Life on Titan? New NASA Mission Will Find Out

Life on Titan? New NASA Mission Will Find Out

Titan, a moon around the planet Saturn¹, has the right materials for life, NASA research has shown. The US space agency’s newly announced Dragonfly mission will explore the icy space object to learn if it ever did hold life.

Titan is similar to a very early Earth, and NASA says it can provide clues to how life may have started on our planet.

In some ways, Titan looks like Earth. There are lakes and seas across the northern half, and sometimes rain hits the sandy surface. But this is where the similarities end.

Titan is so cold that water is rock-hard ice, and oily methane² falls from the sky and into the seas. The beaches are different too. Titan’s sand is made up of carbon, hydrogen, nitrogen and oxygen, unlike any beach on Earth.

“One of the things I think is so exciting about Titan is how it can be alien and familiar at the same time,” said Elizabeth Turtle, Dragonfly’s lead investigator³. At -179 degrees Celsius⁴, “it’s totally different material than what we’re used to interacting with on a daily basis.” For example, there is water-ice bedrock—the material under the surface of the ground and large areas of liquid methane.

Titan’s surface is hidden below its atmosphere which is four times as dense⁵ as Earth’s. But its lower level gravity makes Titan a good place for a flying explorer.

Dragonfly Drone

Drones are small aircrafts that fly without a pilot. With the progress in drone technology, the Dragonfly team recognized that they could make what was once a dream—flying on Titan—a reality.

Dragonfly will be three meters long and more than a meter tall. It will fly with the help of two sets of four propellers⁷. The design will permit Dragonfly to take pictures from above the moon, and to land on Titan’s frozen surface for a closer look.

At first, it will target an area near the moon’s equator, or middle. It is covered in huge sand hills, similar to what is found in Earth’s deserts. From there Dragonfly will move out and explore the moon by taking large jumps to see what lies ahead.

When it lands, it will study samples of the surface, take photographs and look for “titanquakes”— like earthquakes.

Dragonfly will travel at eight kilometers per jump, and make its way to Selk crater⁸, more than 100 kilometers away. The crater was formed when a large object hit the area. Scientists think that the heat from the hit would have turned the ice to water in Titan’s crust. That could have created an environment that would have all the necessary elements for life.

Search for Life

The Dragonfly team hopes to learn whether combining organic material with liquid water and energy in the form of heat could have caused complex molecules⁹ to develop – or even life itself.

“We have this chance to explore a world that we know has all the ingredients for life, but how far did it get towards life?” said Melissa Trainer, the mission’s deputy lead investigator.

If life is, or has been on Titan, Dragonfly should be able to find it. Its instruments will be searching for is a class of molecules called amino acids, which are found in all life on Earth.

Dragonfly is expected to launch in 2026 and arrive at Titan in 2034. The science and engineering teams are designing and building the spacecraft.

The trip may be a long way off, but the team believes the mission will be worth the wait.

I’m Anne Ball.

Words in This Story

mission – n. a task or job that someone is given to do

clue – n. something that helps a person find something, understand something, or solve a mystery or puzzle

beach – n. an area covered with sand or small rocks that is next to an ocean or lake

alien – n. from somewhere other than the planet Earth

familiar – adj. frequently seen, heard, or experienced

propeller⁶ – n. a device with two or more blades that turn quickly and cause a ship or aircraft to move

crust – n. a hard layer on the surface of something

1 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。

2 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

3 investigator   

n.研究者，调查者，审查者

参考例句：

• He was a special investigator for the FBI.他是联邦调查局的特别调查员。
• The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。

4 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。

5 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

6 propeller   

n.螺旋桨，推进器

参考例句：

• The propeller started to spin around.螺旋桨开始飞快地旋转起来。
• A rope jammed the boat's propeller.一根绳子卡住了船的螺旋桨。

7 propellers   

n.螺旋桨，推进器( propeller的名词复数 )

参考例句：

• The water was thrashing and churning about under the propellers. 水在螺旋桨下面打旋、翻滚。 来自辞典例句
• The ship's propellers churned the waves to foam. 轮船的推进器将海浪搅出泡沫。 来自辞典例句

8 crater   

n.火山口，弹坑

参考例句：

• With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
• They came to the lip of a dead crater.他们来到了一个死火山口。

9 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。