February 11th 2017 Penumbral Lunar Eclipse

An eclipse of the moon can only happen at full moon, when the Sun, Earth and moon line up, with Earth in the middle. There are three kinds of lunar eclipses: Total, Partial and Penumbral – At such times, Earth’s shadow falls on the moon creating a lunar eclipse. Lunar eclipse(s) develop at a minimum of two times – to a maximum of five times per year.

In a total eclipse of the moon, the inner part of Earth’s shadow, called the umbra, falls on the moon’s face. At mid-eclipse, the entire moon is in shadow, which mostly appear as shades of gray, and on occasion will appear as shades of reddish/gray.

In a partial lunar eclipse, the umbra appears to take a swath out of a circumference of the moon. The darken shadow grows larger, and then recedes, never reaching the total phase.

In a penumbral lunar eclipse, the diminished outer shadow of Earth falls on the moon’s face. This third kind of eclipse is more subtle and difficult to observe. It is absent of the darker shadow as in a partial eclipse. This eclipse stops short of presenting the dramatic minutes of totality. For those using simple field binoculars or moderate telescopes will be able to witness the transition. If there are clear skies and at the right geographical locations, you will be able to see the event with the naked eye.

NASA astrophysicist Fred Espenak, tells us about 35% of all eclipses are penumbral. Another 30% are partial eclipses, where it appears as if a darkened scoop has been taken out of the moon. And the final 35% go all the way to becoming total eclipses of the moon, a glorious event.

BREAKING NEWS: New Findings Illustrate Secondary Extended Solar Cycles Far Greater Danger than Previously Known

Based on a new study, space scientists at the University of Reading are predicting we are witness to the beginning of a longer-term solar cycle, which will exceed the better-known 11 year and 22 year cycles. Each cycle consist of a ‘solar minimum’ and ‘solar maximum’ measured by the number of sunspots during these periods – and the waxing and waning of charged particles produced by solar flares, coronal mass ejections, coronal holes, and charged filaments.

This research is produced by Dr Mathew Owens, from the University of Reading’s Meteorology department, and Co-author Professor Mike Lockwood FRS, University of Reading. Their paper was published in the journal ‘Scientific Reports’. “The magnetic activity of the Sun ebbs and flows in predictable cycles, but there is also evidence that it is due to plummet, possibly by the largest amount for 300 years”; said Owens.

As the Sun becomes less active, sunspots and coronal ejections will become less frequent. As this trend continues over time, the escalating reduction in solar wind has a direct causal effect on the layers of the Sun’s atmosphere. The most significant effect will be on the ‘heliosphere’ – which like Earth’s magnetic field, shields the Earth dangerous charged particles and radiation.

**I am working on the completion of this study – hope to have it published tomorrow. STAY TUNED…..

Moon Periodically Showered with Oxygen Ions from Earth

A team of researchers affiliated with several institutions in Japan, examining data from that country’s moon-orbiting Kaguya spacecraft, has found evidence of oxygen from Earth’s atmosphere making its way to the surface of the moon for a few days every month. In their paper published in the journal Nature Astronomy, the researchers describe what data from the spacecraft revealed.

Scientists have known for some time that the moon is constantly bombarded with particles from the solar wind and have also known that once a month, as the Earth is positioned between the Sun and moon, the moon is protected from the solar wind. In this new effort, the researchers describe evidence of oxygen ion transport from Earth’s outer atmosphere to the lunar surface during this short periodic time- period.

Prior research has shown that oxygen atoms become ionized in Earth’s upper atmosphere when they are struck by ultraviolet light. Sometimes, this causes them to speed up to the point that they break away from the atmosphere and move into what is known as the magnetosphere, a cocoon that surrounds our planet that is stretched like a flag away from the direction of the Sun due to the solar wind—so far, in fact, that it covers the moon for five days each lunar cycle, causing the moon to be bombarded with a variety of ions. Data from Kaguya now suggests that some of those ions are oxygen. The researchers found that approximately 26,000 oxygen ions per second hit every square centimeter of the moon’s surface during the deluge.

Because the moon is protected from the solar wind by the Earth when the increase in oxygen ions was recorded, the researchers are confident they come from the Earth. Adding even more credence is that the ions were found to be moving slower than those that normally arrive via the solar wind. Also, they note, prior research has found lunar soil samples containing some degree of oxygen-17 and oxygen-18 isotopes, which are not typically found in space, but are found in the ozone layer covering Earth.

Fermi Sees Gamma Rays from ‘Hidden’ Solar Flares

An international science team says NASA’s Fermi Gamma-ray Space Telescope has observed high-energy light from solar eruptions located on the far side of the Sun, which should block direct light from these events. This apparent paradox is providing solar scientists with a unique tool for exploring how charged particles are accelerated to nearly the speed of light and move across the Sun during solar flares.

“Fermi is seeing gamma rays from the side of the Sun we’re facing, but the emission is produced by streams of particles blasted out of solar flares on the far side of the Sun,” said Nicola Omodei, a researcher at Stanford University in California. “These particles must travel some 300,000 miles within about five minutes of the eruption to produce this light.”

Omodei presented the findings on Monday, Jan. 30, at the American Physical Society meeting in Washington, and a paper describing the results will be published online in The Astrophysical Journal on Jan. 31.

Fermi has doubled the number of these rare events, called behind-the-limb flares, since it began scanning the sky in 2008. Its Large Area Telescope (LAT) has captured gamma rays with energies reaching 3 billion electron volts, some 30 times greater than the most energetic light previously associated with these “hidden” flares.

Thanks to NASA’s Solar Terrestrial Relations Observatory (STEREO) spacecraft, which were monitoring the solar far side when the eruptions occurred, the Fermi events mark the first time scientists have direct imaging of beyond-the-limb solar flares associated with high-energy gamma rays.

“Observations by Fermi’s LAT continue to have a significant impact on the solar physics community in their own right, but the addition of STEREO observations provides extremely valuable information of how they mesh with the big picture of solar activity,” said Melissa Pesce-Rollins, a researcher at the National Institute of Nuclear Physics in Pisa, Italy, and a co-author of the paper.

The hidden flares occurred Oct. 11, 2013, and Jan. 6 and Sept. 1, 2014. All three events were associated with fast coronal mass ejections (CMEs), where billion-ton clouds of solar plasma were launched into space. The CME from the most recent event was moving at nearly 5 million miles an hour as it left the Sun. Researchers suspect particles accelerated at the leading edge of the CMEs were responsible for the gamma-ray emission.

Large magnetic field structures can connect the acceleration site with distant part of the solar surface. Because charged particles must remain attached to magnetic field lines, the research team thinks particles accelerated at the CME traveled to the Sun’s visible side along magnetic field lines connecting both locations. As the particles impacted the surface, they generated gamma-ray emission through a variety of processes. One prominent mechanism is thought to be proton collisions that result in a particle called a pion, which quickly decays into gamma rays.

In its first eight years, Fermi has detected high-energy emission from more than 40 solar flares. More than half of these are ranked as moderate, or M class, events. In 2012, Fermi caught the highest-energy emission ever detected from the Sun during a powerful X-class flare, from which the LAT detected high­energy gamma rays for more than 20 record-setting hours.

New Space Weather Model Helps Simulate Magnetic Structure of Solar Storms

The dynamic space environment that surrounds Earth – the space our astronauts and spacecraft travel through – can be rattled by huge solar eruptions from the Sun, which spew giant clouds of magnetic energy and plasma, a hot gas of electrically charged particles, out into space. The magnetic field of these solar eruptions are difficult to predict and can interact with Earth’s magnetic fields, causing space weather effects.

VIDEO – CLICK HERE

A new tool called EEGGL – short for the Eruptive Event Generator (Gibson and Low) and pronounced “eagle” – helps map out the paths of these magnetically structured clouds, called coronal mass ejections or CMEs, before they reach Earth. EEGGL is part of a much larger new model of the corona, the Sun’s outer atmosphere, and interplanetary space, developed by a team at the University of Michigan. Built to simulate solar storms, EEGGL helps NASA study how a CME might travel through space to Earth and what magnetic configuration it will have when it arrives. The model is hosted by the Community Coordinated Modeling Center, or CCMC, at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The new model is known as a “first principles” model because its calculations are based on the fundamental physics theory that describes the event – in this case, the plasma properties and magnetic free energy, or electromagnetics, guiding a CME’s movement through space.

Such computer models can help researchers better understand how the Sun will affect near-Earth space, and potentially improve our ability to predict space weather, as is done by the U.S. National Oceanic and Atmospheric Administration.

Taking into account the magnetic structure of a CME from its initiation at the Sun could mark a big step in CME modeling; various other models initiate CMEs solely based on the kinematic properties, that is, the mass and initial velocity inferred from spacecraft observations. Incorporating the magnetic properties at CME initiation may give scientists a better idea of a CME’s magnetic structure and ultimately, how this structure influences the CME’s path through space and interaction with Earth’s magnetic fields – an important piece to the puzzle of the Sun’s dynamic behavior.

The model begins with real spacecraft observations of a CME, including the eruption’s initial speed and location on the Sun, and then projects how the CME could travel based on the fundamental laws of electromagnetics. Ultimately, it returns a series of synthetic images, which look similar to those produced of actual observations from NASA and ESA’s SOHO or NASA’s STEREO, simulating the CME’s propagation through space.

A team led by Tamas Gombosi at the University of Michigan’s Department of Climate and Space Sciences and Engineering developed the model as part of its Space Weather Modeling Framework, which is also hosted at the CCMC. All of the CCMC’s space weather models are available for use and study by researchers and the public through runs on request. In addition, EEGGL, and the model it supports, is the first “first principles” model to simulate CMEs including their magnetic structure open to the public.

ALMA Starts Observing the Sun – VIDEO

Astronomers have harnessed ALMA‘s capabilities to image the millimeter-wavelength light emitted by the Sun’s chromosphere – the region that lies just above the photosphere, which forms the visible surface of the Sun. The solar campaign team, an international group of astronomers with members from Europe, North America and East Asia, produced the images as a demonstration of ALMA’s ability to study solar activity at longer wavelengths of light than are typically available to solar observatories on Earth.   Atacama Large Millimeter/submillimeter Array (ALMA)

Astronomers have studied the Sun and probed its dynamic surface and energetic atmosphere in many ways through the centuries. But, to achieve a fuller understanding, astronomers need to study it across the entire electromagnetic spectrum, including the millimeter and submillimeter portion that ALMA can observe.

       

Since the Sun is many billions of times brighter than the faint objects ALMA typically observes, the ALMA antennas were specially designed to allow them to image the Sun in exquisite detail using the technique of radio interferometry – and avoid damage from the intense heat of the focused sunlight. The result of this work is a series of images that demonstrate ALMA’s unique vision and ability to study our Sun.The data from the solar observing campaign are being released this week to the worldwide astronomical community for further study and analysis.

The team observed an enormous sunspot at wavelengths of 1.25 millimeters and 3 millimeters using two of ALMA’s receiver bands. The images reveal differences in temperature between parts of the Sun’s chromosphere. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed in the future using ALMA.Sunspots are transient features that occur in regions where the Sun’s magnetic field is extremely concentrated and powerful. They are lower in temperature than the surrounding regions, which is why they appear relatively dark.

The difference in appearance between the two images is due to the different wavelengths of emitted light being observed. Observations at shorter wavelengths are able to probe deeper into the Sun, meaning the 1.25 millimeter images show a layer of the chromosphere that is deeper, and therefore closer to the photosphere, than those made at a wavelength of 3 millimeters.

ALMA is the first facility where ESO is a partner that allows astronomers to study the nearest star, our own Sun. All other existing and past ESO facilities need to be protected from the intense solar radiation to avoid damage. The new ALMA capabilities will expand the ESO community to include solar astronomers.

Realistic Solar Corona Loops Simulated In Lab

Caltech applied physicists have experimentally simulated the Sun’s magnetic fields to create a realistic coronal loop in a lab.

solar-loop

Coronal loops are arches of plasma that erupt from the surface of the Sun following along magnetic field lines. Because plasma is an ionized gas—that is, a gas of free-flowing electrons and ions—it is an excellent conductor of electricity. As such, solar corona loops are guided and shaped by the Sun’s magnetic field.

The Earth’s magnetic field acts as a shield that protects humans from the strong X-rays and energized particles emitted by the eruptions, but communications satellites orbit outside this shield field and therefore remain vulnerable. In March 1989, a particularly large flare unleashed a blast of charged particles that temporarily knocked out one of the National Oceanic and Atmospheric Administration’s geostationary operational environmental satellites that monitor the earth’s weather; caused a sensor problem on the space shuttle Discovery; and tripped circuit breakers on Hydro-Québec’s power grid, which caused a major blackout in the province of Quebec, Canada, for nine hours.

“This potential for causing havoc—which only increases the more humanity relies on satellites for communications, weather forecasting, and keeping track of resources—makes understanding how these solar events work critically important,” says Paul Bellan, professor of applied physics in the Division of Engineering and Applied Science.

Although simulated coronal loops have been created in labs before, this latest attempt incorporated a magnetic strapping field that binds the loop to the Sun’s surface. Think of a strapping field like the metal hoops on the outside of a wooden barrel. While the slats of the barrel are continually under pressure pushing outward, the metal hoops sit perpendicularly to the slats and hold the barrel together.

The strength of this strapping field diminishes with distance from the Sun. This means that when close to the solar surface, the loops are clamped down tightly by the strapping field but then can break loose and blast away if they rise to a certain altitude where the strapping field is weaker. These eruptions are known as solar flares and coronal mass ejections (CMEs).

CMEs are rope-like discharges of hot plasma that accelerate away from the Sun’s surface at speeds of more than a million miles per hour. These eruptions are capable of releasing energy equivalent to 1 billion megatons of TNT, making them potentially the most powerful explosions in the solar system. (CMEs are not to be confused with solar flares, which often occur as part of the same event. Solar flares are bursts of light and energy, while CMEs are blasts of particles embedded in a magnetic field.)

The simulated loops and strapping fields provide new insight into how energy is stored in the solar corona and then released suddenly. Bellan worked with Caltech graduate student Bao Ha (MS ’10, PhD ’16) to create the strapping field and coronal loop. The results of their experiments were published in the journal Geophysical Research Letters on September 17, 2016.

Bellan and his colleagues have been working on laboratory-scale simulations of solar corona phenomena for two decades. In the lab, the team generates ropes of plasma in a 1.5-meter-long vacuum chamber.

“Studying coronal mass ejections is challenging, since humans do not know how and when the Sun will erupt. But laboratory experiments permit the control of eruption parameters and enable the systematic explorations of eruption dynamics,” says Ha, lead author of the GRL paper. “While experiments with the same eruption parameters are easily reproducible, the loop dynamics vary depending on the configuration of the strapping magnetic field.”

Simulating a strapping field with strength that fades over the relatively short length of the vacuum chamber proved difficult, Bellan says. In order to make it work, Ha and Bellan had to engineer electromagnetic coils that produce the strapping field inside the chamber itself.

After more than three years of design, fabrication, and testing, Bellan and Ha were able to create a strapping field that peaks in strength about 10 centimeters away from where the plasma loop forms, then dies off a short distance farther down the vacuum chamber.

The arrangement allows Bellan and Ha to watch the plasma loop slowly grow in size, then reach a critical point and fire off to the far end of the chamber.

Next, Bellan plans to measure the magnetic field inside the erupting loop and also study the waves that are emitted when plasmas break apart.