Japanese scientists want to be first to drill into the Earth's mantle

Story highlights

    Scientists say they still need to do further research before drilling can begin
    But they're hopeful they can begin drilling by 2030

Humans have been to the Moon and explored almost every corner of the planet -- but there's one place they have never been.
A group of Japanese scientists said they plan to be the first group to successfully drill into the Earth's mantle, the planet's vast molten-rock interior, which lies just beneath the outer crust.

Researchers at Japan's Agency for Marine-Earth Science and Technology (JAMSTEC) say they are hoping to discover more about how our planet was formed and what the mantle is composed of. Japanese media first reported on the project earlier this week.
The mantle makes up more than 80% of the entire Earth's mass, lying six miles (10 kilometers) beneath the ocean floor.

A piece of peridotite, the rock believed to make up Earth's mantle.

"We don't know the exact (composition) of the mantle yet. We have only seen some mantle materials -- the rock is very beautiful, it's kind of a yellowish green," researcher Natsue Abe, who works for JAMSTEC, said.
The Japanese government, which is helping fund the expedition, hopes the research could help discover ways to better predict earthquakes, Abe said.
"In Japan we have some volcanoes, earthquakes and such kind of natural hazards. People (want to create) some monitoring or analysis equipment but we don't know ... what kind of factor to use," Abe said.
"So we need to know the natural system more clearly or precisely ... we have to observe the earth more precisely."

Journey to the mantle 

Three drilling sites are currently under consideration, Abe said, all of them in the Pacific Ocean.
"One is off Hawaii -- we're going to survey there -- another one is off Costa Rica, (and) the last one is off Mexico," she said.
To access the mantle, JAMSTEC wants to use one of the most advanced drilling vessels currently available, the Chikyu.
"It's the biggest drilling ship of our science area, so the drilling capability is three times longer, or deeper, than the previous (vessels)," Abe said.
Japan's deep-sea drilling vessel, Chikyu, anchored at a pier in September 2013. 

Japan's deep-sea drilling vessel, Chikyu, anchored at a pier in September 2013.

The researcher said the Chikyu's drill will drop down through almost 2.5 miles (4 kilometers) of ocean before reaching the ocean floor.
It will then bore through 3.7 miles (6 kilometers) of the sea floor, or the planet's crust, before it reaches the mantle.
"We already drilled and have taken some samples from the ocean floor but (only) from the top," Abe said. "(We want) to dig from the ocean floor to the deep pristine mantle."
Drilling will start by 2030 at the latest, according to Abe. 

Four objectives 

Their project has four primary objectives, only the first of which is to access the planet's mantle by drilling through the sea floor.
"The second aim is we want to investigate the boundary between the oceanic crust and the mantle," Abe said. "The third one is we want to know how the oceanic crust formed." 

The final objective is to further examine how deep microbial life exists inside the planet. "(What is) the limit of the life inside the Earth?" Abe said.
Before any drilling can begin, there's more research that needs to be done to build the right technology, Abe said, but she was convinced the project was "feasible."
"If we dig into the mantle we will know the whole Earth history, that's our motivation to search," she said.

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The race to destroy space garbage

A visualization of the satellites and other debris around earth

Millions of pieces of man-made trash are now orbiting the Earth. Some are tiny, others are large enough to be seen with a telescope, but all pose a risk to space craft and satellites. 

And according to experts the threat is growing as space becomes more and more crowded.

Some 23,000 pieces of space junk are large enough to be tracked by the US Space Surveillance Network. But most objects are under 10cm (4in) in diameter and can't be monitored. Even something the size of a paper clip can cause catastrophic damage 

''At the moment we're not tracking stuff that small," says Brian Weeden of the Secure World Foundation, a Washington based organisation dedicated to the sustainable use of space.

"And that's important because something as small as a centimetre can cause problems if it runs into a satellite."

Collisions are rare, but half of all near-misses today are caused by debris from just two incidents. In 2007, China destroyed one of its own satellites with a ballistic missile. In 2009 an American commercial communications satellite collided with a defunct Russian weather satellite.

As recently as 2015, the debris from that collision forced the crew of the International Space Station to evacuate to the Soyuz capsule. No-one was harmed, but the debris will likely remain in the Earth's orbit for hundreds, if not thousands of years. 

Scientists are experimenting with ways to clean up space. So far, there is no space vacuum. And debris have a nasty habit of creating more debris that get exponentially smaller and harder to spot.

More than 7,000 satellites have been put into space but only 1,500 are currently functioning. And within the next decade the number could increase to 18,000 with the planned launch of mega-constellations - large groups of satellites aimed at improving global internet coverage.

"That's going to amplify the problems we have with tracking objects, predicting close approaches and preventing collisions," says Weeden. "The problem is going to become much, much harder in the next several years."

Everything travels at the same speed relative to its altitude in space. That's not a problem if everything moves in the same direction, says Weeden, but objects often follow different orbits and can cross paths - a situation known as a conjunction.

"Think of it like all the cars on a highway are doing a hundred miles an hour. If the car next to you is doing that speed you don't really notice it. But if the car coming at you is doing that speed - you'll collide at 200 miles an hour."

Scientists are experimenting with ways to clean up space. So far, there is no space vacuum. And debris have a nasty habit of creating more debris that get exponentially smaller and harder to spot.
More than 7,000 satellites have been put into space but only 1,500 are currently functioning. And within the next decade the number could increase to 18,000 with the planned launch of mega-constellations - large groups of satellites aimed at improving global internet coverage.
"That's going to amplify the problems we have with tracking objects, predicting close approaches and preventing collisions," says Weeden. "The problem is going to become much, much harder in the next several years."
Everything travels at the same speed relative to its altitude in space. That's not a problem if everything moves in the same direction, says Weeden, but objects often follow different orbits and can cross paths - a situation known as a conjunction.
"Think of it like all the cars on a highway are doing a hundred miles an hour. If the car next to you is doing that speed you don't really notice it. But if the car coming at you is doing that speed - you'll collide at 200 miles an hour."

An impact crater in a window of the International Space Station from debris

Lauri Newman is NASA's traffic cop at Goddard Space Flight Center, Maryland. She is responsible for using military data to decide whether the space agency's unmanned craft such as satellites need to be moved to prevent a collision with debris.

"Satellites can protect themselves from things that are smaller than a centimetre by putting up extra shielding," she says. "But the things between one and 10cm - if you can't track it there's nothing you can do."

Satellite technology is essential to almost every modern convenience - from communications to GPS navigation and downloading movies on demand. It's also vital to national security.

"It affects everything," says Lt Col Jeremy Raley a program manager at Darpa, the Defense Advanced Research Projects Agency. "So I need to be able to see everything (in space) all the time and know what it is when I see it."

That's why Darpa is leading military efforts to find better ways of tracking space debris. In October last year it delivered a massive 90-ton telescope to the US Air Force at White Sands, New Mexico.

The Space Surveillance Telescope is designed to penetrate Geosynchronous orbit (GEO) which is becoming increasingly important. Communications and television satellites in GEO can remain in a fixed position above the Earth, offering uninterrupted service.

"The telescope is a big deal because it can see more objects and smaller objects. And rather than having to take time to look at an object and then look at something else, it can keep track of things on a more persistent basis," says Lt Col Raley.  

The Space Surveillance Telescope and the
US defense department

But that level of scrutiny costs money and also raises the question of whether the US should share its data to improve space safety overall.

That was one of the issues discussed at a recent symposium in Washington organised by the Universities Space Research Association and the Space Policy Institute at George Washington University. Experts discussed who should manage space, who should be responsible for debris and whether there should be an agreed set of international guidelines for the sustainable use of space.

"There's a classic public policy, economic question here," says Weeden. "It's like pollution. It might not be worth it for you to pick up your garbage and avoid polluting the river, but there are costs to society if you don't. How do you get people to be responsible when the costs may not be borne by them?"

No single nation or entity is responsible for space although in 1959 the UN set up a Committee on the Peaceful Uses of Outer Space (COPUOS).

"There are currently 85 countries that are members of this committee and they range from space powers such as the US, Russia and China to countries like Costa Rica that don't even have a satellite in orbit but are an end user of satellite functions," says Weeden. "Getting all of those countries to agree on this stuff is a really difficult challenge."

But with more nations and commercial organisations operating in Earth's orbit and many looking beyond, such issues are becoming increasingly urgent.

Do nothing is no longer an option.

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