December 11, 2017

Astro-Challenge: Can You Spot the Moons of Mars?

This weeks’ challenge is a toughie and not for the faint of eye sight. In 1877, American astronomer Asaph Hall discovered the Martian Moons using the newly installed 26” refracting telescope at the U.S. Naval Observatory. Named appropriately Phobos (fear) and Deimos (terror), the moons were well suited companions for Mars, the god of war. Both moons, however, are tiny; outermost Deimos is 12.6 km in size and orbits Mars once every 30.35 hours, while innermost Phobos is larger, at 22.2 km in size and orbits the Red Planet in only 7.7 hours! In fact, at an orbital radius of only 9,377 km, Phobos orbits its primary closer than any other satellite in the solar system. Both tiny misshapen worlds are believed to be captured asteroids that will, one day millions of years in the future, spiral into Mars. Most of the time, these moons lie out of the range of all but the largest telescopes; but as Mars just passed opposition this past week, however, sighting these elusive moons might just be possible.

To spot Deimos and Phobos, you’ll need an aperture of at least 8” or larger, mid- to high magnification, clear steady skies, and patience. The moons themselves are at magnitudes +11.3 (Phobos) and +12.4 (Deimos), and would not be a tough find were it not for the fact that they never stray far from the bright Mars, which is currently at magnitude -1.2! As the magnitude scale is logarithmic, the difference is well over 25,000 times in favor of Mars! Another strike against sighting these beasts is the fact that this years’ opposition is particularly unfavorable, as Mars and Earth are about as distant as they can be and still be at opposition. In fact, we once attempted sighting these moons from a dark site in Arizona with an 18” Dobsonian during the excellent 2003 opposition, with no luck. A handy tool aid in acquisition is an occulting bar eyepiece; this will block the glare of Mars to give you some hope of spying its moons. Your best shot will be when the moons reach their greatest elongation east or west of the planet; we lovingly hand-crafted a table for this week to aid in this feat. Also, if visual inspection doesn’t yield your quarry, imaging just might; several amateur astronomers have had luck over-exposing Mars with ad-hoc webcams to reveal the elusive moons. Good luck, and remember; Astroguyz will be right there with you attempting this elite feat of visual athletics!

The astro-term for this week is; Mars Moon Hoax. Did you know that there were speculations of dual Martian moons prior to discovery in literature? First proposed by Kepler and later Voltaire, the most famous reference is in Jonathan Swift’s Gulliver’s Travels, in which astronomers in the fabled land of Laputa are described as sighting two Martian moons. So, what gives? Who gave Swift this knowledge, over one century before Hall’s discovery? Or was Swift a Martian? The answer, I believe, lies in the numerology of the day. Kepler was a great lover of mathematics, and spent much of his life chasing after what he believed was the great underlying mathematical symmetry of the solar system. Earth was known to have one large Moon; Jupiter had four known moons at the time. It seemed as if there should be a logical progression, and Mars should have two moons awaiting discovery (1,2,4, etc…) Of course, it’s now known that the universe is, in fact, a messy place that often defies such neat pigeon-holing; at last tally, Jupiter had 63 moons and counting.

Phobos and Deimos also found themselves at the center of controversy more recently in 1959 when Soviet astronomer Iosif Shklovsky postulated that the tiny moons where, in fact, hollowed out artificial satellites! The media of course, ran with the story, in what was to be known as the April Fools hoax. From these tales, to the War of the Worlds broadcast, Mars just seems to invite controversy… these days, of course, we have the “Mars face”, a Martian Bigfoot, and the now yearly hoax e-mail to contend with… all lending themselves to the wacky human Rorschach test that is Mars!

Comments

  1. Ed Kotapish says:

    ELONGATIONS OF THE MARTIAN MOONS

    01 MAR 2010
    PHOBOS 0223 W
    PHOBOS 0613 E
    DEIMOS 0935 W
    PHOBOS 1002 W
    PHOBOS 1353 E
    PHOBOS 1741 W
    PHOBOS 2132 E

    02 MAR 2010
    DEIMOS 0044 E
    PHOBOS 0120 W
    PHOBOS 0511 E
    PHOBOS 0900 W
    PHOBOS 1250 E
    DEIMOS 1553 W
    PHOBOS 1639 W
    PHOBOS 2030 E

    03 MAR 2010
    PHOBOS 0018 W
    PHOBOS 0409 E
    DEIMOS 0702 E
    PHOBOS 0757 W
    PHOBOS 1148 E
    PHOBOS 1536 W
    PHOBOS 1927 E
    DEIMOS 2211 W
    PHOBOS 2316 W

    04 MAR 2010
    PHOBOS 0306 E
    PHOBOS 0655 W
    PHOBOS 1046 E
    DEIMOS 1320 E
    PHOBOS 1434 W
    PHOBOS 1825 E
    PHOBOS 2213 W

    05 MAR 2010
    PHOBOS 0204 E
    DEIMOS 0428 W
    PHOBOS 0553 W
    PHOBOS 0943 E
    PHOBOS 1332 W
    PHOBOS 1723 E
    DEIMOS 1937 E
    PHOBOS 2111 W

    06 MAR 2010
    PHOBOS 0102 E
    PHOBOS 0450 W
    PHOBOS 0841 E
    DEIMOS 1046 W
    PHOBOS 1229 W
    PHOBOS 1620 E
    PHOBOS 2009 W
    PHOBOS 2359 E

    07 MAR 2010
    DEIMOS 0155 E
    PHOBOS 0348 W
    PHOBOS 0739 E
    PHOBOS 1127 W
    PHOBOS 1518 E
    DEIMOS 1704 W
    PHOBOS 1906 W
    PHOBOS 2257 E

    08 MAR 2010
    PHOBOS 0245 W
    PHOBOS 0636 E
    DEIMOS 0813 E
    PHOBOS 1025 W
    PHOBOS 1416 E
    PHOBOS 1804 W
    PHOBOS 2155 E
    DEIMOS 2322 W

    09 MAR 2010
    PHOBOS 0143 W
    PHOBOS 0534 E
    PHOBOS 0922 W
    PHOBOS 1313 E
    DEIMOS 1431 E
    PHOBOS 1702 W
    PHOBOS 2052 E

    10 MAR 2010
    PHOBOS 0041 W
    PHOBOS 0432 E
    DEIMOS 0539 W
    PHOBOS 0820 W
    PHOBOS 1211 E
    PHOBOS 1559 W
    PHOBOS 1950 E
    DEIMOS 2048 E
    PHOBOS 2338 W

    11 MAR 2010
    PHOBOS 0329 E
    PHOBOS 0718 W
    PHOBOS 1109 E
    DEIMOS 1157 W
    PHOBOS 1457 W
    PHOBOS 1848 E
    PHOBOS 2236 W

    12 MAR 2010
    PHOBOS 0227 E
    DEIMOS 0306 E
    PHOBOS 0615 W
    PHOBOS 1006 E
    PHOBOS 1354 W
    PHOBOS 1745 E
    DEIMOS 1815 W
    PHOBOS 2134 W

    13 MAR 2010
    PHOBOS 0125 E
    PHOBOS 0513 W
    PHOBOS 0904 E
    DEIMOS 0924 E
    PHOBOS 1252 W
    PHOBOS 1643 E
    PHOBOS 2031 W

    14 MAR 2010
    PHOBOS 0022 E
    DEIMOS 0032 W
    PHOBOS 0411 W
    PHOBOS 0802 E
    PHOBOS 1150 W
    PHOBOS 1541 E
    DEIMOS 1541 E
    PHOBOS 1929 W
    PHOBOS 2320 E

    15 MAR 2010
    PHOBOS 0308 W
    DEIMOS 0650 W
    PHOBOS 0659 E
    PHOBOS 1047 W
    PHOBOS 1438 E
    PHOBOS 1827 W
    DEIMOS 2159 E
    PHOBOS 2218 E

    16 MAR 2010
    PHOBOS 0206 W
    PHOBOS 0557 E
    PHOBOS 0945 W
    DEIMOS 1308 W
    PHOBOS 1336 E
    PHOBOS 1724 W
    PHOBOS 2115 E

    17 MAR 2010
    PHOBOS 0103 W
    DEIMOS 0417 E
    PHOBOS 0454 E
    PHOBOS 0843 W
    PHOBOS 1234 E
    PHOBOS 1622 W
    DEIMOS 1926 W
    PHOBOS 2013 E

    18 MAR 2010
    PHOBOS 0001 W
    PHOBOS 0352 E
    PHOBOS 0740 W
    DEIMOS 1035 E
    PHOBOS 1131 E
    PHOBOS 1520 W
    PHOBOS 1911 E
    PHOBOS 2259 W

    19 MAR 2010
    DEIMOS 0143 W
    PHOBOS 0250 E
    PHOBOS 0638 W
    PHOBOS 1029 E
    PHOBOS 1417 W
    DEIMOS 1652 E
    PHOBOS 1808 E
    PHOBOS 2156 W

    20 MAR 2010
    PHOBOS 0147 E
    PHOBOS 0536 W
    DEIMOS 0801 W
    PHOBOS 0927 E
    PHOBOS 1315 W
    PHOBOS 1706 E
    PHOBOS 2054 W
    DEIMOS 2310 E

    21 MAR 2010
    PHOBOS 0045 E
    PHOBOS 0433 W
    PHOBOS 0824 E
    PHOBOS 1213 W
    DEIMOS 1419 W
    PHOBOS 1604 E
    PHOBOS 1952 W
    PHOBOS 2343 E

    22 MAR 2010
    PHOBOS 0331 W
    DEIMOS 0528 E
    PHOBOS 0722 E
    PHOBOS 1110 W
    PHOBOS 1501 E
    PHOBOS 1849 W
    DEIMOS 2037 W
    PHOBOS 2240 E

    23 MAR 2010
    PHOBOS 0229 W
    PHOBOS 0620 E
    PHOBOS 1008 W
    DEIMOS 1145 E
    PHOBOS 1359 E
    PHOBOS 1747 W
    PHOBOS 2138 E

    24 MAR 2010
    PHOBOS 0126 W
    DEIMOS 0254 W
    PHOBOS 0517 E
    PHOBOS 0905 W
    PHOBOS 1257 E
    PHOBOS 1645 W
    DEIMOS 1803 E
    PHOBOS 2036 E

    25 MAR 2010
    PHOBOS 0024 W
    PHOBOS 0415 E
    PHOBOS 0803 W
    DEIMOS 0912 W
    PHOBOS 1154 E
    PHOBOS 1542 W
    PHOBOS 1933 E
    PHOBOS 2322 W

    26 MAR 2010
    DEIMOS 0021 E
    PHOBOS 0313 E
    PHOBOS 0701 W
    PHOBOS 1052 E
    PHOBOS 1440 W
    DEIMOS 1530 W
    PHOBOS 1831 E
    PHOBOS 2219 W

    27 MAR 2010
    PHOBOS 0210 E
    PHOBOS 0558 W
    DEIMOS 0639 E
    PHOBOS 0950 E
    PHOBOS 1338 W
    PHOBOS 1729 E
    PHOBOS 2117 W
    DEIMOS 2147 W

    28 MAR 2010
    PHOBOS 0108 E
    PHOBOS 0456 W
    PHOBOS 0847 E
    PHOBOS 1235 W
    DEIMOS 1256 E
    PHOBOS 1626 E
    PHOBOS 2014 W

    29 MAR 2010
    PHOBOS 0006 E
    PHOBOS 0354 W
    DEIMOS 0405 W
    PHOBOS 0745 E
    PHOBOS 1133 W
    PHOBOS 1524 E
    PHOBOS 1912 W
    DEIMOS 1914 E
    PHOBOS 2303 E

    30 MAR 2010
    PHOBOS 0251 W
    PHOBOS 0643 E
    DEIMOS 1023 W
    PHOBOS 1031 W
    PHOBOS 1422 E
    PHOBOS 1810 W
    PHOBOS 2201 E

    31 MAR 2010
    DEIMOS 0145 E
    PHOBOS 0154 W
    PHOBOS 0545 E
    PHOBOS 0933 W
    PHOBOS 1324 E
    DEIMOS 1653 W
    PHOBOS 1712 W
    PHOBOS 2103 E

Trackbacks

  1. [...] astronomical highlights of the year.  This is also a good time to try to sight the elusive Martian moons of Deimos and [...]

  2. [...] instalado refractor centímetros del Observatorio Naval de Estados Unidos 65. Las lunas son sólo al alcance de los aficionados con ojos de lince cerca de oposición. Tienes otra oportunidad de cruzar estas [...]

  3. [...] instalado refractor centímetros del Observatorio Naval de Estados Unidos 65. Las lunas son sólo al alcance de los aficionados con ojos de lince cerca de oposición. Tienes otra oportunidad de cruzar estas [...]

  4. [...] the United States Naval Observatory’s newly installed 65 centimetre refractor. The moons are just within the grasp of eagle-eyed amateurs near opposition. You’ve got another opportunity to cross these elusive [...]

  5. [...] works nicely) for the central bar. An occulting bar eyepiece is also handy for hunting down the moons of Mars near [...]

  6. [...] impossibly remote, a year straight out of science fiction. And while we’re not vacationing on Phobos and traveling via teleporter just yet, we are all carrying computers in our pocket, and everything [...]

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