By Will Dunham
WASHINGTON (Reuters) – Data obtained by the bounce of radio waves from Venus – treating them, as one scientist said, like a giant disco ball – gives a new idea of the nearest planetary neighbor on Earth, including an accurate calculation of the length of Venus’s day.
The study also measures the inclination of the axis of Venus and the size of the planet’s core, allowing a deeper understanding of a mysterious world, sometimes called the “evil twin” of Earth.
It was already known that Venus had the longest day – the time it takes for a planet to rotate on its axis ̵
The study found that a single rotation of Venus takes 243.0226 Earth days. This means that one day lasts more than a year on Venus, making a complete orbit around the Sun in 225 Earth days.
Researchers transmitted radio waves to Venus 21 times from 2006 to 2020 from NASA’s Goldstone antenna in the Mojave Desert in California and studied the radio echo, which provides information about some planetary features, in Goldstone and the Green Bank Observatory in West Virginia. .
“Each individual measurement was obtained by treating Venus like a giant disco ball. We illuminated Venus with a giant flashlight, the Goldstone radar, and observed the reflections as they spread across the Earth’s surface,” said Jean-Luc Margot, UCLA professor of planetary astronomy. who led the study, published in the journal Nature Astronomy.
“Venus is an amazing laboratory for understanding the formation and evolution of planets, and it’s just a stone’s throw away. There are probably billions of Venus-like planets in the galaxy,” Margo added.
New data show that the planetary core of Venus is about 4,360 miles (7,000 km) in diameter, comparable to the Earth’s core. Previous estimates of the Venus nucleus are based on computer modeling, not observational data.
Its core is almost certainly composed of iron and nickel, although it is unclear whether it is solid or molten, Margo said.
Venus rotates on its axis almost upright – which means it lacks noticeable seasons – while the Earth has a greater inclination. The study calculates the inclination of Venus at about 2.64 degrees. The earth is about 23.5 degrees.
Venus, the second planet from the sun, is similar in structure, but slightly smaller than Earth, with a diameter of about 12,000 km. Above its premonitory landscape is a dense and toxic atmosphere, which consists mainly of carbon dioxide, with clouds of sulfuric acid droplets. With an evasive greenhouse effect, its surface temperatures reach 880 degrees Fahrenheit (471 degrees Celsius), hot enough to melt lead.
Venus rotates from east to west, in the opposite direction from all other planets in our solar system except Uranus. In another oddity, its day-night cycle – the time between sunrises, as opposed to the length of an axial spin – takes 117 Earth days because Venus rotates in the opposite direction to its orbital path around the sun.
Venus has received less scientific attention than Mars, the planet’s other planetary neighbor, and other destinations in the solar system.
“I don’t think Venus would be harder to understand than other planets if we had adequate data, but there is a deplorable lack of data on Venus,” Margo said.
“There have been no NASA missions to Venus in almost 30 years and about a dozen NASA missions to Mars in that time frame,” Margot said, adding that new discoveries about how Venus rotates could help future landing attempts .
(Report by Will Dunham, Edited by Rosalbe O’Brien)