Three times further away from the sun than the Earth lies an enormous lump of metal. Around 252km in diameter, the metallic 'M-class' asteroid 16 Psyche is the target of NASA's next mission to the belt of giant rocks that encircles the inner solar system. And the space agency now plans to visit it much sooner than originally planned.
Not only has the launch has
been brought forward one year to the summer of 2022, but NASA's scientists have
also found a way to get to Psyche (pronounced SYKe-ee) much faster by taking a
more efficient trajectory. The new route
means the Psyche spacecraft won't have to swing around the Earth to build up
speed and won't pass as close to the sun, so it needs less heat protection.
It is now due to arrive in
2026, four years earlier than the original timeline. The main aim of the
journey to Psyshe is to gather more information about our own solar system. Psyche
is one of many wandering members of the asteroid belt. Unlike the rest of its
rocky neighbours, Psyche appears to be entirely made of nickel and iron, just
like the Earth's core. This, together
with its size, has led to the theory that it might be the remains of the inside
of a planet.
Asteroids are made up of
primitive materials, leftovers from the dust cloud from which our solar system
originated. Different types of asteroids resemble the various steps it took to
form planets from this dust cloud. This means they reveal a lot about the
origin and evolution of our solar system.
Scientists think Psyche
could be what's left of an exposed metal core of a planet very similar to
Earth. We actually derive much of our knowledge about asteroids and the
evolution of planets from the study of meteorites. Many asteroids and comets are primitive
protoplanetary bodies accumulated from the same dust cloud our solar system
originates from.
As these protoplanetary
bodies collide, gravity pulls them together into ever-larger bodies. Eventually
these bodies become big and hot enough to partially melt, allowing heavy
materials such as iron to sink to the core – and lighter material such as
silicon to rise to the surface.
This process, known as
differentiation, explains why Earth and other planets such as Mercury, Venus or
Mars have an iron core and silicon-rich mantle and crust. The 16 Psyche
asteroid is thought to be the leftover iron core of a planet stripped of its
mantle in a giant collision. But many questions regarding the formation of
Psyche remain.
How do you strip a planet of
its mantle only leaving the core? Perhaps there is an alternative formation
mechanism of an iron-rich body that does not involve differentiation? Psyche
may once have been molten and, if so, did it cool from the inside out or from
its surface to the core?
Also, Earth's magnetic field
comes from a liquid outer core circling around a solid inner core. Did these
processes occur on Psyche and create a magnetic field? What elements other than
iron accumulate in a core? And how does the surface geology of an iron body
look compared to a rocky or icy body?
There are other reasons for
visiting asteroids. For one thing, possible collisions with Earth can have
devastating effects. The impact of an 15km-wide asteroid approximately 65m
years ago is linked to the extinction of the dinosaurs. And the explosion of
the 30m-diameter Chelyabinsk asteroid over Russia in 2013 led to injuries and
damage on the ground. We need to know as much as possible about the composition
and physical make-up of asteroids to devise the best ways to defend our planet.
Asteroids also provide
resources. Those containing water or other valuable materials may act as
stepping stones for human exploration of the solar system. And asteroids
crossing Earth's orbit may become convenient targets for mining operations,
providing materials that are running out on Earth and potentially taking
environmentally detrimental extraction methods off Earth. Companies
including Planetary Resources and countries like Luxembourg have already
started to pursue these ideas in earnest.
The Psyche spacecraft will
carry four instruments to gather as much information about the asteroid as it
can: a camera, a gamma-ray spectrometer to record what chemical elements are
there, a magnetometer, and a radio gravity experiment. The data these
devices collect should help us work out if Psyche is the frozen core of a
former planet or simply a lump of unmelted metal.
If it is a core, then it
might help us determine exactly what's at the centre of our own planet. Lindy
Elkins-Tanton, the lead scientist of the mission, probably summarised it best:
'We learn about inner space by visiting outer space'. Christian
Schroeder, Senior Lecturer in Environmental Science and Planetary
Exploration, University
of Stirling.
This article was originally
published on The Conversation.
Read the original
article. It may be 230 million miles (370 million km) away from Earth, but
this asteroid could be worth a fortune.
16 Psyche is one of the most
mysterious objects in our solar system, and scientists could soon be getting a
close-up view thanks to a NASA mission. The space agency today revealed its
plan to launch the mission to visit the asteroid a year earlier than planned,
in 2022, and arrive four years earlier than planned in 2026.
If the asteroid could be
transported back to Earth, the iron alone would be worth $10,000 quadrillion
(£8,072 quadrillion). It's value would be large enough to destroy commodity
prices and cause the world's economy - worth $73.7 trillion (£59.5 trillion) –
to collapse. 16 Psyche is located in the large asteroid belt between Mars and
Jupiter, and may have started as a planet, before it was partially destroyed
during the formation of the solar system.
Now, it is a 130 mile
(200km) wide chunk of metal, made up of iron, nickel and a number of other rare
metals, including gold, platinum and copper.
'We challenged the mission
design team to explore if an earlier launch date could provide a more efficient
trajectory to the asteroid Psyche, and they came through in a big way,' said
Jim Green, director of the Planetary Science Division at NASA Headquarters in
Washington. 'This will enable us to
fulfill our science objectives sooner and at a reduced cost.’
'The biggest advantage is
the excellent trajectory, which gets us there about twice as fast and is more
cost effective,' said Principal Investigator Lindy Elkins-Tanton of Arizona
State University in Tempe. 'We are all extremely excited that NASA was able to
accommodate this earlier launch date.
'The world will see this
amazing metal world so much sooner.'
The revised trajectory is
more efficient, as it eliminates the need for an Earth gravity assist, which
ultimately shortens the cruise time. In addition, the new trajectory stays
farther from the sun, reducing the amount of heat protection needed for the
spacecraft.
The trajectory will still
include a Mars gravity assist in 2023.
'The change in plans is a
great boost for the team and the mission,' said Psyche Project Manager Henry
Stone at NASA's Jet Propulsion Laboratory, Pasadena, California. 'Our mission
design team did a fantastic job coming up with this ideal launch opportunity.'
Much like a sports car, by
combining a relatively small spacecraft body with a very high-power solar array
design, the Psyche spacecraft will speed to its destination at a faster pace
than is typical for a larger spacecraft. The scientific goals of the Psyche
mission are to understand the building blocks of planet formation and explore
firsthand a wholly new and unexplored type of world. The mission team seeks to
determine whether Psyche is the core of an early planet, how old it is, whether
it formed in similar ways to Earth's core, and what its surface is like.
The spacecraft's instrument
payload will include magnetometers, multispectral imagers, and a gamma ray and
neutron spectrometer. Lindy Elkins-Tanton the lead scientist on the Nasa
mission and the director of Arizona State University's School of Earth and
Space Exploration, said: '16 Psyche is the only known object of its kind in the
solar system, and this is the only way humans will ever visit a core.
'We learn about inner space
by visiting outer space.'
Dr Elkins-Tanton has
calculated that the iron in 16 Psyche alone, would be worth $10,000 quadrillion
(£8,072 quadrillion). Assuming the market for asteroid materials is on Earth,
this could cause the value of precious metals to plummet, completely
devaluing all holdings including those of Governments, and all companies
involved in mining, distributing and trading such commodities. Ultimately,
it could lead to the collapse of the entire economy.
Speaking to Global News Canada, Dr Elkins-Tanton said: 'Even if
we could grab a big metal piece and drag it back here, what would you do?
'Could you kind of sit on
it and hide it and control the global resource - kind of like diamonds are
controlled corporately - and protect your market? What if you decided you were
going to bring it back?
You were just going to solve
the metal resource problems of humankind for all time? This is wild speculation
obviously.'
NASA does not plan to bring
the asteroid back to Earth, but instead, the space agency will explore the
asteroid in the hope of understanding how planets separated into layers in their
early histories. The mission is targeted to launch in October 2023, arriving at
the asteroid in 2030, following a Mars flyby in 2025.
Dr Elkins-Tanton said:
'Short of it being the Death Star, one other possibility is that its material
formed very near the (sun) early in the solar system.' Dr Elkins-Tanton
believes that this extreme heat would have melted the iron, and the asteroid
could have stayed in that primordial state until now.
She added: 'I figure we're
either going to go see something that's really improbable and unique, or
something that is completely astonishing.' In December, researchers also put
forward the suggestion that Psyche could contain water, which could make it a
'resource stopover' as humans try to colonise Mars.
Dr Elkins-Tanton said: 'That
water can be used to make rocket fuel or be drunk by people, so then we'd have
a resource stop that has metal and water.'
Via Dailymail