Questions tagged [astronomical-unit]

Use for questions that are related to the astronomical unit (AU), the mean distance between the Sun and the Earth.

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What is the most accurate measurement of the Astronomical Unit?

I am using the Earth-Sun distance to teach kids the usefulness of trigonometry. This site is helpful. But one of the more engaged asked what the most accurate measurement is. After some research, I ...
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25 votes
4 answers
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Is the Astronomical Unit measured from the Sun's center or from the surface?

1 AU is defined as the distance between the Sun and the Earth, which is roughly 150 million km. But is this supposed to be from the Sun's center (Solar system's center of mass) or from the Sun's ...
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1 vote
1 answer
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Is life possible on other celestial objects (apart from planets) even theoretically? [closed]

For example, asteroids, comets, stars, heliosphere etc?
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1 vote
1 answer
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Rayleighs units conversion

I have a question regarding the units conversion from photon counts on a detector to Rayleighs. I am pretty new to the subject but I would like to know more. The problem is the following : I know that ...
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0 votes
1 answer
271 views

If it only takes 8 minutes for that light to reach the Earth, what took up most of the time? [closed]

If it only takes 8 minutes for that light to reach the Earth, what took up most of all that time to get to the Earth?
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3 votes
1 answer
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How do you go from transit times to Earth-Sun distance?

In the early 18th century, Halley described a method to determine the value of the astronomical unit by observing a transit of Venus from multiple locations on Earth. How do you go from the transit ...
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