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Transit of Mercury —
A Special Event
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Altitude: 50 Meters (more or less)		   Updated Nov. 13, 2006
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2006 TRANSIT OF MERCURY
Wednesday, November 8

See Planet Mercury in Front of Sun — Don't Miss This Rare Celestial Phenomenon!

Introduction    Animation    Calendar of Transits    Observing Schedule & Map    Precautionary Note    Some Details    Transit Flyer    Web Links    2006 Photos
An Alachua Astronomy Club, Inc. (AAC), Florida Museum of Natural History (FLMNH)
and UF Department of Astronomy Event with the Cooperation of Mother Nature

« TELESCOPES WILL BE AVAILABLE BEHIND THE MUSEUM DURING THIS AFTERNOON EVENT »

Transit Big Success! — See Photo by Chuck Broward + More

SHORT INTRODUCTION

One typically has six or less chances to see
this event during their lifetime!

  • Mercury is closest planet to Sun
  • Few people ever see Mercury from Earth because Mercury always appears near Sun on sky
  • But, this year you can see Mercury's small disk move across Sun's face!
  • This phenomenon is called a transit (meaning to "cross over")
  • See drawings on right (Fig. 1 & Fig. 2) including locations on Earth where transit visible (Fig. 3)
    Animation Also see animated version of Fig. 1.
    with larger version here — takes longer to download
    (Nearly 5 hours compressed into a few seconds)
    • Mercury's diameter is only 3/8 of Earth's diameter
    • Mercury's disk will appear only about 1/200 of the Sun's diameter
    • A telescope with a safe solar filter required to see this event
    • Telescopes will be available behind University of Florida museums in the UF Cultural Plaza during this afternoon event
    • See schedule below for times and exact location
  • This event (a transit) occurs only 13 to 14 times per century
  • Mercury orbits the Sun every 88 days but
    • Mercury's orbit tilts to Earth's orbit by 7°
    • So, Mercury usually passes either above or below Sun's disk on the sky each time it comes between Sun and Earth
    • A transit is possible only when Mercury passes through the Earth's orbital plane as it passes between Sun and Earth (near "line of nodes" in Fig. 4)
     
  • OBSERVING SCHEDULE See the AAC observing schedule below
  • DETAILS For details on this event as seen from Gainesville, go down page.
  • CALENDAR For a seven century calendar of Mercury transits (1601–2300) including some interesting Mercury transit tidbits and historical notes, click here

Transits of Venus These are more spectacular since the disk of Venus appears about 1/30 of the Sun's diameter. (Venus is closer to us than Mercury and has nearly the same diameter as Earth.) However, transits of Venus are very rare. Pairs of Venus transits (separated by about 12 years) occur at intervals of over a century! The last three were 1874, 1882 and 2004; the next is 2012 and then the next pair is not again until 2117 and 2125! See photo on right (Fig. 5) for a photograph of the 2004 transit of Venus. (No one alive today had ever seen a transit of Venus until 2004 since the last was in 1882!)


Don't Miss This Unique Event!

Nearly ten years will pass before Mercury again transits Sun! (See Calendar)


THE AAC, FLMNH & DEPT. OF ASTRONOMY
WILL HAVE TELESCOPES SET UP

OBSERVING SCHEDULE
OBSERVING ALERT

Spaceweather.com reports Mercury might eclipse Sunspot 921 during the transit. See Greg Piepol's (Rockville, Maryland) animation showing path of Mercury & expected position of sunspot on Nov. 8th. Spaceweather.com writes, "In Greg's simulation, the background image is real. He took it on Nov. 3rd using his Coronado SolarMax90. The photo was rotated just as the sun spins to move the sunspot into position for the transit. Bulls-eye! 921 is going to provide a pleasing backdrop for Mercury's journey across the sun." (However, since the Sun will set for Florida observer's before the transit ends, Mercury will not have reached the sunspot before the Sun disappears from view.)



  • Observing a transit like this requires looking at the Sun (with a telescope due to the small apparent size of Mercury)
  • Observing the Sun can be very dangerous
  • Severe and permanent injuries to eye can result
  • Do not try to observe the Sun yourself unless you are knowledgeable & experienced with solar observing
    • Safe solar filters are especially made for viewing the Sun
    • Any dark material is not necessarily safe (may pass UV & IR or may have holes)
    • Filters must also be placed in front of the telescope (not behind) to block light before entering the instrument
    • Also see warning note about locating Venus
  • Here is a good link about How to View it Safely
 Instead of trying to view this event yourself, come and enjoy this spectacle with the AAC and the FLMNH!
(See location map.)

(We will have safe solar filters attached to the front of our telescopes)

See ScheduleTHE SUN WILL SET BEFORE THE TRANSIT ENDS. However, we have the chance to see about two-thirds of this event. But, people should arrive well before sunset since trees, buildings, clouds and horizon haze will make it difficult to see the Sun as sunset time approaches.
SOME TRANSIT DETAILS
FOR THOSE WHO WANT MORE

2006 Transit of Mercury
(Times for Gainesville, Florida)
(Also See Fig. 2)

Transit Starts 2:12 p.m. EST
(Sun's Altitude 36°,
Azimuth 216°)
Maximum Transit 4:41 p.m. EST
(Sun's Altitude 11°,
Azimuth 244°)
Sunset 5:38 p.m. EST
(Azimuth 251° or
3.5° W of WSW horizon)
Transit Ends 7:10 p.m. EST
(Sun's Altitude -20°,
i.e. 20° below horizon)
Duration 4h58m
Duration from Gainesville
(Before Sun sets)		 3h26m or 69% of total duration
Angular Distance from Sun's
Center at Maximum Transit		 7' 03"
Angular Diameter of Mercury 10.0" (0.52% or
1/194 of a Solar Diameter)
Angular Diameter of Sun 1937.4"
(32.29' or 0.538 degrees)



FIGURES

[Click Each Figure for Largest Version Available]

Fig. 1. Mercury Crosses Sun's Disk—2006 Nov. 8
(Sun's Orientation for Start of Transit, Gainesville, FL)
2006 Transit of Mercury (Click for Animation)
Drawing by H.L. Cohen
– For Animation Click Here or Above Figure –
[ Larger Version — takes longer to download ]
(Nearly 5 hour transit compressed into a few seconds)



Fig. 2. Transit of Mercury Diagram—2006 Nov. 8
(Sun's Orientation for Start of Transit, Gainesville, FL)
Transit of Mecury
(Also see commented version of above)
Figure by H.L. Cohen



Fig. 3. World Map Showing Zones of Visibility
Zone of Visibiltiy
Diagram by Fred Espenak (NASA/GSFC)



Fig. 4. Orbits of Mercury & Earth
Transits possible only when planets near line of nodes
 (Inclination exaggerated—only 7°)
Orbits of Mercury and Earth
Diagram by H.L. Cohen



Fig. 5. 2004 Transit of Venus
(Venus shows a larger disk than Mercury)
Transit of Venus 2004
Photo by H.L. Cohen



Fig. 6. 2003 Transit of Mercury Movie From SOHO
(Click here for larger version of movie)

2003 May 7 Transit of Mercury
Cred. SOHO/EIT, SOHO/MDI (ESA & NASA)
(Movie may not show up in all browsers)


Fig. 7. Mercury Transit Flyer

Transit Flyer

See image of flyer to be handed out at our transit event
or see a pdf version


Fig. 8. Transit of Mercury Photo: 2006 Nov. 8
by AAC Member Chuck Broward

Transit of Mercury by Chuck Broward

Picture taken shortly after transit began (time abt. 2:15 p.m. EST).
A large sunspot (#923) also appears near limb of Sun.
Can you tell which is Mercury?

Chuck Sets Up for the Transit

Chuck Sets Up


Venus

LOCATION OF VENUS This brilliant planet will be located about six solar diameters East of Sun at maximum transit. However, extreme precautions must be taken to observe Venus so close to the Sun since no solar filter can be used to see Venus. The chance of pointing a telescope at the Sun without a proper solar filter poses great risk to eyesight and is extraordinarily dangerous.

Advice: Don't do it!

Venus At Mid-Transit: 3.1°E of Sun, magnitude -3.9 (99.9% illuminated, Angular Diameter 9.75")


FOR THOSE WHO STILL WANT MORE INFO & DETAILS
WebCasts

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