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New Horizons Just Found Hints of a Huge Structure at The Edge of Our Solar System

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According to ScienceAlert (This article and its images were originally posted on ScienceAlert August 15, 2018 at 02:25AM.)

Way out past Pluto, in the region of asteroid-filled space known as the Kuiper belt, NASA probe New Horizons just got a tantalising hint of a long-sought structure in the outer Solar System.

An ultraviolet glow picked up by the probe’s Alice UV spectrometer could be evidence of the ‘hydrogen wall’, a region of dense hydrogen on the boundary between the Solar System and interstellar space.

“We’re seeing the threshold between being in the solar neighborhood and being in the galaxy,” astronomer Leslie Young of the Southwest Research Institute and New Horizons team told Science News.

Although space has extremely low pressure, it still exists, and the solar wind exerts an outward pressure. At a certain point, however, that wind is no longer strong enough to push back against interstellar space.

This boundary is known as the heliopause, which marks the official edge of the Solar System.

Just on the other side of the heliopause, neutral hydrogen atoms moving through interstellar space should, theoretically, slow down when they reach that barrier – a sort of neutral hydrogen “traffic jam” that causes a buildup next to the heliopause.

Between 2007 and 2017, New Horizons detected a distinctive ultraviolet glow called the Lyman-alpha line, produced by solar photons hitting the hydrogen atoms and scattering.

This occurs as sunlight travels through the Solar System. But there’s a mysterious background source in the signal detected by New Horizons, much farther away.

This was also detected by Voyager 30 years ago. New Horizons is the first probe in all that time that has had the same opportunity to take measurements of this phenomenon – and its best explanation is the hydrogen wall.

“Both sets of data are best explained if the observed ultraviolet light is not only a result of the scattering of sunlight by hydrogen atoms within the solar system, but includes a substantial contribution from a distant source,” the researchers wrote in their paper.

“This distant source could be the signature of a wall of hydrogen, formed near where the interstellar wind encounters the solar wind.”

The background glow could be something else, farther away out there in space; the only way to be sure is to do more sciencing. Which means more Alice observations with New Horizons – around twice a year for the foreseeable future, according to the paper.

Voyager 1 has already moved on into interstellar space. It breached the heliopause in 2013, and is still beaming signals back to Earth as it moves farther and farther away into the infinite cosmos.

Voyager 2 is in the heliosheath, the outer reaches of the Solar System where the solar wind is slowed by interstellar gas. It’s expected to cross the heliopause sometime before 2030.

New Horizons won’t reach that point until sometime after, but if it’s still in operation, it may be able to take more observations as it glides through. Which is quite a comforting thought, really: humans may come and go, but our scientific efforts live on.

In the meantime, New Horizons has other work to do. It’s already dished the dirt on Pluto, which it flew past in 2015.

The probe’s next encounter will be with a Kuiper belt object named Ultima Thule, a minor planet the probe will explore on 1 January 2019.

The team’s research has been published in the journal Geophysical Research Letters.

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This article and its images were originally posted on [ScienceAlert] August 15, 2018 at 02:25AM. All credit to both the author MICHELLE STARR and ScienceAlert | ESIST.T>G>S Recommended Articles Of The Day.

Exiled asteroid discovered in outer reaches of solar system

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According to Phys.org – latest science and technology news stories

Cover Image:
This artist’s impression shows the exiled asteroid 2004 EW95, the first carbon-rich asteroid confirmed to exist in the Kuiper Belt and a relic of the primordial solar system. This curious object likely formed in the asteroid belt between Mars and Jupiter and must have been transported billions of kilometers from its origin to its current home in the Kuiper Belt. Credit: ESO/M. Kornmesser

An international team of astronomers has used ESO telescopes to investigate a relic of the primordial Solar System. The team found that the unusual Kuiper Belt Object 2004 EW95 is a carbon-rich asteroid, the first of its kind to be confirmed in the cold outer reaches of the Solar System. This curious object likely formed in the asteroid belt between Mars and Jupiter and has been flung billions of kilometres from its origin to its current home in the Kuiper Belt.

The early days of our Solar System were a tempestuous time. Theoretical models of this period predict that after the gas giants formed they rampaged through the Solar System, ejecting small rocky bodies from the inner Solar System to far-flung orbits at great distances from the Sun. In particular, these models suggest that the Kuiper Belt—a cold region beyond the orbit of Neptune—should contain a small fraction of rocky bodies from the inner Solar System, such as carbon-rich asteroids, referred to as carbonaceous asteroids.

Now, a recent paper has presented evidence for the first reliably-observed carbonaceous asteroid in the Kuiper Belt, providing strong support for these theoretical models of our Solar System’s troubled youth. After painstaking measurements from multiple instruments at ESO’s Very Large Telescope (VLT), a small team of astronomers led by Tom Seccull of Queen’s University Belfast in the UK was able to measure the composition of the anomalous Kuiper Belt Object 2004 EW95, and thus determine that it is a carbonaceous asteroid. This suggests that it originally formed in the inner Solar System and must have since migrated outwards.

The peculiar nature of 2004 EW95 first came to light during routine observations with the NASA/ESA Hubble Space Telescope by Wesley Fraser, an astronomer from Queen’s University Belfast who was also a member of the team behind this discovery. The asteroid’s reflectance spectrum—the specific pattern of wavelengths of light reflected from an object—was different to that of similar small Kuiper Belt Objects (KBOs), which typically have uninteresting, featureless spectra that reveal little information about their composition.

“The reflectance spectrum of 2004 EW95 was clearly distinct from the other observed outer Solar System objects,” explains lead author Seccull. “It looked enough of a weirdo for us to take a closer look.”

The team observed 2004 EW95 with the X-Shooter and FORS2 instruments on the VLT. The sensitivity of these spectrographs allowed the team to obtain more detailed measurements of the pattern of light reflected from the asteroid and thus infer its composition.

However, even with the impressive light-collecting power of the VLT, 2004 EW95 was still difficult to observe. Though the object is 300 kilometres across, it is currently a colossal four billion kilometres from Earth, making gathering data from its dark, carbon-rich surface a demanding scientific challenge.

“It’s like observing a giant mountain of coal against the pitch-black canvas of the night sky,” says co-author Thomas Puzia from the Pontificia Universidad Católica de Chile.

“Not only is 2004 EW95 moving, it’s also very faint,” adds Seccull. “We had to use a pretty advanced data processing technique to get as much out of the data as possible.”

Two features of the object’s spectra were particularly eye-catching and corresponded to the presence of ferric oxides and phyllosilicates. The presence of these materials had never before been confirmed in a KBO, and they strongly suggest that 2004 EW95 formed in the inner Solar System.

Seccull concludes: “Given 2004 EW95’s present-day abode in the icy outer reaches of the Solar System, this implies that it has been flung out into its present orbit by a migratory planet in the early days of the Solar System.”

“While there have been previous reports of other ‘atypical’ Kuiper Belt Object spectra, none were confirmed to this level of quality,” comments Olivier Hainaut, an ESO astronomer who was not part of the team. “The discovery of a carbonaceous asteroid in the Kuiper Belt is a key verification of one of the fundamental predictions of dynamical models of the early Solar System.”

There Is Evidence That a Planet in Our Solar System Was Destroyed

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According to Live Science

This long-lost planet would have existed at the very start of our solar system, billions of years ago. Shown here, an artist’s illustration of a baby solar system forming, with a ring of debris around a young star.

Credit: NASA/JPL-Caltech

An asteroid that slammed into the Sudan desert on Oct. 7, 2008, shot out lots of little space rocks holding a precious secret: diamonds that likely formed billions of years ago inside the embryo of a now-decimated planet.
That lost planet was the size of Mercury or perhaps Mars, researchers now say.
In the space rocks, which are also called meteorites, researchers found compounds common to diamonds on Earth, such as chromite, phosphate and iron-nickel sulfides. It’s the first time these diamond components have been found in an extraterrestrial body, the researchers said in a new study describing the findings. [See Photos of Meteorites Discovered Around the World]
The finding provides more information on the early days of our solar system about 4.4 billion years ago, when the zone near the sun had several planetary embryos. Many of them coalesced into the planets we see today. Others fell into the sun or were ejected into interstellar space.

Diamond inclusions appear blue in this colorized scanning transmission electron microscope image of Almahata Sitta meteorite No. 15.

Credit: Dr. F. Nabiei/Dr. E. Oveisi/Prof. C. Hébert, EPFL, Switzerland

The meteorites were formed after an asteroid slammed into Earth’s atmosphere — making it technically a meteor — exploding 23 miles (37 kilometers) above the Nubian Desert in Sudan. The explosion from the 13-foot-wide (4 meters) body shot fragments all over the desert below. Researchers picked up 50 of these pieces, which ranged in size from 0.4 to 4 inches (1 to 10 centimeters).
(An asteroid is a space rock, a meteor is a space rock burning up in Earth’s atmosphere, and a meteorite is the leftover fragment that reaches Earth after a meteor comes through the atmosphere.)
Researchers collected these tiny meteorites into a collection called “Almahata Sitta”; this is the Arabic word for “Station Six,” a train station nearby the meteorite fall and between Wadi Halfa and Khartoum. After collecting the tiny meteorites, researchers discovered nano-size diamonds inside them. But at first, the origins of the diamonds eluded researchers.

The black “rock” is an Almahata Sitta meteorite found in the Nubian Desert in northern Sudan.

Credit: Peter Jenniskens (SETI Institute/NASA Ames)

Nanodiamonds can form from “normal” static pressure inside a large parent body like Earth, but there are other origin theories as well. High-energy collisions between worlds in space can leave such diamonds behind, as can deposition by chemical vapor,according to a statement from the Federal Polytechnic School of Lausanne in Switzerland.
The new study, however, revealed that the diamonds in the meteorite could form only under pressures higher than 20 gigapascals. This is an extremely high form of pressure that humans can generate with certain explosives.
“This level of internal pressure can only be explained if the planetary parent body was a Mercury- to Mars-sized planetary ’embryo,’ depending on the layer in which the diamonds were formed,” the researchers said in a statement from the Federal Polytechnic School of Lausanne in Switzerland. Farhang Nabiei, a doctoral student at the institution, led the research.
That planetary embryo would have then been destroyed through violent collisions, the researchers noted.
The research was published online yesterday (April 17) in the journal Nature Communications.

Moon rocks reveal that we were very wrong about the age of the Moon

Thanks to rocks collected during the Apollo 14 mission, researchers say they’ve finally pinpointed the exact age of the Moon, and it turns out, our lunar neighbour is an incredible 4.51 billion years old.

These findings suggest that the Moon was formed roughly 60 million years after the Solar System first formed, making it up to 140 million years older than previous estimates.

“Establishing the age of the Moon is critical to understanding Solar System evolution and the formation of rocky planets, including Earth. However, despite its importance, the age of the Moon has never been accurately determined,” reports the team, led by Melanie Barboni from the University of California, Los Angeles.

In case you need a refresher, the Moon is thought to have formed from the leftover matter that was sheared off Earth after a collision with Theia – a planet-sized object that existed in the early Solar System – or perhaps a bunch of smaller objects.

The impact that formed the Moon could have been large enough to wipe out any living thing on Earth, so knowing when that collision occurred is important if we hope to understand the evolution of our own planet, and when early life took root here.

And the new research suggests that it happened earlier in the timeline of the Solar System than we thought – just 60 million years after our star system’s birth, compared to previous estimates of 150 to 200 million years afterwards.

To come up with the new lunar age estimate, the team analysed Moon rocks taken from the lunar surface during the Apollo 14 mission.

The reason we’ve never been able to accurately date the age of the Moon in the past is that there’s very few well-preserved Moon rocks left on its surface.

Most of the rocks brought back by Apollo astronauts are breccias – mixes of different rocks that have been mashed together by the meteorite strikes that plague the Moon, thanks to its lack of atmosphere.

So instead of trying to find chunks of rock that had been there since the early days, the team instead turned to zircon – a mineral that would have formed as the Moon was cooling from its fresh, molten state into the rocky satellite we see today.

Once formed, zircon crystals stay perfectly intact as little time signatures of geological events. Studying zircon allows researchers to see when parts of the rock solidified, which is exactly what they needed to figure out when the Moon had fully formed.

“This mineral is just the king when you try to understand any processes, because it is amazingly sturdy,” Barboni told Loren Grush at The Verge.

The team performed a process known as uranium-lead dating on zircon samples that were extracted from the Apollo 14 space rocks.

This required them to liquefy the zircon samples in acid, destroying the space rock artefacts.

But inside the zircon, the team was able to pull out four different elements: uranium, lead, lutetium, and hafnium.

Since uranium – a radioactive element – eventually turns into lead after long periods of time, the researchers could analyse how long the lead had been forming, giving them an accurate date of the Moon’s birth.

The ratios of lutetium and hafnium in the zircon also indicated how long the mineral had been around for.

Combining these analytical techniques, the team found that the Moon is 4.51 billion years old, making it far older than we previously thought, and providing us with a more accurate picture of how our Solar System formed.

“The evolution of Earth could only have started after this impact,” Barboni told The Verge. “And that’s why it’s so important to date this impact, because you want to know when Earth started to evolve into the beautiful planet we all know today.”

While the new measurement is the most precise to date, some outside researchers have said that the act of dissolving the zircon in acid might have changed some of the results slightly, but Barboni says they accounted for these concerns.

“We were able to correct for everything that was a problem before, the reasons people said zircon couldn’t be used,” she told Mike Wall at Space.com.

Hopefully, as these measurements become more and more precise, we will gain a full understanding of how the Moon – and the rest of the Solar System – formed, giving us more details about life on Earth, and the possibility of life on other planets.

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This article was originally posted on ScienceAlert

by JOSH HRALA

NASA is sending a probe to a bizarre metallic world

NASA has green-lit a plan to send a probe to a strange metal asteroid called 16 Psyche, which experts think could be the core of an ancient planet, stripped bare of its original surface and outer crust.

16 Psyche, which sits in the asteroid belt between Mars and Jupiter, is unlike anything else in our Solar System, and that means it could have plenty to reveal to researchers about how the earliest planets orbiting the Sun formed.

A team from Arizona State University led by planetary scientist Lindy Elkins-Tanton proposed the mission in 2015, and now it’s been confirmed by NASA – meaning the Psyche probe could be on its way into space as early as 2023.

“This is an opportunity to explore a new type of world – not one of rock or ice, but of metal,” says Elkins-Tanton. “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.”

In other words, the mission could help tell us what Earth’s core is like, without the need to drill down thousands of kilometres into our own planet.

We’ve known about 16 Psyche since 1852, but this is the first opportunity where we’ll get a close look at it. Measuring more than 200 kilometres (124 miles) in diameter, indications are that it’s mostly made up of iron and nickel.

Scientists think 16 Psyche could’ve once been a planet the size of Mars, but that a series of violent collisions with other objects in the Solar System whittled it down to just its core.

What’s more, it could’ve been around in the very earliest days of the Solar System, just 10 million years after the birth of the Sun, and so could hold clues about how the planets evolved and formed their layers more than four billion years ago.

After zooming past Mars, the uncrewed Psyche probe should reach the metal asteroid that it shares a name with by 2030. From there it will spend 20 months in orbit, taking snaps of 16 Psyche, and measuring its composition, plus the strength and gravity of its magnetic field.

Part of what makes the Psyche mission so exciting is that we know so little about the asteroid right now. Just last year, observations from the NASA Infrared Telescope suggested that water or hydroxyl could be present on the surface of 16 Psyche, something the probe should be able to confirm.

And it’s not the only mission NASA has just approved as part of its Discovery Program, funding lower-cost explorations of the Solar System: another mission, called Lucy, will visit six Trojan asteroids – space rocks caught in Jupiter’s gravitational pull.

As with Psyche, the aim is to learn more about the early days of our Solar System and the way it was formed. Lucy is going to launch first, setting off in 2021, and should reach its first destination in 2025.

“This is what Discovery Program missions are all about,” says NASA’s Thomas Zurbuchen. “Boldly going to places we’ve never been to enable groundbreaking science.”

Video Via NASA

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By DAVID NIELD

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