Transit of Venus on June 6

Pada 6 Jun 2012, planet Zuhrah akan melintas di antara Matahari dengan Bumi dan ia dapat dilihat pada permukaan Matahari .  Semasa transit, planet Zuhrah akan kelihatan seperti satu tompok kecil berwarna hitam melintas di hadapan permukaan Matahari.  Di Malaysia, ia akan bermula Matahari terbit dan akan berakhir jam 12:50 p.m.  Fenomena ini pernah berlaku pada 8 Jun 2004. 

Transit Zuhrah yang akan berlaku pada 6 Jun 2012 akan dapat dilihat dari semua tempat di Malaysia.  Transit Zuhrah kali ini bermula (sentuhan I) pada pukul 06:09:29 am, berada di fasa maksimum pada jam 09:29:28 am dan berakhir (sentuhan IV) pada jam 12:49:57 pm.  Rajah 2 menunjukkan gambar dan waktu mula transit, waktu sentuhan dan waktu transit berakhir mengikut waktu Malaysia. Penduduk di Sabah dapat menyaksikan keseluruhan fasa Transit Zuhrah berlaku kerana Matahari telah terbit sebelum Transit bermula manakala penduduk di Semenanjung dan Sarawak dapat menyaksikan Transit Zuhrah apabila Matahari terbit.

Rajah 1 : Geometri Transit Zuhrah

Rajah 2: Keseluruhan Fasa Transit Zuhrah 6 Jun 2012

Tidak kira di mana anda berada di Malaysia, sekiranya langit berada dalam keadaan cerah selepas Matahari terbit, lihat ke arah barat laut di mana Matahari berada.  Anda berpeluang menyaksikan fenomena tersebut dengan menggunakan teleskop atau binokular yang dilengkapi dengan penuras suria yang selamat.

Location, location, location. Whether and when you can see the 2012 transit of Venus depends on your location.  Key highlights include the four "contacts" near the beginning and end of the transit when Venus appears to touch the edge of the sun.  Most of North America sees the beginning of the transit in the afternoon and evening (find a clear western horizon!) on June 5, whereas much of Eurasia sees the end of the transit in the morning (find a clear eastern horizon!) on June 6.
Click to access and enlarge PDF version of map showing visibility of 2012 transit of Venus.  Courtesy of Fred Espenak (NASA GSFC), who provides additional transit of Venus data from NASA.
To see an animation of how the sun appears at Region X, near Iceland, see http://youtu.be/3b7a_zXMnnU.

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Time is of the Essence

The diagram (click for enlarged PDF version) shows the path of Venus across the sun and the contact times from an earth-centered perspective.  However, from different locations on earth, the exact contact times vary by minutes or seconds.  That slight difference in times is the essence of a transit's value, for it allowed astronomers to calculate the size of the solar system.  The entire event takes about 6 hours 40 minutes.  The times in the diagram are in Universal Time, or essentially Greenwich Time. 

For simplicity, visit http://www.transitofvenus.nl/details.html, or select a nearby city from one of the Links: Where to Be.

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So, is the transit of Venus visible June 5 or June 6?

It depends on your time zone.  Generally, for the Americas where it is visible (blue colors on map below) the 2012 transit occurs the evening of Tuesday, June 5, 2012.  For Eurasia and Africa where it is visible (sage colors on map), the latter part of the transit is seen the morning of June 6, 2012.  Map courtesy of Steven van Roode.

[Note: Some confusion may arise from published tables with a title stating the 2012 transit of Venus is on June 6.  By default, these tables are titled by the mid-transit point in Universal Time.  Because the middle of the transit occurs just after midnight on June 6 in Greenwich Time (even though it's not visible then in Greenwich), the title nonetheless affirms June 6