UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Augusto Carballido, Baylor University; Jorge Carmona-Reyes, Baylor University, and Truell Hyde, Baylor University

In 1981, the Voyager 2 space probe took intriguing images of Saturn’s rings as it passed by the giant planet on its way to Uranus.

The images showed what looked like ghostly “spokes” moving on the rings, much like the spokes of a bicycle wheel as it turns. After some head-scratching, scientists realized that the Saturnian spokes most likely were tiny specks of dust moving around the rings due to electric and magnetic forces. These forces result from electrically charged gases known as plasma.

Even though you might not realize it based on our daily experiences, researchers think that 99 percent of the matter in our universe is in a plasma state. Many processes that occur in the universe are due in part to the presence of plasma.

Here on Earth, industry uses techniques that involve manipulating these ionized gases for microchip production, as well as for welding materials such as aluminum. Research facilities study plasma in hope of hitting on an efficient nuclear fusion process for energy production. In all these instances micron-size dust is present – which can be a good or a bad thing, depending.

The presence of dust in plasma makes it tricky to study them in a laboratory setting. Here at Baylor University’s Center for Astrophysics, Space Physics and Engineering Research (CASPER), we’ve built a sophisticated experimental facility to investigate these dusty plasma systems. We hope to answer fundamental questions related to dust-plasma interactions both on Earth and in space, in the process advancing our understanding of physics and astrophysics. Our investigations will allow us to untangle issues like the role of dust buildup in super-high-speed crashes in space, the formation of planets, and even areas belonging to life sciences, such as double-helix molecular interaction.

Solid swimmers in an electrical sea

Dusty plasma, also called complex plasma, contains small, solid particles distributed throughout the ionized gas. These particles can have the shape of a sphere, a rod or an irregular “pancake.” The reason dusty plasma are very interesting, and even technologically valuable, comes down to the fact that the dust particles themselves can become electrically charged.

We can think of dust particles as swimmers in a sea of electrons and ions – negative and positive charges, respectively. Electrons are so tiny compared to the dust that they easily stick to the particles' surfaces. When that happens, a dust particle will become negatively charged.

Because like charges repel each other, that bit of dust will now feel a push from other negatively charged dust particles. Likewise, that same negatively charged dust particle will feel a pull by the positive ions in the plasma, because charges of opposite signs attract each other. The net result is that dust particles will be pushed and pulled in many different directions, making them move in complex and fascinating ways.

Dusty plasma ‘in the wild’

One place to find dusty plasma is in Earth’s atmosphere, where they’re generated when meteoroids enter the atmosphere’s upper layers at speeds of several kilometers per second. Researchers study them with specialized radars that can detect the ball of plasma that forms around the meteroids as they heat up due to friction with the air.

**Photo taken by astronauts of noctilucent clouds in Earth’s atmosphere above the midnight sun (above the blue layer).**
**Credit: NASA**

At high geographic latitudes (between 50° and 70° north and south of the equator) an intriguing phenomenon occurs. Clouds made of tiny ice crystals and dust appear at an altitude of about 80 kilometers during the summer months. Known as noctilucent clouds, they are too thin to be visible in daylight, but they glow before sunrise or after sunset when the sun is below the horizon.

The clouds' icy dust particles are thought to play a role in the chemical composition of the atmosphere at those altitudes. In particular, their presence may be related to depletion of sodium and potassium. And since noctilucent clouds reside in an ionized region of the atmosphere (specifically, the lower ionosphere), their icy dust particles become electrically charged by electrons. These conditions give rise to a variety of electromagnetic phenomenaresearchers are actively investigating.

**Artist’s concept of a comet, with solar wind blowing back the coma into a tail.**
**Credit: NASA, CC BY-ND**

Farther from home, but still within our planetary neighborhood, comets can put on an amazing showthanks to dusty plasma effects. As a comet approaches the sun, the sun’s heat transforms part of the comet’s ice into vapor. This vapor, which contains many tiny dust grains, engulfs the comet nucleus to form a “coma.” The solar wind, which is a plasma made mostly of electrons and protons, pushes the cometary coma away from the sun and forms the spectacular tail with which we are familiar.

Even farther from us still, at distances of hundreds of light-years, dust particles embedded in huge, donut-shaped gas clouds move in orbits around young stars. These disks, known as protoplanetary disks, arewhere planets are formed. Portions of protoplanetary disks may be electrically charged and perhaps threaded by magnetic fields. The dust grains that have been detected in many of these disks are small enough to soak up plasma electrons, and it’s likely that grain charging affects how easily grains can grow to form planet precursors.

**Illustration of a star surrounded by a protoplanetary disk.**
**Credit: NASA/JPL-Caltech, CC BY-ND**

Astronomers detect these dusty plasma in space by capturing the light dust particles re-emit after being illuminated by stars. It requires extremely sophisticated instruments, such as the Hubble Space Telescope. From these observations, one can infer things like the dust size and chemical composition.

Dusty plasma in the lab

From a long distance, we can obtain only a limited amount of information about natural dusty plasma. By carrying out controlled experiments in laboratories, we can learn more about dusty plasma properties. For example, by directly manipulating the amount of ionization, we can control the arrangement of the dust particles. In contrast, at this time it is generally not possible to infer the precise arrangement of dust particles in space from telescopic observations.

To experimentally study dusty plasma, a lab must be capable of producing, confining and manipulating an ionized gas – that is, one that contains electrically charged particles. This is possible here at Baylor’s CASPER, where we use advanced instrumentation to investigate the behavior of dusty plasma. For example, we use an instrument called an inductively driven plasma generator – basically a wind tunnel containing electrically charged gases – to study a plasma’s interaction with lunar dust.

We’re also interested in what happens in the plasma when very fast dust particles collide with different targets. Understanding more about these collisions could help with designing better protection for spacecraft from micrometeorite impacts.

CASPER is one of a very few experimental facilities in the world that has three operating complex plasma cells – the chambers into which different gases can be injected to be ionized. Two are Gaseous Electronics Conference radio-frequency reference cells, a standardized plasma-producing chamber. The third is a custom-built device designed here that allows for the formation of much larger complex plasma systems than normally possible. The laboratory within which these cells reside was built from the ground up specifically for them. It’s a highly stable environment with regard to temperature and vibration, making it possible to produce extremely low-noise systems.

**A typical experimental setup for studying dust structures in plasma.**
**Credit: Truell W. Hyde, Jie Kong and Lorin S. Matthews**

A typical experiment looks like this: a glass box can be placed between two electrodes to create an electric potential that will confine the dust-plasma system. The dust particles, which are made of melamine formaldehyde and have a diameter of less than 9 micrometers (about a thousandth of a centimeter in size), are introduced into the box through a dust shaker. Once the system power is turned on, the electric forces will change the arrangement of the dust particles, which will form linear or helical chains, depending on the amount of power used. Images of the dust structures can be captured by telescopic cameras.

**Top and side views of different dust structures formed in a Gaseous Electronics Conference radio-frequency reference cell.**
**Credit: Truell W. Hyde, Jie Kong and Lorin S. Matthews**

These experiments open a window into the way the universe works, whether we are looking for improved efficiency of industrial processes or trying to understand how our solar system formed.

Augusto Carballido, Assistant Research Professor, Baylor University; Jorge Carmona-Reyes, Assistant Director of Educational Outreach and Research, Center for Astrophysics, Space Physics, and Engineering Research , Baylor University, and Truell Hyde, Professor of Physics and Vice Provost of Research, Baylor University

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Space.com.

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OSIRIS-Rex: Bringing Home Pieces of an Asteroid — **NASA's OSIRIS-Rex mission will map and study the asteroid Bennu before bringing a sample home.**
**Credit: NASA/Goddard/University of Arizona**

In 2023, a bit of the primordial solar system will return to Earth. That's when NASA's OSIRIS-Rex mission will return a sample of the asteroid Bennu, a carbon-rich rock hosting traces of the early solar system. While there, the mission will conduct an in-depth study of the rocky body, learning more about how sunlight can shift its position, before gathering a small sample to return to Earth.

Visiting an asteroid

After its September 8, 2016, launch, the Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-Rex, will spend two years traveling through space to arrive at Bennu in 2018. The second mission in the world to bring back a bit of an asteroid, OSIRIS-Rex will follow in the footsteps of Japan's Hayabusa, which in 2010 became the first spacecraft to bring a bit of an asteroid back to Earth. It will be the first U.S. asteroid sample return mission.

The bits and pieces left over from the formation of the planets, asteroids carry the blueprints of the early solar system. Studying them allows scientists to see what the early solar system was like, and get a handle on how planets formed.

NASA's Dawn mission visited the asteroid Vesta before moving on to the dwarf planet Ceres. In contrast, OSIRIS-Rex will bring home a piece of Bennu for in-depth laboratory studies not possible while orbiting in space. The team hopes to collect at least 2 ounces (60 grams) of material to achieve their scientific goals.

Understanding how asteroids form will not only provide insight about the early solar system, but also help scientists better understand their makeup today. That could be helpful should any space rocks threaten to collide with Earth. It could also assist in future efforts to mine asteroids.

"The mission will develop important technologies for space exploration that will benefit anyone interested in exploring or mining asteroids, whether it's NASA or a private company," Dante Lauretta said in a statement. Lauretta, a planetary scientist at the University of Arizona, Tucson, is the principal investigator for OSIRIS-Rex.

OSIRIS-Rex will also help astronomers study the Yarkovsky effect on asteroids. Heat from the sun provides a tiny push that can affect the movement of an asteroid. Although the push is minimal, it can build over time, helping to change the path a space rock travels. But the effect can be a challenge to study, as it varies based on the shape of each asteroid.

"The knowledge from the mission will help us to develop methods to better track the orbits of asteroids," Jim Green, director of NASA 's Planetary Science Division, said in a statement.

Sampling an asteroid

Once OSIRIS-Rex reaches Bennu, five instruments on board the spacecraft will study, map and analyze the asteroid in unprecedented detail.

OSIRIS-Rex Visible and Infrared Spectrometer (OVIRS) — By measuring visible and near-infrared light, OVIRS will hunt for organics and other minerals.
OSIRIS-Rex Thermal Emission Spectrometer (OTES) — Using the thermal infrared, OTES take Bennu's temperature and map mineral and chemical abundances. Together, OVIRS and OTES will map Bennu over a wave of interesting wavelengths to help select the best site to sample the asteroid.
OSIRIS-Rex Camera Suite (OCAMS) — A three-camera suite will help map Bennu. PolyCam, the largest, will acquire the first images of Bennu from 1.2 million miles (2 million kilometers) and capture high resolution images of the sample site. MapCam will hunt for satellites and dust plumes around the asteroid, map it in color, and take the photographs to create topographic maps. SamCam will document the collection of the sample and its capture.
OSIRIS-Rex Laser Altimeter (OLA) — By scanning the entire surface of Bennu, OLA will create highly accurate 3-D shape models of the asteroid.
Regolith X-ray Imaging Spectrometer (REXIS) — Studying X-ray emissions of Bennu will help provide an elemental abundance map of its surface. Unlike other imaging instruments, REXIS will examine the composition of the asteroid at the level of individual atomic elements.

Once the asteroid has been studied in significant detail, scientists will identify a region to sample. That's where the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) will come into play. As OSIRIS-Rex draws closer to the asteroid, TAGSAM will blast a sample of pure nitrogen gas at the surface. Regolith (dust and broken rock) blasted from the surface will be pushed into the chamber of the sampler.

To complete all of the planned science, OSIRIS-Rex needs to collect at least 2 ounces (60 grams). The goal is to collect 5 ounces (150 g) to account for any errors in measurement. Three bottles of nitrogen gas allow for multiple collection attempts, and TAGSAM can carry as much as 70 ounces (2,000 g). To weigh the sample in the low-gravity environment, scientists will measure the angular acceleration of the spacecraft before and after the sample is collected.

Although OSIRIS-Rex will sample Bennu, it will never actually land on the surface. Contact during the collection process will be brief, lasting only a few seconds.

"We kiss the surface," OSIRIS-Rex principal investigator Mike Drake, of the University of Arizona, told reporters.

After scooping up the sample OSIRIS-Rex will return to Earth, arriving home in 2023.

**NASA's OSIRIS-Rex mission will spend 2 years mapping an asteroid before returning a sample to Earth.**
**Credit: NASA**

Meet Bennu

Originally known as 1999 RQ36, the rock OSIRIS-Rex will visit was renamed Bennu by 9-year-old Mike Puzio in a 2013 contest. Bennu is an Egyptian god usually depicted as a gray heron. Puzio chose the name because he thought TAGSAM and the solar panels resembled the bird god's neck and wings.

Bennu is one of several thousand Near-Earth Objects orbiting within 120 million miles (190 million kilometers) of Earth. Among those, Bennu was one of less than 200 whose orbit was well known and sufficiently Earth-like. It orbits the sun every 436 days, and comes very close to Earth every six years.

It's also relatively large, about 1,650 feet (500 meters) wide. Rocks smaller than 650 feet (200 m) spin too rapidly to allow a spacecraft to safely land on them. Only a handful of the asteroids in appropriate orbits were large enough to allow a visit.

Among those deemed appropriate, the asteroid has just the right composition. Bennu is relatively rich in carbon-based material. The asteroids that may have brought water and organic material to Earth that helped kick off life would look like Bennu.

"We're going for something rich in organics, which might have had something to do with life getting started," Drake said.

"That's the idea — time capsule, containing probably the building blocks of life."

Bennu's close orbit also makes it a potentially hazardous object, but unlike some media reports, it isn't a definite threat. NASA scientists calculated that there is an 0.037 percent (or 1-in-2,700) chance that it will strike Earth in the last quarter of the 22nd century. For that to happen, the asteroid would need to have its orbit altered in its 2135 flyby of Earth. Studying Bennu today will help them further calculate the orbit, potentially ruling it out.

If the asteroid does collide with Earth, it won't destroy the planet, though it will wreak havoc wherever it touches down. Experts say that the size of the asteroid would likely devastate the local area, but won't cause mass extinctions. In order to cause a global catastrophe, a space rock must be at least twice as large, at 0.6 miles (1 km) wide. Still, the advanced warning provided by OSIRIS-Rex could help scientists take preventative measures long before the potential impact.

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