Fortunately, this one lasted for 150 days. Calculating

the distance, scientists then determined the new planet’s mass.

Thanks to Spitzer, scientists can find and characterize far-

away exoplanets and ultimately learn how they’re distributed

throughout our galaxy. AMW Sources: spitzer.caltech.edu.

Also Seen in Space WISE Finds the Brightest Galaxy in the Universe

NASA’s Wide-field Infrared Survey Explorer

(WISE) mission ended almost five years ago, but its data

continues to astonish – in May, scientists announced finding

the brightest known galaxy. WISE conducted an infrared

survey of the entire sky in 2010. (Renamed NEOWISE, it

imaged near-Earth

objects before its

2011 decommission;

observations re-

sumed in 2013.)

WISE has revealed a

new class of objects

called ELIRGs, ex-

tremely luminous

infrared galaxies,

found in the distant universe and undetectable in visible light.

There are about 20 of these most luminous galaxies, and

WISE J224607.57-052635.0 is the brightest yet. 12.5 billion

light-years away, the light from a quasar at its giant black hole

shines 300 trillion times brighter than the Sun. Although

smaller than our Milky Way, the galaxy generates 10,000

times more energy. "This dazzling light may be from the main

growth spurt of the galaxy’s black hole," said Chao-Wei Tsai

of NASA. Supermassive black holes are common at galactic

centers, but it is rare to find one so far back in time. How did

it get so big when the universe was still so young? "How do

you get an elephant?" asked Peter Eisenhardt, project scientist

for WISE. "One way is start with a baby elephant." Perhaps, it

was just born big. Another explanation is a voracious appe-

tite. The pressure of radiating light pushes gas away from a

black hole, limiting its consumption – and while it is possible

to overcome that, this black hole would have had to break the

limit over and over to become so enormous. Or perhaps, it

pushes the limit during a long binge – if it isn’t moving too

fast. If a black hole spins slowly enough, it repels less food,

and it can gorge itself for longer. “It’s like winning a hot-dog

-eating contest lasting hundreds of millions of years,” said co

-author Andrew Blain. AMW Source: nasa.gov.

Out of This World Boeing and Space X Race to Restore American Crew Launches

In May, NASA placed an order with Boeing for a crew mission to the International Space Station,

and another order is on the way for rival SpaceX. The U.S. space agency is pitting the companies against

each other for a 2017 slot to be the first crew launch by America since the Space Shuttle program ended. Since

2011, U.S. astronauts have had to use Russian Soyuz to get to the ISS. NASA’s Commercial Crew Program

has enlisted private companies to restore human spaceflight capability to the U.S. A standard mission would

carry four astronauts, but Boeing’s CST-100 can hold up to seven. “It also will give us crew return capability...letting us complete

a backlog of hands-on critical research that has been building up,” said ISS chief scientist Julie Robinson.

SpaceX’s Dragon has hauled cargo to and from the ISS since 2012, and a modified Crew Dragon completed a key

flight test in May. But if program funding is not approved for 2016, certification for either capsule will be de-

layed, extending reliance on Russian crew vessels. Yet, the U.S. is also dependent on Russian rocket engines –

and so is one of the competitors. Boeing and Lockheed Martin form the United Launch Alliance (ULA), which

uses Russian engines in Atlas rockets for U.S. defense launches. ULA has a monopoly over the launches and sup-

ported a Pentagon request to ease the U.S. ban on the engines imposed following Russia’s annexation of Crimea.

Meanwhile, SpaceX’s Falcon 9 rocket just received certification from the Air Force. The ban was lifted in June,

so SpaceX will not take over the monopoly, and Russian rockets remain. AMW Sources: nasa.gov; nytimes.com.

NASA/JPL-Caltech

Spitzer found an exoplanet toward our galaxy’s center, one of the furthest away discovered.

NASA/JPL-Caltech

Artist’s concept of the brightest galaxy in our universe, WISE J224607.57-052635.0.

NASA

Boeing’s CST-100.

SpaceX

Crew Dragon.

4

Eyeing the Inside

By Stan Honda

We’ve all looked through a telescope, but have you

ever wondered what it’s like to be inside a telescope? In

April, I had the unique pleasure of walking through the tube

of the McMath-Pierce Solar Telescope at Kitt Peak, near Tuc-

son, Arizona. The visit was part of a weeklong trip I took

with Ken Spencer, President of the Astronomical Society of

Long Island. We joined friends Mike Terenzoni, who works

at Kitt Peak’s 90” telescope, and Dean Ketelson, a former Kitt

Peak employee now at University of Arizona’s Mirror Lab.

First up that week, Dean arranged a tour of the Large

Binocular Telescope (LBT) on Mount Graham, a three-hour

drive from Tucson. Daytime temperatures were in the 90s in

the city, but we took winter clothes, because the LBT sits atop

a 10,700-ft. mountain, where it can be 40°F and colder. The

LBT offered a great view from above its twin mirrors, and we

were permitted to take pictures inside the dome that night

while two astronomers conducted observations.

The LBT isn’t just large, it’s huge! It has two 8.4-meter

mirrors, each ranking as the second-largest optical telescope

in the world. The dome is cube-shaped, and separate doors

open for each mirror, leaving a skeletal structure visible while

observing. I could barely fit it all into frame for a picture. I

selected a Nikon 16mm fisheye mounted on a Sony a7S cam-

era; the a7S has an extremely high ISO setting, making it

great for night photography. Several companies make adapt-

ers to use Canon, Nikon, or Leica lenses on the a7 models. I

own a Novoflex, which is very sturdy. I tried to position my-

self as far into a corner as possible to get the scope and the

dome in one shot. Motors whirred as the scope repositioned

itself throughout the evening. To move in azimuth, the whole

dome rotates. Standing on the floor, we couldn’t feel the

movement. Later, I noticed star trails in one of my photos,

though I had taken short exposures. I was confused, until

Dean pointed out that we were the ones moving, not the stars.

I set my camera at 12,800 ISO to record the faint light

hitting the scope. As darkness fell, the stars shone brightly

through the dome openings. My best exposures were 15 sec.,

f2.8. I was able to capture the telescope and keep the stars

sharp with the short shutter speed.

We returned to Tucson at 2:30 AM – the start to a week

of sleep deprivation – and later that morning we headed to

July 2015

Kitt Peak for a tour of the McMath-Pierce with solar astrono-

mer Matt Penn. I was fortunate to meet Matt at the Northeast

Astro-Imaging Conference earlier that month. He generously

offered the tour, when I mentioned my upcoming trip.

We started in the McMath-Pierce observing lab. The

Sun’s image is directed toward the instruments, and an opera-

tor has to wear sunglasses. Then, we entered the telescope

tube itself – a bizarre notion indeed. At 400 ft., it’s the long-

est in the world. The structure is permanently inclined at 32

degrees to match the observatory’s latitude. Inside, the walls

are diagonal; anyone working long hours there leaves feeling

disoriented. Halfway along, we looked up to see heliostats

reflecting the solar image down the tube. At the top, we were

treated to a panoramic view of all the Kitt Peak observatories.

It was too windy to set up our scopes that night, so we

tried the 20” telescope at the Kitt Peak Visitor Center. It was

wondrous to see star clusters, galaxies, and other objects

through that large aperture scope. Ken and I attempted some

long-exposure, hand-held photos of the open dome, scope,

and night sky, supporting our cameras on chairs or on our

knees and turning up the ISO to

get short shutter speeds. Finally, I

gave in and set up my small tripod

to take a few more relaxed shots.

Over the next few days, we

attended a talk by astroimager

Adam Block at the Mount Lem-

mon Observatory near Tucson,

and Ken and I drove to the dark

skies of Cave Creek Canyon in

southeast Arizona for binocular

observing and photography. By

the end of the trip, we finally

caught up on our sleep – rested

and ready to reflect on a wondrous

week of astronomy adventures.

FOCUS ON THE UNIVERSE

Submit your photography questions to stanhonda@gmail.com.

Explore night sky photography at

www.stanhonda.com

Stan Honda is a professional photographer. Formerly with Agence

France-Presse, Stan covered the Space Shuttle program. In his

“Focus on the Universe” column, he shares his night sky images and

explores his passions for astronomy and photography.

Stan Honda

Looking up the tube of the McMath-Pierce Solar Telescope.

Stan Honda

Red lights illuminate the dome of the 20” telescope at the Kitt Peak visitor center.

Stan Honda

The Large Binocular Telescope on Mount Graham in AZ.

5

July 2015

AAA Around Town Stargazing at the World Science Festival in May

In May,

AAA joined the

World Science

Festival (WSF)

for an evening

of astronomy

and a day of

solar observing.

Saturday,

May 30 was an

event-filled night

at Brooklyn

Bridge Park with

various talks

about space. NASA astronauts Lee Morin and Nicole Scott

were on hand to answer questions, and AAA’s own Irene

Pease took to the stage with Emily Rice from Astronomy on

Tap to play a game called “Earth or Other Worlds.” AAA

members also came out in force to set up telescopes along the

Pier 1 waterfront. The view of the Manhattan skyline was

spectacular, but the real attractions were Jupiter, Venus, Sat-

urn, and the Moon. Hundreds of people filled the park, pa-

tiently waiting in long lines to see the great celestial sights,

while AAA’s Susan Andreoli handed out red glow sticks to

the kids. This was my fourth year observing for the annual

WSF Night Lights, Big City event, which is extremely dedi-

cated to making it easy to bring a telescope. Parking is free,

and the WSF staff will help you unload your equipment and

even bring it down to the waterfront for you. WSF really sup-

ports observers and makes them feel special. I’m already

looking forward to next year!

The next day, WSF held its Ultimate Science Street Fair,

and AAA was back for solar observing fun. Washington

Square Park was filled with tents sporting all sorts of science

themes with hands-on activities, demonstrations, and interac-

tive experiments. The AAA tent was abuzz with activity too:

UV bracelet-making for kids, raffles for four telescope prizes,

and the fan favorite—a mini Martian rover demo by AAA’s

“Jupiter” Joe Martinez. AAA President Marcelo Cabrera set

up the club’s brand new Lundt solar telescopes, treating peo-

ple to fantastic views of the Sun in H-Alpha light. If you

think the only place to get a sun tan is the beach, think again!

AAA member volunteers also distributed promotional materi-

als and spoke to

people about the

many great ways

that AAA brings

astronomy to the

public. It was a

wonderful day,

and the rain held

off for most of it,

so we all felt

pretty lucky.

Rori Baldari

destination. Not only is the extra fuel itself expensive, but it

requires a larger, heavier, and costlier vessel to hold it.

LightSail’s spacecraft is only the size of a loaf of bread.

Of course, this mini spacecraft (made of three stacked

10cm3 experimental satellites called CubeSats) comes

wrapped in a vast sail that unfurls to 32 square meters. The

sail is constructed of four triangular pieces of Mylar that form

a square. Astoundingly thin yet strong, the material is only 5

microns thick, about the diameter of a red blood cell.

In 1976, Carl Sagan, a co-founder of the Planetary Soci-

ety, proposed solar sailing in an interview on Johnny Carson’s

Tonight Show. Almost forty years later, his dream is now

realized with Lightsail, which hitched a free ride to orbit from

NASA aboard an Atlas V rocket. But, it won’t be doing any

sailing. This mission is designed simply to test equipment,

electronics, and communications. After it drifts away from

other CubeSats launched, its sail will unfurl. Shortly thereaf-

ter, drag will pull Lightsail toward Earth to meet a fiery end in

the Earth’s atmosphere. All will be over in a matter of weeks.

The night before launch, Society members gathered for

dinner in anticipation of the event. This would be the second

attempt to send up a solar sail. Ten years ago, the first one

perished aboard a Russian rocket that failed to achieve orbit.

On the morning of May 20, we sat together in the Florida heat

in bleachers at the Kennedy Space Center, listening to pre-

launch checks: “X system: Go!” “Y system: Go!” We had

all seen this scene in Apollo 13 and countless other films, but

there’s nothing like being there – a real launch is thrilling!

However, we weren’t very close to the action. There was a

good distance between the rockets and onlookers “in case

anything goes wrong,” as a NASA spokesperson wryly put it.

The last ten seconds of countdown began, an orange flame

appeared below the rocket, and then liftoff! The rocket rose,

accelerating incredibly fast. Less than a minute later, it was

out of view in the mist above the horizon, far from the cheers

of the crowd crying out, “Go LightSail!”

Lightsail’s 25-day mission ended on June 15 when it

burned up in the Earth’s atmosphere. Although the spacecraft

ran into several technical problems, its mission is considered a

success. The vessel proved spaceworthy and it was able to

deploy its sail. Another Lightsail model will launch in late

2016 aboard a SpaceX Falcon rocket to a higher orbit, where

it will finally use photon-powered propulsion and fly!

LightSail Launch (cont’d from page 1)

Stanley Fertig

AAA’s Stanley Fertig witnessed the launch of the Planetary Society’s LightSail at Cape Canaveral on March 20.

Greg Kessler

AAA Member Bart Fried with his antique brass refractor at the World Science Festival’s Night Lights, Big City event on May 30.

Rori Baldari

AAA President Marcelo Cabrera observing at WSF’s Ultimate Science Street Fair on May 31.

6

July 2015

ever launched. With the quickest launch speed ever at about

36,000 mph in January 2006, New Horizons then received a

gravity-assist at Jupiter in 2007 to slingshot it to a current

speed of about 51,000 mph on its path to Pluto. It will slow

down to 30,800 mph to grab pics of Pluto during the flyby this

month, but its data won’t be downloaded for another 9 months.

After that, the data will still need to be analyzed, so it could be

a year or so before we learn anything from the probe.

Once finished with its departure phase from Pluto-Charon

in 2016, the New Horizon’s science team hopes to extend the

mission for a flyby of a distant Kuiper Belt Object (KBO) in

2018 or 2019. A candidate KBO will be selected soon, and the

probe will fire its engines this fall to reach the target. Howev-

er, funding for an extended mission has not yet been granted,

so we may never get to see it. But the probe itself is destined to

keep going; it will continue on forever. Whether or not New

Horizons gets to study a KBO, it will finally help us fill in the

gaps about icy dwarfs and propel exploration out to the furthest

reaches of our Solar System, and beyond.

AAA Around Town Stargazing at OutdoorFest in May

AAA members

rallied to bring the

night sky within reach

to spirited attendees

at the opening of New

York’s annual Out-

doorFest on May 29.

Now in its second

year, OutdoorFest,

aims to connect urban

dwellers with an

awareness and appreci-

ation for nature and

outdoor adventure. Sarah Knapp, founder of the ten-day festi-

val, asked AAA to return this year with an observing session

at the opening event, the 5K Headlamp Trail Run and Cam-

pout at the Henry Kauffman Campgrounds in Staten Island.

I was joined there by AAA Members Joe DiNapoli, Otto

Chin, Rich Dewar, and Siyu Tu, along with friends Nina

Shankar and Charlie Ridgway. Each volunteered their time,

equipment, and unique enthusiasm for the night sky with the

OutdoorFest participants. Visitors included runners, campers,

event staff, and vendors.

Through a hazy sky with thin, cirrus clouds, we aimed

six scopes at Solar System objects that spanned the ecliptic

from the west to east: Venus in Gemini, Jupiter in Cancer, the

Moon in Virgo, and Saturn in Libra. Bright stars and constel-

lations were traced out with fingertips, and a partial 22° lunar

halo could be seen.

At the end of the night, we packed our scopes into dew-

dampened bags and chatted in the open field, surrounded by

trees and rolling hills. We amused each other with stories

about our observing experiences before making our merry

ways home around midnight. AAA’s participation in Out-

doorFest gave us a wonderful opportunity to enjoy the special

gratification that observing offers with fellowship and the joy

of a shared interest in astronomy. Peter Tagatac

orbit each other as a binary,

unique in our Solar System.

Together, their size is less

than that of the continental

U.S. The other four known

moons were only discovered

in the past ten years—Nix and

Hydra in 2005, Kerberos in

2011, and Styx in 2012—so

there could be more out there

for New Horizons to find.

Pluto itself was discov-

ered in 1930 by Clyde Wil-

liam Tombaugh at the Lowell

Observatory in Flagstaff, Ari-

zona. Founder Percival Low-

ell began a search in 1906, ten

years before his death, for a

“Planet X,” which he believed was responsible for discrepan-

cies in the observed orbits of Uranus and Neptune. In 1978,

when Charon was discovered and Pluto’s mass could be deter-

mined, astronomers realized the system’s gravitational effects

were negligible on those gas giants. In fact, the discrepancies

were due to an error in the calculation of Neptune’s mass.

Pluto was considered to be the ninth planet in our Solar

System when discovered, but in 2006 it was reclassified as a

dwarf planet. The International Astronomical Union then

defined a planet as a body that orbits a star, is spherical in

shape, and clears the neighborhood around its orbit. In binary

with Charon, Pluto does not meet the last criterion—but a new

“dwarf planet” category was created for it.

On July 14, New Horizons will come closest to Pluto at

only 7,750 miles away. Images will pick up surface features

as small as 200 feet across. The icy dwarf’s atmosphere is

thin enough for its surface to be visible. However, scientists

are anxious for the probe to get there as soon as possible,

while there’s enough of an atmosphere to study at all.

Pluto’s atmosphere comes and goes. The icy dwarf’s

orbit is very elliptical, bringing it closer to and farther away

from the Sun at various points. Since 1989, Pluto has been

moving away from the Sun, and as it does, it will lose its at-

mosphere. Pluto has a rocky core with a –387°F surface of

mostly nitrogen ice, along with methane and carbon monoxide

ices. Closer to the Sun, the ices thaw and vaporize into a gas-

eous atmosphere. In a sort of “anti-greenhouse effect,” also

unique to our Solar System, Pluto cools itself down by this

evaporation. These atmospheric gases then tend to escape into

space, because Pluto’s low mass does not have enough gravity

to keep its clouds together. Farther from the Sun, the gases

solidify and fall back down to the surface, freezing as ice.

Scientists also want to arrive in time to see as much of

Pluto-Charon as we can. Just as Earth’s poles spend half a

year in daylight and half a year in night, parts of the double-

planet can be shadowed in “arctic night” for decades at a time

(one Plutonian year lasts 248 Earth years). The timing of the

mission is critical to be able to map as much as possible.

The $300 million New Horizons is the fastest spacecraft

Vince Bly

Atop an Atlas V rocket, New Horizons launched with the fast-est speed ever at over 36,000 mph in January 2006.

Astro Answers (cont’d from page 1)

OutdoorFest

AAA hosted an observing session at the 2nd annual OutdoorFest’s 5K Headlamp Trail Run and Campout on May 29.

7

Telescope of the Month Sliding Spring Observatory in Australia

On the dark, cloudless Mount Woorut near the town of Coonabarabran in New South Wales,

Australia, sits the largest telescope on that continent – the 3.9m Anglo-Australian Telescope (AAT) –

one of nine active telescopes at the Sliding Spring Observatory (SSO). Operated by the Australian Astro-

nomical Observatory, the AAT simultaneously observes hundreds of galaxies, collecting data for the 2-

degree-field Galaxy Redshift Survey. The SSO site itself is owned by Australian National University

(ANU), which hosts the AAT, along with telescopes from the UK, Sweden, Poland, Korea, and several

international collaborations, as well as ANU’s own 2.3m Advanced Technology Telescope. It is also

home to ANU’s SkyMapper, a state-of-the-art, automated wide-field telescope, which is conducting the

first comprehensive digital survey of the entire southern sky. With its 1.35m modified Cassegrain optics

and f4.79 focal ratio, SkyMapper can view to a sensitivity of one million times fainter than the human

eye. Its 268 million-pixel digital camera captures a different region every 20 seconds to image every part of the southern sky 36

times over 5 years. Able to detect changes over time, it can discover large dwarf planets in the outer solar system and track aster-

oids. Astronomers also hope to use SkyMapper data to map the invisible dark matter of the Milky Way galaxy, using samples of

rare stars, and to find the first quasars and stars that formed in our universe. In addition to surveys, SSO telescopes image gamma-

ray bursts, search for transiting Hot Jupiter exoplanets, and look for extrasolar planets orbiting binary stars via the eclipse timing

method. SSO is also home to the southern hemisphere station of iTelescope.Net, a global network of robotic telescopes designed

for amateur astronomers and astrophotographers. Members of the public can remotely access the telescopes from anywhere

around the world through the internet at http://www.itelescope.net/. AMW Source: rsaa.anu.edu.au; wiki.

Celestial Selection of the Month Polar Ring Galaxy NGC 4650A

Two galaxies for the price of one! About 130 million

light-years away in the constellation Centaurus lies the peculi-

ar polar-ring galaxy NGC 4650A. A rare type of galaxy , it

has a ring of stars, gas, and dust that orbits nearly perpendicu-

lar to its main, inner disk. Astronomers believe it acquired

the ring during a collision with a neigh-

bor galaxy at least a billion years ago.

Only about 100 polar-ring galaxies

have been discovered so far. Most

seem to occur at lenticular galaxies,

otherwise known as S0s – a transition

state between spiral and elliptical gal-

axies. Viewed edge-on, S0s are shaped

like spiral galaxies with a disk sur-

rounding a bright, central, spherical

bulge. But, they do not have arms or

very much interstellar material.

Viewed face-on, they can be mistaken

for smooth, featureless elliptical galax-

ies. And like ellipticals, S0s consist

primarily of old, red stars that formed

early in the life of the galaxy. S0s do

not produce new stars in any significant

quantity; however, 4650A’s younger,

polar ring does have active star-

forming regions. These unique, multigenerational objects are

helping astronomers understand one of the most mysterious

aspects of galaxy structure. From the observed motions of its

older inner disk and its younger polar ring, astronomers have

determined that the ring of NGC 4650A is rotating faster than

it should – too fast to be held together by only the stars we

can see. An additional invisible source of gravity – dark mat-

ter – must be present. They are then able to estimate both the

amount and shape of the dark matter in the galaxy. AMW

Sources: apod.nasa.gov; spacetelescope.org; wiki..

July 2015

Hubble Hubbub Moon Madness at Pluto

As if in anticipation of New Horizons’ arrival at

Pluto, Hubble has produced strange new data about the

dwarf planet’s weird and wild moons. In June, Hubble

revealed that Nix and Hydra tumble willy-nilly in their orbits

at the Pluto-Charon system. Pluto and its largest moon, Char-

on, share a center of gravity lying between the two bodies, so

they form a binary as a “double-planet.” The gravitational

field of the double-planet shifts, causing the other moons to

wobble. Nix and Hydra are also shaped like footballs, which

exaggerates the effect. “It’s not just a little bit chaotic,” said

study author Mark Showalter. “Nix can flip its entire pole. It

could actually be possible to spend a day on Nix in which the

sun rises in the east and sets in the north.” Pluto’s other two

moons, Styx and Kerberos, likely wobble too. Extrasolar

planets have been discovered orbiting binary stars, and the

Pluto moon dance demonstrates how such exoplanets might

behave. “We are learning chaos may be a common trait of

binary systems,” said co-author Doug Hamilton. Meanwhile,

Hubble revealed that the orbits of Nix, Hydra, and Styx are

locked in resonance; there is a precise ratio to their orbital

periods. All five moons may have been in resonance at one

time. Hubble also showed that Kerberos is much darker than

its comrades. Scientists believe the system formed during a

collision of Pluto and another body. Is it possible that char-

coal-black Kerberos is a

remnant of the invader?

“Pluto will continue to

surprise us when New

Horizons flies past it in

July,” said Showalter.

“Our work with the Hub-

ble telescope just gives us

a foretaste of what’s in

store.” AMW Sources: nasa.gov; nytimes.com.

Julia Karrer

The Skymapper telescope at Sliding Spring Observatory.

NASA/ESA/M. Showalter (SETI)/G. Bacon (STScI)

The orientation of Pluto’s moon Nix changes unpredictably as it orbits the “double planet” Pluto-Charon.

AURA/STScl/NASA/ESA

The unique shape of polar ring galaxy NGC 4650A can be used to calculate dark matter.

8

A Message from the AAA President

Dear AAA Members,

Summer weather and summer skies make for great observ-

ing! Dates are now set for dark sky observing at North-South

Lake. The next AAA trip to this premier location is on July 18.

Check out http://www.aaa.org/north-south-lake/ for more details.

If you would like to receive planning information about AAA

trips to North-South Lake and Ward Pound Ridge, email me at

president@aaa.org to be added to the Dark Skies Google Group.

Again this year, the Rockland Astronomy Club has extend-

ed a generous invitation to join its Summer Star Party with a 20%

discount on registration for AAA Members. The 10-day event in

the beautiful Berkshire Mountains runs from August 7-16. See

offer details at http://www.aaa.org/links/rac-ssp2015/.

For more observing events this summer, AAA’s calendar

updates frequently with location and other information – be sure

to check back often at http://www.aaa.org/calendar.

Marcelo Cabrera

president@aaa.org

July 2015

Eyepiece Staff July Issue

Editor-in-Chief: Amy M. Wagner Copy Editor: Richard Brounstein

Contributing Writers: Rori Baldari, Tony Faddoul, Stanley Fertig,

Stan Honda, Peter Tagatac, and Amy Wagner

Eyepiece Logo and Graphic Design: Rori Baldari

Administrative Support: Joe Delfausse

Printing by McVicker & Higginbotham

FRI, July 3

@ 7:30 pm – 11 pm Next: Every Friday & Saturday Night

AAA Observing at Lincoln Center Plaza – Manhattan, PTC

SAT, July 4

@ 7:30 pm – 11 pm Every Friday & Saturday Night

AAA Observing at Lincoln Center Plaza – Manhattan, PTC

@ 9 pm – 11 pm Next: Aug 1

AAA Observing at Brooklyn Museum Plaza – Brooklyn, PTC

TUES, July 7

@ 7:30 pm – 11 pm Every Tuesday Night

AAA Observing at the High Line – Manhattan, PTC

THURS, July 9

@ 7:30 pm – 11 pm Every Thursday Night

AAA Observing at Brooklyn Bridge Park – Brooklyn, PTC

SAT, July 13 @ 7:00 pm

AMNH Special Presentation at the Hayden Planetarium, P

“Manhattanhenge” with Jackie Faherty. The setting sun will align per-

fectly with Manhattan’s East-West numbered streets tonight, creating a

cinema-worthy photo opportunity. Learn about the history and astrono-

my behind this fascinating phenomenon. (Enter 81st St)

FRI, July 17

@ 7 pm Columbia Summer Film & Stargazing at Pupin Hall, P

Guardians of the Galaxy (Observing 8:30 pm, C)

SAT, July 18 – 19

@ 8:00 pm – 2:30 am Next: Aug 15 – 16

AAA Observing at North-South Lake, Haines Falls, NY MPTC

Take a field trip with AAA to the Catskill Mountains in an exceptionally

dark location for deep sky observing. For AAA members only. Reserve

a spot by emailing treasurer@aaa.org.

@ 8:30 pm – 11 pm Next: Aug 15

AAA Observing at Great Kills – Staten Island, PTC

FRI, July 24

@ 6:45 pm – 11 pm Next: June 26

Astronomy Night at the Intrepid with AAA – Manhattan, PTC

Stargaze with AAA on the flight deck of the Intrepid! Learn about ex-

oplanets with Astrophysicist Steve B. Howell and see Andrew Daw-

son’s Space Panorama, a performance recreating the 1969 Apollo 11

Moon landing. Also enjoy live demos and trivia games with prizes!

The event is free and open to the public, but registration is required at:

http://www.intrepidmuseum.org/astronomynights.aspx.

@ 8 pm – 11 pm Next: June 26

AAA Observing at Carl Schurz Park – Manhattan, PTC

SAT, July 25

@ 11:00 am – 1:00 pm Next: Aug 29

AAA Solar Observing at Poe Park – Bronx, PTC

@ 8 pm – 10 pm Next: Aug 29

AAA Observing at Parkchester – Bronx, PTC

TUES, July 28

@ 6:30 pm AMNH Astronomy Live at the Hayden Planetarium, P

“Grand Tour of the Universe” with Br ian Abbot. Travel from Ear th

to the most distant objects of the observable universe. (Enter 81st St)

@ 6:00 pm – 8:30 pm Next: Aug 25

AAA Solar Observing at the Highline – Manhattan, PTC

C: Cancelled if cloudy; M: Members only; P: Public event; T: Bring telescopes, binoculars.

For location & cancellation information visit www.aaa.org.

AAA Events on the Horizon

The Amateur Astronomers’ Association of New York Info, Events, and Observing: president@aaa.org or 212-535-2922

Membership: members@aaa.org Eyepiece: editor@aaa.org

Visit us online at www.aaa.org.

AAA Around Town Educational Outreach at PS 116

On June 18, AAA visited the Science Lab Club at the

PS 116 Mary Lindley Murray School for some daytime

observing and astronomy appreciation. The after school

club is one of several offered at PS 116. I gave a talk to the

club’s students, aged 7 to 10, about telescopes, observing, and

Solar System objects. They sketched concepts on a white-

board and shared their own stories of past astronomy events.

The breadth of their knowledge and experience was impres-

sive for such young people! We went outside and set up a

four-inch refracting telescope in the playground, although

clouds threatened above. But our persistence paid off, and

students from the whole school were finally treated to a view

of three sunspot groups and a waning crescent planet Venus.

To learn more about AAA’s Educational Outreach Program,

email schooloutreach@aaa.org. Peter Tagatac