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kiwikiwi79
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Why is it difficult to measure the perihelion advance of the planet Venus? Please help me answer this question in details...Thank you~ :rofl:
Venus' orbit is practically circular so the perihelion location is less distinct. Venus' orbital plane in inclined more than 3 degress to the plane of the Earth's orbit. I don't know if that makes it more difficult to measure. The main reason is probably that the rate of advance is so small. Mercury's perihelion advance is about 10 minutes/century. Venus' is about 8 seconds of arc per century.kiwikiwi79 said:Why is it difficult to measure the perihelion advance of the planet Venus? Please help me answer this question in details...Thank you~ :rofl:
pinkie said:The curvature of space time closer to the sun is also a factor, right?
So, it would appear to be a matter of precision of either measurement or calculation, and a matter of the geometry of the orbit (almost circular). I imagine the perturbations in the orbit due to other planets are on the order of a few seconds of arc.Andrew Mason said:Venus' orbit is practically circular so the perihelion location is less distinct. Venus' is about 8 seconds of arc per century. AM
Perihelion advance is the phenomenon where the point of closest approach of a planet to the Sun, called the perihelion, shifts slightly with each orbit. This shift is caused by the gravitational effects of other planets and is measured in seconds of arc per century.
Measuring the perihelion advance of Venus is important because it provides evidence for the theory of general relativity. According to this theory, the gravitational pull of massive objects, such as the Sun, can cause the fabric of spacetime to bend, resulting in a shift in the perihelion of Venus.
There are several factors that make it difficult to measure the perihelion advance of Venus. One is the small magnitude of the shift, which is only about 8 arc seconds per century. This requires precise and accurate measurements. Another factor is the presence of other planets, particularly Jupiter, which can also cause a shift in the perihelion of Venus. Additionally, the highly elliptical orbit of Venus can also affect the measurements.
Scientists use a technique called astrometry to measure the perihelion advance of Venus. This involves tracking the position of Venus in the sky over a period of time and comparing it to its predicted position based on its orbit. The difference between the two positions can then be used to calculate the perihelion advance.
Yes, the perihelion advance of Venus has been accurately measured and has been found to be in agreement with the predictions of general relativity. However, due to the difficulty of the measurements, it has taken several decades and multiple experiments to achieve this level of accuracy. Scientists continue to refine their techniques and measurements in order to further confirm the theory of general relativity.