Jupiter, the largest planet in the solar system, is slightly smaller and flatter than scientists had believed for the past 50 years, according to a breakthrough discovery by Israeli researchers.

Leading an international team from Italy, the United States, France and Switzerland, Weizmann Institute of Science researchers have produced more precise measurements of Jupiter’s size and shape than ever before, using new data from NASA’s Juno spacecraft.

The peer-reviewed research, published today in Nature Astronomy, shows that the radius of Jupiter is about four kilometers (2.5 miles) thinner at its equator and 12 kilometers (7.5 miles) flatter at the poles than believed in earlier assessments.

The scientists determined the planet has a radius of 71,484 kilometers (44,418 miles). Earlier data measured it at 71,492 kilometers (44,423 miles). The fifth planet from the sun, Jupiter is large enough to hold more than 1,300 Earths.

“We have now, for the first time, an accurate measurement of the size of Jupiter,” said Prof. Yohai Kaspi of Weizmann’s Earth and Planetary Sciences Department, speaking to The Times of Israel. “It’s a big deal in the sense that we never really knew the radius of this planet. We always had estimates. And now we have something more accurate, which has helped us solve a lot of things that were mysterious to us.”

Jupiter contains mostly hydrogen and helium. The massive giant was “likely the first planet to form in the solar system,” Kaspi said.

“We know that because it’s the biggest,” he said. “There’s no way that a small planet would form before such a big........

© The Times of Israel