How long is a day on Venus? – The day length, axial inclination and forecast of our neighboring planet are determined very accurately for the first time

Revealed secrets: Astronomers have finally succeeded in accurately determining some of the basic features of Venus, including the speed of rotation, axial inclination and forecast. It also provides valuable information about your inner self. Radar measurements reveal that a Venus day lasts about eight Earth months and that the length of our neighboring day’s day fluctuates up to 20 minutes, according to the group’s special journal Nature.

The Venus In many ways the sister of the earth – it is the same size, similarly structured and may one day be right Life friendly Would have been. Yet our closest neighbor presents a puzzle. This is because even basic properties such as the speed of its proper rotation, the tilt of its axis, or the size and nature of its center are beginning to be known to Venus. Because of her dense veil Atmosphere It is difficult to hide everything and even research the processes on its surface.

Radar reflections as an operating meter

The team, now led by Jean-Luc Margot of the University of California, Los Angeles, has succeeded in measuring Venus’ vital fundamental features more accurately than ever before. To do this, they have repeatedly sent strong radar beams to Venus from California’s Goldstone radio telescope over the past 14 years, where they penetrate the clouds and reflect on the surface of Venus. The reflected radiation was then captured again by the radio telescope of the Green Banks in West Virginia.

“In principle, we use Venus as a giant disco ball, a radio telescope to attract attention and the planet’s terrain as millions of small reflectors,” Margot explains. The speckle pattern of the reflected radar beams then reveals how certain reference points on the surface of Venus move over time – and it provides information about rotation, axial tilt and planetary depression.

The length of a day on Venus varies by 20 minutes

Measurement data reveal: Venus requires an average of 243.0226 Earth days per cycle – so one day is two thirds of Earth on our neighboring planet. But when Earth Day Length Varies only by milliseconds, which can fluctuate significantly on Venus: a day on Venus may be about 20 minutes longer or less than one measurement the next. Margot said, “This explains why previous estimates of the length of the day were so far.

The reason for these strong fluctuations throughout the day is the enormous mass and density of the Venus gas envelopes. By contacting the surface of the planet, it affects rotation and can slow or accelerate it. “Venus has about 180 times the strongest atmospheric angular velocity, which contributes to 60,000 times the total angular velocity of the Earth’s crust,” the researchers explained.

Lower axis slope, slower forecast

The new measurements also provide more accurate values ​​for the inclination and motion of the Venus axis. Accordingly, its rotation point is inclined at 2.6392 degrees compared to its orbit – which is significantly less than the approximate 23 degree inclination of the Earth’s axis. However, like Earth, the Venus axis makes slight pendulum and stumble movements over time. Since these prototypes are partially affected by mass distribution and processes within the planets, it provides valuable information about the internal nature of Venus.

The team found that the Venus axis changes its background with a stellar background at 44.58 seconds per year. As a result, it completes a small circle in 29,000 years and takes 3,000 years longer than Earth for such a pre-cycle.

The core of Venus is as large as Earth

From the combination of these values, Margot and his colleagues were able to calculate the idle moment of the planet, thus allowing a body size to be drawn about its internal structure. “Based on the approximate two-tier model, we reach the radius of the Venus Center at about 3,500 kilometers,” they say. However, due to the large uncertainty the actual core size can vary up to 500 km.

However, if this value is to be confirmed, Venus will have not only the overall size of the Earth, but also a large center. However, it is not yet known whether the Venus nucleus is solid or liquid, or whether it is divided into two distinct zones similar to Earth. (Natural Astronomy, 2021; doi: 10.1038 / s41550-021-01339-7)

Quell: University of California – Los Angeles

3. May 2021

– Natja Bodybreaker