Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: mabsj2 on 28/01/2010 09:36:52

Title: Is an eclipse of the sun by venus or mercury on earth possible?
Post by: mabsj2 on 28/01/2010 09:36:52

Venus and mercury have shorter distances from the sun than Earth. Is it possible that these planets can cause an eclipse on earth if anyone of them is in the same alignment as the sun and earth. and how often does it happen??

Title: Is an eclipse of the sun by venus or mercury on earth possible?
Post by: RD on 28/01/2010 09:42:43

Quote

Transits of Venus are among the rarest of predictable astronomical phenomena and currently occur in a pattern that repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years ... Before 2004, the last pair of transits were in December 1874 and December 1882. The first of a pair of transits of Venus in the beginning of the 21st century took place on 8 June 2004 and the next will be on 6 June 2012. After 2012, the next transits of Venus will be in December 2117 and December 2125.

http://en.wikipedia.org/wiki/Transit_of_Venus

Quote

Transits of Mercury can happen in May or November. November transits occur at intervals of 7, 13, or 33 years ; May transits only occur at intervals of 13 or 33 years. The last three transits occurred in 1999, 2003 and 2006 ; the next will occur in 2016.

http://en.wikipedia.org/wiki/Transit_of_mercury


NB: looking directly at the sun can permanently damage your vision, (no event is worth risking blindness to see).

Title: Is an eclipse of the sun by venus or mercury on earth possible?
Post by: mabsj2 on 28/01/2010 09:55:15

so these transits don't cause much blockage of the sun like the moon does. i am guessing it's because venus and mercury are far away from the earth compared to the moon.

Title: Is an eclipse of the sun by venus or mercury on earth possible?
Post by: graham.d on 28/01/2010 10:43:15

Yes, Mercury is very small and close to the sun. It would be like a fly on the front glass of a searchlight. There is nowhere on earth that it could cause an eclipse. Venus is just like a bigger fly! We only get an eclipse from the moon because it so happens that the angular dimension of the moon is almost the same as that of the sun. Of course if the angular dimension of the moon was bigger it would still eclipse the sun, but without the nice effects at the edges.

Title: Is an eclipse of the sun by venus or mercury on earth possible?
Post by: syhprum on 28/01/2010 13:17:24

There is an excellent calculator for the 2012 transit of Venus at http://www.transitofvenus.nl/details.html.
Unfortunately most of it happens before sunrise at my location.