Upload
others
View
10
Download
0
Embed Size (px)
Citation preview
Journal of the Amateur Astronomers Association of New York
December 2015 Volume 64 Number 12; ISSN 0146-7662
Our Solo Sun Stranded without Star Siblings
By Rafael Ferreira
Double-sun planets like Tatooine from Star Wars are no
longer the stuff of science fiction – thanks to Kepler. That
exoplanet-hunting space telescope has discovered planets in
multiple star systems, like Kepler-16b. So, is our Sun’s single
status unusual? On Nov 6, Stella Offner from the University
of Massachusetts presented “Our Lonely Sun: Exploring Why
Many Stars are Born with Siblings” as part of the AAA Lec-
ture Series, explaining how unique our Sun really is.
Before we
can understand our
unusual Sun, we
must first look at
the overall picture
of stellar for-
mation. Stars
form in Giant Mo-
lecular Clouds
(GMCs). GMCs
contain enough
dense gas and dust
to form hundreds
of thousands of
Sun-like stars.
GMCs are very cold, and their density is very high, about
1,000 to 10,000 atoms per cubic centimeter on average. By
way of comparison, average density in interstellar space is
just one hydrogen atom per cubic centimeter. To make the
dense core of a star like our Sun, you need 106 cm3 hydrogen
atoms occupying a given space within the GMC. So how do
you increase density by two orders of magnitude?
Gravity! Yes, the gravity that you experience on Earth
every day is the key component to making stars. Once a
clump of gas within the GMC reaches a certain density, gravi-
ty takes over and works its magic. The force of outward gas
pressure that could fight gravity is weak, because the GMC
temperature is so cold. The dense clump, or core, reaches a
critical point where the gravity wins and a runaway collapse
forms a protostar. Ultimately, the gas becomes hot enough to
prevent further gravitational collapse. An accretion disk of
THIS MONTH: AAA Winter Class begins Dec 2 and AAA Lecture Series continues on Dec 6
AAA LECTURE SERIES
The Giants of Black Holes and the Information Paradox
By Alan Rude
For three decades, Stephen Hawking and his colleague
Jacob Bekenstein were either collaborators or adversaries.
The friendly fights of Hawking and Bekenstein, who passed
away this year, changed our understanding of black holes .
Their greatest work was in connection with what is
called the Black Hole Information Paradox (BHIP). BHIP
reflects the conflict between the two main theories of the uni-
verse: quantum mechanics and general relativity. The
“Theory of Everything,” a Holy Grail for physicists, seeks to
unite the two.
Due to its very nature, quantum mechanics cannot be
used to make precise predictions. It can only determine the
probability that a particular thing will happen. Information
about objects or systems is encoded in a wave function; there-
fore, information is never truly lost. Einstein’s theory of gen-
eral relativity, which celebrated its 100th anniversary last
month, concerns gravity and space-time. Unlike quantum
mechanics, it predicts exactly what will happen. General rela-
tivity determined that extremely compact and massive objects
would form black holes.
Gravity is immensely
strong in their vicinity,
warping space-time dra-
matically. An object
drawn that gets too close
and crosses the black
hole’s event horizon will
never be able to escape.
That object and all its in-
formation becomes lost,
violating quantum theory.
In 1972, Bekenstein suggested that black holes should
have a well-defined entropy, the degree of disorder for a ther-
modynamic system. He defined the entropy of a black hole as
proportional to its event horizon. Hawking initially opposed
Bekenstein on the grounds that a black hole could not radiate
energy, so it could not have entropy. But two years later,
Hawking determined that black holes did emit a very small
amount of particle radiation, known as Hawking Radiation.
Black Holes (cont’d on Page 4) Our Solo Sun (cont’d on Page 4)
UNDERSTANDING THE UNIVERSE
NASA/M. Weiss (Chandra X-ray Center)
Hawking believes he can solve the black hole information paradox.
NASA/JHUAPL/SwRI
New Horizons’ false color image shows subtleties of Pluto’s regions. Final maneuvers in Nov were made for a 2019 Kuiper Belt Object visit.
Stella Offner
Mizar in Ursa Major is a quadruple star sys-tem. Most stars similar in mass to our Sun
formed with companions, but the Sun is single.
2
December’s Evening Planets: Neptune is in Aquarius
the Water Bearer until 11 PM and setting earlier every night
until 9 PM by the end of the month. Uranus is in Pisces the
Fish until 2 AM and setting earlier until midnight by the end
of the month. Jupiter will be between in Leo the Lion and
Virgo the Virgin as of midnight rising earlier every night
until 10 PM by the end of the month.
December’s Evening Stars: Spot The Winter Trian-
gle: Sirius, the brightest star viewed from Earth, in Canis
Major the Great Dog, Betelgeuse in Orion the Hunter, and
Procyon in Canis Minor the Small Dog as of 8 PM. Find
Castor and Pollux in Gemini the Twins, Rigel in Orion,
Aldeberan in Taurus the Bull, and bright Capella in Auriga
the Charioteer. See the stars of constellations Andromeda,
Cassiopeia, Perseus, Cepheus, Draco, Aries, Taurus, and
Ursa Major and Ursa Minor (the Big and Little Dippers).
December’s Morning Planets: Find bright Venus
between Virgo and Libra the Balance around 4 AM until
sunrise. Mars will be in Virgo, and Jupiter will be between
Leo and Virgo until sunrise. Mercury is in Sagittarius the
Archer around 5 PM for about one hour during the second
half of December. Saturn will be in Scorpio the Scorpion for
one hour before sunrise in the second half of the month.
December’s Morning Stars: The Winter Triangle of
Sirius, Betelgeuse, and Procyon will be up until morn-
ing. Find Capella in Auriga, Arcturus in Boötes the Herds-
man, Spica in Virgo, and Aldeberan in Taurus until the
morning. See the stars of Leo, Gemini, Orion, Cassiopeia,
Cepheus, Draco, Perseus, Ursa Major, and Ursa Minor.
Dec 3 Last Quarter Moon at 2:40 AM
Dec 5 Moon at apogee (251,530 miles away)
Dec 11 New Moon at 5:30 AM
Dec 14 Geminid Meteor Shower peaks, pre-dawn
Dec 18 First Quarter Moon at 10:14 AM
Dec 21 Winter Solstice at 11:49 PM
Moon at perigee (228,920 miles away)
Dec 25 Full Moon at 6:11 AM
Dec 31 Moon near bright Jupiter, pre-dawn
Times given in EST.
WHAT’S UP IN THE SKY
December 2015
The 2015 Gemenids
The Geminid Meteor Shower is one of the most stable shoot-
ing star events each year. This year, it peaks on a moonless
December night and will provide a spectacular show of about
a hundred meteors per hour.
When is the Peak? The Geminids will
peak in the early
hours of Dec
14. The best view-
ing window is late
night on Dec 13
until morning twi-
light. Under per-
fect conditions
(clear, dark skies),
you’ll be able to view over 100 shooting stars every hour at
the peak. The nights before and after will have similar num-
bers of visible meteors. The moon will set before mid-
night, allowing for a perfect show.
Who can see the Geminids? This bright meteor shower favors the skies of the northern
hemisphere. Those who live further south will see fewer
meteors. The southern hemisphere can see about 25 meteors
per hour at peak under dark skies.
What color are the Geminids? Geminid meteors hit Earth’s upper atmosphere at 80,000
mph and vaporize in a multi-colored display. Approximate-
ly 65% of the shooting stars are white, 25% yellow, and the
remaining 10% are blue, red and green.
How do I view the meteor shower? Looking north to northeast, the meteors will seem to origi-
nate from the constellation Gemini, but you don’t need to
locate their radiant – the Geminids appear to strike every-
where across the sky. Find a dark spot, as far away as possi-
ble from light pollution, and hope for clear skies. There is no
need for any equipment. Just look up, and enjoy.
What is the mythology behind the Geminids? Castor and Pollux were the twin sons of Tyndareus and Leda,
King and Queen of Sparta. Castor was a mortal, but Pollux
was a demigod. He was the result of a union between Leda
and the god Zeus, who disguised himself as swan one night.
Pollux was a fighter, and Castor was a horseman who were
among the heroes who sailed with Jason and the Argonauts.
Extraordinarily brave, they were inseparable and always
fought as a team. One day, they got into a quarrel with their
cousins, and Castor was killed. Devastated by his brother’s
death, Pollux was offered a choice by Zeus to keep his im-
mortality or share it with Castor and save him. He chose the
latter, and Zeus placed them together forever in the sky as
stars. You can see the constellation Gemini manly during
fall and winter. Sources: timeanddate.com; wiki; earthsky.org.
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
December “Skylights”
3
Urban Astrophotography AAA Style
By Stan Honda
Who says New York City is no place for astrophotog-
raphy? AAA members have been turning their telescopes to
the sky from balconies and rooftops across town, photo-
graphing night sky objects. They post their spectacular imag-
es and share their experiences on AAA-Astrophotography
Google Groups, which anyone can join. Sign up and prepare
to be wowed by the work of our members!
Michael Krypel recently shared a stunning image of
M42, the Orion Nebula, taken on Nov 4. It showed detail
from the core, all the way out to its fringes of reddish gas.
Although M42 is one of the most photographed deep sky ob-
jects, Michael’s photo is especially remarkable, because he
shot it from the roof of his apartment building on East 65th
Street and Second Avenue in Manhattan. How did he do it?
“I have wanted to photograph the Orion Nebula since I
first saw pictures of it as a child,” Michael said. “I am a be-
ginner astrophotographer, and this was my first attempt at
stacking images to photograph a deep sky object. I have seen
the Orion Nebula many times through a telescope so I knew
that it was bright and visible from New York City. It seemed
like a good object with which to start. It was a clear night
here, so I set up just after sunset on my roof. While I was
waiting for Orion to rise, I practiced taking pictures of the
Andromeda galaxy, the Pleiades star cluster, the Double
Cluster and the M15 globular cluster. Once Orion rose, I
focused on it. The images of the Orion Nebula became clear-
er as it rose further from the horizon. As this was my first
time, I wasn't sure whether any of the images would come out
well or be good enough to stack. I think I lucked out.”
All astro-
photographers
will attest that
the closer an
object gets to
the zenith, the
better the im-
age. Michael’s
best shots were
taken between
midnight and
1:00 AM.
His set up included a Takahashi FSQ85-ED refractor
telescope, Celestron AVX mount, and a Canon 60Da camera
(digital SLR factory-modified to be sensitive to the hydrogen
alpha wavelength), with ISO 800 for 30-second exposures.
As for processing the image, Michael said, “Out of the 80
frames [I shot during the night] only 34 seemed good enough
to stack; in the others the stars were somewhat oblong instead
of round. So the total exposure time for this image is 17
minutes. I ended up aligning these manually in Photoshop,
stacking them using a median filter and then applying the Lev-
els and Curves adjustment layers.”
December 2015
The lovely composition of Michael’s image is very dif-
ferent from how M42 is normally shown: “I aligned the im-
age in this way because I was hoping to also capture the Run-
ning Man Nebula and place it to the left of the Orion Nebula.
Unfortunately, I wasn't able to pick up enough signal to image
it this time -- that's okay, though, I'm still learning!”
Meanwhile,
across the East
River, Stephen
DiCasa posted an
image taken on
Oct 19 of an ob-
ject closer to
home – the Moon:
“Celestron re-
tweeted this tweet
of mine. It's a
shot of the moon I
took a few nights ago from my balcony in Astoria.”
New to AAA, Stephen only purchased his telescope in
July. The beautiful shot from a day before first quarter shows
an almost 3-dimensional view of the Moon’s craters and other
features near the terminator. “I took this while I was on Peri-
scope with my telescope. Thought it was a cool idea, and
people seemed to like it. If you're not aware, Periscope is a
live-streaming app where you broadcast right from your
phone. At first I tried to hold the phone up to the eyepiece,
but it worked out much better attaching the DSLR to the tele-
scope and showing people the LCD screen (on the back of the
camera). I snapped the shot, tweeted it out about an hour
later, and Celestron retweeted it. I picked the moon because
really, that's the only object that can show up well enough for
Periscope, at least for right now.”
Setting his Celestron Nexstar Evolution 8-inch reflector
telescope (2000mm, f10) to prime focus, Stephen shot with a
Canon 5D Mark III camera, using 1/250 shutter speed at ISO
1250. The Canon 5D full-frame digital SLR camera provides
a high level of sharpness and detail. “I did some work to it in
post [processing]. Brought up the blacks and [brought] down
the highlights to make it as dynamic as possible without mak-
ing it look weird and distorted. I was attempting to just make
it look in the picture how it does to your eye.”
More of Michael’s photos can be found at http://
www.aaa.org/gallery-2/astrophotography/michael-krypel-
gallery/. Follow Stephen on Twitter/Periscope at https://
twitter.com/DiCasaFilm/status/656271100716949504.
From a Manhattan rooftop to a Queens balcony, AAA
Members prove that New York City is a great place for astro-
photography. To join the AAA-Astrophotography Google
Groups, email me at [email protected].
AAA AROUND TOWN &
FOCUS ON THE UNIVERSE
Stephen DiCasa
The Moon from a balcony in Queens.
Michael Krypel
The Orion Nebula (M42) imaged from Manhattan.
Explore more night sky photography at
www.stanhonda.com.
Submit your photography questions to [email protected].
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.
4
December 2015
material surrounds the protostar to fuel the potential star. The
law of conservation of angular momentum comes into play,
and as the core draws in material, it spins faster, like a figure
skater pulling in his or her arms.
Offner's job is to model the extreme conditions that oc-
cur within GMCs and look at the physics affecting the for-
mation of protostars. During the collapse process, instability
can cause a protostar to fragment either in its core or accretion
disk. This can lead to multiple protostars that create a binary,
triple, or quadruple star system. Disk fragmentation usually
occurs for stars with 10 or more solar masses. Core fragmen-
tation occurs when the extended structure around its equator,
causes the core split. For some reason, fragmentation did not
occur during the formation of our Sun.
According to Offner, most star systems are single or
binary; triple and quadruple systems are more rare. Massive
stars of 10 solar masses or more are more likely to form in
GMCs. They have a higher tendency to have siblings, so mul-
tiple star systems are common. About 60% of observed stars
similar to our Sun have a stellar companion. Stars less mas-
sive than the Sun tend to be single.
But scientists like Offner struggle to be able to observe
star formation and the fragmentation process in GMCs.
That’s where the Atacama Large Millimeter Array (ALMA)
can help. An interferometer, ALMA’s array of antennas work
together as one telescope, collecting multiple images and data
that can be pieced together. It is particularly useful for fine
resolution of luminous objects like close binary stars. ALMA
will be able to probe the light within the cold, dense GMCs to
see star formation, but it is not yet fully operational. Offner’s
role is to provide theory to fill in the gaps from the limited
observations ALMA makes now. She starts with the basic
physical variables in GMCs such as mass, density, velocity,
temperature, and position and then makes predictions about
what ALMA’s full array may observe.
Until ALMA is fully operational, observations from the
Kepler Space Telescope can help identify multiple star sys-
tems. It sees light dips from the transit of planets crossing in
front of a star. Kepler has discovered several multiple star
systems, even a quadruple star system. Some binary systems
have been found with a protoplanetary disk – actual Tatooines
in the making!
The observations made so far and the theoretical work
by scientists like Offner suggest that our Sun is unique to be a
star without a sib-
ling. Most of the
stars being formed
in stellar nurseries
like GMCs do have
stellar companions.
ALMA may be able
to confirm that
some day soon, and
shed some light on
how these multiple
star systems are
formed.
Our Solo Sun (cont’d from Page 1)
Hawking not only showed that black holes emit particle
radiation, but also that they will eventually radiate themselves
out of existence. But this presented a new problem: where
does the information in the black hole go once the black hole
evaporates? If it disappears along with the black hole, that
again violates quantum mechanics. But if the information
leaves with the radiation, that violates general relativity,
which holds that nothing, not even light, can escape a black
hole. Herein lies the black hole information paradox. Hawk-
ing’s calculations showed that Hawking Radiation did not
preserve the information inside an evaporating black hole.
For three decades, Hawking’s position was clear: there
was no paradox. Quantum theory must be incomplete, and a
new and improved version will one day show that matter and
information can be completely destroyed when a black hole
evaporates. But quantum mechanics has remained solid over
the years, so several physicists began to think that it was gen-
eral relativity that needed altering. In 1992, Leonard Suss-
kind, Larus Thorlacius, and Gerard ’t Hooft introduced the
notion of “complementarity.”
Complementarity relies on “holography,” whereby three-
dimensional equations inside a black hole that factor in gravity
become two-dimensional quantum equations just above the
event horizon that don’t. One physics mysteriously trans-
forms into another. Information is both inside and outside of
the black hole, depending on your perspective. Outside, an
observer sees it accumulate at the event horizon where it is
stored until it leaves with Hawking Radiation. Observers fall-
ing into a black hole see the information inside. Complemen-
tarity preserves quantum theory, but it does require some fine
tuning to general relativity. In 2005, Hawking came around to
this point of view that information in black holes is not lost.
But complementarity doesn’t answer everything. There
are no equations yet that can describe the subtle evaporation
process. Joseph Polchinski and his colleagues made an at-
tempt and discovered a flaw in complementarity. It breaks
down when a black hole is half-way evaporated. At that point,
too much information has radiated away for holography to
hold up for the interior. With no interior, an observer cannot
fall into a black hole. In fact, he would burn to a crisp just
outside the event horizon at a place called a “firewall.” But,
no such site should exist. General relativity states than the
event horizon is merely a point of no return and nothing else
should happen there. For complementarity to work, general
relativity would need a major overhaul.
This has caused a lot of consternation for physicists.
There just aren’t enough equations to describe how evapora-
tion and firewalls work. This summer, Hawking embraced
holography and the idea that information is stored in 2D at the
event horizon, evaporating away with Hawking Radiation. He
plans to publish soon, but he will still have to modify general
relativity to prove that information is not lost.
Despite all this confusion, the essential properties of
black holes remain the same. And certainly, if you fell in, you
wouldn’t be able to get out. Sources: profmattstrassler.com; cnn.com; huffingtonpost.com; “Guest
Post: Joe Polchinski on Black Holes, Complementarity, and Firewalls;
Cosmic Variance,” blog.discovermagazine.com; nature.com, nytimes.com.
Black Holes (cont’d from page 1)
ALMA (ESO/NAOJ/NRAO)
The high resolution and sensitivity of the Atacama Large Millimeter Array in the Chile-
an Andes may detect star birth during the early universe and detailed imaging of local
star and planet formation.
5
December 2015
There are addi-
tional benefits to min-
ing asteroids. Once
you’ve bored a hole
in a near-Earth aster-
oid with a tunnel-
boring machine and
removed the valuable
water and minerals,
the hollowed-out inte-
rior can then provide
a safe place to con-
struct a colony or space station. The exterior of the asteroid
can provide unmatched protection against both meteorites and
radiation. Now, attach a rocket engine to your asteroid-cum-
space-station, and you’ve got yourself a robust, interplanetary
spaceship that could possibly travel to Mars or beyond. This
would kill several birds with one stone. A spaceship that lives
in space saves on the enormous costs of lifting a large vessel
off the Earth and into space. No need. It’s already there.
Unfortunately, the asteroid giveth, and it taketh away.
Ask any dinosaur. Oh wait, you can’t. One thing we know for
sure is that somewhere, some time, some asteroid has got our
number. It’s not a matter of if but rather of when a large aster-
oid will impact the Earth again and potentially cause humans to
suffer the same fate as the dinosaurs. But unlike those early
reptilian inhabitants of Earth, humans possess the ability to
track asteroids and perhaps prevent such a catastrophe. Vari-
ous technological solutions have been proposed, including ab-
lation via large mirrors and sunlight or with lasers, or by exert-
ing gravitational tugs with rockets in close proximity. But it is
critical that we test such technologies in advance so that we
have the solution ready when needed. By visiting an asteroid,
we can have an in situ laboratory to conduct those tests. Let’s
figure out how to nudge an asteroid and save the world!
Although most asteroids lie in the Asteroid Belt beyond
Mars, more than 10,000 near-Earth asteroids have been locat-
ed. An estimated million more are yet to be discovered. We
closely monitor those that we have identified for obvious rea-
sons. But those same potential threats can become potential
targets for manned missions.
At distances not much further away than the Moon, near-
Earth asteroids offer a great destination for exploration that is
much easier to get to than any planet. And because asteroids
are small and have low gravity, takeoff for a return trip home is
easier too. So, look out Bruce Willis, here we come! Sources: planetaryresources.com; abundantplanet.com; space.com;
nasa.gov.
Where Do We Go From Here?
Let’s Go to an Asteroid! By Stanley Fertig
Really, I mean it! An asteroid is by far our best bet for
the next celestial body where humans should set foot.
Why, you ask? Well, asteroids offer several tangible
advantages over other potential targets for manned explora-
tion. Think of the science we can learn, the resources we can
find, and the money we can make.
First, by examining asteroids close-up, we can study the
very origins of the Solar System and the Earth. After all, our
planet began as a large asteroid. Asteroids today are like the
leftover building materials from a construction project. From
them, we can learn a great deal about the Solar System’s for-
mation and composition, and by extrapolation, about those
processes in exoplanet systems.
More specif-
ically, going to an
asteroid can help
us uncover the
source of the wa-
ter that today co-
vers two thirds of
our planet. The
Rosetta mission
recently disquali-
fied comets simi-
lar to 67P as the
source by analyzing isotopes in its water. A similar analysis
needs to be done on asteroids. The largest asteroid, Ceres, is
estimated to possess more subsurface water than is found in
all the oceans of Earth combined! At present, asteroids are the
prime suspects for bringing H2O to early Earth and enabling
life as we know it.
As a matter of fact, it is possible that asteroids seeded the
that life itself by panspermia, delivering microorganisms or
the chemical building blocks of life. We won’t know unless
we go find out.
Of course, you say, all that could be done via robotic
exploration. It is true that we require special transportation
and life support, but humans are better explorers, quicker and
more discerning than machines. Humans could do much more
at an asteroid than just analyze water and organics.
Asteroids are rich not only in water, but also in valuable
metals and minerals. It’s not simply altruism or scientific
curiosity that drives companies like Planetary Resources to
want to visit near-Earth asteroids – they aim to capture and
mine them. A relatively small rock, say 500 meters in diame-
ter, can contain tens of billions of dollars worth of materials.
That’s before you even take into account the fact that a kilo-
gram of something in space is worth far more than a kilogram
of the same material on Earth, due to the cost involved in ac-
quiring it. Asteroid mining could arguably fund itself or po-
tentially pay off all of Earth’s collective space programs com-
bined, and still make a profit.
BOTH SIDES NOW
Touchstone Pictures
Asteroid drilling depicted in Armageddon.
Washington State Department of Transportation
“Big Bertha,” is the largest-diameter tunnel-boring machine at 57.5 feet across.
Adolphis, will come dangerously close to Earth in 2029.
6
December 2015
there. Rare on Earth, Helium-3 gas could potentially fuel fu-
ture nuclear fusion power plants. Efficient and with virtually
no waste or radiation, Helium-3 fusion reactors could be the
greatest energy source in all of history.
An initial lunar colony doesn’t have to be a thriving me-
tropolis of thousands of relocated Earthlings. It can serve more
as a science and refueling station. On lunar outposts, scientists
and engineers can work for months or years and still be able to
return to home to Earth. There, they can develop and test the
technologies and skills needed to maintain a self-sufficient
space colony, which could be used for future colonies on an
asteroid, Mars, or elsewhere in the Solar System.
Much of the Moon remains unexplored, and there is a
great deal of science to accomplish there. Aside from what we
can learn about the Moon itself, its location offers us an oppor-
tunity to learn about other celestial bodies. The Moon is a
great place to house observatories. It has virtually no atmos-
phere to interfere with a telescope. An observatory on the lu-
nar surface offers the advantages of a space telescope with the
access and maintainability of ground-based observatory.
A lunar base could also serve as a waystation to resupply
and refuel spacecraft travelling throughout the Solar System. It
is cheaper and easier to launch from the surface of the Moon
than from the surface of Earth. Today, it costs about $10,000 a
pound to launch a payload from Earth. Vehicles that touch
down on the Moon would be able to replenish food, fuel, and
essential supplies and return to space more quickly. A lunar
base could sell fuel and even booster rockets manufactured
there. It would be our first gas station in space. Meanwhile,
manned missions sent from a lunar colony could be deployed
to repair satellites and space telescopes. The ISS could be a
customer of a lunar outpost repair service.
And of course, lunar tourism would be very popular for
wealthy private explorers. The infrastructure of a lunar base
would be a boon to the lunar tourism industry
Once we've mastered the skills we need for colonization
on the Moon, we will have a model to establish new permanent
human colonies elsewhere in the Solar System. Perfecting
those systems first on a cheaper and less risky prospect like the
Moon, we could then focus on the challenges of sending hu-
mans to Mars. As technologies will inevitably improve over
time, a lunar base will become more independent, and living in
space will seem routine. The Moon is our stepping-stone to
long-term living that is out of this world. Sources: popsci.com; space.com; nbcnews.com; nasa.gov; wiki.
Make the Moon a Priority By Richard Brounstein
The next venture astronauts make into space should be to
visit an old friend, the Moon. This destination makes the most
sense for continued human exploration of the Solar System.
Despite over 50 years of human activity in space, including
six successful landings on the Moon in the 1960s and 1970s,
we still don’t know how to establish a permanent, self-
sustained presence on another world. Let’s finish what we
started!
Launching to and landing heavy objects on the Moon is
difficult, but we know how to do it. We’ve done it before.
However, current space technology is still lacking in many of
the areas necessary for building a permanent settlement off-
Earth. The challenges of colonizing another celestial body are
many: we must protect against deadly cosmic radiation, pro-
duce abundant and various foods, harness water from ice and
rocks, extract oxygen, prospect, mine, and refine materials for
construction and repairs, manufacture fuel for vehicles, and
keep humans healthy and safe in a low-gravity environment
without assistance from Earth.
The International Space Station is currently making ad-
vancements in some of these areas. But the ISS is an Earth-
dependent system. It has no access to materials that aren’t
brought there from Earth. In order to learn how to gather re-
sources in situ, we need to practice in a place where local ma-
terials exist. The Moon is the best place for this. The lunar
poles have deep craters that almost certainly have trapped
water ice. Rare Earth elements like europium, lanthanum, and
cerium, used in electronic devices and energy plants, are
found in large quantities on the Moon. As these minerals be-
come more rare and prohibitively expensive to mine safely
and in an environmentally-friendly manner on Earth, an alter-
nate source like the Moon is worth considering.
In fact, the greatest reason to settle on the Moon may be
the economic value it offers Earth. Space agencies already
struggle to find support for expensive manned missions from
their home nations, and governments will likely refuse to
keep funding unprofitable endeavors. We could end up with
another 50 years of exploration stagnation. But, a lunar base
could partially pay for itself. In addition to the valuable rare
earth elements that can be mined there, Helium-3 is abundant
ESA/Forster + Partners
Artist’s rendering of a 3-D printing robot adding a protective layer to the inflatable dome shell of a lunar base.
NASA/SAIC/Pat Rawlings
Artist’s concept of a lunar mining facility harvesting oxygen from the volcanic soil of the eastern Mare Serenitatis.
7
Exo-citement An Exoplanet is Born and Nearby Rocky Worlds Found
Last month, astronomers using the Large Binocular Telescope in Arizona and the Magellan
Telescopes in Chile saw for the first time the birth of an exoplanet. Thanks to the Kepler Space
Telescope and other observatories, we’ve discovered thousands of extrasolar planets over the past 27
years, so why has it taken so long for us to see one form? Formation lasts for only a short period of a
planet’s life, so “it’s unlikely that you’ll come across a planet when it’s still forming,” said study co-
leader Stephanie Sallum. They also form in regions that are full of gas and dust, obscuring observa-
tions by the transit method. The baby planet that is forming around Sun-like LkCa15, a 2-million-year-
old star that is 450 light-years away, was found in a relatively empty gap between the star and a ring of
dust and gas. Hydrogen-alpha emissions in infrared images of the LkCa15 system indicated that hydro-
gen atoms were falling through the magnetic field of a hot new planet. Meanwhile, scientists using the MEarth-South telescope
array in Chile announced in November the discovery of Gliese 1132b, the nearest Earth-sized rocky exoplanet at only 39
light-years away. In July, super -Earth HD 219134b was confirmed by the Spitzer Space Telescope as our closest rocky neighbor
at only 21 light-years away. It’s hot and lifeless, orbiting close to its home star. Both rocky exoplanets are ripe for study, but
Gliese 1132b may be easier to examine. The light from its home star, a small, faint, red dwarf, doesn’t drown out the exoplanet.
Red dwarfs are the most common type of star in our galaxy, and astronomers estimate about 1.4 rocky planets orbit each. And,
while Gliese 1132b is also hot and uninhabitable – average surface temperature is 260°C – it is cool enough to support a substan-
tial atmosphere. “This will probably be our first opportunity to study the atmosphere of a rocky planet outside our Solar System ,”
said Zach Berta-Thompson, who found Gliese 1132b. By analyzing wavelengths of light passing through the edges of its atmos-
phere, scientists can learn its composition. AMW Sources: arstechnica.com; spitzer.caltech.edu; techtimes.com; theverge.com.
Mad for Mars Solar Wind Killed the Martian Climate
Launched in 2013,
NASA’s Mars Atmosphere
and Volatile EvolutioN
(MAVEN) spacecraft en-
tered Mars’ orbit last year
and discovered the culprit
behind its climate change –
the Sun. Ancient Mars was
a warm water world; valleys
and mineral deposits today
indicate the presence of riv-
ers and lakes and maybe
oceans in Mars’ past. Its
atmosphere was thick enough
to support liquid water on the
surface. But billions of years
ago, Mars began to lose its atmosphere, and it became a cold,
dry place. So, how did that happen? Mars also lost its global
magnetic field long ago and became unprotected from solar
wind. The stream of particles that flows out from the Sun’s
atmosphere achieves speeds of one million mph. As that solar
wind races by unprotected Mars, it generates an electric field
that hits Mars’ upper atmosphere with an energy equivalent to
a million tons of TNT an hour, accelerates ions there and
shooting them into space. “That’s one large nuclear weapon
per hour, if you like,” said MAVEN team member Jasper
Halekas. Results show that ion loss occurs in three regions at
a rate of 0.25 lbs. per second. 75% escapes down the “tail” of
solar wind flowing behind Mars; another 25% leaves through
polar plumes and a small amount from an extended cloud of
gas surrounding Mars. During solar storms, atmosphere ero-
sion will increase 10 to 20 times, losing as much as five lbs.
of ions a second. AMW Source: mars.nasa.gov; nytimes.com.
December 2015
Celestial Selection of the Month Galaxy Cluster Abell 1689
2.2 billion light-
years away in the con-
stellation Virgo is one
of the most massive
galaxy clusters known. Abell 1689 contains
over 160,000 globular
clusters. Those dense,
spherical objects host
hundreds of thousands
of stars that orbit a ga-
lactic core. About 95%
of globular clusters
formed in the first cou-
ple billion years after
the Big Bang, so their
stars are some of the
oldest in the universe. 2 million light-years across, Abell
1689 is speeding away from us at 49,863 km/sec, and gasses
there can reach temperatures up to 100 million degrees. Im-
ages of this enormous galaxy cluster demonstrate the effect of
gravitational lensing. Einstein’s theory of general relativity
predicted that massive objects can bend and magnify the light
that’s behind it, like a lens, which lets an observer see objects
that are even further away. In the Hubble image above, the
yellow galaxies reside in Abell 1689, while the streaks and
arcs of blue are galaxies perhaps 13 billion light-years away
that are forming hot, new stars. Studying images like these
not only brings the distant universe closer to us but also re-
veals its invisible wonders. The visible matter in Abell 1689
is responsible for only 1% of the mass required to warp space
enough for this lensing, so dark matter must account for the
rest. AMW Sources: spacetelescope.org; apod.nasa.gov; wiki.
NASA Goddard Space Flight Center
Charged solar particles hit Mars’ upper atmosphere. With no pro-
tecting magnetic field, they pile up in a bow shock. During solar
storms, they push into the atmos-phere and accelerate ion escape.
NASA/JPL-Caltech/R. Hurt (IPAC)
Exoplanet HD 219134b was confirmed by Spitzer as our nearest rocky neighbor at
21 light-years away.
NASA, ESA, STScI/AURA, J. Blakeslee (NRC Herzberg Astro-physics Prog., Dominion Astrophysical Obs.), H. Ford (JHU)
Abell 1689 galaxy cluster was imaged in visible and infrared by Hubble with a 34-
hour exposure. Gravitational lensing magnifies distant galaxies behind it.
8
A Message from the AAA President
Hello Members,
In the next month, you will be receiving an AAA member-
ship renewal letter in the mail. Please renew as soon as you can. If
you joined in just the last few months, no renewal is necessary, but
a donation would be greatly appreciated.
AAA’s Lecture Series continues strong on Dec 4 with Bret
Lehmer (NASA) presenting “The Story of Galaxy Evolution from
an X-ray Perspective.” Find the full schedule of 2015-2016 lec-
tures at: www.aaa.org/lectures.
The AAA calendar updates frequently with events through-
out New York, so be sure to check it often at www.aaa.org/
calendar.
I would like to wish you all Happy Holidays and a very pro-
ductive New Year, and I hope you will consider including AAA in
your year-end giving.
Marcelo Cabrera
President, AAA
December 2015
Eyepiece Staff December 2015 Issue
Editor-in-Chief: Amy M. Wagner Copy Editor: Richard Brounstein
Contributing Writers: Richard Brounstein, Tony Faddoul, Rafael Ferreira, Stanley Fertig, Stan Honda, and Alan Rude
Eyepiece Logo and Graphic Design: Rori Baldari
Administrative Support: Joe Delfausse
Printing by McVicker & Higginbotham
DECEMBER 2015
WED, Dec 2, 9, & 16 Continued in Jan & Feb 2016
AAA Winter Astronomy Class at Cicatelli Center – Manhattan, M
@ 6:30 pm – 8:30 pm
The first three classes of David Kiefer’s advanced course, “Measuring
Distances in Space,” will explore methods used by astronomers to deter-
mine the distance to the Sun, the size of the Solar System, the distance to
nearby stars, and stars’ magnitude and luminosity.
Registration is closed.
FRI, Dec 4 Next: Jan 8
AAA Lecture at the American Museum of Natural History, P
@ 6:15 pm – 8 pm
“The Story of Galaxy Evolution from an X -ray Perspective” presented by
Bret Lehmer from NASA. Free admission; open to the public.
(In the Kaufmann Theater; Enter at 77th St)
FRI, Dec 18
AAA Observing at Floyd Bennett Field – Brooklyn, PTC
@ 7:30 pm – 9:30 pm
Fund us in the Community Garden parking lot.
MON, Dec 21
AMNH Winter Telescope Party with AAA – Manhattan, P
@ 7 pm
Enjoy hot chocolate and the night sky with AAA members on the Arthur
Ross Terrace at the American Museum of Natural History, following a
presentation in the Hayden Planetarium. (Purchase tickets at amnh.org.)
M: Members only; P: Public event; T: Bring telescopes, binoculars; C: Cancelled if cloudy.
For location & cancellation information visit www.aaa.org.
AAA Events on the Horizon
The Amateur Astronomers’ Association of New York Info, Events, and Observing: [email protected] or 212-535-2922
Membership: [email protected] Eyepiece: [email protected]
Visit us online at www.aaa.org.
Other Astronomy Events in NYC
FRI, Dec 4
@ 7 pm Columbia Stargazing/Lecture Series at Pupin Hall – Manhattan, F
“On the Care and Feeding of Black Holes” with Aleksey Generozov. Ob-
serving will follow, weather permitting. (outreach.astro.columbia.edu)
SAT, Dec 5
@ 7 pm Our Solar System at Fort Greene Park – Brooklyn, FT
NYC Urban Park Rangers guide naked eye observing and discuss the science,
history, and folklore of the universe. (nycgovparks.org)
MON, Dec 7
@ 7:30 pm AMNH Frontiers Lecture (Kaufmann Theater) – Manhattan, X
“Dark Matter and the Dinosaurs” with Lisa Randall at the American Museum
of Natural History explores an idea that connects a mass extinction event on
Earth with a dark matter disk at the edge of the Solar System. (amnh.org)
SAT, Dec 12
@ 6 pm Astronomy at Fort Totten Park Visitors Center – Queens, FT
The New Moon tonight offers the best time of the month to observe faint
objects such as galaxies and star clusters. (nycgovparks.org)
@ 7 pm Astronomy at Van Cortlandt Park Nature Center – Bronx, FT
Experience the Geminids Meteor Shower, which produces up to 120 multi-
colored meteors per hour at its peak. (nycgovparks.org)
SUN, Dec 13
@ 7 pm Dark Nights, Bright Lights at Marine Park – Brooklyn, F
NYC Urban Park Rangers guide naked eye observing and discuss the science,
history, and folklore of the universe. Avenue U/E 33rd St. (nycgovparks.org)
FRI, Dec 18
@ 7 pm Columbia Stargazing/Lecture Series at Pupin Hall – Manhattan, F
“Our Magnetic Universe” with Susan Clark. Observing will follow, weather
permitting. (outreach.astro.columbia.edu)
SAT, Dec 19
@ 6 pm Astronomy at the Great Lawn in Central Park – Manhattan, FT
NYC Parks Astronomy programs feature the use of telescopes and binoculars
to observe the night sky. (nycgovparks.org)
SUN, Dec 20
@ 6 pm Ursids Meteor Shower at Wolfe’s Pond Park – Staten Island, FT
At its peak, the shower produces 10 meteors per hour. (nycgovparks.org)
TUES, Dec 29
@ 7 pm AMNH Astronomy Live (Hayden Planetarium) – Manhattan, X
“Grand Tour of the Universe” with Carter Emmart and Jackie Faherty ex-
plores the entire observable universe and gives a cosmic understanding of
where we are and how we came to be. (amnh.org)
F: Free; X: Tickets required (contact vendor for information); T: Bring telescopes, binoculars.
Now Playing… INSIGNIFICANT Insignificant tells the true stories of Cecilia Payne and
Annie Jump Cannon, the pioneering women behind the
stars, and their unheralded triumphs in astronomy. On Stage at the Kraine Theater (85 E 4 St) Dec 3-19
$15 Discounted Tickets for AAA Members! Use code “Leavitt” www.infinitevarietynyc.org