Posted on 02/04/2026 10:03:49 AM PST by Diana in Wisconsin
Jupiter is slightly smaller and flatter than scientists thought for decades, a new study finds.
Researchers used radio data from the Juno spacecraft to refine measurements of the solar system's largest planet. Although the differences between the current and previous measurements are small, they are improving models of Jupiter's interior and of other gas giants like it outside the solar system, the team reported Feb. 2 in the journal Nature Astronomy.
"Textbooks will need to be updated," study co-author Yohai Kaspi, a planetary scientist at the Weizmann Institute of Science in Israel, said in a statement. "The size of Jupiter hasn't changed, of course, but the way we measure it has."
Until now, scientists' understanding of Jupiter's size and shape have been based on six measurements performed by the Voyager 1 and 2 and Pioneer 10 and 11 missions. Those measurements, which have since been adopted as standard, were performed around 50 years ago using radio beams, according to the statement.
But the Juno mission, which has been gathering data on Jupiter and its moons since it arrived at the gas giant in 2016, has collected much more of this radio data in the past two years. With that additional data, researchers have now refined measurements of Jupiter's size down to about 1,300 feet (400 meters) in each direction.
(Excerpt) Read more at livescience.com ...
same scientists say they can look at a rock and tell if it originated on Mars.....Yeah, right.
Somewhat. The equatorial diameter is about 112 kilometers greater than the polar diameter.
"When the facts change, I change my opinion. What do you do, sir?" - Disraeli
The best estimates of the polar and equatorial diameter of the earth have been in flux for the past two hundred years, settling down to the current values in WGS-84, as more or less semi-official definitions.
Remarkably enough, instrumentation and measurements have improved in the past 50 years, especially astronomical measurements. If you had bothered to read the article, the current measurements have error bars of 400 meters, so if future measurements refine the error bars by a factor of four or ten, are you going to be accusing the scientist of today of lying?
By golly you’re prickly. The implication wasn’t that anyone is lying but that it’s all a constantly changing guesswork for the very reasons you stated, people should be wary of calling things certainties when there’s so much room for error. Pointing out that science is provisional doesn’t make anyone a Luddite.
Since when is this group about astronomy? Can we all agree that we shouldn’t post about 8 of the planets, and just stick to Uranus?
Heh heh..heh heh
I believe Jupiter has to contract more before the fusion reaction ignites...
I find this whole “scientist keep changing their mind” theme obnoxious. Instrumentation has improved in the past 50 years, and Juno stayed and made many, many more “observations” or measurements. If a better estimate is available, it is good practice to simply publish it.
There is no evidence that “scientists” made exaggerated claims about the accuracy of the previous measurements, simply that current measurements are more accurate and the difference went in a certain direction.
Effectively, its as if the measurements went from tape measure to micrometer.
If the earth was really flat, cats would have pushed everything off the side......
Think of how Giuseppe Piazzi felt about Ceres.
It's amazing that we continue to spend prodigious amounts of money to study things of interest that are of no value to us in our lives.
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