Published on November 5, 2007
Slide1: Mid Atlantic Star Party Professor John C. Mannone November 5, 2005 Slide2: The Light of Stars is replete with stellar metaphors, but Longfellow attempts to preserve the accuracy of the celestial globe, a consequence of his didactic style. Published in the Voices of the Night in 1839. An illuminating remark, ex post facto, to his wife Fanny Appleton Longfellow, when reflecting on the poem (October 6, 1846): "This poem was written on a beautiful summer night. The moon, a little strip of silver, was just setting behind the groves of Mount Auburn, and the planet Mars blazing in the southeast. There was a singular light in the sky; and the air cool and still" Slide3: The original publication (The Second Psalm of Life, Knickerbocker magazine 1838) opens with an extra stanza Borrowed from Henry Vaughan They are all Gone into the World of Light (Silex Scintillans, Part II 1655) Longfellow included it since it parallels his theme and provides corroborating stellar clues: It glows and glitters in my cloudy breast, Like stars upon some gloomy grove, Or those faint beams in which this hill is drest After the sun’s remove Slide4: Boston and vicinity, 1830 Mount Auburn The sun had set and the observation from atop the 125-ft ridge, “this hill”, called Mount Auburn shows starry sky over the graveyard, “stars upon some gloomy grove.” Adapted from a map published in 1830 by Abel Brown Slide5: Mount Auburn Peak 125 ft MSL A GRAVE , A GROVE A CEMETERY, A HILL Slide6: Courtesy of Katarina Neef Slide7: A west southwest star field is suggested. The “faint beams” could easily be diffuse light of stars from the Milky Way. In late summer, the Milky Way is oriented as a vertical swath in the southwest together with the star studded Sagittarius and Scorpio constellations. Slide8: Milky Way : Light Pollution-Free Late Summer Night rotation Slide9: The first two stanzas verify a sliver of silver, a crescent moon; “the little moon” is in the process of setting. Furthermore, the time is between 8 PM and midnight (local time) as evidenced by “the first watch”: The night is come, but not too soon; And sinking silently, All silently, the little moon Drops down behind the sky There is no light in earth or heaven But the cold light of stars; And the first watch of night is given To the red planet Mars. Slide10: Time Name of Watch Noon to 4 pm Afternoon watch 4 pm to 6 pm First dog watch 6 pm to 8 pm Second dog watch 8 pm to midnight First watch Midnight to 4 am Middle watch 4 am to 8 am Morning watch 8 am to noon Forenoon watch (Compare these military (nautical) watches with the watches spoken of in the Old Testament and with the Roman army/navy in the New Testament) Slide11: 8 PM Local Time in Boston is 7:37 EST (Time Zones Established in USA by RxR in 1863) Slide12: Additional clues in the next two stanzas suggest Mars is in the earlier part of the first watch. The “blue tent above” and “suspended in the evening skies” hint of a time not much past twilight. The indigo blue hue betrays the Rayleigh scattering of light by the moisture in the air: Is it the tender star of love? The star of love and dreams? O no! from that blue tent above, A hero's armor gleams. And earnest thoughts within me rise, When I behold afar, Suspended in the evening skies, The shield of that red star. Slide13: “The Blue Tent” Slide14: When was the astronomical landscape from Mount Auburn painted by Longfellow’s words in 1838 observed? Mars was not visible during nighttime hours in 1838. Mars not in the SE during the summers 1831-1839 (not before 3 or 4 AM, well past the first watch). Longfellow not a permanent resident of Cambridge until December 1836 (accepted the Smith Chair of Modern languages at Harvard College). How are the facts reconciled with the poetic literature? Poetic License Typographical or Directional Errors Misidentification Observation/Publication at Different Times Slide15: Poetic License Longfellow is not averse to poetic license; he has used it in The Occultation of Orion. Anticipating criticism, Longfellow wrote, “Astronomically speaking, this title is incorrect; as I apply to a constellation what can properly be applied to some of its stars only. But my observation is made from the hill of song, and not from that of science; and will, I trust, be found sufficiently accurate for the present purpose.” (The Complete Poetical Works of Henry Wadsworth Longfellow. Boston: Houghton, Mifflin and Company. James R. Osgood and Company. 1881, p. 290.) Slide16: On the other hand, his precision in scientific detail, as evidenced in much of his poetry, is more often the case than simple metaphor (e.g., The Bridge, Building of a Ship, and The Galaxy). There is no precedent in the use of poetic license in remarks or statements of facts. Longfellow’s remark reads more like an observer’s log entry, rather descriptive and factual, not something privy to distortion. Poetic license may be expected in his poetry, but not in his journals concerning historical recollections. Slide17: a) Mars is not blazing bright (unimpressive magnitude 0.56-1.0). b) There is no a singular light, but two, three, or four bright planets visible throughout the entire summer during the first watch (Jupiter, Saturn, Venus and Mercury). Typographical or Directional Error: SW vs. SE Did Longfellow mean Mars in the southwest and not in the southeast? Then there is only one candidate in that decade; the year 1839. In June, Mars is high in the southwest during the first watch, while Moon, phased as a sliver, sets. Unfortunately, there are several objections: Slide18: c) Both views are possible from Mount Auburn, but a southeast view makes more sense since the setting Moon could be seen to disappear behind the groves. A southwest view has the setting Moon directly in front of the viewer. Therefore, the possibility of a typographical (or directional) error is unsupported. courtesy of Tropozone Slide19: Confusion of Mars with a Red Star Mars, when normal in size and magnitude, could be confused with the bright reddish star if certain necessary conditions are all met: a) If there was a red star is in the southeast Antares, a red supergiant of magnitude 1.06, is the only possible summer red star (class M1 IB). Unfortunately, it is low in the southeast during late spring and early summer, moving south as the summer progresses. Slide20: BRIGHTEST RED GIANT & SUPERGIANT STARS. Rank among all the brightest stars Slide21: b) If the star doesn’t appear to twinkle Stars normally twinkle since they are like point lights. Their distant light rays suffer multiple refraction in a turbulent upper atmosphere. Planets are much closer and are considered extended bodies of light, not point light sources. The reflected sun light is coming from all over their surface. All the refractions are averaged by the turbulent atmosphere. Therefore, planets don’t normally twinkle. A stable upper atmosphere is required for slow and little twinkling of stars, a condition not often met in New England. Slide22: c) If Longfellow expected to see a planet in the southeast. Since his childhood to the time of publication of Voices of the Night, Longfellow had opportunities to witness Mars in the southeastern sky; however, Mars does not exclusively appear there in the first watch. Therefore, a positional precedence cannot be firmly asserted. d) If this star was rivaled by only one singular bright light There are several brighter stars in the summer sky. Arcturus, Altair, and Vega are all present and brighter. Therefore, the “singular (bright) light” criterion is immediately violated These facts strongly discourage the possibility of Mars being confused with a red star. Slide23: Observation and Publication at Different Times The only remaining possibility that fits all the conditions is the perihelion opposition of Mars. Every fifteen to seventeen years, Mars approaches close to the Sun with Earth in between. Mars will be very close (and appear relatively large) as well as very bright. It will outshine all other planets except Venus. Mars was in these positions in 1815, 1830, and 1845. The 1830 Martian configuration is most likely scenario and very defendable. A protracted investigation into Longfellow’s letters and biographies has provided clues, but the question may not be permanently resolved without a “smoking gun” entry in his daily journal. It can be shown that Longfellow had often traveled to Boston in his pre-Harvard years. Longfellow had opportunity in September 17-21 to be in Cambridge. Longfellow had motive to be in the area. Slide24: The Tentative Conclusion Longfellow observed Mars in perihelion opposition in late summer of 1830 Jupiter was the comparable singular bright light A thin crescent moon was setting Cool calm nights are consistent with late New England summers Slide25: BOSTON SKY 9/21/1830 MARS IN PERIHELION OPPOSITION 1. Perihelion opposition September 19, 1830 (m = -2.75) Antares sets with the Moon. Antares and other stars are not comparable to the brightness of Mars that night. No bright objects (comets or planets) visible except for Jupiter. Early in the first watch, the sky could appear as a “blue tent.” Slide26: Perihelion Opposition of Mars 2003 An even more remarkable perihelion opposition of Mars graced the skies over Boston the summer of 2003. As it loomed closer than it has ever been to Earth in nearly 60,000 years. Again, the first watch belongs to Mars blazing in the Southeast, but it share the “lime-light” with no other object. Courtesy of European Space Agency/Science & Technology Slide28: Boston, MA September 21, 1830 8 PM Sky View III Slide29: Boston, MA September 21, 1830 8 PM Starry Night Backyard Slide30: Mars Opposition Mars 2003 2005 Won't Be As Close 0.34 AU 0.46 AU (24% farther) Won't Appear as Bright m -2.9 m -2.3 (58% dimmer) Won't Appear as Large 25.1" 20.2" (20% smaller) But Mars will appear much higher in USA skies in 2005 compared with 2003! and will not appear larger than 20 arcsec until 2018 Chronology Mars Apparition: Chronology Mars Apparition Sep 15, 2004 Mars in conjunction with the Sun from Earth, in Leo near the border to Virgo. Earth in superior conjunction with the Sun from Mars. Distance about 400 million km (2.67 AU) at this aphelic conjunction; the planet's apparent diameter is only 3.5". From Mars, this is seen as a superior conjunction of Earth with the Sun. This conjunction, which also ends the great 2003 apparition of Mars, starts the planet's 2005 apparition. Slide32: Sep 17, 2004 Mars leaves constellation Leo and enters Virgo. Sep 20, 2004 Northern Summer, Southern Winter solstice on Mars. Nov 22, 2004 Mars leaves constellation Virgo and enters Libra. Dec 31, 2005 Mars leaves constellation Libra and enters Scorpius. Jan 1, 2005 Mars is seen in the morning sky in constellation Scorpius, still close to the border of Libra, at a distance of 332 million km (2.221 AU), mag +1.1 and diameter 4.2". Jan 7, 2005 Mars passes 5deg north of Antares. Jan 8, 2005 Mars leaves constellation Scorpius and enters Ophiuchus. Slide33: Jan 15, 2005 Mars passes the descending node of its orbit, moving to the south of the ecliptic, thus getting southern ecliptic latitudes. Apparent brightness of Mars exceeds +1.5 mag Feb 2, 2005 Mars leaves constellation Ophiuchus and enters Sagittarius. Feb 23, 2005 Apparent diameter of Mars exceeds 5". Mar 20, 2005 Mars leaves constellation Sagittarius and enters Capricornus. Mar 21, 2005 Mars' apparent brightness exceeds +1.0 mag. Apr 27, 2005 Mars leaves constellation Capricornus and enters Aquarius. May 10, 2005 Mars' apparent brightness exceeds +0.5 mag. Slide34: Jun 7, 2005 Mars leaves constellation Aquarius and enters Pisces. Jun 20, 2005 Mars at southernmost heliocentric ecliptical latitude (1.85 deg). Jun 21, 2005 Mars leaves constellation Pisces and enters Cetus. It is going to change between these two constellations several times for the next few weeks. Jun 30, 2005 Mars leaves constellation Cetus and enters Pisces. Jul 1, 2005 Mars' apparent brightness exceeds 0.0 mag. Jul 12, 2005 From Mars, Earth is at its greatest Eastern elongation from the Sun at about 43 deg. From Earth, Mars phase is minimal, angle is 43 deg. Only 84 percent of the visible Mars hemisphere is illuminated. Slide35: Jul 13, 2005 Apparent diameter of Mars exceeds 10". Jul 17, 2005 Mars in Perihel (207 million km, 1.38 AU from the Sun) Aug 2, 2005 Mars leaves constellation Pisces and enters Cetus. Aug 5, 2005 Mars' apparent brightness exceeds -0.5 mag. Aug 7, 2005 Mars leaves constellation Cetus and enters Aries. It will come to opposition in this constellation in about three months. Aug 12, 2005 Mars Reconnaissance Orbiter (MRO) spacecraft launched to Mars Aug 17, 2005 Northern Winter, Southern Summer solstice on Mars Slide36: Sep 2, 2005 Mars' apparent brightness exceeds -1.0 mag. Sep 8, 2005 Apparent diameter of Mars exceeds 15". Sep 22, 2005 Mars leaves constellation Aries and enters Taurus (just for a few days). Oct 1, 2005 Mars becomes stationary and then starts its retrograde opposition loop, as Earth passes between the Red Planet and the Sun. Oct 11, 2005 Mars leaves constellation Taurus in retrograde motion and enters Aries where it will come into opposition next month. Oct 17, 2005 Mars' apparent brightness exceeds -2.0 mag. Oct 23, 2005 Apparent diameter of Mars exceeds 20". Slide37: Oct 30, 2005 Closest approach of Mars and Earth (0.464 AU = 69.42 million km). Apparent diameter of Mars is 20.19". Nov 6, 2005 Apparent diameter of Mars decreases below 20". Nov 7, 2005 Mars opposition on Earth, Earth in inferior conjunction on Mars. Apparent brightness of Mars reaches -2.3 mag in constellation Aries. Nov 15, 2005 Mars passes the ascending node of its orbit, moving to the north of the ecliptic, thus getting northern ecliptic latitudes. Nov 19, 2005 Mars' apparent brightness becomes fainter than -2.0 mag. Slide38: Dec 6, 2005 Mars' apparent brightness becomes fainter than -1.5 mag. Dec 10, 2005 Mars becomes stationary to end its retrograde opposition loop as the Earth has passed it on its inner orbit, and proceeds in prograde apparent motion. Dec 15, 2005 Apparent diameter of Mars decreases below 15". Dec 20, 2005 Mars' apparent brightness becomes fainter than -1.0 mag. Jan 1, 2006 Mars is seen prominently in the evening sky in constellation Aries, at a distance of 116 million km (0.78 AU), mag -0.6 and 12.1" diameter. Jan 5, 2006 Mars' apparent brightness becomes fainter than -0.5 mag. Slide39: Jan 19, 2006 Apparent diameter of Mars decreases below 10". Jan 20, 2006 Mars' apparent brightness becomes fainter than 0.0 mag. Jan 22, 2006 Northern Spring, Southern Autumn equinox on Mars. Feb 7, 2006 Mars leaves constellation Aries and enters Taurus. Feb 14, 2006 Mars' apparent brightness becomes fainter than +0.5 mag. Feb 17, 2006 Mars passes the Pleiades (M45) at 2.5 deg South. Mar 4, 2006 Mars Reconnaissance Orbiter (MRO) spacecraft to arrive at Mars and to enter Mars orbit. Slide40: Mar 18, 2006 Mars' apparent brightness becomes fainter than +1.0 mag. Apr 25, 2006 Apparent diameter of Mars decreases below 5". May 1, 2006 Mars' apparent brightness becomes fainter than +1.5 mag. Jun 26, 2006 Mars in its aphel (249 million km or 1.66 AU from the Sun). Oct 1, 2006 Mars at its greatest distance from Earth: 390 million km (2.607 AU). Mars' apparent disk measures now only 3.6" in diameter. Oct 23, 2006 Mars in conjunction with the Sun from Earth, in Virgo. Earth in superior conjunction with the Sun as seen from Mars. Distance 388 million km (2.594 AU), apparent diameter 3.6". This conjunction ends the 2005 apparition of Mars. It also starts the 2007 apparition of Mars. Slide41: The 2005 close approach of Mars to Earth comes on an auspicious day—nearly on Halloween 67th anniversary of the notorious Sunday Oct 30, 1938 (8-9 pm) Orson Welles broadcast about an invasion from Mars (adapted from H.G. Wells' 1898 novel, The War of the Worlds). Closest Approach 2005 Oct. 30, 3h UT (Oct. 29, 11:00 p.m. EDT) 0.464 AU (69,420,000 km or 43,140,000 mi) Opposition 2005 Nov. 07, 8h UT (Nov. 7, 3:00 a.m. EST) 0.470 AU (70,240,000 km or 43,650,000 mi) Slide42: The Light of Stars Henry Wadsworth Longfellow The night is come, but not too soon; And sinking silently, All silently, the little moon Drops down behind the sky. There is no light in earth or heaven But the cold light of stars; And the first watch of night is given To the red planet Mars. Is it the tender star of love? The star of love and dreams? O no! from that blue tent above, A hero's armor gleams. Slide43: And earnest thoughts within me rise, When I behold afar, Suspended in the evening skies, The shield of that red star. O star of strength! I see thee stand And smile upon my pain; Thou beckonest with thy mailed hand, And I am strong again. Within my breast there is no light But the cold light of stars; I give the first watch of the night To the red planet Mars. Slide44: The star of the unconquered will, He rises in my breast, Serene, and resolute, and still, And calm, and self-possessed. And thou, too, whosoe'er thou art, That readest this brief psalm, As one by one thy hopes depart, Be resolute and calm. O fear not in a world like this, And thou shalt know ere long, Know how sublime a thing it is To suffer and be strong.