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The solar system’s current planetary orbits seem stable, but that’s only because the planets have settled into them over billions of years.  The early solar system was a much different place than that seen today, and for almost 20 years, scientists thought they had a good handle on how it got that way.  But more recently, data had started pointing to some flaws in that understanding – especially about how the giant planets in the outer solar system got where they are today.  Now an international team of astrophysicists thinks they have a better understanding of that process, and they believe it could help solve a long-standing argument about the early solar system.

Currently, the best model scientists have for the formation of the solar system is known as the Nice model, after the town in France, where it was first developed in 2005.  As part of this model, the gas giants that currently reside in the outer fringes of this solar system originally orbited what became the sun much more closely with more circular orbits. However, something caused instability in the system that kicked those planets out into the much more unevenly spaced and oblong orbits we see them in today.

What exactly caused that anomaly has thus far been a mystery. However, a team comprised of researchers from Michigan State University, Zhejiang University, and the University of Bordeaux think they have an answer.  It’s as simple as dust in the (solar) wind.

Our new paper in @Nature re-interprets a key event in Solar System history: the giant planet instability

“Early Solar System instability triggered by dispersal of the gaseous disk”
by @beibeiliu, @sethajacobson and myself.

A thread…https://t.co/ukR1kcQgxX

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— Sean Raymond (@sraymond_astro) April 27, 2022

In the early solar system, the gas giants sat in a dusty cloud around the nascent sun in nearly circular orbits.  When the sun ignited, it began to blow the dust in the circumstellar disc away.  Some of that dust happened to blow past the orbit or the gas giants, causing the instability that the Nice model sees.

However, how the researchers fleshed out the idea also solves some problems the Nice model had.  One major one was data, such as that collected from moon samples, pointed to a much quicker path to this instability that was typically found in the original Nice model.  With this updated “inside-out” dust cloud evaporation model, that instability’s laborious path of hundreds of millions of years is condensed down to a timeline of a few million years, which matches much better with the existing data.

That’s not the only data it matches well with, however.  The Nice model itself is partially controversial for pointing to a potential ninth planet in the early solar system – and it doesn’t mean Pluto.  A favorite of many a conspiratorial skywatcher, Planet 9 (or Planet X) has been garnering more and more attention after a Caltech study in 2015 found there might be something huge lurking around 50 billion miles away from the Sun.  

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Author Sean Raymond of the University of Bordeaux demonstrates how dispersion can have a massive effect on the surrounding material.
Credit – Sean Raymond / MSU

The original Nice model actually works better with five gas giant inner planets, but in those calculations, one of those planets is ejected out into interstellar space to become a rogue planet. In the updated model, the outcome of the planetary orbital alignment is essentially the same whether there are four or five starting gas giants in the system.  However, they do match reality slightly better if there are only four planets initially introduced into the model.

As with much theory, this new model could potentially impact our understanding of the formation of the early solar system and could resolve a long-standing argument over what the original trigger of the instability that so shaped our planetary neighbors was.  But ultimately, even this new model will have to hold up to the data, and that is plenty more to collect before the true story of our early solar system is clear.

Learn More:
MSU – The instability at the beginning of the solar system
Nature – Early Solar System instability triggered by dispersal of the gaseous disk
UT – Rings in the Early Solar System Kept our Planet From Becoming a
Did you miss our previous article…
https://www.mansbrand.com/scouring-through-old-hubble-images-turned-up-1000-new-asteroids/

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Advanced Optics Could Help Us Find Earth 2.0

DUET Deployment

NASA has long been interested in building bigger and better space telescopes. Its Institute for Advanced Concepts (NIAC) has funded several methods for building and deploying novel types of telescopes for various purposes. Back in 2019, one of the projects they funded was the Dual Use Exoplanet Telescope (DUET), which would use an advanced form of optics to track down a potential Earth 2.0.

So far, the largest telescope launched into space is JWST, with a 6.5m primary mirror. However, even with that big of a mirror, it is difficult to differentiate exoplanets from their stars, which may be only a few milliarcseconds away from each other. Larger telescopes on the ground have slightly higher resolutions, but they suffer from other limitations, such as atmospheric distortion and cloud cover.

A larger telescope in space would solve many of those problems, but launching one that is simply a larger version of JWST is prohibitively expensive or just plain prohibited, depending on whether it would fit in a rocket fairing. Even Starship and other next-generation launch systems couldn’t fit a 10 m assembled primary mirror.

PI Tom Ditto gives a talk at the SETI Institute about the DUET telescope.
Credit – SETI Institute YouTube Channel

So, researchers have started to turn to alternative optical techniques that could solve this problem. One commonly known optical phenomenon is diffraction. The best-known example is the famous “slit” experiment that many kids perform in physics class. Light bends when going around an edge, and engineers can take that principle, scale it up, and build something that bends the light from far-away stars.

That is the underlying principle of DUET – it uses a technique called primary objective grating (POG) to focus specific wavelengths that might be of interest – for example, that wavelength that would show oxygen in an exoplanet’s atmosphere. In particular, DUET uses a type of POG that results in a circular spectrogram. Although this idea is novel in astronomy, it has been used in other fields. Tom Ditto, the PI on the project, was originally an artist before converting into a technologist focusing on optics.

With the NIAC Phase I funding, Ditto and his team developed a bench-top experiment that proved the technology underlying DUET. It consists of a slatted first data collection stage that focuses the light from a star of interest on a secondary stage and, thereby, a collector, which captures the data that could be translated into a circular spectrograph. 

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Graphic of deployment of the slits in the outer primary of the DUET telescope.
Credit – Ditto et al.

In particular, the researchers were interested in UV light, as Earth would appear like a bright candle from far away, at least compared to light in other spectra. They tested a violet laser on their bench setup and analyzed the resulting circular spectrograph. It showed great promise for detecting something with a spectrum like Earth’s from very far away.

But there are still hurdles to overcome. One of the bigger concerns was the efficiency of the grating structure used in the experiments. Its 20% efficiency would make it barely feasible to detect the kind of faint objects the telescope is designed for. The deployment mechanism for the grating, which requires the assistance of additional spacecraft separate from the telescope itself, would also be a challenge.

How would we build large telescopes in space? Fraser explains.

That’s where the experiment stands, as NASA has not elected to support the project with a Phase II grant so far. Given the history of exoplanet discovery, it’s only a matter of time before we find Earth 2.0. What technology we will use to do so is up in the air.

Learn more:
Ditto et al. – DUET The Dual Use Exoplanet Telescope
UT – Building Space Telescopes… In Space
UT – Future Space Telescopes Could be 100 Meters Across, Constructed in Space, and Then Bent Into a Precise Shape
UT – Using Smart Materials To Deploy A Dark Age Explorer

Lead Image:
Graphic of the DUET Space Telescope Fully Deployed.
Credit – Ditto et al.

The post Advanced Optics Could Help Us Find Earth 2.0 appeared first on Universe Today.

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Satellites are Going to Track Garbage Drifting Across the Oceans

Eastern Mediterranean Sea Area June 1993

We are all too aware of the pollution on planet Earth. There are increased amounts of plastic and garbage on the world’s beaches and debris littering the oceans. Until now, it was thought that satellites weren’t capable of tracking marine debris but a supercomputer algorithm challenges that. 300,000 images were taken every three days at a resolution of 10 metres and were able to identify large concentrations of debris. 

Upper estimates of plastic in our oceans peak at around 200 million tons! Every day it is believed another 8 million pieces of plastic make their way into the marine environment. Now, a study led by a team at the Institut de Ciencies del Mar at the University of Cadiz believe it may be possible to study and track the surface debris in the oceans. Using supercomputers and advanced algorithms, the team have shown that satellites can indeed be used.

Using data from the European Copernicus Sentinel-2 satellite, a total of 300,000 images of the Mediterranean Sea were analysed. The images were taken every 3 days at a resolution of 10 metres. Typically of course, there is not much debris in the sea which is that big but accumulations of debris have grown to that size. The aggregations are known as ‘windrows’ and have built up as ocean currents and winds bring debris together to form large structures.

The output from the study reveals the most polluted areas of the Mediterranean and the main entry points from the mainland. It will help us to improve our understanding of the processes and mechanisms that transport debris across the ocean and even help us to perhaps predict movement. The results also show that the amount of debris in the Mediterranean covers around 95 square kilometres.

Eastern Mediterranean Sea Area June 1993
Eastern Mediterranean Sea Area June 1993

Unfortunately the research does not help resolve the issue of pollution but it does help us understand the scale. The team propose future satellites should be equipped with detectors to monitor the debris. It would increase the ability to detect plastic in the open ocean by a factor of 20 and help to model the impact of marine pollution on first, tourism and the marine ecosystem.

One element of the studies conclusion is that population density, geography and rainfall patterns play an important part in the accumulation of marine litter. Dry arid lands like deserts that play host to cities seem to contribute much less to marine litter while those that are much more temperate with higher rainfall seem to contribute more.

It is also interesting to note that the majority of litter that originates from land masses seems to be confined to 15 kilometres form the coast and subsequently returns after a few days of months. The team conclude that satellite based monitoring is an essential element in our battle against litter in the ocean. The technology can also be used for the detection of other floating objects such as the loss of ships, oil spills and even search and rescue elements.

Source : Satellites to monitor marine debris from space

The post Satellites are Going to Track Garbage Drifting Across the Oceans appeared first on Universe Today.

Did you miss our previous article…
https://mansbrand.com/will-space-tourists-be-getting-heart-attacks-in-space/

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Will Space Tourists Be Getting Heart Attacks in Space?

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Astronauts are considered by many to be an elite bunch of people; healthy, fit and capable in many disciplines. Went they travel into space they can face health issues related to weightlessness from reduction in bone density to issues with their eyesight. These are people at the peak of physical fitness but what will happen to the rest of us when space tourism really kicks off. It is likely that anyone with underlying health issues could worsen in space. A new study suggests those with cardiovascular issues may suffer heart failure in space!

Space travel and automatic intelligence (AI) are two fabulously interesting topics. Combine them and you have a fascinating story. Dr Lex Van Loon from the Australian National University has been using AI and mathematical models to explore human physiology and the impact of space exploration. In a recent study he created digitally identical AI twins, one with an underlying heart condition.

The interest driving the study is the advancement toward space tourism and the opening up of space to those less physically fit than astronauts. As space travel becomes more available to the mass population we will start to see a shift in demographic of space travellers to older, more wealthy individuals but they are more likely to have health issues. We will eventually see people with a whole multitude of conditions wanting to holiday in space, but what are the likely impacts. 

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ESA astronaut Alexander Gerst gets a workout on the Advanced Resistive Exercise Device (ARED). Credit: NASA

Microgravity causes a redistribution of fluids around the body and can cause conditions like ‘puffy face bird leg syndrome.’ The name aptly describes the effect, the face swells up and the legs thin. It results in an increase in venous pressure in the upper body, this is fine for healthy people but heart failure sufferers are at a much higher risk. Given that there are over 100 million people around the world that suffer heart failure it is essential this is explored.

Looking at the wide spectrum of heard failure, conditions can be grouped into two categories; a weak hart that cannot pump effectively and a heart that cannot relax and fill properly. All possible conditions need to be studied with specific ways to treat and mitigate the risk during space travel.

This is a study that is difficult to collect real data in space so we have to turn to computer modelling to simulate the effects. The team led by Dr Loon showed that a microgravity environment leads to an increase in cardiac output (the quantity of blood pumped by the heart in a given period of time.) This is not a problem for most people but with heart failure patients it is accompanied by a rise in pressure in the left atrial region of the heart, to dangerous levels. If left unchecked, it can lead to a condition where fluid accumulates in the lungs known as a pulmonary edema, making it difficult to breathe!

With the increase in corporate interest in space travel, space tourism is slowly becoming a reality. People can already pay for trips into space but as costs come down, the number of people heading out into space will increase. Eventually, trips into space will be as common as trips to other countries. It is imperative we understand the impact on our health and what we can do to make space as widely accessible as possible without putting our health at risk.

Source : Heart failure in space: scientists calculate potential health threats facing future space tourists in microgravity

The post Will Space Tourists Be Getting Heart Attacks in Space? appeared first on Universe Today.

Did you miss our previous article…
https://mansbrand.com/astronomers-see-a-black-hole-wake-up-from-its-ancient-slumber/

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