Scientists Discover 12 New Moons Orbiting Jupiter

Scientists Discover 12 New Moons Orbiting Jupiter

Astronomers² have discovered 12 additional moons orbiting Jupiter. That means Jupiter now has a total of 92 moons, more than any other planet in our solar system.

The new moons were recently added to a list kept by the internationally recognized Minor³ Planet Center. The center –operated by the International Astronomical⁴ Union – continually records the positions of planets, moons and other space objects.

Scott Sheppard is an astronomer¹ with the Carnegie Institution of Science. He was a member of the team that made the latest discoveries.

Sheppard told The Associated Press (AP) that the new moons were found using telescopes in Hawaii and Chile in 2021 and 2022. The first sightings were confirmed with additional observations.

The latest moons are between one and three kilometers in size, he said. "I hope we can image one of these outer moons close-up in the near future to better determine their origins," Sheppard added.

Sheppard has already taken part in 70 moon discoveries for Jupiter. He also discovered moons orbiting Saturn⁵.

Sheppard noted⁶ that Jupiter's newly discovered moons have not yet been named. He said only half of them are big enough – at least 1.5 kilometers – to justify⁷ a name.

In our solar system, some planets have numerous moons while some have none.

The American Space Agency NASA reports that Saturn had been the planet with the most moons until the most recent announcement. Saturn currently is known to have 83 moons. Saturn held the top position since 2019 when Sheppard's team discovered 20 additional moons. Before that, Jupiter was the solar system's leader with 79 confirmed moons.

Sheppard told the AP he expects to keep adding moons to both Jupiter and Saturn in the future.

Scientists believe Jupiter and Saturn's many small moons formed from crashes with larger moons, asteroids⁸, or other space objects. Uranus⁹ and Neptune¹⁰ also have many small moons. But since those planets are much farther from Earth, discovering new moons orbiting those planets is more difficult, Sheppard said.

Saturn has two so-called "ocean moons," called Enceladus and Titan. The pieces of ice and rock that form rings around Saturn are not considered moons themselves, NASA said. But moons do exist within the planet's rings and help to keep the rings in line.

Jupiter's moons include the largest in the solar system, Ganymede, an ocean moon called Europa and a volcanic¹¹ moon named lo. NASA notes that many of Jupiter's outer moons have what are called retrograde orbits. That means they orbit in the opposite direction that the planet spins in.

Of the other major planets in our solar system, Uranus has 27 confirmed moons, while Neptune has 14. Mars has two and Earth has one. Venus and Mercury have no confirmed moons.

Earth's moon is thought to have formed when a large space body about the size of Mars crashed into Earth. Scientists believe material from the resulting crash came together to form our moon about 4.5 billion years ago.

The huge gas planet Jupiter remains¹² one of the most interesting for astronomers. Jupiter's atmosphere is made up mostly of hydrogen and helium. It orbits about 778 million kilometers from our sun.

This year, the European Space Agency (ESA) plans to launch a spacecraft to explore Jupiter. The Jupiter Icy Moons Explorer spacecraft, called JUICE, is expected to launch sometime in April. The mission will make detailed¹³ observations of Jupiter and its three large moons.

ESA says it hopes the observations will help scientists learn more about Jupiter's complex environment as they use the planet as a model for other gas giants across the universe.

Words in This Story

determine – n. to discover facts or truth about something

origins – n. where something begins or comes from

justify – v. to give a good enough reason to make something seem acceptable

1 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。

2 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

3 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

4 astronomical   

adj.天文学的，（数字）极大的

参考例句：

• He was an expert on ancient Chinese astronomical literature.他是研究中国古代天文学文献的专家。
• Houses in the village are selling for astronomical prices.乡村的房价正在飙升。

5 Saturn   

n.农神，土星

参考例句：

• Astronomers used to ask why only Saturn has rings.天文学家们过去一直感到奇怪，为什么只有土星有光环。
• These comparisons suggested that Saturn is made of lighter materials.这些比较告诉我们，土星由较轻的物质构成。

6 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

7 justify   

vt.证明…正当(或有理)，为…辩护

参考例句：

• He tried to justify his absence with lame excuses.他想用站不住脚的借口为自己的缺席辩解。
• Can you justify your rude behavior to me?你能向我证明你的粗野行为是有道理的吗？

8 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

9 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。

10 Neptune   

n.海王星

参考例句：

• Neptune is the furthest planet from the sun.海王星是离太阳最远的行星。
• Neptune turned out to be a dynamic,stormy world.海王星原来是个有生气、多风暴的世界。

11 volcanic   

adj.火山的；象火山的；由火山引起的

参考例句：

• There have been several volcanic eruptions this year.今年火山爆发了好几次。
• Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

12 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

13 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。