Shocking Blue - Venus (The Original Version) | Single Version | written by Edward Marshall
Posted on 05/11/2021 3:47:32 AM PDT by SunkenCiv
Astronomers have long struggled to pin down how long a day lasts on Venus, but new research suggests the difficulty stems not from flawed measurements but from real variations in the planet's spin.
In a new study, scientists used a massive radar system to bounce lightwaves off our neighboring planet over the course of more than a decade. As a result, the researchers were able to measure how tilted Venus' axis is, how big its core is, and how long it takes the planet to complete one full rotation...
Between 2006 and 2020, the team used this radar system to bounce a beam from Goldstone to Venus. The researchers then studied the signals that returned to both sites on Earth, comparing the time between when each facility caught the echo, about 20 seconds apart.
All told, the researchers used the system to gaze at Venus a total of 121 times. Because the technique is so finicky, requiring both facilities to be in perfect shape, the researchers were able to gather useful data with just 21 of those attempts.
...the scientists were able to calculate the precise tilt of Venus' spin (2.6392 degrees, much smaller than Earth's 23-degree tilt)... also estimate the size of Venus' core to be about 4,350 miles (7,000 kilometers) across, or 58% of the planet's diameter, although the scientists emphasize that calculation is quite uncertain.
The day-length calculations, on the other hand, the scientists were able to measure quite precisely, and the team's results explain why previous analyses haven't matched each other. A day on Venus, the researchers determined, lasts an average of 243.0226 Earth days — but from one Venusian day to another, the time needed for the planet to make one complete spin can vary by up to 20 minutes.
(Excerpt) Read more at space.com ...
Shocking Blue - Venus (The Original Version) | Single Version | written by Edward Marshall
PERELANDRA by C.S. Lewis was good also.
After thinking about changes to the length of a day on any planet, I am inclined to suspect the measuring system in use rather than any change in the rotational velocity of a body as huge as a planet. I mean, you are talking about some seriously huge forces that need to come into play when discussing a change to the inertial forces involved. But errors introduced while setting up and operating the measuring system could easily produce data that is a tiny bit random.
JMHO ...
The article makes sense. If the rotation rate is slow, as compared to Earth, variations in the rate will be of longer periods. The Earth spin rate also varies, but its measured in fractions of seconds. However, Earth spins faster and spin provides a stability of its own.
In both cases, the variations can be caused by fluid cores. Think if spinning two eggs on a counter top, one raw and one hard boiled. The hard boiled eggs spins at a near constant rate. The raw egg will have a lot of wobble.
Also, this makes no sense:
The researchers then studied the signals that returned to both sites on Earth, comparing the time between when each facility caught the echo, about 20 seconds apart.
Really? They have radar stations on earth that are 20 light-seconds apart? WTF? I think the 'reporter' for this article has no idea at all what the hell he's talking about.
The mag field is actually a result of, not an effect on, the interior molten core. It is the movement of the liquid ferrous magma that creates the field.
That was fun to say :)
The earth's gravitational pull on Venus must be responsible in some way for that relationship. I read somewhere that Venus always turns the same side to the earth (like the moon does) but my math skills aren't good enough to be able to verify that.
Nonsense. Tides are caused by cow flatulence. That's why the Green New Deal folks want to get rid of cows. No tides and the rising ocean levels won't inflict as much damage on low-lying Pacific islands.
/s
You need a fixed point of reference to determine when a full rotation has occurred, don’t you? And correct me if I’m wrong, but isn’t the surface of Venus totally obscured by cloud cover?
That’s why they’ve been using radar.
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