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Transit of Venus 2012 - 05/06 June

Venus - Frequency Cycle of Transits

 

 

Venus in Natural Visible Light

image credit; Pioneer Venus Orbiter Team NASA

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Transit: Definition: A transit is when a smaller celestial body passes across the disc of a larger celestial body as viewed from Earth. As observed from Earth, Mercury and Venus are the only two planets of the solar system that make transits of the Sun. This is because they are the only two planets that have orbits which lie between Earth and the Sun.  

 

A Transit of Venus occurs when Earth, Venus and the Sun are aligned. Venus can then be observed from various locations on Earth, and observers can view Venus passing across the disc of the Sun.

 

Mercury makes an average of 13 transits of the Sun each century.

Transits of Venus across the disc of the Sun; only 7 of them have occurred between 1639 and 2004..

 

If an observer stood on the surface of Mars and looked up to the pink Martian sky, when all three bodies of Mars, Earth and the Sun were in alignment, then it would be possible to see Earth make a transit of the Sun.

 

The moons of Jupiter make regular transits, and the Galilean moons of Io, Europa, Ganymede and Callisto, can easily and regularly be observed using a small telescope or binoculars.

 

Extrasolar Planets Transits: Transits also occur with extrasolar planets and their parent star: OGLE-TR-56b was the first extrasolar planet discovered using the transit method in 2002 - orbiting its parent star OGLE-TR-56. It was not the first extrasolar planet to be discovered but it was the first extrasolar planet to be detected using the transit method. 

 

The alignment of Earth, Venus, and the Sun is rare: The Transit of Venus 05/06 June 2012 will probably be the only opportunity of viewing a Transit of Venus.

Quick Facts - Venus

 

   Venus day:    243 Earth Days

   Venus year:   225 Earth Days

 

  Hottest planet in Solar System

   864 fahrenheit / 462 Celsius  

The next Transit of Venus does not occur until the 22nd century, 11 December 2117 and then again on 08 December 2125

A Global Perspective -Transit of Venus 05/06 June 2012

 

The Transit of Venus will look diferent according to your location.

You may think that the Sun looks the same from wherever you may be in the World

But things are not quite that way.

 

You may think that the Sun looks the same from wherever you may be in the world, and in essence it does, but if the Sun had a big stick stuck on its top saying, 'This Way Up' or 'North Pole' then you would easily know that you were looking at an upside down Sun compared to the one you usually see. The Sun has a North and South Pole just as on Earth, and when viewed from Earth's Northern Hemisphere, the Sun has its north pointing upwards, but travel to the Southern Hemisphere to perhaps New Zealand or Australia and the North Pole of the Sun actually points downwards.  The same can be said for the Moon and a Half illuminated Moon in one hemisphere is the opposite way round in the other hemisphere.    

 

The same affect ocurrs with the Transit of Venus and although viewers in Earth's northern hemisphere will see Venus pass across the top of the Sun's Northern Hemisphere, viewers in Earth's southern hemisphere (from their perspective) will see Venus pass across the bottom of the Sun, with the Sun's North Pole pointing downwards: And observers on the equator will see Venus Transit the Sun from the side. Cestial events such as these make you realise that we indeed live on a round ball sliently turning in Space.  It is quite clear by looking at the images below, the different way the transit will appear according to ones location.

Rusia-Novosibirsk-1st-contact-transit-venus-diagram-eclipse-geeks Australia-Melbourne-Transit-Venus-diagram-Eclipse-Geeks

Map credit: eclipse-maps.com/Michael Zeiler, Santa Fe, New Mexico, USA

 

click map of Venus visibility to enlarge

 

The Global Map above gives a clear illustration and useful information about World Wide visibility of the transit.  It 's easy to see regions of the world where the Transit of Venus can be seen and those regions from which there will be no visibility.

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Venus-Transit-Times-Venus-05-06-June-2012-diagram-

1st contact: The instance Venus touches the outer rim of the Sun;  

                        beginning of transit. (Ingress, exterior contact)    

 

2nd contact: The instance the whole of Venus is entirely inside the inner  rim of the Sun at beginning of transit. (Ingress, Interior contact).

 

Maximum or Greatest Transit; the moment when Venus passes closest to the centre of the Sun (this moment is also called, minimum separation) The two terms, Maximum Transit and Minimum Separation are used collectively togeter, the former is Venus's postion, the latter is a measurment of Venus to the centre of the Sun.

 

Greatest/Maximum Transit: Greatest transit is the instant when Venus passes closest to the Sun's centre (i.e. minimum separation).

 

Minimum Separation: Minimum angular separation is measured in ‘arc-seconds’ between the centre of Venus and the centre of the Sun and it occurs at the instant of greatest transit.

 

3rd Contact: The instance when Venus touches the opposite inside rim

                        of the Sun at the end of the transit. (egress, interior contact.

 

4th contact: The instance when Venus is leaving its transit and last's

                        touches the outer rim of the Sun - transit ends.

                        (egress, exterior  contact)

Contact Description

Transit of Venus 05/06 June 2012

and Technical terms used by astronomers

 Global Map and description of General Curcumstances

 A Transit of Venus can only occur when Earth, Venus and the Sun are Aligned

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Venus Transit - Honolulu, Hawaii, USA - 05 June 2012 - Local Times

 

First Contact:         12:09:59  

Second Contact:   12:27:38

Maximum Transit: 15:26:12

Third Contact:        18: 26:30

Forth Contact:        18:44:29

 

Venus Transit - Novosibirsk, Russian Federation - 06 June 2012 - Local Times

 

First Contact:          05::07:12  

Second Contact:    05:24:59

Maximum Transit:  08:30:39

Third Contact:         14:34:37

Forth Contact:         14:52:05

 

Venus Transit - Beijing, China - 06 June 2012 - Local Times

 

First Contact:        06::09:53  

Second Contact:   06:27:40

Maximum Transit: 09:30:32

Third Contact:       12:31:51

Forth Contact:       12:49:20

China-Beijing-1st-contact-Transit-Venus-diagram-Ec USA-Honolulu-Hawaii-1st-contact-transit-Venus-diagram-Eclipse-Geeks Global-World-Map-info-Transit-Venus-Eclipse-Geeks

Global Visibility - Transit of Venus 05/06 June 2012 - World Maps - Times of Contact

World Visibility Map of the Transit of Venus 05/06 June 2012

Complete Guide to the Transit of Venus 2012

 

A Global User Guide for Observing the Venus Transit

Diagrams, photos and Local Prediction Times of the Venusian Transit

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click Sun to enlarge

click Venus image to enlarge

Map credit: eclipse-maps.com/Michael Zeiler, Santa Fe, New Mexico, USA

click map of Venus visibility map to enlarge

 

 

 

 

Transit of Venus: times are in Universal Time: UT

                                    Greenwich Meantime: GMT

 

1st contact:  05 June 2012;   22h 09m 40.6s    (40.7")

2nd contact; 05 June 2012;   22h 27m 28.7s    (38.2")

Maximum:    06 June, 2012;  01h 29m 35.9s    (345.4")

3rd contact:  06 June 2012;   04h 31m 42.8s    (292.7)

4th contact:  06 June 2012;   04h 49m 30.9s    (290.2")

Venus-Earth-Transit-diagram- synodic-cycle-eclipse

 

Venus Transit - Melbourne, Australia - 06 June 2012 - Local Times

 

First Contact:        08:16:03

Second Contact:   08:34:10

Maximum Transit: 11:30:39

Third Contact:       14:26:35

Forth Contact:       14:44:35

The Principal Events of a Transit are Caracterised by a series of Contacts.

Julian Date - JD: 2456084.562219

 

Constants:     T:67.20s

Venus Transit Geocentric Data:

General Duration of Venus Transit;  06h 39m 48s

Central  Duration of Venus Transit;  06h 04m 12s

Minimum Separation; 554.4°

During the transit, the diameter of the Sun is 1891.4 arcseconds and that of Venus is 57.8 arcseconds. This means that the diameter of Venus is 0.03 that of the Sun, making Venus look like a rapidly moving sunspot. The complete transit lasts just under six and three quarter hours.

 

Observing and the Effect of Atmospheric Refraction 

Atmospheric-Refraction-Sun-Earth-Horizon-Diagram-E

Reason why Transit's of Venus Occur

 

The orbit of Venus is inclined 3.4° with respect to Earth's orbit. Although Venus's orbital period of the Sun is only 224.7 days, it does not pass between the Earth and Sun again for 583.9 days. This period of 583.9 days is Venus's synodic period  (or conjunction to conjunction). Most inferior conjunctions do not result in a transit because the planet passes too high above or too far below the ecliptic, sometimes as much 9.6°as viewed from Earth, and therfore Venus does not cross the face of the Sun. If Venus passes through its orbital node (the ecliptic plane) at the same time it arrives between the Earth and the Sun (its inferior conjunction) a transit will occur.

 

A Transit of Venus is only possibly during early June or December when Venus passes across the ecliptic plane (its orbital node).

 

Transits of Venus are rare due to the long cycle it takes for Earth, Venus and the Sun to align somwhere along the ecliptic plane.

Surface of Planet Venus

Venus and Earth

 

Venus and Earth are similar in mass and density, and initially may have contained the same amount of ‘volatile’ substances; But they have become very diferent worlds.

 

The most likely reason is the way the atmospheres of Venus and Earth evolved. Venus has no intrinsic magnetic field and therefore has no shield to protect it from the continuous attack of the violent solar wind. Venus is embedded only by a local magnetic field which is induced by the solar wind, and perhaps a little more is produced from the local magnetism derived from the surface.

 

Venus is the hottest planet in the solar system, its surface pressure of 93 bar (90 times higher than the pressure on Earth’s surface), and has a super thick atmosphere mainly composed of carbon dioxide, and it has thick clouds of sulphuric acid, Venus is a very inhospitable place. (image; artist impresion) source unknown.

Southern Hemisphere perspective - Transit of Venus

 

Transit of Venus

times of contact in Universal Time -  UT

 

1st contact:  05 June 2012;       22h 09m 40.6s

2nd contact; 05 June 2012;       22h 27m 28.7s

Maximum:    06 June, 2012;      01h 29m 35.9s

3rd contact:  06 June 2012;       04h 31m 42.8s

4th contact:  06 June 2012;       04h 49m 30.9s  

 

Venus Transit Geocentric Data

General Duration of Venus Transit;  06h 39m 48s

Central  Duration of Venus Transit;  06h 04m 12s

Minimum Separation; 554.4°

Transit-Venus-June-2012-Australia-Eclipse-Geeks

The Transit of Venus across the surface of the Sun; 05/06 June 2012 

 

Regions of the world where the rare transit of Venus can and can not be seen.

 

Entire Venus Transit visible from:

 

central and eastern Australia, New Zealand, Hawaii, Alaska, north west Canada, mid to eastern Asia, the western Pacific,  Papua New Guinea, North Korea, South Korea, Japan, Phillines, and south eastern China..

 

 

 

No visibility: No part of the transit of Venus can be seen from Portugal, southern Spain, South Africa, western Africa, and the south east 2/3 of South America. 

Transit of Venus, 2nd contact, ingress interior contact. Taken from Southern California, U.S.A

05 June 2012

 

 

 

Jeff Scott sent this photograph, through EclipseGeeks facebook page, of the Transit of Venus. The wonderful photograph shows  Venus at 2nd contact, ingress interior contact. Taken from Southern California, U.S.A

Transit-of-Venus-USA-Southern-California-Eclipse-G

 

Reasons and Answers to why transits of venus occur:

Definition of a Transit / Cycle Pattern of Venusian Transits / Global Contact Times /

World Map Guides of Visability / Effects of Parallax and Atmospheric Refraction on Viewing the Transit /

Explanation of the Black Drop Effect / Frequency Cycle of Venus Transits

 

The Transit of Venus June 2012

 

We encourage everyone in the regions of the world where the transit is visible to view the Transit of Venus June 2012: Not all places will be able to watch the transit, while others may catch a glimpse of either the beginning or end of Venus’s Transit as the Sun sets or rises during the last stages of the event.  Therefore for those lucky enough to be in the regions where the Venus Transit can be seen, we encourage everyone to observe this rare phenomena.

Diagrams of First Contact

how the difference the Transit of Venus will appear from various locations across the World

Global Visibility of the Tansit of Venus 05/06 June 2012

 

For Northern Hemisphere locations above latitude ~67° north; the complete transit is visible everywhere at all longitudes.

 

The complete Transit of Venus can be viewed from;

Eastern Australia, New Zealand, Alaska, Hawaii, Papua New Guinea, Philippines, South Korea, North Korea, Japan, north west British Columbia, extreme north west Canada, Alaska, eastern Russian Federation, south east China, and eastern Asia region.

 

Transit already in progress as the Sun sets; The Sun sets while the transit is already in progress from most of North America, the northwest of South America and the Caribbean.

 

Transit is already in progress at sunrise; The Sun is risning with the transit already in progress from Western Australia, west to central Asia, India, Thailand, Iran, Turkey, the Middle East, Europe, Ireland, United Kingdom, and eastern Africa. For most of Europe, the transit ends soon after sunrise, including the British Isles .

 

Two consecutive sunrises with Venus transiting the Sun: Observers from Iceland will see two consecutive sunrises with Venus transiting the Sun. Iceland is in a unique wedge-shaped part of Venus’s Transit path. The Sun will rise and before the Sun sets at the end of the day, the transit will begin; the Sun will set before maximum (greatest) part of the transit, and then the Sun will rise again with the transit still in progress. Icelanders will be then able to view the transit until it ends.

 

No visibility: No part of the transit can be seen from Portugal, southern Spain, west Africa, and the south east 2/3 of South America.

The Transit of Venus across the surface of the Sun; 05/06 June 2012

 

Regions of the world where the rare transit of Venus can and can not be seen.

 

Part Transit of Venus visible:

 

The Sun sets while the transit is still in progress from most of North America, the northwest of South America and the Caribbean. The transit is already in progress at sunrise from west to central Asia, the Middle East, Europe, United Kingdom, and eastern Africa.

 

No visibility: No part of the transit of Venus can be seen from Portugal, southern Spain, South Africa, western Africa, and the south east 2/3 of South America. 

No visibility: 

 

No part of the transit of Venus can be seen from Portugal, southern Spain, South Africa, western Africa, and the south east 2/3 of South America. 

Guide to Observing the Transit of Venus and The Black Drop Effect

 

 

Observing the Transit of Venus

Safety First and Foremost

 

All children who want to see the Transit of Venus should be supervised

 

All children who want to see the Transit of Venus should be supervised by adults to ensure that all safe solar protocols

are adhered. The Sun is extremely powerful and permanent eye damage can occur if safe solar guidelines e ignored.

 

The Sun is powerful and permanent eye damage can occur if viewed directly without eye protection.

Viewing a Transit of Venus requires the same safety guide-lines as when viewing a solar eclipse.

For advice and guidance on safe viewing the Venusian transit please go to: Eye Safety on Solar Eclipses.

 

continued

 

Black Drop Effect

 

Remember to account for the the Black Drop Effect: Just before contact 2 the so-called 'Black Drop Effect' may be seen. At that time, Venus seems to be attached to the Sun's limb by a thin thread. When the thread breaks and the planet is completely surrounded by sunlight - marks the true instant of contact 2. Contact 3 occurs in the opposite order. Therefore this Black Drop Effect can often make it changing to accurately measure contact timings with a precision no better than several seconds.

 

Black Drop Effect is an optical phenomenon visible during a transit of Venus - and to a lesser extent - a transit of Mercury.

 

Explanation of the Black Drop Effect: 

 

The Black Drop Effect is the illusion which takes place when Venus is just entirely inside the Sun’s inner rim at Contact 2. Some number of seconds before the circular disc of Venus separates from the inner limb of the Sun, the planet begins to "drag" a black shadow extension behind itself; this persists long after the moment when sunlight apparently should surround the entire disc. of Venus. Then rapidly, the black shadow disappears and the disc of Venus looks circular. At the end of the transit a similar event occurs on the opposite rim of the Sun;  the round disc of Venus approaches the Sun's opposite inner limb. And; distinctly just before Venus reaches there - a black extension rapidly appears between the disc of Venus and the inner limb of the Sun.  For both interior ingress and interior egress, the appearance of this extension is known as the "Black Drop Effect.'

 

To find your own time zone compared to Greenwich Meantime GMT / Universal Time UT use the: World Time Zone Map.

View Transit of Venus without any optical magnification:

 

Diameter of Venus is almost 1 arc-minute

 

The apparent diameter of Venus is almost 1 arc-minute; therefore it is possible to view the transit of Venus without any optical magnification: BUT, you must use solar protection glasses or some type of recognised safety equipment. Venus appears approximately 1/32 of the Sun's apparent diameter so a pair of binoculars or a small telescope of modest power will offer a much better view; however, it is extremely important that any binoculars and telescopes used, must be suitably equipped with adequate filtration to ensure safe solar viewing.

 

For visual and photographic requirements, observing a transit of Venus is identical to those for solar viewing.

 

It is possible for amateurs, students and anyone who is interested in the Transit of Venus, to make scientific contributions; by timing the four contacts at (exterior and interior ingress) aand (interior and exterior egress). However, poor seeing conditions can impair the accuracy of contact-timings, so an estimate of the possible error associated with ‘each timing’ should be included, along with your geographic coordinates (measured with topographic map or GPS receiver).  You can send your results to participating National Amateur Associations; you may also want to particapate in the ‘Venus Transit Phone APP’ where with just a few clicks on a smartphone can take part in a word wide project, or send you can send your results to: ALPO Transit Section, c/o Dr. John E Westfall, P.O. Box 2447, Antioch, CA 94531-2447, USA.

 

Solar White Light Observations of contacts 2 and 4 are not technically possible because Venus only becomes visible after contact 1 and before contact 4. However, if a hydrogen-alpha-filtration is used, Venus becomes visible against either prominences or the chromosphere of the Sun before and after contacts 1 and 4; observations of contacts 1 and 2, also require amplification. However, remember to take into the account the Black Drop Effect.

 

Observing Venus and the Effect of Atmospheric Refraction

 

Atmospheric Refraction: Is caused by the bending of light by Earth's atmosphere. When viewing celestial bodies close to the horizon, they can be displaced, appearing higher in the sky to their true geometric position.

 

Transit Times may therefore differ by up to seven minutes depending on one's location or if veiwing the Venus Transit at sunset or sunrise.

Click diagram of Atmospheric Refraction to enlarge.

Diagram:

The Sun when close to the horizon at sunset or sunrise

is dispalced by Earth's atmosphere 

Atmospheric Refraction and Venus

 

Important  Note - Venus Transit Times: Effects of Parallax: and Atmospheric Refraction

 

The ‘times’ of Venus's transit have been calculated to the first decimal point of a second and for an observer at Earth's centre - viewing from locations around the world where Venus is seen overhead.

 

However due to paralllax and those viewing the transit of Venus close to sunset or sunrise  times may differ by several minutes due to parallax and atmospheric refraction.

 

Effects of Parallax: Venus's 58 arc-second diameter disc can be shifted by up to 30 arc-seconds from its geocentric coordinates depending on the observer's exact position on Earth. This can affect 'the time' at which any stage of the transit of Venus is seen due to the observers viewing angle.

 

Example of Parallax: can be seen when driving a car or being carried as a passenger. If the dashboard uses a needle-style speedometer gauge, when viewed from directly in front of the driver, the speed may show 60, but when viewed from the passenger's seat, the speed usually looks different due to the angle of viewing.

 

Atmospheric Refraction: is caused by Earth's atmosphere bending light. It causes celestial bodies, when viewed close to the horizon, to be dispalced and appear higher in the sky then there true astronomical position.

Frequency of Transits - Venus

 

Venus transits occur at regular cylces in a pattern that repeats itself every 243 years. One cycle of this pattern is a transit every 105.5 years followed by a transit in 8 years;

 

and the another cycle of this pattern is; a transit every 121.5 years followed by a transit in 8 years.

 

This current pairng of (105.5, 8 / 121.5, 8) will continue until 2846, when it will be replaced by a different pattern of 105.5 years followed by one in 8 years; and then a transit in 129.5 years followed by one in 8 years.  

 

Venus has an orbit that is inclined 3.4° to the orbit of Earth. A Transit of Venus is only possibly during early June or December when Venus passes across the ecliptic plane between the Earth and Sun (its orbital node).

 

If Venus passes through its orbital node, when at the same time it is between the Earth and the Sun (its inferior conjunction) a transit will occur.

 

Although Venus's orbital period of the Sun is only 224.7 days, it does not pass between the Earth and Sun again  for  583.9 days. This period of 583.9 days is Venus's synodic period  (or conjunction to conjunction).

 

Due to the 3.4° inclination of Venus, most inferior conjunctions of Venus do not result in a transit because the planet passes too far above or too far below the ecliptic and therefore does not cross the face of the Sun as viewed from Earth.

Orbit of Venus

Orbit of Venus is inclined 3.4° with respect to Earth's orbit. Most inferior conjunctions do not result in a transit because the planet passes too high above or too far below the ecliptic, therefore as viewed from Earth, Venus does not cross the face of the Sun.

Hottest-Planet-Solar-System-image-Venus-surface-Eclipse-Geeks.com

Upside-down world and the Transit  of Venus

 

The Transt of Venus viewed from the Southern Hemisphere from locations of latitude such as Australia and New Zealand will see Venus Transit across the lower limb of the Sun. Venus will also traverse the Sun from right to left - opposite to the Northern Hemisphere.

Click Southern Hemisphere diagram of venus transit to enlarge

Southern Hemisphere perspective - Transit of Venus

A list of United States Transit Times 60 cities.

Venus Transit Times USA.

World transit times of Venus from 121 cities.

World transit times.