Name: 美國宇航局的洞察號著陸器的第一個結果!| 科學秀新聞 (The First Results from NASA's Insight Lander! | SciShow News)
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基礎被動語態

In 2021, Mars is set to receive new robotic inhabitants.

But until then, we have other explorers hard at work

and its first results were finally released this week in two Nature journals.

The results reveal a seismically active world with magnetic

and atmospheric phenomena, all begging for further investigation.

InSight lives in a sediment-filled crater in the Elysium Planitia region

a volcanic plain a bit north of where Curiosity is.

Its mission is to learn what it's like beneath Mars's surface.

And to do that, it brought along some really cool instruments.

For one, it has Mars's first seismometer in forty years!

At first, that could seem like a weird thing to bring to Mars.

Because until recently, we thought the planet was geologically dead,

with not an earthquake, or... a marsquake, to be found.

But the hope was that this seismometer could at least help us learn about

other seismic activity, from things like meteorite impacts or dust devils.

As of September, InSight had recorded 174 seismic events.

And at least twenty-four of them bore resemblance to minor earthquakes.

the main thing that causes earthquakes here at home,

but this suggests it still has some kind of quakes!

We're still learning how these things work, but they may be caused

by Mars's continual cooling over the billions of years since it formed.

As it cools, it contracts, which applies stress.

And given enough time, the material under stress could break, causing a quake.

These twenty-four events happened so deep

that you and I probably couldn't feel them from the surface.

And by looking at how the vibrations travel through the planet,

it could teach us about Mars's geology and what the planet is made of.

Besides the seismometer, InSight also has

the first magnetometer to grace the Martian surface.

Mars doesn't have a planet-wide magnetic field anymore,

but some of the rocks deep in its crust are still magnetic.

And InSight's instrument can detect that.

So far, it's measured the strength of these local magnetic fields

and how they change over the course of the day.

But it's also teaching about Mars a whole.

Given how deep these rocks appear to be buried,

scientists estimate they're about 3.9 billion years old.

That's slightly younger than when most scientists believe

Mars's planet-wide magnetic field shut down,

so it could mean that field lasted a little longer than we thought!

Finally, this is all cool, but InSight is leaving us with a few mysteries, too.

Like, its atmospheric instruments found that night-time gravity waves

are more abundant than prior data suggest.

Gravity waves are regular, periodic changes in air pressure, temperature,

or wind speed, caused by changes in the air buoyancy.

And they're entirely different from gravitational waves,

the distortions in space-time we detect when black holes collide.

But despite seeing them on Mars, we don't really know what they mean.

InSight also found the first evidence of infrasound on Mars

sound waves with frequencies lower than what we can hear.

But again, we're not sure what that can teach us.

And we're also waiting for two of InSight's other instruments,

including its heat probe, to collect enough data to publish.

Fortunately, the mission was expected from the outset

to take twenty-four months to meet all its objectives,

Phobos and Deimos, are scheduled to get their own visitor!

Last week, the Japanese Space Agency JAXA announced

that their Martian Moons eXploration mission, or MMX,

That means it's no longer just a research project:

Engineers can officially start developing hardware and software.

Mars may have two moons to Earth's one, but they're way smaller.

On average, Phobos is only twenty-three kilometers across,

roughly the length of a half-marathon, and Deimos is about half of that.

They may have started in the asteroid belt,

then been flung towards Mars by Jupiter's gravity.

Or they could have formed like Earth's moon probably did:

from the debris left over after something smashed into Mars.

One way to answer this question would be to study the moons's compositions

and see how similar they are to Mars itself.

After surveying both moons, the spacecraft will land on Phobos

from at least two centimeters below the surface.

Then, it will return that sample to Earth for analysis.

No one has ever gone to Phobos like this,

but sample return missions are no stranger to JAXA.

Their Hayabusa2 probe is currently on its way home

But the MMX mission takes further strides by collecting more material and by

using a corer instead of a tiny cannonball to blast material off the surface.

The craft will also have to navigate another planet's gravitational field,

rather than visit a space potato freely orbiting the Sun like Ryugu.

Besides helping us understand where the moons came from,

studying bits of Phobos will help scientists answer questions

about the history of water in the solar system.

For instance, if the moon formed from Mars,

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美國宇航局的洞察號著陸器的第一個結果!| 科學秀新聞 (The First Results from NASA's Insight Lander! | SciShow News)

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