Astronomy
Collision with Mercury-like object billions of years ago might have created Earth’s magnetic field
Even though we’ve ventured far into the Solar System and our telescopes tell us a lot about distant stars and galaxies, the inner workings of our own planet have remained shrouded in mystery. Much of our understanding of what it’s like underground comes from what are basically educated guesses, because we can’t really send probes down to the center of the Earth. There are some inconsistencies with these models, like why are there certain elements in certain proportions in the planet’s crust and below. Another great problem is the fact that we don’t understand how the Earth’s magnetic field, one of our planet’s most remarkable features, works. Recently, however, scientists from Oxford University have proposed a possible explanation – and it involves a massive collision between our planet in its youth and a smaller cosmic object with similar properties to those of Mercury.
Like all the objects in our Solar System, the Earth formed from a huge molecular cloud which spanned this area of space about 4.6 billion years ago. The early Solar System comprised a young Sun and probably hundreds of planets, which either merged with one another or were destroyed by the gas giants like Jupiter. A lot of what we know about the composition of these celestial objects comes from the study of meteors called chondrites, which have underwent little change since the formation of the Solar System billions of years ago. It is believed these kinds of rocks clumped together under the effect of gravity to create the rocky planets, such as our own.
There is, however, recent data which isn’t entirely consistent with this model, namely there’s a shortage of neodymium relative to samarium (two elements with magnetic properties) in the Earth’s crust and mantle compared to what is found in chondrites. This seems like a rather small and innocuous anomaly, nevertheless it’s something which puzzles scientists, who haven’t managed to come up with a definitive explanation for it. The key, according to Oxford University geochemists Bernard J. Wood and Anke Wohlers, who have recently published a study in the journal Nature, might be sulfur, which made its way into our planet’s crust after it “consumed” a Mercury-like planet the size of Mars early in its lifetime.
The closest planet to the Sun, Mercury is a hellish world which is, quite appropriately, rich in sulfur. If an object with a similar composition had smashed into the Earth billions of years ago, the resulting iron sulfide would have mixed with the neodymium, and subsequently sink together to the core of the planet, leaving relatively more samarium (which is more attracted to the silicate rock found in the crust and mantle and thus less likely to sink) behind in the upper layers. To test this hypothesis, scientists added sulfur to a mixture of elements similar in composition to the primitive Earth, then subjected the sample to the conditions thought to have occurred at that time: temperatures between 1,400 and 1,640 °C (2,550 and 3,000 °F) and pressures of 1.5 gigapascals (150,000 times greater than atmospheric pressure at sea level today!). After adding sufficient quantities of sulfur, neodymium sunk to the core of the model planet, which is consistent with the theory.
This could also help explain the origin of the Earth’s magnetic field. The planet’s inner core is mainly made up of iron which is extremely hot (about 5,700 °C or 10,300 °F), however due to the huge pressure at that depth it remains solid. Higher up, where the pressure isn’t as high, there’s an outer core of molten iron. Convection currents, as well as the Coriolis force cause the flow of torrents of liquid iron, generating electric currents, which then produce magnetic fields. How the core has remained molten for so long is another mystery, which could be explained by uranium (which generates heat through nuclear decay) also sinking together with the iron sulfide.
If a catastrophic collision with a Mercury-like, Mars-sized object sounds a bit far-fetched, it shouldn’t. Remember there were perhaps hundreds of objects of various sizes and compositions in the young Solar System, which were constantly jostling for position. It’s not inconceivable that many of them collided, getting obliterated and forming new celestial bodies or merging together. In fact, one of the most widely accepted theories regarding the Moon’s formation holds that the Earth collided with a planet similar in size to Mars we now call Theia, and the debris resulting from the crash clumped together to form our sole natural satellite.
Artist’s depiction of the impact between the Earth and a planet-sized object called Theia, which could have resulted in the formation of the Moon. Scientists believe a similar impact could have created our planet’s magnetic field. Image: NASA/JPL-Caltech.
Our magnetic field is extremely important for life on Earth. It protects us from potentially devastating solar winds and cosmic rays, which would otherwise blow away the upper parts of the atmosphere, and it also helps birds, turtles, and even humans navigate. You could argue we wouldn’t be here if it didn’t exist. Although the collision with a Mercury-like object hypothesis is still far from being confirmed, it’s still interesting to think life on Earth was made possible by a cataclysmic event early in our planet’s lifetime.
At the time of impact, the impactor vehicle, about the size of a vending machine, was moving at about 14,000 mph.
After traveling for over a year, NASA‘s Double Asteroid Redirection Test (DART) mission, which attempted to provide answers, “Could a specially crafted satellite be used to divert an asteroid from its planet-destroying course? How about a number? “has effectively impacted the Dimorphos asteroid. However, NASA ground control has confirmed that the DART impact vehicle has intercepted the target asteroid. The results and data from the collision are still being received. Yes, Dimorphos is about the size of a football stadium, but space is very big, extremely dark, and both the asteroid and the spaceship were traveling rather quickly at the time.
“It’s been a successful completion of the first part of the world’s first planetary defense test,” NASA Administrator Bill Nelson said after the impact. “I believe it’s going to teach us how one day to protect our own planet from an incoming asteroid. We are showing that planetary defense is a global endeavor and it is very possible to save our planet.”
In an effort to investigate the employment of defensive satellites as a method of planetary defense against Near Earth Objects, NASA launched the DART mission in November 2021. Nearly 68 million miles from Earth, the DART impactor vehicle, about the size of a vending machine, tragically crossed Dimorphos’ path while traveling at about 14,000 MPH.
It remains to be seen if future generations of a planetary defense system will be packed with satellites ready to go full June Bug vs. Chrysler Windshield against real planet-killer asteroids. Dimorphos is one of two asteroids that are gravitationally entangled; its parent rock is more than five times larger than Dimorphos itself, but both are dwarfed by the space rock that struck Earth 66 million years ago and destroyed 75% of the planet’s multicellular life while gouging out the Gulf of Mexico.
The world of science and technology brings us yet another crazy possibility that’s going to be explored quite soon. Fourth Generation Cellular Networks are seeing implementations on various places. One of them could be the natural satellite orbiting the earth: The Moon.
A partnership between Nokia, Vodafone and Audi is looking to implement cellular networks on the moon sometime next year. Even if the proposition sounds crazy, it seems like they have a lot of plans to make this dream a reality.
Vodafone will be designing the lunar network and will make use of equipment designed by Nokia Bell Labs. This connectivity will allow two Audi Lunar Quattro rovers to communicate wirelessly with a base station at the Autonomous Landing and Navigation Module.
Using existing satellites, mission organizer Part Time Scientists will also be able to live stream scientific data and HD video content from the Moon to viewers on Earth. In other words, we will be getting some very detailed views of Earth for public viewing.
The networking equipment will be launched into space aboard a SpaceX Falcon 9 rocket. If you think it’s going to be very heavy and sloppy to handle. Nokia’s engineers have worked really hard to make it weigh less than one kilogram.
We’re seeing the vestiges of life in the moon very frequently now. All thanks to the options becoming more and more accessible with the fast advancements in technology. Of course, this rapid growth is far from reaching its peak potential.
Who knows? Maybe we will be able to look at interplanetary travels and living. The sky is the limit when it comes to the amount of creations. Nowadays bizarre ideas like mobile networks in different planets aren’t that far fetched eiher.
It’s going to be an interesting ride, for sure. However, we must be also conscious about the planet we’re currently living in. Even though there are efforts to make this planet greener, there is a lot left to do.
Alright, it’s been some time since we’ve talked about developments in Space Technology. This development in particular can actually save the lives of countless astronauts who find themselves in quite nightmarish situations. I mean, being “lost in space” is a very serious issue for a lot of astronauts.
A recent patent made by Kevin Duda, a space systems engineer at the Charles Stark Draper Laboratory in Cambridge, Massachusetts shows a self-return system that allows safety for spacewalking astronauts. Even in the most threatening scenario of the crewmates not being able to rescue the astray spaceman.
The self-return spacesuit system, Duda explained, had to be capable of determining a precise location in a harsh space environment where GPS is unavailable. This basically makes for a “Return to Home” button that is very tricky to develop.
The system has to compute an optimal return trajectory that accounts for time, oxygen consumption, safety and clearance requirements. Not only that but the system has to be able to guide a disoriented and possibly unconscious astronaut to safety effectively.
Draper Director of Space Systems Séamus Tuohy said the return-home technology is an advance in spacesuits that is long overdue. He mentions how current spacesuits feature no navigation system and could be a very challenging aspect for astronauts in the current age.
The patent also shows how the system works. It monitors the movement, acceleration and position of the crewmember relative to a fixed object nearby. The navigation module can also be configured using GPS, vision-aided navigation or a star-tracker system.
Additionally, to improve the astronaut’s positioning and orientation, Draper has developed software that fuses data from vision-based and inertial navigation systems and that benefits from the advantages of both sensing approaches. The development of this and other kinds of spacesuits will be handled by NASA
Not only that, but this technology can be used to help Earth’s inhabitants as well. Clothing equipped with sensors of this caliber could help First Response members and even firefighters during dire situations. If you want to see the full patent listing, I’d suggest you read it right here.
- Gadgets8 years ago
Why the Nexus 7 is still a good tablet in 2015
- Mobile Devices8 years ago
Samsung Galaxy Note 4 vs Galaxy Note 5: is there room for improvement?
- Editorials8 years ago
Samsung Galaxy Note 4 – How bad updates prevent people from enjoying their phones
- Mobile Devices8 years ago
Nexus 5 2015 and Android M born to be together
- Gaming8 years ago
New Teaser For Five Nights At Freddy’s 4
- Mobile Devices8 years ago
Google not releasing Android M to Nexus 7
- Gadgets8 years ago
Moto G Android 5.0.2 Lollipop still has a memory leak bug
- Mobile Devices8 years ago
Nexus 7 2015: Huawei and Google changing the game