Galactic Observer - McCarthy Observatory1968 into Earth orbit. A week or so later, the Soviets launched two Soyuz space craft into Earth orbit (one manned and one unmanned for a planned

First Image of the surface of Mars as transmitted by the InSight spacecraft momentsafter landing on November 26th . The image was transmitted via the MarCO cubesats.The dust cover (covered with black specks) will be ejected once the dust settles (approxi-mately two days after landing)

Image Credit: NASA/JPL-Caltech

G

GG John J. McCarthy Observatory

John J. McCarthy ObservatoryJohn J. McCarthy ObservatoryDecember 2018Volume 11, No. 12

alactic Observer

alactic Observeralactic Observer

http://www.mccarthyobservatory.org2 • Dec 2018 JJMO

The John J. McCarthy ObservatoryNew Milford High School388 Danbury RoadNew Milford, CT 06776

Phone/Voice: (860) 210-4117Phone/Fax: (860) 354-1595www.mccarthyobservatory.org

Route

It is through their efforts that the McCarthy Observatoryhas established itself as a significant educational andrecreational resource within the western Connecticutcommunity.

Galactic ObserGalactic ObserGalactic ObserGalactic ObserGalactic ObservvvvverererererEditorial CommitteeEditorial CommitteeEditorial CommitteeEditorial CommitteeEditorial Committee

Managing EditorBill Cloutier

Production & DesignAllan Ostergren

Website DevelopmentMarc Polansky

Technical SupportBob Lambert

Dr. Parker Moreland

JJMO Staff

"OUT THE WINDOW ON YOUR LEFT" .................................. 3MOUNT MARILYN ........................................................... 3ENTRY, DESCENT AND LANDING ........................................ 4APOLLO 8 - 50 YEAR LOOKBACK ..................................... 5OSIRIS-REX ............................................................... 6DECEMBER COMET ......................................................... 7COMET FINDER CHART ................................................... 8EXOMARS UPDATE ......................................................... 8NEWLY DISCOVERED IMPACT CRATER ............................... 9MISSION TO THE FAR SIDE ............................................... 9FIRST ENCOUNTER ......................................................... 11IMPACT RELICS? ........................................................... 11SPACESHIP EARTH AND THE BLUE MARBLE ........................ 12PURCHASING A TELESCOPE .............................................. 13DECEMBER NIGHTS ....................................................... 15SUNRISE AND SUNSET ...................................................... 15ASTRONOMICAL AND HISTORICAL EVENTS ......................... 15COMMONLY USED TERMS ............................................... 18

In This IssueREFERENCES ON DISTANCES ............................................ 18NASA'S GLOBAL CLIMATE CHANGE ............................... 19EARTH-SUN LAGRANGE POINTS ....................................... 19INTERNATIONAL SPACE STATION/IRIDIUM SATELLITES .......... 20SOLAR ACTIVITY ........................................................... 20CONTACT INFORMATION ................................................. 21DECEMBER GRAPHIC CALENDAR ..................................... 22

Jim JohnstoneCarly KleinSternBob LambertRoger MooreParker Moreland, PhDAllan OstergrenMarc PolanskyJoe PriviteraMonty RobsonDon RossGene SchillingKatie ShusdockPaul WoodellAmy Ziffer

Steve BaroneColin CampbellDennis CartolanoMike ChiarellaJeff ChodakBill CloutierDoug DelisleCecilia DetrichDirk FeatherRandy FenderLouise GagnonJohn GebauerElaine GreenTina Hartzell

http://www.mccarthyobservatory.org Dec 2018 • 3JJMO

Mare Serenitatis

“Out the Window on Your Left”

IT’S BEEN 45 YEARS sincewe left the last footprint on thedusty lunar surface. Sadly, as a

nation founded on exploration andthe conquest of new frontiers, weappear to have lost our will to leadas a space-faring nation. But, whatif the average citizen had the meansto visit our only natural satellite;what would they see out thewindow of their spacecraft as theyentered orbit around the Moon? Thiscolumn may provide some thoughts

to ponder when planning your visit(if only in your imagination).

Prior to 1968, a triangular-shaped outcrop of rock located be-tween two dark patches of lava(Mare Tranquillitatis and MareFecunditatis) was noteworthy onlyfor a small crater located on its

flank. Jim Lovell, the CommandModule Pilot on the crew ofApollo 8, was one of the firstpeople to circumnavigate theMoon. He named that ancient rockoutcrop "Mount Marilyn" as atribute to his wife. Forty-nine yearslater (in 2017), the InternationalAstronomical Union (IAU)formally adopted the name forthe lunar feature, based upon itssignificance as a navigationlandmark for the Apollo 11landing (along with Little Westand Double craters).

Apollo 10 was a dress rehearsalfor Apollo 11, with astronautsThomas Stafford and EugeneCernan taking the Lunar Moduledown to within 9 miles (14 km) ofthe lunar surface. Along the way,the Apollo 10 crew created dozensof informal landmarks (like BootHill and Sidewinder Rille) thatcould be used by Armstrong andAldrin, and mission control, aswaypoints to check their progressagainst the nominal descenttimeline. The names appear on thecharts used by the astronauts, in

The Apollo 10 Command Module asseen from the Lunar Module with Mt.Marilyn visible in the background

NASA Photo

MountMarilyn


technical reports, and in transcriptsof communications between theastronauts and the ground.

The 4,593 foot (1,400 meters)high Mt. Marilyn is just one of thelandmarks identified on the follow-ing page. It was likely created over4 billion years ago in the aftermathof the impact that formed thenearby basins.

Entry, Descentand Landing

The Interior Exploration usingSeismic Investigations, Geodesyand Heat Transport (InSight)spacecraft separated from its cruisestage on November 26th and en-tered the Martian atmosphere ap-proximately 80 miles (128 km)above the planet's surface at 12,300miles per hour (5.5 km/sec). It wasprotected from the heat of reentryby an aeroshell (which experienceda peak temperature of approxi-mately 2,700°F or 1,500°C). Theaeroshell's heatshield, a large para-chute and twelve retrorockets(braking rockets) slowed down thespacecraft for a gentle landing onits three shock-absorbing legs.

Just before 3 pm EST, on awinter's day in the northern hemi-sphere of Mars, the InSight space-craft set down on an expansive lavaplain, Elysium Planitia, 373 miles(600 km) from Gale Crater, cur-rently being explored by the MarsScience Laboratory (Curiosity)rover. The high temperature on land-ing day was a chilly -4ºF (-20ºC).

The landing ellipse (area inwhich the spacecraft had a 99 per-cent chance of landing when tar-geting the center of the ellipse) was81 miles (130 km) long and 17miles (27 km) wide. Unlike otherMartian landing sites, with com-pelling geologic features, ancientwater-carved channels or riverdelta deposits, Elysium Planitiawas selected for its lack of diver-

The first instrument, a six-sen-sor seismometer called the SeismicExperiment for Interior Structure(SEIS), will record seismic waves(from impacts or marsquakes) asthey travel through the planet. Sci-entist use the waves' characteris-tics and speed of travel, to build amodel of the planet's interior.InSight's seismometer will be the

sity. The lander's science team isinterested in probing below thesurface and that requires a smooth,level area upon which to set downits experiments. InSight will spendthe first two to three months on thesurface surveying its landing area,before using its robotic arm toplace its two instruments on thesurface.

Mission Planning and Sequencing Engineers post-landing celebration(Kyle Cloutier center) Image Credit: NASA/JPL-Caltech


first to be placed on the surface andis thousands of times more sensitivethan the ones permanently mountedon the Viking landers. Because of theinstrument's extreme sensitivity(SEIS is sensitive enough to detectvibrations smaller than the widthof a hydrogen atom), a wind andthermal shield will be placed overthe seismometer to eliminatevibrations from the wind andtemperature fluctuations.

InSight will also measure theheat flowing out of the planet's corewith a self-burrowing, mechanicalmole. The Heat Flow and PhysicalProperties Package (HP3), thesecond instrument, will burrowinto the soil to a maximum depthof 16 feet (5 meters). At that depth,the instrument will be able todetect heat trapped below thesurface.

InSight's lander's two X-bandantennas will also be used tomeasure the wobble in Mars'rotation over time. The "wobble"about the rotational axis providesscientists information about themakeup of the planet's interior, andwhether the core is still liquid.

Apollo 8 - 50 YearLookback

1968 was a year of turmoil. TheUnited States was entangled in awar that even the Secretary ofDefense concluded could not bewon and he resigned from office.The My Lai massacre was one ofmany atrocities of the Vietnam Warperpetrated by both sides duringthis year. Major U.S. cities were thetarget of race riots and anti-warprotests. Chicago police violentlyclashed with protesters at theDemocratic National Conventionand civil rights leader MartinLuther King and presidentialcandidate Robert Kennedy wereassassinated in 1968. To manyAmericans, the only heartening

event in this otherwise horrific yearwas the reading from the Book ofGenesis by the crew of Apollo 8as they orbited the Moon onChristmas Eve.

The race to beat the Soviets tothe Moon took a dramatic turn in1968 and saw the United Statestake its first lead by year's end.Apollo 7 was launched in October1968 into Earth orbit. A week orso later, the Soviets launched twoSoyuz space craft into Earth orbit(one manned and one unmannedfor a planned rendezvous). InNovember, another unmannedZond flew around the Moon andphotographed the unseen far side.The United States expected thatthe Soviets would attempt anothermoon shot in early Decemberwhen the launch window forthe Baikonur space center inKazakhstan reopened (a Zondstood poised on the launching pad).Curiously, the opportunity passedwithout any activity. CosmonautAlexei Leonov would laterattribute the Soviet's loss ofinitiative and resolve to thepremature death of Sergei Korolev,the "Chief Designer" of the Sovietspace program as well as thedesign complexities of their Moonrocket (the N1).

While Apollo 7 had been asuccessful maiden voyage of thecompletely redesigned commandmodule (after the Apollo 1 fire), theUnited States had yet to leave Earthorbit. NASA's original plan was tolaunch a series of increasinglycomplex missions to near-Earthorbit before attempting a lunarexcursion. Development of thelunar lander was behind scheduleand violent vibrations in the Sat-urn rocket's main stage needed tobe corrected before NASA felt con-fident of sending men to the Moon.However, the apparent progress bythe Soviets threatened to upstage

the United States once again. It wasa proposal by a quiet engineeringgenius, George Low, (Manager ofthe Apollo Spacecraft Program Of-fice) to send the Apollo 8 com-mand module alone into lunar or-bit that would ultimately place theUnited States in a position toachieve President Kennedy's goalto land a man on the Moon andsafely return him to Earth by theend of the decade.

Apollo 8 was launched onDecember 21st under the commandof Frank Borman with astronautsWilliam Anders and Jim Lovell(Lovell replaced Michael Collinson the original team; Collins, whorequired back surgery, would go onto be the Command Module Pilotfor Apollo 11). The launch wasscheduled so that the crew wouldarrive at the Moon as the Sun wasrising on the Sea of Tranquility.With the Sun low in the sky, theastronauts could photographpotential landing sites and resolvesurface detail that would otherwisebe washed out in the glare from ahigher Sun.

The crew of Apollo 8 was thefirst to ride the three stage SaturnV rocket, with the explosive energyof an atomic bomb (the Saturn Vhad only been launched twice be-fore - both unmanned). The nightbefore the launch, the astronautswere visited by Charles Lindbergh.During the visit, it was discussedthat the engines on the Saturn Vwould burn 10 times the amountof fuel every second that Lindberghhad used to fly nonstop from NewYork to Paris.

The Apollo 8 astronauts werealso the first humans to leave Earthorbit and pass through the VanAllen radiation belts that extend upto 15,000 miles from Earth. Toaccomplish the mission, Apollo 8had to cross the 240,000 mile voidbetween the Earth and the Moon


with sufficient precision so as tointercept the Moon (traveling at2,300 miles an hour throughspace) just 69 miles above the lu-nar surface. By successfully do-ing so, the astronauts were thefirst humans to witness the ris-ing of the Earth above the Moon'shorizon (Earthrise). They wouldalso be the first to return to Earthand reenter the atmosphere at aspeed of 25,000 miles an hour.

The highlight of the mission,to many, was the broadcast fromthe Apollo 8 command moduleduring the ninth orbit of theMoon. After a brief introductionof the crew and their general im-pressions of the lunar landscape,William Anders said that thecrew had a message for all thoseon Earth. The astronauts tookturns reading from the book ofGenesis, the story of creation.Frank Borman closed the broad-cast with: "And from the crew ofApollo 8, we close with: Goodnight, Good luck, a Merry Christmas,and God bless all of you, all youon the good Earth." It is estimatedthat a quarter of Earth's popula-tion saw the Christmas Eve trans-mission.

In order to safely return toEarth, the main engine had to berestarted on the far side of theMoon (out of contact with Earth).If successful, Apollo 8 wouldreappear from behind the Moonat a predetermined time. As pre-dicted, the spacecraft re-emergedon time, and when voice contactwas regained, astronaut Jim Lovellwould announce: "Please beinformed, there is a Santa Claus."It was Christmas Day. Apollo 8would return safely to the Earthtwo days later, splashing down inthe Pacific Ocean shortly beforesunrise. The astronauts and thecapsule were recovered by theaircraft carrier USS Yorktown.

Apollo 8's view of Tsiolkovsky crater with its lava covered floor onthe Moon's far side Credit: NASA

Following the success ofApollo 8, the Soviet Moonprogram fell further behind withcatastrophically unsuccessfullaunches of their N1 booster inFebruary and again in July of1969. An unmanned, sample re-turn mission attempted to upstagethe Apollo 11 landing, but Luna15 crashed into Mare Crisiumshortly before Armstrong andAldrin were scheduled to lift offfrom the Moon. The Soviets of-ficially cancelled their Moon pro-gram in the early 1970s.

OSIRIS-RExNASA's OSIRIS-REx space-

craft is closing in on its target,the asteroid Bennu, with arrivaltargeted for December 3rd. Thespacecraft successfully executeda series of maneuvers over thepast two months to slow the

spacecraft and match its relativevelocity with that of the asteroid.

Bennu is a carbonaceous aster-oid, 1,614 feet (492 meters) across.With an average orbital distance of105 million miles (168 million km)from the Sun, it has an orbital pe-riod of 438 days. The asteroidmakes a close approach to Earthevery six years, although thedistance varies due to its 5 degreeorbital inclination relative to Earth.It is considered a potentiallyhazardous asteroid with a non-zeroprobably of impacting the Earth inthe distant future.

Discovered in 1999, scientistsbelieve that Bennu is a fragmentof a much larger asteroid that wasbroken off in a cataclysmiccollision between 1 to 2 billionyears ago. Bennu is likely tocontain material from theformation of the early solar


system which could includeorganics, water and preciousmetals.

OSIRIS-REx will survey theasteroid for almost two yearsbefore attempting to collect asample from its surface. Ifsuccessful, the sample will bereturned to Earth in 2023. Bennuwas selected as a samplingtarget for its proximity to Earth,but also for its size. It is largeenough that its rotation rate (onceevery 4.3 hours) is slow enough fora spacecraft to match velocitieswhen attempting a landing.

While Bennu's current orbithas been determined with greatprecision, it has also slowlydrifted towards the Sun (0.18miles or 280 meters per year)since it was discovered. This,comparatively inconsequentialchange in position, becomesimportant when calculatingfuture encounters with the Earth.The asteroid is predicted to passcloser to the Earth than theMoon in 2135, and possibly evencloser in the distant future. Thesmall changes in the asteroid's or-bit are believed to be relatedto a phenomenon called theYarkovsky effect, first describedby Ivan Yarkovsky, a Russiancivil engineer, around the year1900. Yarkovsky described aprocess where sunlight warmsone side of a small, darkasteroid. As the asteroid rotates,the heat energy is radiated intospace, providing a small thrust.OSIRIS-REx should be able tomeasure the Yarkovsky effectduring its stay, which willenable scientists to refine theirpredictions as they relate to theopportunities for close encoun-ters of near-Earth asteroids. It isbelieved the Yarkovsky effect,over eons, has nudged Bennufrom the main asteroid belt to

This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a rangeof 15 miles (24 km). Credit: NASA/Goddard/University of Arizona

an orbit that intersects Earth's.Understanding the effect could

December Comet

help in formulating our planetarydefense plans.

46P/Wirtanen is a short periodcomet (comets with orbital peri-ods less than 200 years). Its 5.4year orbit carries the dirty snow-ball almost out to the orbit of Ju-piter at its furthest (5.1 Astro-nomical Units or AUs) and justbeyond the orbit of Earth whenclosest to the Sun (1.05 AU). Inmid-December, the comet willpass by Earth. Originally, thecomet was predicted to be asbright as magnitude 6.1 (just be-yond visual range), based uponprevious apparitions. However,observers in early November re-ported that the comet is alreadyas bright as a magnitude 6 object,suggesting that it will reach mag-nitude 3 at its peak. Since com-

ets are not points of light likestars - and relatively diffuse -binoculars or a small telescopemay still be required to observeWirtanen.

As shown on the finder chart(next page), comet 46P Wirtanenstarts off the month of Decemberin the constellation Eridanus, rac-ing through the sky at 4 degreesper day (eight times the diameterof the Full Moon). The cometwill be well placed in the south-ern sky before midnight as itpasses through the constellationsTaurus and Auriga. On or aroundDecember 16th, the comet will benear the Pleiades open cluster(M45), providing a celestial sign-post and a nice photo opportunity.


ExoMars UpdatThe ExoMars Landing Site Selection

Working Group has recommended OxiaPlanum as the future landing site for theEuropean Space Agency (ESA)-Roscosmos Mars lander and rover. Thespacecraft is scheduled to launch in 2020(a July-August launch window) witharrival at Mars in March of 2021. Theplanned surface operation is the continu-ation of a mission that began with thelaunch of the ExoMars Trace Gas Orbiterin 2016 (the orbiter is searching for traceamounts of gases such as methane thatcould be linked to biological or geologi-cal activity on the surface).

Oxia Planum was one of two sites un-der consideration (Mawrth Vallisbeing the second). Both sites are locatedin regions characterized by featuresassociated with a wetter and warmer Marssome four billion year ago (withdiscernable channels appearing to havebeen carved by water, delta-like structuresand paleolakes).

The ExoMars surface mission isengineered to look for biosignatures,indicators of past or present life on Mars.The rover will be able to drill to a depth ofsix feet (two meters) to extractunspoiled samples that are shelteredbeneath the radiation-sterilized surface(see next page)

Orbital surveys have identified thepresence of clay-rich minerals in the OxiaPlanum region, indicative of a long-lasting body of standing water in thedistant past. The landing area is located atthe terminus of several channels and wherethe layers of clay-rich material have beenexposed by erosion.

While Mawrth Vallis was considereda scientifically unique site, its higher el-evation put it at a disadvantage in the se-lection process (the lower altitude of OxiaPlanum provides an additional margin ofsafety for entry, descent and landing byparachute in the thin Martian atmo-sphere). The recommendation is ex-pected to be confirmed in mid-2019,after an internal review by ESA andRoscosmos officials.

Position of Comet 46P/Wirtanen on December 17, 2018Earth Distance: 0.078 au or 7.25 million miles (11.7 million km)

Comet 46P/Wirtanen in the December night skyCopyright: Dominic Ford and In-The-Sky.org

Comet Finder Chaart


Candidate Landing Areas TopographyMars Global Surveyor, Mars Orbiter Laser Altimeter (MOLA)

Copyright NASA

Newly DiscoveredImpact Crater

NASA's Operation IceBridgeconducts aerial surveys of theEarth's polar regions, assessing theextent and measuring the depth ofsea and land ice.

Scientists flying out of theThule Air Base in northernGreenland use radar to map thethickness of glacial ice. On theirway to and from their targets, theywould fly over Hiawatha glacier,located about 150 miles to thenorth of the base. Surveys are gen-erally performed at lowaltitudes, but, by happenstance, ahigh altitude test while flying overHiawatha glacier showed evidenceof a bowl-shaped depression underthe ice.

The finding triggered a moredetailed examination of the areafrom both the air and on theground. The structure of thedepression is consistent with animpact crater, with a raised rim andcentral peak(s). It is 19 miles acrossand covered by approximately3,000 feet of ice. Scientists havepreliminarily dated the age of thecrater between 3 million and12,000 years old. The 12,000 ageis particularly intriguing since itcoincides with the Younger Dryasevent, a 1,000 year long cold snapthat occurred 12,800 years ago. Ittemporarily reversed a warmingtrend that had started after the endof last ice age. A meteoritic impacthad been suspected, but, up to now,no crater had been found from thattime period. Determining a moreprecise age may provide the an-swer.

Mission tothe Far Side

China is preparing to send aspacecraft to the far side ofthe Moon in early December.

Topography under Hiawatha glacier in Greenland. Black trianglesand purple circles are elevated peaks around the rim and in thecenter of the depression. Credit: Kjæer et al./Science Advances


South Pole-Aitken Basin (red circle) and Von Kármán crater(yellow star). Credit: Lunar Reconnaissance Orbiter/NASA/GSFC/Arizona State University

Likely landing area of Chang'e-4 inside the Von Kármán crater Credit:Lunar Reconnaissance Orbiter/NASA/GSFC/Arizona State University

Launched from the XichangSatellite Launch Centre in south-western China, the Chang'e-4lander and rover are expected tosoft-land in the Moon's South Pole-Aitken Basin, one of the largestimpact features in the solar system.

The South Pole-Aitken Basin isthe most expansive and oldestimpact basin on the Moon (pre-Nectarian period) with a diameterof approximately 1,550 miles(2,500 km). The basin is more than5 miles (8 km) deep and some ofthe deeper areas likely penetratethe Moon's crustal layer, exposingupper mantle material. While theexact landing site hasn't beenofficially announced, the VonKármán crater has been identifiedas the likely target in severalChinese scientific publications onthe exploration of the South Pole-Aitken Basin.

Chang'e-4 was a backup toChina's Chang'e-3 spacecraft thatsoft-landed on the Moon's MareImbrium and deployed the Yutu(Jade Rabbit) rover in 2013. Sincea lander on the far side won't beable to communicate directly withthe Earth, China launched a relaysatellite (called Queqiao) into ahalo orbit around the Earth-MoonL2 (Lagrande 2) point. The satellitewill allow simultaneous commu-nications with the lander and Earthstations.

The Chang'e-4 lander will beequipped with a number ofscience instruments including aLow Frequency Spectrometer, aLanding Camera, Terrain Camera,and the Lunar Lander Neutrons andDosimetry Experiment. The roverwill carry a Panoramic Camera,Lunar Penetrating Radar, Visibleand Near-Infrared ImagingSpectrometer and the AdvancedSmall Analyzer for Neutrals.

Chang'e-4 is a precursor to asample return mission (Chang'e-

5). The Chang'e-5 lander will tar-get another unexplored area ofthe Moon, the Rümker region innorthern Oceanus Procellarum.

The region includes what isbelieved to be the youngest marelavas on the Moon (less thanthree billion years old). The high-


titanium basalts also contain highlevels of thorium, uranium, andpotassium (heat producingelements through decay) andKREEP (an acronym for potas-sium, rare earth elements andphosphorus). Samples returnedby Chang'e'5 may provide someinsight into why KREEP is foundalmost exclusively in theOceanus Procellarum region.

First EncounterThe Parker Solar Probe

successfully executed its first peri-helion (close pass of the Sun) onthe evening of November 5th. Onthis first pass, the spacecraft wasmoving at a top speed of 213,200miles per hour (343,112 km/hr),relative to the Sun, and camewithin 15 million miles (24 millionkm) of the Sun's surface.

Solar radiation increased thetemperature of the spacecraft'scarbon-composite thermal shieldto approximately 820°F (438°C)during the pass. The shield keptthe spacecraft's systems andinstruments in the shield'sshadow in the mid-80s °F (20s°C). Since the Sun is such anintense radio source, communi-cations are limited during closeencounters. The spacecraft didtransmit a status beacon two dayslater on November 7th, indicat-ing that all systems are nominal(the best of all four possiblesignals). Science transmissionsare expected to begin in earlyDecember.

Over its seven year mission,the Parker Solar Probe wllcomplete 24 orbits around theSun. It will use Venus' gravity (onseven separate encounters) tomodify the spacecraft's orbit,for increasingly closer passesthrough the Sun's outer atmo-sphere. At its closest, the space-craft will come within 3.8 million

miles (6.1 million km) of the Sun ata speed approaching 430,000 milesper hour (692,000 km per hour).Thetemperature of the spacecraft'sthermal shield is expected to reach2,500°F (1,370°C) during theclosest encounter.

The Parker Solar Probe's transitsof the Sun's outer atmosphere (thecorona) will help scientists betterunderstand the inner workings ofour closest star and its connectionwith the space weather experi-enced by life on Earth.

Phobos, from a distance of about 4,200 miles (6,800 km)Credit: NASA/JPL/University of Arizona

Impact Relics?The planet Mars has two small and irregular lumps of rocks for moons.

Phobos, the larger of the two moons, is 17 x 14 x 11 miles (27 x 22 x 18km) in size. Deimos, by comparison, is only 9 x 7 x 6.8 miles in size (15x 12 x 11 km). Phobos orbits the planet three times a day, while Deimoscompletes one orbit every 30 hours.


The spectra best matched finelyparticulate basalt, a materialabundant on the surface of Mars. Theauthors suggest that the basaltic com-ponent may be from the planet'scrust, with the moons (includingDeimos), relics of an ancient impact.

The moons are thought to becaptured asteroids, based upon their

Credit: NASA

similarity to carbonaceous chon-drite asteroids, but that thinkinghas been recently challenged by theauthors of an article published inthe September issue of the Jour-nal of Geophysical Research.Theauthors revisited the mid-infraredspectra acquired by the Mar Glo-bal Surveyor's Thermal Emission

Spectrometer, or TES, from Phobos,collected during almost ten years onorbit around Mars.

Phobos' days are numbered, itsorbit decaying at a rate of six feet(1.8 meters) every hundred years. Atthat rate, the moon will either breakup or crash into the surface in ap-proximately 50 million years.

Spaceship Earth and the Blue MarbleOn December 7, 1972, the crew of Apollo 17 captured this iconic image of the receding Earth. Christened the

“Blue Marble,” the image underscored the fragility of humanity’s only sanctuary. The photo, taken at a distanceof 28,000 miles (45,000 km), provides a view extending from the Mediterranean Sea, across the African conti-nent, to the south polar ice cap.


Purchasing aTelescope

DURING THE HOLIDAYSit’s not uncommon to seeparents and grandparents

carrying around a telescope thatthey just picked up at the mall orwarehouse store for their buddingastronomer. Unfortunately,too many of theset h o u g h t f u lgifts end up ina basement orattic after oneor two uses. Alltoo often, telescope manufacturersprey on consumer’s expectations,which are often out of line with thecapabilities of the product, result-ing in frustration and disillusion-ment. However, even a crudelyconstructed telescope can becoaxed to produce acceptable im-ages, if the observer understandsthe limitations of his or her instru-ment.

There is no perfect telescope foreveryone. An inexpensive, mass-produced telescope that gets cartedout of the house and set up everyclear night, stimulates the users’imagination and encourages themto push the instrument’s capabili-ties to its limits is far more valu-able than the most highly craftedoptical masterpiece that spends itsnights in a closet.

There are several types of tele-scopes available to the general con-sumer. Each has advantages anddisadvantages, and with a littleeducation, a consumer can find atelescope that fits his or her needsand lifestyle. Again, if you don’t useit, a telescope is about as useful as agarden gnome and not as ute

TTTTTypes ofypes ofypes ofypes ofypes of TTTTTelescopeselescopeselescopeselescopeselescopesThere are three basic types of

telescopes: refractors, reflectorsand compound or catadioptric tele-scopes.

Refractors have been around for400 years and use a series of lensesto bring the light rays from distantobjects to focus. They are highlyregarded for their unobstructed andhigh-contrast images. The opticaltubes are sealed and generally morerugged that other designs. As such,the optics rarely need to be ad-justed (realigned) which makes therefractor a good choice as a traveltelescope. Refractors are an excel-lent choice for planetary and lunarviewing and for double stars, butgenerally do not have the largelight gathering capacity needed forfaint objects such as nebula andgalaxies. The disadvantages of re-fractors include: the potential fordifferent wavelengths of light to di-verge from a common focus as theypass through the glass (producingcolor “fringing” around bright ob-jects), the position of the eyepieceat the rear of the optical tube (re-quiring the telescope to bemounted fairly high off the groundfor comfortable viewing), theclosed tube that can take some timeto cool down, and the price (high-est cost per inch of aperture of thebasic telescopes designs).

Reflectors have been around foralmost as long as refractors, but usemirrors instead of lenses to bringlight to the observer’s eye. A largemirror located at the closed end ofthe optical tube reflects light backup the tube to a smaller mirrormounted near the open endand out to an eyepiece.Mirrors are mucheasier and less ex-pensive to manu-facture than lenseswith only an opticalcurve required on thefront of the mirror.With mirrors, thelight never passes through theglass, so there is no divergence ofthe light rays. However, since the

optical tube is open to the atmo-sphere, mirrors will require peri-odic cleaning, adjustment and,eventually, recoating. Reflectorsoffer the best value, particularly forlarger apertures.

The most popular compound orcatadioptric telescopes combine alarge, rear spherical mirror with afront corrector lens to create a verycompact optical tube. Companiessuch as Meade and Celestron builttheir businesses on the Schmidt-Cassegrain design. While generallymore expensive than reflectors, thecompound telescope offers a veryportable alterative for large aper-ture telescopes. Disadvantages in-clude cool down time (since theoptical tubes are sealed), and a rela-tively large secondary mirror thatdegrades the image of high contrastobjects (planets or the Moon). Thefront corrector plate is also suscep-tible to dew formation althoughthis can be managed with a dewshield or corrector plate heater.

There are several terms that areused in the sales promotion of tele-scopes. Some of the common onesare discussed below:

ApertureAperture refers to the size of the

largest lens or mirror in the tele-scope, for example, the primarymirror in an 8-inch reflector is 8-inches in diameter. As a generalrule, bigger is better, as light gath-ering and resolution increase withthe size of the optics. However, aswith everything else, there areother considerations that limit thepractical size of a particular instru-ment. Alvan Clark & Sons figuredthe 40-inch lens for the YerkesObservatory’s refractor, deliveringthe lens in 1897. More than 100years later, it is still the world’slargest working refractor. Why?The weight of the glass and thecomplexities in supporting a large


lens by its edge and the absorptionof light passing through the glasswere factors; however, the refrac-tor was ultimately done in by SirIsaac Newton when he built thefirst reflecting telescope in 1668.Mirrors, unlike lenses, can be com-pletely supported from the back.Since light does not pass throughthe glass, reflected images do notsuffer from “chromatic aberra-tion.” Today single mirrors are rou-tinely produced with diameters ex-ceeding 28 feet and telescopes areconstructed combining multiplemirrors to achieve even larger lightgathering capabilities. So what sizeis good for you? Before you an-swer, you may want to consider:

• Are you planning on setting upyour telescope in a permanent in-stallation, e.g., backyard observa-tory, or will you be moving it inand out of your home every timeyou plan on observing. If the lat-ter, then weight, portability andease of set up are important con-siderations. Due to its size andweight, my telescope saw verylittle use until I invested in awheeled platform that allows meto easily roll the fully assembledtelescope in and out of my garagein minutes.

• Are you planning on takingyour telescope on the road, withyou on vacation or planning totravel some distance to find trulydark skies or observe a “once in alifetime event?” Whether by train,plane or automobile, care must betaken to protect your telescope andensure that it arrives at its destina-tion in working order (mechani-cally and optically). If this is im-portant to you, a smaller and sim-pler design such as a refractor maybe a good choice.

• What are you interested inlooking at? Spectacular views ofthe Sun, Moon and planets can beacquired with a relatively modest

instrument. However, if your pas-sion is hunting down the more elu-sive and distant residents our theMilky Way Galaxy or exploringother galaxies far, far, away, it willrequire a much larger aperture tocapture those meager photons.

MagnificationMagnification is likely the most

overrated measure of a telescope’scapabilities. Magnification is a func-tion of the eyepiece placed in the pathof the incoming light and in front ofthe observer’s eye; the observer canchange the magnification by simplyselecting a different eyepiece. Assuch, it shouldn’t be a criterion in se-lecting a telescope.

The limiting useful magnifica-tion is approximately 50 times thediameter of the objective lens orprimary mirror. For example, asmall refracting telescope with a 4-inch objective lens can be pushedto a magnification of 200 times;however, only under the best ob-serving conditions and, in general,only on bright objects such as theMoon and planets. Most astrono-mers prefer the views that lowermagnification provides with awider field and brighter image. So,the next time you are captured bythe stunning views of the universeon the packaging of a modest in-strument, remember that the poten-tial of most telescopes is rarely re-alized, particularly if you reside inthe light polluted skies of the north-east. A higher power eyepiece mag-nifies not only the telescope’s in-tended target but also the side-ef-fects of living under 20 miles ofEarth’s atmosphere.

MountsWhile generally not at the top

of the list as far as features, thetelescope’s mounting system andconstruction is key to its ease of

use and the stability of the image.A poorly designed mount or onewith flimsy construction can bejust as frustrating todeal with as pooroptics. An altitude-azi-muth or alt-az mount is thesimplest type of telescopemount and generally theeasiest to set up. In thisarrangement, the mountallows the telescope to move leftand right while pivoting up anddown. It is commonly found onDobsonian* telescopes, is userfriendly and can be mechanized totrack celestial objects across the sky.

Another common mount designis the equatorial mount. In thisdesign, one axis is aligned with thecelestial pole, requiring only themovement around this axis to fol-low objects across the sky. It is theeasiest configuration for trackingand is generally preferred forastrophotography. Some alt-azmounts can be converted to anequatorial configuration with theaddition of an “equatorial wedge.”Equatorial mounts, however, canbe heavier than their alt-az coun-terparts.

Go-ToEssentially a computer con-

trolled pointing system, “go-to”allows the user to select an objectfrom a data base and command thedrive motors on the mount to movethe telescope to the object’s locationin the sky. This presupposes thatthe telescope user has properly setup the telescope and successfullynavigated through the alignment

* Dobsonian telescopes arereflectors on a simple, swivelmount. They offer a low-costsolution for those on a limitedbudget with aperture fever (aninsatiable desire for a largertelescope).


process (a process by which thetelescope’s computer determineswhere it’s pointed, the local time,and its position on the Earth). Most“go-to” telescopes come with alarge database, some of which canbe modified (supplemented) by theuser. While “go-to” capability is ex-tremely convenient and can take youto thousands of objects in its data-base in a blink of an eye, it doesn’tnecessarily mean that you will beable to see the object. Dependingupon the size of your telescope (seeAperture), many objects in thesedatabases are just too dim to seewith the equipment provided. CCDcameras are much more sensitivethan your eye and can accumulatelight for long durations. So, if youare planning on using your tele-scope primarily as a camera lens,then some of the disadvantage of a

small aperture can be overcome.However, if you plan on doingmost of your observing at the eye-piece, you may want to considerspending the money on a larger ap-erture rather than on “go-to” elec-tronics.

What to DoIf you are seriously considering

acquiring a telescope, a little bit ofresearch can go a long way in en-joying your final purchase. If pos-sible, try to observe through thetelescope(s) that you are consider-ing. The McCarthy Observatoryhas a monthly open house. Whenthe skies are clear, up to a dozentelescopes can be found on the pre-mises (including refractors, reflec-tors, a Dobsonian, and severalSchmidt-Cassegrains). Comparethe same celestial objects throughdifferent scopes, talk to the own-

ers about portability, ease of setupand operation. Check out productreviews in trade magazines such asSky and Telescope and Astronomyand on their websites. Contactreputable dealers and visit tradeshows such as the Northeast As-tronomical Forum where you canpick the brains of industry experts.

December NightsNights in December are not to

be missed. While the often frigidand turbulent atmosphere can befrustrating for astronomers, the re-flection of shimmering starlight (ormoonlight) off a snow coveredlandscape can be truly magical.The bright stars of the winter skyglow with color from orange toyellow to brilliant blue-white. Astar-filled sky in December is un-surpassed in grandeur.

Sunrise and Sunset (from New Milford, CT)Sun Sunrise SunsetDecember 1st (EDT) 07:01 16:24December 15th (EST) 07:13 16:24December 30th 07:20 16:33

Astronomical and Historical Events1st Apollo Asteroid 2012 MM11 near-Earth flyby (0.086 AU)1st Apollo Asteroid 10563 Izhdubar closest approach to Earth (1.131 AU)1st Apollo Asteroid 314082 Dryope closest approach to Earth (1.923 AU)1st Kuiper Belt Object 145453 (2005 RR43) at Opposition (38.694 AU)1st History: launch of Soviet satellite Sputnik 6 and two dogs: Pchelka and Mushka (1960)2nd Apollo Asteroid 2018 TG6 near-Earth flyby (0.010 AU)2nd Kuiper Belt Object 2006 QH181 at Opposition (83.021 AU)2nd History: dedication of the John J. McCarthy Observatory in New Milford, CT (2000)2nd History: launch of SOHO solar observatory (1995)2nd History: launch of space shuttle Endeavour (STS-61), first servicing of the Hubble Space Tele

scope, including the installation of corrective optics and new solar panels (1993)2nd History: Pioneer 11 spacecraft makes its closest approach to Jupiter; encounter redirects the

spacecraft to Saturn and an escape trajectory out of the solar system (1974)2nd History: touchdown of Soviet Mars 3 lander: communications were lost with the lander, the first

spacecraft to touch down on the Red Planet, after 20 seconds, possibly due to raging dust storm (1971)3rd NASA spacecraft OSIRIS-REx arrives at asteroid Bennu3rd Kuiper Belt Object 229762 (2007 UK126) at Opposition (41.244 AU)


3rd Scheduled launch of a Russian Soyuz spacecraft from the Baikonur Cosmodrome, Kazakhstanto the International Space Station with the next Expedition crew

3rd History: Pioneer 10 spacecraft makes its closest approach to Jupiter; first space probe to flythrough the asteroid belt and to an outer planet (1973)

3rd History: discovery of Jupiter's moon Himalia by Charles Perrine (1904)4th Scheduled launch of a SpaceX Falcon 9 rocket and carrying-cargo Dragon spacecraft to the

International Space Station from the Cape Canaveral Air Force Station, Florida4th History: launch of space shuttle Endeavour (STS-88), first International Space Station construc-

tion flight, including the mating of the Unity and Zarya modules (1998)4th History: launch of the Pathfinder spacecraft to Mars (1996)4th History: Pioneer Venus 1 enters orbit, first of two orbiters (and probes) to conduct a comprehen-

sive investigation of the atmosphere of Venus (1978)4th History: launch of Gemini 7 with astronauts Frank Borman and Jim Lovell, spending almost 14

days in space (1965)4th History: launch of Gemini Joe 2 rocket, test flight for the Mercury capsule and first U.S. animal

flight with Sam, a Rhesus monkey (1959)5th Aten Asteroid 2017 RH16 near-Earth flyby (0.081 AU)5th Aten Asteroid 2010 TK7 (Earth Trojan) closest approach to Earth (0.208 AU)6th Apollo Asteroid 161989 Cacus closest approach to Earth (1.803 AU)6th Kuiper Belt Object 145451 (2005 RM43) at Opposition (35.987 AU)6th History: Japanese spacecraft Akatsuki enters around Venus five years after unsuccessful first

attempt and main engine failure (2015)7th New Moon7th Apollo Asteroid 2212 Hephaistos closest approach to Earth (2.697 AU)7th History: arrival of the Galileo space probe at Jupiter (1995)7th History: launch of Apollo 17 with astronauts Ronald Evans, Harrison Schmitt (first scientist -

geologist) and Eugene Cernan (last man on the Moon - so far) (1972)8th Second Saturday Stars - Open House at the McCarthy Observatory (7:00 pm)8th Apollo Asteroid 9162 Kwiila closest approach to Earth (0.385 AU)8th Tentative launch date for the Chinese Chang'e 4 spacecraft to the far side of the Moon from the

Xichang, China launch site8th History: a Dragon spacecraft, launched by SpaceX into low-Earth orbit, is recovered in the Pa-

cific Ocean: first time a spacecraft recovered by a commercial company (2010)8th History: discovery of asteroid 5 Astraea by Karl Hencke (1845)9th Apollo Asteroid 2013 VX4 near-Earth flyby (0.011 AU)9th Apollo Asteroid 29075 (1950 DA) closest approach to Earth (1.556 AU)9th History: Pioneer Venus 2 enters orbit, second of two orbiters (and probes) to conduct a compre-

hensive investigation of the atmosphere of Venus (1978)10th Apollo Asteroid 2015 XV129 near-Earth flyby (0.060 AU)10th Apollo Asteroid 2003 NW1 near-Earth flyby (0.069 AU)10th Aten Asteroid 2017 NK near-Earth flyby (0.090 AU)10th History: launch of the X-ray Multi-Mirror Mission (XMM-Newton), the largest scientific satel-

lite built in Europe and one of the most powerful (1999)10th History: launch of Helios 1 (also known as Helios A) into solar orbit; joint venture by Federal

Republic of Germany and NASA to study the Sun (1974)11th Apollo Asteroid 12923 Zephyr closest approach to Earth (1.590 AU)11th Centaur Object 8405 Asbolus at Opposition (20.963 AU)11th History: launch of the Boeing X-37B Orbital Test Vehicle 1 (unmanned space plane) from the

Cape Canaveral Air Force Station (2012)12th Moon at apogee (furthest distance from Earth)

Astronomical and Historical Events (continued)


12th Comet 46P/Wirtanen Perihelion - closest to the Sun (1.055 AU)12th Kuiper Belt Object 2004 XR190 at Opposition (56.215 AU)12th History: discovery of Saturn moons Fornjot, Farbauti, Aegir, Bebhionn, Hati and Bergeimir by

Scott Sheppard, et al's (2004)12th History: discovery of Saturn moons Hyrrokkin by Sheppard/Jewitt/Kleyna (2004)12th History: launch of Uhuru, the first satellite designed specifically for X-ray astronomy (1970)12th History: launch of Oscar, first amateur satellite (1961)13th Geminids meteor shower peak13th Apollo Asteroid 2015 XX169 near-Earth flyby (0.043 AU)13th History: flyby of Asteroid 4179 Toutatis by the Chang'e 2 spacecraft, China's second lunar probe

(2012)13th History: discovery of Saturn's moons Fenrir and Bestla by Scott Sheppard, et al's (2004)13th History: launch of Pioneer 8, third of four identical solar orbiting, spin-stabilized spacecraft (1967)13th History: Mt. Wilson's 100-inch telescope used to measure the first stellar diameter (Betelgeuse);

measured by Francis Pease and Albert Michelson (1920)13th History: first light of Mt. Wilson's 60-inch telescope (1908)14th Plutino 84922 (2003 VS2) at Opposition (35.694 AU)14th Plutino 307463 (2002 VU130) at Opposition (38.981 AU)14th History: landing of China's Chang'e 3 Moon lander on Mare Imbrium (2013)14th History: flyby of Mars by Japan's Nozomi spacecraft after an attempt to achieve orbit fails (2003)14th History: creation of the Canadian Space Agency (1990)14th History: flyby of Venus by Mariner 2; first spacecraft to execute a successful encounter with

another planet, finding cool cloud layers and an extremely hot surface (1962)14th History: Weston meteorite fall: first documented fall in the United States (1807); best coordi-

nates for the fall are based upon investigative research by Monty Robson, Director of the McCarthyObservatory, published in 2009

14th History: birth of Tycho Brahe, Danish astronomer noted for his observational skills, the preci-sion of his observations, and the instruments he developed; builder of the Uraniborg and Stjenborgobservatories on the Swedish island of Ven (1546)

15th First Quarter Moon15th Mercury at its Greatest Western Elongation (21°) in the morning sky15th History: launch of Soviet spacecraft, Vega 1 to Venus and then to Comet Halley (1984)15th History: landing of Soviet spacecraft Venera 7 on the surface of Venus (1970)15th History: discovery of Saturn's moon Janus by Audouin Dollfus (1966)15th History: launch of Gemini 6 with astronauts Walter Schirra and Thomas Stafford (1965)15th History: Gemini 6 and 7 execute the first manned spacecraft rendezvous (1965)16th History: launch of Pioneer 6, the first of four identical solar orbiting, spin-stabilized spacecraft (1965)17th Comet 46P/Wirtanen near-Earth flyby (0.077 AU)17th Apollo Asteroid 6239 Minos closest approach to Earth (0.956 AU)17th Kuiper Belt Object 19521 Chaos at Opposition (40.318 AU)17th History: Project Mercury publicly announced (1958)17th History: Wright Brothers' first airplane flight, Kitty Hawk, North Carolina (1903)18th History: discovery of Saturn's moon Epimetheus by Richard Walker (discovery shared with

Stephen Larson and John Fountain) (1966)19th Amor Asteroid 2014 JU54 near-Earth flyby (0.086 AU)19th History: launch of the Gaia spacecraft from French Guiana to survey more than one billion stars

in an effort to chart the chart the evolution of the Milky Way galaxy (2013)19th History: launch of space shuttle Discovery (STS-103), third servicing of the Hubble space tele-

scope including the installation of new gyroscopes and computer (1999)




19th History: launch of Mercury-Redstone 1A; first successful flight and qualification of the space-craft and booster (1960)

20th Apollo Asteroid 2012 MS4 near-Earth flyby (0.082 AU)20th History: Ames Research Center founded as the second National Advisory Committee for Aero-

nautics (NACA) laboratory at Moffett Federal Airfield in California (1939)20th History: founding of the Mt. Wilson Observatory (1904)20th History: launch of the Active Cavity Radiometer Irradiance Monitor satellite (ACRIMSAT); de-

signed to measure Sun's total solar irradiance (1999)21ST Winter Solstice at 5:23 pm EST (22:23 UT)21ST Asteroid 6 Hebe closest approach to Earth (1.257 AU)21ST History: launch of the Soviet spacecraft Vega 2 to Venus, continued on to Comet Halley (1984)21ST History: landing of Soviet spacecraft Venera 12 on the surface of Venus, found evidence of thun-

der and lightning in the atmosphere (1978)21ST History: launch of Apollo 8 with astronauts Frank Borman, Jim Lovell and William Anders, first

to circumnavigate the Moon (1968)21ST History: launch of Luna 13, Soviet moon lander (1966)22nd Full Moon (Long Night or Cold Moon)22nd Ursids Meteor Shower peak22nd Aten Asteroid 163899 (2003 SD220) near-Earth flyby (0.019 AU)22nd Apollo Asteroid 2016 AO131 near-Earth flyby (0.052 AU)22nd History: first asteroid (323 Brucia) discovered using photography (1891)23rd Apollo Asteroid 418849 (2008 WM64) near-Earth flyby (0.043 AU)23rd Apollo Asteroid 2010 GT7 near-Earth flyby (0.057 AU)23rd Apollo Asteroid 2015 YQ1 near-Earth flyby (0.077 AU)23rd History: discovery of Saturn's moon Rhea by Giovanni Cassini (1672)24th Moon at perigee (closest distance from Earth)24th Asteroid 2062 Aten closest approach to Earth (1.218 AU)24th Centaur Object 154783 (2004 PA44) at Opposition (20.397 AU)24th Plutino 55638 (2002 VE95) at Opposition (29.023 AU)24th Kuiper Belt Object 78799 (2002 XW93) at Opposition (44.715 AU)24th History: inaugural of ESA's Ariane 1 rocket and first artificial satellite carried by an ESA rocket (1979)24th History: Deep Space Network created (1963)24th History: Jean-Louis Pons born into a poor family with only basic education, took post at observa-

tory at Marseilles as concierge, went on to become most successful discover of comets (discov-ered or co-discovered 37 comets, 26 bear his name) (1761)

24th History: inaugural launch of the Arianne rocket, Europe's attempt to develop a cost-effective thST

History: European Space Agency's Mars Express spacecraft enters orbit around Mars (2003)25th History: landing of Soviet spacecraft Venera 11 on Venus, second of two identical spacecraft (1978)26th Amor Asteroid 1943 Anteros closest approach to Earth (0.670 AU)26th Aten Asteroid 2014 BA3 closest approach to Earth (1.853 AU)26th Apollo Asteroid 4486 Mithra closest approach to Earth (2.426 AU)26th History: launch of Soviet space station Salyut 4 from Baikonur Cosmodrome; third Soviet space

station and second space station devoted primarily to civilian objectives; deorbited in 1977 (1974)27th Apollo Asteroid 488789 (2004 XK50) near-Earth flyby (0.089 AU)27th Plutino 2002 XV93 at Opposition (37.658 AU)27th History: discovery of the ALH84001 Martian meteorite in the Allan Hills, Far Western Icefield,

Antarctica, made famous by the announcement of the discovery of evidence for primitive Martianbacterial life (1984)


Commonly Used Terms• Apollo: A group of near-Earth asteroids whose orbits also cross Earth's orbit; Apollo

asteroids spend most of their time outside Earth orbit.• Aten: A group of near-Earth asteroids whose orbits also cross Earth's orbit, but un

like Apollos, Atens spend most of their time inside Earth orbit.• Atira: A group of near-Earth asteroids whose orbits are entirely within Earth's orbit• Centaur: Icy planetesimals with characteristics of both asteroids and comets• Kuiper Belt: Region of the solar system beyond the orbit of Neptune (30 AUs to 50

AUs) with a vast population of small bodies orbiting the Sun• Opposition: Celestial bodies on opposite sides of the sky, typically as viewed from Earth• Plutino: An asteroid-sized body that orbits the Sun in a 2:3 resonance with Neptune• Trojan: asteroids orbiting in the 4th and 5th Lagrange points (leading and trailing) of

major planets in the Solar System

Lagrange PointsFive locations discovered by mathematician

Joseph Lagrange where the gravitational forces ofthe Sun and Earth (or other large body) and theorbital motion of the spacecraft are balanced, al-lowing the spacecraft to hover or orbit around thepoint with minimal expenditure of energy. The L2point (and future location of the James Webb tele-scope) is located 1.5 million kilometers beyond theEarth (as viewed from the Sun).

References on Distances• The apparent width of the Moon (and Sun) is approximately one-half a degree (½°), less than

the width of your little finger at arm's length which covers approximately one degree (1°);three fingers span approximately five degrees (5°)

• One astronomical unit (AU) is the distance from the Sun to the Earth or approximately 93million miles


27th History: Johannes Kepler born, German mathematician and astronomer who postulated that theEarth and planets travel about the sun in elliptical orbits, developed three fundamental laws ofplanetary motion (1571)

29th Last Quarter Moon30th Apollo Asteroid 137052 Tjelvar closest approach to Earth (1.281 AU)30th Apollo Asteroid 3838 Epona closest approach to Earth (1.685 AU)30th History: Army Air Corp Captain Albert William Stevens takes first photo showing the Earth's

curvature (1930)30th History: flyby of Jupiter by Cassini spacecraft on mission to Saturn (2000)30th History: discovery of Uranus' moon Puck by Stephen Synnott (1985)31st History: GRAIL-A, lunar gravity mapping spacecraft enters orbit (2011)


Image CreditsFront page design and graphic calendar: Allan Ostergren

Second Saturday Stars poster: Marc Polansky

All other non-credited photos were taken by the author: Bill Cloutier

Solar ActivityFor the latest on what’s happening on the Sun and the current forecast for flares and aurora, check out

www.spaceweather.com.WMA

International Space Station and Iridium SatellitesVisit www.heavens-above.com for the times of visibility and detailed star charts for viewing the

International Space Station and the bright flares from Iridium satellites.

NASA’s Global Climate ChangeFor the latest on what’s happening on the Sun and the current forecast for flares and aurora, check out

www.spaceweather.com.

Contact Information

The John J. McCarthy Observatory P.O. Box 1144 New Milford, CT 06776 New Milford High School 388 Danbury Road New Milford, CT 06776 Phone/Message: (860) 946-0312 www.mccarthyobservatory.org

www.mccarthyobservatory.org

@McCarthy Observatory

@McCarthy Observatory

[email protected]

@JJMObservatory

Route 7

December 2018Celestial Calendar

Arrival ofGalileo space

probe atJupiter(1995)

Launch ofSoviet satelliteSputnik 6 with

two dogs,Pchelak and

Mushka (1960)

Dedication ofJohn J.

McCarthyObservatory inNew Milford,CT (2000)

Flyby ofJupiter byPioneer 11spaccraft

(1974)

Launch of Pathfinderspacecraft to Mars

(1996)

Pioneer orbits Venusto study atmosphere

(1978)

Launch of SOHOsolar observatory

(1995)Space Shuttle

Endeavour firstHubble servicingmission (1993)

Discovery of Jupiter moonHimalia by Charles Perrine

(1904)

Launch of Little Joe 2rocket, test flight for theMercury capsule with

Sam, a Rhesus monkey(1959)

America's first attempt atputting a satellite into orbit

failed as Vanguard TV3rose only about four feet offa Cape Canaveral launchpad before crashing back

down and exploding (1957)

Discovery of Kepler-22b, byNASA's Kepler Space

Telescope in the constellationof Cygnus - the first known

transiting planet to orbit withinthe habitable zone of a Sun-

like star (2011)

Pioneer 10 closestapproach to Jupiter (1973)

Gerard Kuiper born -proposed belt ofminor planetaryobjects beyond

Neptune (1905)

New Horizonsspacecraft wakesup to prepare for

its July 2015encounter withthe dwarf planet

Pluto

Gemini 7launch -

Borman/Lovell(1965)

Discovery ofasteroid 5Astraea by KarlHencke (1845)

Launch of Oscar,first amateur satellite

(1961)

Weston, CTMeteorite,first documentedU.S. strike (1807)

Tycho Braheborn,

1546 - Danishastronomer

Discoveryof Saturn

moon Janus byAudouin Dollfus

(1966)

Gemini 6launch

(Schirra,Stafford)

1965

Wright Brothers firstflight, Kitty Hawk, NC

(1903)

Mercury 1,unmannedspacecraft

(1960)

Apollo 8 (Borman,Lovell, Anders), first tocircumnavigate the Moon- 1968

WinterSolstice

Discoveryof LEW

88516 meteorite-Martian origin

(1988)

Ursidsmeteor

shower peak

Discovery of Saturn'smoon Rhea by

Giovanni Cassini(1672)

Jean-LouisPons born -

discoveror ofcomets (1761)

Mars Expressspacecraftorbits Red planet(2003)

Venera 11 on Venus,4 days after sisterlander Venera 12

(1978)

Johannes Keplerborn 1571 -

established laws ofplanetary motion

Discovery ofUranus' moon

Puck by StephenSynnott (1985)

Cassini meetsGalileo atJupiter and getsJovian gravityboost, whileen route toSaturn (2000)

Aussonmeteorite fall,hits buildingin France (1858)

Launch ofXMM-NewtonEuropean X- Raysatellite (1999)

Mars origin meteoriteQUE 94201

discoveredin Queen

Alexandrarange,

Antarctica(1994)

Launch ofDiscovery STS-103, 3rd Hubble

servicingmission (1999)

Benaresmeteorite, hitshouse in India

(1798)

Launch of Sovietspacecraft Vega 2to Venus and on

to Comet Halley -(1984)

Geminids meteorshower peak

ALH 84001 meteorite inAntarctica - cross section

shows signs of possible Martianbacterial life (1984)

Launch ofPioneer 6,first of foursolar orbitingspacecraft(1965)

inaugurallaunch of theAriane rocket

(1979)

Galileo spacecraftexplores auroras duringeclipse of Jovian moon

Ganymede (2000)

Galileo spacecraft1st Earth flyby

(1990)

SpaceX Dragon,launched into low-Earth orbit, isrecovered in thePacific Ocean: firstby a commercial company (2010)

Asteroid 2011WU4 Near-EarthFlyby (0.084 AU)

Challenger, the Lunar Landerfor Apollo 17, touched downon the Moon's surface withastronauts Harrison Schmitt

and Eugene Cernan - last twomen to walk on moon (1972)

Soviet Venusmissions: landingof Venera 7 onthe surface ofVenus (1970);Vega 1 to Venusand Comet Halley (1984);

NASA showed the firstimages from the $670 million

Spitzer Space Telescope,launched 4 months earlier

(2003)

Launch of SovietSalyut 4 space

station(1974)

Soviet cosmonautGeorgy Grechkomakes the first

spacewalk duringthe Salyut 6 EO-1

mission (1977)

Comet 21P Giacobini–Zinnerdiscovered in the constellation

Cygnus byMichel Giacobini

from (Nice,France) (1900)

Charles Babbage born -British mathematician,co-founder of RoyalAstronomical Societyand inventor of first

mechanical computer(1791)

Nancy Jane Sherlock Currieborn - an engineer, US Armyofficer and a NASA astronaut,designed hardware for space

station and served on fourshuttle missions (1956)

John Michelborn, gravityscientist and first topredict existence of"dark stars", latercalled black holes(1724)

St Louis meteorite, hits automobile (1950)Claxton, GA, hits mailbox(1984) Mihonoseki, Japan,hits house (1992)

Pioneer Venus2 in orbit, 2nd

to study planet'satmosphere

(1978)Launch of Helios 1

into solar orbit -joint project of

NASA and FederalRepublic of

Germany (1974)

First light of Mt. Wilson's60-inch telescope (1908)

Flyby of Venus byMariner 2; first

spacecraft to executea successful

encounter withanother planet (1962)

Foundingof the Mt.

WilsonObservatory

(1904)

Launch ofLuna 13,

Soviet moonlander (1966)

Deep SpaceNetwork

created (1963)

GRAIL-A spacecraft(Gravity Recovery And

Interior Laboratory) enterslunar orbit, to be followedby GRAIL-B the following

day. Duo will map themoon's gravity field (2011)

2nd SaturdayStars

New MilfordHigh School

Moon atapogee(farthest

from Earth)

Phases of the Moon

Dec 26Dec 15Dec 7 Dec 22

Documents

Galactic Observer - McCarthy Observatory1968 into Earth orbit. A week or so later, the Soviets launched two Soyuz space craft into Earth orbit (one manned and one unmanned for a planned