On June 6, transit will appear next time you have to wait until 2117
June 6-sky will be a rare astronomical phenomenon of transit. Yesterday, former Director of the Observatory, Shanghai, Shanghai Zhao Junliang Honorary President of the Astronomical Society Observatory organization of lectures presented in Shanghai, and observation if you miss this opportunity, the next transit of Venus until 2117. He also revealed that the transit principle can be used to look for aliens.
Observation observe the “black drop” and “Halo”
The morning of June 6, if the weather is fine, in the eastern area of China citizen will be able to see a small black dot in the slow-moving on the surface of the Sun, this is the phenomenon of the transit. According to Zhao Junliang introduction, characteristics of transit in Shanghai: 6:10:57 Ling beginning circumscribed (Venus at first contact to the Sun); 6:28:46 Ling began cutting (fully into the Sun of Venus); 12:30:58 ling in the final cut (edges left of Venus to the Sun), 12:48:30 Ling circumscribed (Venus completely out of the Sun), the whole process lasted 6 hours. Because Venus orbital speed is faster than the Earth’s revolution around the Sun, so transit route was moved from the left side to the right of the Sun.
Principle of transit and solar eclipses, Earth, Venus and the Sun has been on the line, Venus appears as small black spots on the Sun s disc. Phenomenon rare transit, transit occurs for all through the 20th century, most recent was on June 8, 2004, but residents in Shanghai at that time to the half, when the Sun, transit of Venus has not yet ended, is lucky, June 6, members of the public can see the whole of this year.
Zhao Junliang advised in observing the transit process, should strive to observe two interesting phenomena–the “black drop” and “Halo”, both appear in the Ling Ling Houhe out within a short time before. The “black drop” effect in the course of transit, when Venus and in-plane shear, Venus and the Sun edges drop shadows by oil “adhesions” phenomenon, this quiet, light and atmospheric diffraction limited resolution and telescope related. While in transit, and the Ling stage, sometimes Venus round face will adorn the edge a bit of very fine “Halo ring” or “Halo”, which is a reflection at the top because of Venus’s atmosphere, scattering the Sun formed.
Principles of the transit can be used to look for aliens
Outside the transit of Venus in addition is a rare astronomical phenomenon, its principles can also be used to detect extrasolar planets. According to Zhao Junliang introduction, in order to find the aliens, humans have sent strong radio signals to the space, also fired to bring “Earth business card”, “sounds of Earth” records of the spacecraft, but so far has not been alien echo.
Since 1980, astronomers began by Ling Xing method to detect extrasolar planets possible planets around other stars. Astronomers idea, if the star is surrounded around the turn of one or more extraterrestrial planet, so it possible to observe the planet from the star periodically through the front, this is the transit of planets star. During the transit of the planets star, the star brightness will be weakened, and showed very regular periodicity, which could ascertain planets around the star. Find a suitable planet, will be the first step to find aliens.
In 2009, the United States launched the Kepler space telescope, designed by planet to search for alien planets by Ling Xing, high metering accuracy of it, can ensure the detection of the size of the Earth, or even a small alien planets. May 2009, “Kepler” 997 found 1235 candidate planet around the star, which are found before that number more than twice times the total number of alien planets, astronomers now also looking for more planets in this way.
Observations available Eclipse card
Transit one, observing successful, to be well prepared. Shanghai Sheshan station science haiming Tang, head of the Observatory reminds the public, the most critical is the need to protect the eye, must not wear ordinary sunglasses or direct observation with the naked eye. Fully reduced sunlight, people can use Eclipse, some members of the public also collects Eclipse observations of the 2009 total solar eclipse purchase card, you need to first check whether there is damage prior to use. In addition, the telescope is also a good choice, but the telescope needs to be fitted with filters. In addition, people can also watch Shanghai Astronomical Observatory of transit across the network broadcast.