Avi Blizovsky
Direct link to this page: https://www.hayadan.org.il/venuspass00001.html
The planet Venus completed its rare transit in front of the Sun - an event not observed by the human eye since 1882.
The transit of Venus began around 08:20 Israel time (05:20 GMT) when the small black circle began to penetrate the bright circle of the Sun. The phenomenon lasted for about six hours and ended at 14:24 Israel time. Luckily for us, it was possible to fully watch the entire celestial event (unlike the Americans who saw its end or the Japanese who saw its beginning and the sun together with Venus set in the middle), and the sky was completely clear.
Over two thousand people crowded the plaza next to the Smolarch Auditorium at Tel Aviv University. In the square, the members of the Astronomical Club of Tel Aviv University, and many amateur astronomers who are active in the Israel Astronomical Society and the Nene Astronomy Forum, placed their telescopes on which special filters were mounted that made it possible to view the event at a magnification of 100 times or more.
The photo is taken from a website abroad, and later I will try to bring a photo taken in Israel.
Also, in the coming days, we will provide a summary of the lectures of Prof. Yuval Naaman, Prof. Michael Har-Segur and more
In the meantime - here is the summary of Prof. Zvi Maza's lecture. Prof. Zvi Maza, from the Faculty of Astronomy at Tel Aviv University, explained, among other things, in his scholarly lecture that dealt with the history of research expeditions why these transits occur in clusters of two transits every eight years and a long break until the next transit.
Here is part of the explanation: following Copernicus who almost accurately predicted the relationships between the orbits of the planets and Kepler who further refined the mathematics after observations made by him and Tycho Braha before him. In 1627, Kepler published a book called the plates named after Rudolph - the emperor of Germany at the time, in which he gave the exact paths of the planets as much as he could, with the first prediction of when there would be a transit, when one of the planets would pass over the sun.
The first transit was actually of the planet Hema. Kepler predicted in 1627 that on November 7, 1631 (plus or minus a day or two) the planet Mercury would pass across the Sun. It requires precise knowledge of the orbits, including their ellipses, the transit of the planets at varying speeds. All this data is necessary for us to know what is happening. On November 7, 1631, Pierre Xandy in Paris watched the transit exactly according to Kepler's calculations. This is a tremendous victory for the Copernican model, with the sun in the center, which previously had no proof, and it is a victory for the Kepler researcher. The fact that it is possible to predict exactly the position of each of the planets is observational proof that the theory works. A classical approach to testing a scientific theory.
The transit of Venus can happen when Venus is between the Earth and the Sun, but it is not that simple. From the knowledge of the rotational speeds of the Earth and Venus around the Sun we know that 583.92 days pass between one conjunction and the next when Venus catches up with the Sun. One can apparently think that every 584 days will be a transition, but since the orbit of Venus is inclined at a small angle compared to the orbit of the Earth. Therefore, if there is a merger when the orbit of Venus is above or below the orbit of the Earth, there is no transition. Only around the months of December and June when the Earth and Venus are at the intersection of the planes of their orbits.
The next time it happens - after eight years. By chance it turns out that if you take 584 days multiplied by 5 that is approximately 2920 - eight years minus two days. Therefore, the next time there will be a conjunction - of both Earth and Venus in June is in eight years, when there will be five more conjunctions. Eight years later the coalescence will move a little further back and we will have to wait more than a century, until coalescence takes place in December. Therefore there are 4 transits in over 200 years: two occurring in June and two in December. This is the explanation for the complicated legality of the transition.
Robert Walsh, senior lecturer at the Center for Astrophysics of the University of Central Lancashire (UCLAN) tells the BBC that the transit of Venus occurs 4 times in 243 years, more precisely in pairs of events with eight years separating them. Zvi Mza'a.
The events have occurred only six times since the invention of the telescope: in 1631, 1639, 1761, 1769, 1874 and 1882. Therefore the next event of transiting Venus will occur in June 2012 and the next only in December 2117.
As mentioned, the best places for viewing were Europe, most of the African continent and Asia.
The transitions were very significant in the past, when scientists used them to measure the distance between the earth and the sun - and thus get a more accurate scale of the solar system. Today, their value is in their uniqueness. "This is an extremely rare astronomical event," says Gordon Bromage, Professor of Astronomy at UCLAN. "The last time the transit could be seen for its full six hours in Britain was in 1283. The next time will be in 2247, so we will try to make the most of the event.
The planet itself will soon be examined by the European spacecraft Venus Express, a twin of Mars Express currently orbiting Mars. Venus Express is scheduled to launch next year and will explore the planet's dense atmosphere and look for signs of volcanic activity that may be occurring on the planet today.
"This is an extraordinary world. Its thick yellowish clouds contain sulfur oxides. The atmospheric pressure on the surface is the same as that at a depth of 900 meters in the Earth's oceans. And because Venus rotates slowly on its axis, its year (225 Earth days) is shorter than its day (243 Earth days).
"In many ways, Venus can be considered Earth's hellish twin because it evolved in a different way than Earth," says Dr. Andrew Coates, BONUS Expressor mission scientist. "It has an acceleration of the greenhouse effect that made its atmosphere one of the hottest in the solar system - 460 degrees Celsius."
Another report from the symposium in Tel Aviv, and from around the country and the world - towards the end of the week.
After 122 years: Venus hid the Sun again and the scientists of the world were excited
By Zahar Rotem and the "Haaretz" service
In 1882 the planet Venus passed between the Earth and the Sun, yesterday it happened again. In the photos: watching the phenomenon, a fisherman in the United States, a Bedouin in Jordan and a girl who arrived at the auditorium plaza at Tel Aviv University
Photographs: AP, Reuters and Oriel Sinai
The planet Venus passed yesterday in a rare way exactly between the Earth and the Sun - an event that last happened in 1882. The passage of Venus across the Sun began at 08:19 am (Israel time), when it was visible from Earth as a tiny black ball, moving across the circle of the Sun for about six hours until 14:23 pm. Experts have warned the public against observing the sun without proper protective measures.
The transit of Venus across the Sun is a rare phenomenon. The large time differences between the events are due to the fact that the orbits of Venus and the Earth are in different planes. The passage of Venus across the Sun and in front of the Earth can only occur when the three stars: Venus, the Earth and the Sun, are in one plane and in one line. The transitions occur in pairs, between which eight years separate, and between one pair and another 120 years. Thus, the next transition is expected to occur in 2012, and the one after that only in 2117. In the past, this phenomenon had special scientific importance, because astronomers tried to use it to calculate the distance between the Earth and the Sun. Today the main value of the phenomenon is its rarity.
Around the world, many curious gathered to witness the phenomenon. In Britain, a crowd gathered at the Royal Observatory in Greenwich. "It was amazing!" said astronomer Professor Colin Pillinger. "We couldn't have hoped for a better six-hour view of the sun. Look around you, and you will see that the people here are enchanted. It's wonderful to see that astronomy is so popular with the public." Dr. Jim O'Donnell of the Royal Observatory said: "Seeing it in pictures or on TV is one thing, but looking through a telescope and seeing it with your own eyes is something else entirely!" The best observation of the phenomenon was received in Europe, and in most areas of Africa and Asia.
In Israel, about 1,500 people gathered in the square of the Smolrash Auditorium at Tel Aviv University to witness the event. The astronomical club of the university, which initiated the event, was overjoyed at the large number of participants.
"It's very exciting," explained David Polishok, a young student from the organizers of the event, with bright eyes, "we were surprised to find out that so many people came to share this experience with us."
A film that describes the physics of the transit of Venus in a very tangible way
Yadan Astronomy 2 - eclipses and transits
For a report on the BBC
https://www.hayadan.org.il/BuildaGate4/general2/data_card.php?Cat=~~~866967976~~~171&SiteName=hayadan
