#solar atmosphere

[wayti-blog]

"In a new study published in The Astrophysical Journal, a researcher from The University of Alabama in Huntsville (UAH), a part of the University of Alabama System, explores critical aspects of a phenomenon called kinetic Alfvén waves (KAWs) to provide fresh insights into an age-old heliophysics mystery.

Syed Ayaz, a graduate research assistant at the UAH Center for Space Plasma and Aeronomic Research (CSPAR), examined the potentially pivotal role of KAWs in heating the solar corona, moving science one step closer to solving the puzzle of why the corona is many times hotter than the surface of the sun itself.

"For decades, Alfvén waves have been proven to be the best candidates for transporting energy from one place to another," Ayaz says, noting the potential role of KAWs in driving coronal heat.

"This paper utilizes a novel approach to model energetic particles in space plasmas, as observed by satellites like Viking and Freja, to answer how the electromagnetic energy of the waves, interacting with particles, transforms into heat during the damping process as the waves move through space."

"The corona, or solar atmosphere, is an enigmatic region surrounding our home star that extends far beyond the visible disk of the sun, stretching some 8 million kilometers above the sun's surface. Yet, the corona is also characterized by extraordinarily high temperatures, a mystery that has captivated astrophysicists for nearly seventy years."

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[thepastisalreadywritten]

2 September 2022

Fresh off its success at the moon, India is now headed for the sun.

The nation launched its first-ever solar observatory today (Sept. 2), sending the Aditya-L1 probe skyward atop a Polar Satellite Launch Vehicle (PSLV) from Satish Dhawan Space Centre at 2:20 a.m. EDT (0620 GMT; 11:50 a.m. local India time).

The PSLV deployed Aditya-L1 into low Earth orbit (LEO) as planned about 63 minutes after liftoff, sparking applause and high fives in mission control.

"Congratulations, India, and congratulations, ISRO [the Indian Space Research Organisation]," Jitendra Singh, India's Minister of State for Science and Technology, said shortly after deployment on ISRO's launch webcast.

"While the whole world watched this with bated breath, it is indeed a sunshine moment for India," Singh added.

The successful launch followed on the heels of another big milestone for India: On August 23, its Chandrayaan-3 mission became the first to land softly near the moon's south pole.

Chandrayaan-3's lander-rover duo are expected to conk out in a week or so, when the harsh lunar night falls at their touchdown site. But Aditya-L1's long journey has just begun.

A long road to a good sun-viewing spot

Aditya-L1 won't stay in LEO forever:

After a series of checkouts, it will use its onboard propulsion system to head toward Earth-sun Lagrange Point 1 (L1), a gravitationally stable spot about 1 million miles (1.5 million kilometers) from our planet in the direction of the sun.

That destination explains the latter part of the mission's name. And the first part is simple enough: "Aditya" translates to "sun" in Sanskrit.

The 3,260-pound (1,480 kilograms) observatory will arrive at L1 about four months from now, if all goes according to plan.

But the long trek will be worth it, according to the ISRO.

"A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the sun without any occultation/eclipses," ISRO officials wrote in an Aditya-L1 mission description.

"This will provide a greater advantage of observing the solar activities and its effect on space weather in real time."

Indeed, another sun-studying spacecraft is already at L1 — the Solar and Heliospheric Observatory (SOHO), a joint NASA-European Space Agency mission that launched in December 1995.

(Several other spacecraft, including NASA's James Webb Space Telescope, are at Earth-sun Lagrange Point 2, which is a million miles from Earth, in the direction away from the sun.)

Solar flares, the coronal heating mystery and more

Once it's settled in at L1, the solar probe will use four three science instruments to study the particles and magnetic fields in its immediate surroundings and four others to scrutinize the sun's surface (known as the photosphere) and its atmosphere.

This work will help scientists better understand solar activity, including the dynamics of solar flares and coronal mass ejections (CMEs), ISRO officials say.

Flares are powerful flashes of high-energy radiation, and CMEs are huge eruptions of solar plasma.

Both types of outburst can affect us here on Earth. Intense CMEs that hit our planet, for example, trigger geomagnetic storms that can disrupt satellite navigation and power grids.

(As a side benefit, such storms also supercharge the gorgeous light shows known as auroras.)

Aditya-L1 will also tackle the "coronal heating problem," one of the biggest mysteries in heliophysics.

The corona — the sun's wispy outer atmosphere — is incredibly hot, reaching temperatures around 2 million degrees Fahrenheit (1.1 million degrees Celsius), according to NASA.

That's about 200 times hotter than the solar surface, which is "only" 10,000 degrees F (5,500 degrees C) or so.

It's still unclear what is responsible for this startling and counterintuitive discrepancy.

(Why would it be hotter away from the sun's core, where the energy-producing nuclear fusion reactions are occurring?)

Aditya-L1 has other science goals as well. For instance, the mission also aims to more fully flesh out the solar wind, the stream of charged particles flowing constantly from the sun, ISRO officials said.

Aditya-L1 will measure the composition of the solar wind and attempt to determine how it is accelerated.

And Aditya-L1 will do all this work on the cheap:

The mission's price tag is about 3.8 billion rupees, or $46 million US at current exchange rates.

That's in the same ballpark as Chandrayaan-3

India's first successful moon-landing mission costs about 6.15 billion rupees, or $74 million US.

For comparison, NASA's most recent big-ticket sun mission, the record-setting Parker Solar Probe, costs roughly $1.5 billion.

This disparity should not be viewed as an indictment of NASA, however; labor costs are much higher in the United States than in India, among other differences between the two nations' economies.

Aditya-L1 is a coronagraphy spacecraft to study the solar atmosphere, designed and developed by the Indian Space Research Organisation (ISRO) and various other Indian research institutes.

[gkonboard]

🌞 Prepare to be mesmerized as Aditya-L1, India's remarkable space mission, captures a breathtaking selfie and stunning images of our home planet Earth and the serene Moon! 🚀

ISRO's Aditya-L1 is on a mission like no other, headed for the Sun-Earth L1 point to study the Sun. But it's also treating us to a spectacular visual treat along the way.

[theofficialastronomy101]

Earth is such a beautiful planet

[mindblowingscience]

A severe solar storm sparked by an intense flare from the sun could reach "extreme" levels as it bombards Earth, officials with the U.S. National Oceanic and Atmospheric Administration (NOAA) warned on Thursday (Oct. 10). Scientists with NOAA's Space Weather Prediction Group (SWPC) said that a cloud of charged solar material, called a coronal mass ejection, slammed into Earth around midday, triggering a "severe" geomagnetic storm that could impact power grids and GPS and radio communications systems, as well as amplify aurora displays in regions that typically don't see them.

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[quiltofstars]

Comet C/2023 A3 (Tsuchinshan-ATLAS) hanging above the island of Great Farilhão // Luis Novo

[briery]

An astronaut took this photograph of the Aurora Australis in August 2017. At the time, the International Space Station was moving over the southern Indian Ocean towards the Great Australian Bight and Melbourne, Australia.

[krakenmare]

Perseverance: Drifting clouds just before sunrise on Mars (March 18, 2023)

[simpsforscience]

Sun's not all fire! 🌞 It's got a 4-layer atmosphere of scorching plasma. Corona's the hottest, millions of degrees! Read through to know more about these layers.

[maeamian]

One of my favorite space facts is that Pluto does have an atmosphere but only for another half decade or so.

[tilbageidanmark]

Northern Lights in Alaska

[wayti-blog]

"NOAA today shared the first images from the Compact Coronagraph (CCOR-1), a powerful solar telescope onboard the new GOES-19 satellite. CCOR-1, the world's first operational, space-based coronagraph, began observing the sun's corona, the faint outermost layer of the solar atmosphere, on September 19, 2024."

(Credit: NOAA Headquarters)

"CCOR-1 monitors the corona to forecast coronal mass ejections (CMEs), which are large expulsions of plasma and magnetic fields from the sun that can produce space weather impacts on Earth."

Video

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[ton-618-ton-618]

2024 April 2

The Sun is shown during a total solar eclipse. Accentuated is the expansive corona of the Sun, which is shown streaming out in all directions.

Detailed View of a Solar Eclipse Corona

Image Credit & Copyright: Phil Hart

Explanation: Only in the fleeting darkness of a total solar eclipse is the light of the solar corona easily visible. Normally overwhelmed by the bright solar disk, the expansive corona, the sun's outer atmosphere, is an alluring sight. But the subtle details and extreme ranges in the corona's brightness, although discernible to the eye, are notoriously difficult to photograph. Pictured here, however, using multiple images and digital processing, is a detailed image of the Sun's corona taken during the April 20, 2023 total solar eclipse from Exmouth, Australia. Clearly visible are intricate layers and glowing caustics of an ever changing mixture of hot gas and magnetic fields. Bright looping prominences appear pink just around the Sun's limb. A similar solar corona might be visible through clear skies in a narrow swath across the North America during the total solar eclipse that occurs just six days from today

[unsolicitedadvicecatlady]

1.6 million miles from where you were yesterday

The Earth is spinning at about 1,000 miles per hour. The Earth is orbiting the Sun at about 67,000 miles per hour. The Solar System is being dragged at about 490,000 miles per hour toward the area known as the Great Attractor, a region of space about 150,000,000 light-years away. The Solar System, going almost half a million miles per hour, is in an orbit that will take approximately 230 billion years to complete, going around the Milky Way. We're moving at a rate of approximately 250 miles per second through the Universe.

Our atmosphere has to go with us. The ultimate apocalyptic biohazard is that the Earth stops spinning. If it stops spinning the atmosphere would keep moving, instantaneously ripping everything off of the surface of the Earth, stripping it down to absolutely nothing, taking with it the magnetic field which protects us from the Sun, and the Earth would be instantly incinerated.

Everything in the physical world operates on absolute, fixed laws. Violating those laws has consequences, sometimes deadly. If there was any question about the absolute nature of these laws, the whole thing would crumble. The physical Universe is complex, structured, and perfectly balanced.

We're 1.6 million miles away from where we were yesterday, and all this movement and motion is happening seemingly unnoticed. Life is happening here, now. Isn't it wonderful?

[theofficialastronomy101]

Who loves Autumn????

[quiltofstars]

A Leonid meteor and its plasma tail // Tim McCollum