More Information about Little-Known Venus

A recent study of Earth's closest planetary neighbor has provided new understanding about Venus.

Recently, scientists gathered data about Venus by bouncing radio waves off the planet. The study measured the tilt¹ of the Venusian axis² and size of the planet's center, or core. It also studied the planet turning.

All this data is giving a deeper understanding of the strange planet, sometimes called Earth's "evil twin."

It was already known that Venus has the longest day. The time the planet takes for one full turn, or rotation³, on its axis is longer than any other planet in our solar system. However, some earlier estimates were not completely correct.

The study found that a single Venusian rotation takes about 243 Earth days. That means a day on Venus lasts longer than a year on Earth. Scientists also say that Venus makes a complete orbit around the sun in 225 Earth days.

The researchers sent radio waves toward Venus 21 times from 2006 to 2020 from NASA's Goldstone Antenna⁴ in the Mojave Desert of California. Then they studied the radio echo, the sound that traveled back to two places on Earth: Goldstone and at the Green Bank Observatory⁵ in West Virginia.

Jean-Luc Margot is a planetary astronomy professor at the University of California, Los Angles. He led the study. The findings were published online by Nature Astronomy.

He said the radio waves lit up Venus with a huge "flashlight." The scientists then observed the reflections as they came back to Earth.

Margot praised Venus as an excellent "laboratory" for understanding how planets are formed and how they change.

"There are likely billions of Venus-like planets in the galaxy⁶," he said.

The new data showed that the Venusian planetary core is about 7,000 kilometers (4,360 miles) across. That is similar in size to the Earth's core. Earlier estimates of Venus's core were based on computer modeling rather than observational data. Its core is very likely made of iron and nickel. However, Margot said that it is unclear whether the core is solid or liquid.

Venus, the second planet from the sun, is similar in structure but slightly smaller than Earth. The planet is about 12,000 kilometers wide.

Its poisonous atmosphere is mainly made up of carbon dioxide, with clouds of sulfuric acid. This creates a greenhouse effect. So, its surface temperatures can reach 471 degrees Celsius⁷. That is hot enough to melt lead.

Venus turns on its axis almost upright. This means it lacks separate seasons. The Earth has more of a tilt. The study found that the Venusian tilt is about 2.64 degrees. Earth's is about 23.5 degrees.

Venus turns from east to west. This is the opposite direction from all other planets in our solar system except Uranus⁸.

Here is another strange thing about Venus: the time between sunrises (as opposed to the length of a single axial turn) takes 117 Earth days. This is because Venus rotates in the direction opposite of its orbit around the sun.

Venus has received less attention than Mars, Earth's other planetary next-door neighbor, and other places in the solar system. Margot said this extreme lack of data about Venus has led to an extreme lack of understanding.

"There have been no NASA missions to Venus in almost 30 years and about a dozen NASA missions to Mars in this time ...," Margot said. He added that the new findings on how Venus turns could help any future landing attempts.

Words in This Story

data – n. facts about something that can be used in calculating, reasoning, or planning

tilt – v. to move or shift so as to slant⁹ or tip

axis – n. the imaginary straight line that something (such as the Earth) turns around

spin – v. to turn or cause someone or something to turn around repeatedly

rotation – n. the action or process of rotating on or as if on an axis or center

reflection – n. an image that is seen in a mirror or on a shiny surface

galaxy – n. any of the very large groups of stars and associated matter that are found throughout the universe

diameter – n. mathematics : the length of a straight line through the center of an object or space

greenhouse effect – n. warming of the lower atmosphere of the earth that occurs when radiation from the sun is absorbed by the earth and then given off again and absorbed by carbon dioxide and water vapor¹⁰ in the atmosphere gases

mission – n. a definite military, naval, or aerospace task

1 tilt   

v.(使)倾侧；(使)倾斜；n.倾侧；倾斜

参考例句：

• She wore her hat at a tilt over her left eye.她歪戴着帽子遮住左眼。
• The table is at a slight tilt.这张桌子没放平，有点儿歪.

2 axis   

n.轴，轴线，中心线；坐标轴，基准线

参考例句：

• The earth's axis is the line between the North and South Poles.地轴是南北极之间的线。
• The axis of a circle is its diameter.圆的轴线是其直径。

3 rotation   

n.旋转；循环，轮流

参考例句：

• Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
• The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。

4 antenna   

n.触角，触须；天线

参考例句：

• The workman fixed the antenna to the roof of the house.工人把天线固定在房顶上。
• In our village, there is an antenna on every roof for receiving TV signals.在我们村里，每家房顶上都有天线接收电视信号。

5 observatory   

n.天文台，气象台，瞭望台，观测台

参考例句：

• Guy's house was close to the observatory.盖伊的房子离天文台很近。
• Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。

6 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

7 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

8 Uranus   

n.天王星

参考例句：

• Uranus is unusual because it is tilted.天王星非常特殊，因为它是倾斜的。
• Uranus represents sudden change and rebellion.天王星代表突然性的改变和反叛。

9 slant   

v.倾斜，倾向性地编写或报道；n.斜面，倾向

参考例句：

• The lines are drawn on a slant.这些线条被画成斜线。
• The editorial had an antiunion slant.这篇社论有一种反工会的倾向。

10 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。