From Simple English Wikipedia, the free encyclopedia
The
2004 transit of Venus
A
transit of Venus
across the
Sun
happens when the
planet
Venus
goes between the Sun and
Earth
. It is a syzygy and a partial
occultation
of the Sun. When a
transit
happens, Venus can be seen as a small black dot going across the Sun. Transits of Venus usually take several hours.
Transits of Venus are among the rarest of predictable events which happen in
astronomy
. They 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.
The most recent transit of Venus happened on 5 and 6 June 2012. It was the last Venus transit this century. The one before took place on 8 June 2004. The next transits of Venus will be in December 2117 and December 2125.
The transit on 5 and 6 June 2012 was broadcast live on the
Internet
.
[1]
During the 18th century, astronomers tried to use transits of Venus to measure the
astronomical unit
, the distance from the Earth to the Sun. Many countries sent expeditions to distant lands to observe the transits from places as far apart as possible for maximum
parallax
.
One of the most famous expeditions was the voyage of Lieutenant
James Cook
in the
HMS
Endeavour
.
- ↑
"2012 Transit of Venus"
. NASA. Archived from
the original
on 2012-06-09
. Retrieved
2012-06-09
.