New Study Proposes a Giant, Space-Based Solar Flare Shield for Earth

A team of scientists from the Harvard Smithsonian Center for Astrophysics have proposed a bold idea for protecting Earth against solar flare activity – placing a giant magnetic shield in orbit!

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Witnessing the 2017 Total Solar Eclipse Across America Mesmerizes Millions: Photo/Video Gallery

SANTEE, SOUTH CAROLINA – Witnessing ‘Totality’ during Monday’s ‘Great American Solar Eclipse’ was a truly mesmerizing experience far beyond anything I imagined and something I will never forget -That’s a sentiment shared by millions upon millions of fellow gushing spectators.

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Weekly Space Hangout – June 2, 2017: Mike Simmons of Astronomers Without Borders

Host: Fraser Cain (@fcain) Special Guest: Mike Simmons is the President of Astronomer Without Borders. Mike is joining us today to discuss how AWB will be engaging the public and our schools both during and following the total solar eclipse on August 21, 2017. You can find the AWB Eclipse education program website here. Guests: […]

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Carl Sagan’s Theory Of Early Mars Warming Gets New Attention

Carl Sagan hit on the idea 40 years ago. Now, a team of scientists have discovered that a trifecta of gases may have warmed Mars enough for liquid water to gush.

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The Photon Sieve Could Revolutionize Optics

Scientists at NASA"s Goddard Space Flight Center are developing small, inexpensive optics to study the Sun's corona. Credit: NASA's GSFC, SDO AIA Team

Ever since astronomers first began using telescopes to get a better look at the heavens, they have struggled with a basic conundrum. In addition to magnification, telescopes also need to be able to resolve the small details of an object in order to help us get a better understanding of them. Doing this requires building larger and larger light-collecting mirrors, which requires instruments of greater size, cost and complexity.

However, scientists working at NASA Goddard’s Space Flight Center are working on an inexpensive alternative. Instead of relying on big and impractical large-aperture telescopes, they have proposed a device that could resolve tiny details while being a fraction of the size. It’s known as the photon sieve, and it is being specifically developed to study the Sun’s corona in the ultraviolet.

Basically, the photon sieve is a variation on the Fresnel zone plate, a form of optics that consist of tightly spaced sets of rings that alternate between the transparent and the opaque. Unlike telescopes which focus light through refraction or reflection, these plates cause light to diffract through transparent openings. On the other side, the light overlaps and is then focused onto a specific point – creating an image that can be recorded.

The photon sieve operates on the same basic principles, but with a slightly more sophisticated twist. Instead of thin openings (i.e. Fresnel zones), the sieve consists of a circular silicon lens that is dotted with millions of tiny holes. Although such a device would be potentially useful at all wavelengths, the Goddard team is specifically developing the photon sieve to answer a 50-year-old question about the Sun.

Essentially, they hope to study the Sun’s corona to see what mechanism is heating it. For some time, scientists have known that the corona and other layers of the Sun’s atmosphere (the chromosphere, the transition region, and the heliosphere) are significantly hotter than its surface. Why this is has remained a mystery. But perhaps, not for much longer.

As Doug Rabin, the leader of the Goddard team, said in a NASA press release:

“This is already a success… For more than 50 years, the central unanswered question in solar coronal science has been to understand how energy transported from below is able to heat the corona. Current instruments have spatial resolutions about 100 times larger than the features that must be observed to understand this process.”

With support from Goddard’s Research and Development program, the team has already fabricated three sieves, all of which measure 7.62 cm (3 inches) in diameter. Each device contains a silicon wafer with 16 million holes, the sizes and locations of which were determined using a fabrication technique called photolithography – where light is used to transfer a geometric pattern from a photomask to a surface.

However, in the long-run, they hope to create a sieve that will measure 1 meter (3 feet) in diameter. With an instrument of this size, they believe they will be able to achieve up to 100 times better angular resolution in the ultraviolet than NASA’s high-resolution space telescope – the Solar Dynamics Observatory. This would be just enough to start getting some answers from the Sun’s corona.

In the meantime, the team plans to begin testing to see if the sieve can operate in space, a process which should take less than a year. This will include whether or not it can survive the intense g-forces of a space launch, as well as the extreme environment of space. Other plans include marrying the technology to a series of CubeSats so a two-spacecraft formation-flying mission could be mounted to study the Sun’s corona.

In addition to shedding light on the mysteries of the Sun, a successful photon sieve could revolution optics as we know it. Rather than being forced to send massive and expensive apparatus’ into space (like the Hubble Space Telescope or the James Webb Telescope), astronomers could get all the high-resolution images they need from devices small enough to stick aboard a satellite measuring no more than a few square meters.

This would open up new venues for space research, allowing private companies and research institutions the ability to take detailed photos of distant stars, planets, and other celestial objects. It would also constitute another crucial step towards making space exploration affordable and accessible.

Further Reading: NASA

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A Dark Region Is Growing Eerily On The Sun’s Surface

NASA's Solar Dynamics Observatory has captured images of a growing dark region on the surface of the Sun. Called a coronal hole, it produces high-speed solar winds that can disrupt satellite communications. Image: Solar Dynamics Observatory / NASA

NASA has spotted an enormous black blotch growing on the surface of the Sun. It looks eerie, but this dark region is nothing to fear, though it does signal potential disruption to satellite communications.

The dark region is called a coronal hole, an area on the surface of the Sun that is cooler and less dense than the surrounding areas. The magnetic fields in these holes are open to space, which allows high density plasma to flow out into space. The lack of plasma in these holes is what makes them appear dark. Coronal holes are the origin of high-speed solar winds, which can cause problems for satellite communications.

The images were captured by the Solar Dynamics Observatory (SDO) on July 11th. Tom Yulsman at Discover’s ImaGeo blog created a gif from several of NASA’s images.

[embed]https://www.youtube.com/watch?v=hMVAIy17XFs[/embed]

High-speed solar winds are made up of solar particles which are travelling up to three times faster than the solar wind normally does. Though satellites are protected from the solar wind, extremes like this can still cause problems.

Coronal holes may look like a doomsday warning; an enormous black hole on the surface of our otherwise placid looking Sun is strange looking. But these holes are a part of the natural life of the Sun. And anyway, they only appear in extreme ultraviolet and x-ray wavelengths.

The holes tend to appear at the poles, due to the structure of the Sun’s magnetosphere. But when they appear in more equatorial regions of the Sun, they can cause intermittent problems, as the high-speed solar wind they generate is pointed at the Earth as the Sun rotates.

In June 2012, a coronal hole appeared that looked Big Bird from Sesame Street.

The Big Bird hole was the precursor to an extremely powerful solar storm, the most powerful one in 150 years. Daniel Baker, of the University of Colorado’s Laboratory of Atmospheric and Space Physics, said of that storm, “If it had hit, we would still be picking up the pieces.” We were fortunate that it missed us, as these enormous storms have the potential to damage power grids on the surface of the Earth.

It seems unlikely that any solar wind that reaches Earth as a result of this current coronal hole will cause any disruption to us here on Earth. But it’s not out of the question. In 1989 a solar storm struck Earth and knocked out power in the province of Quebec in Canada.

It may be that the only result of this coronal hole, and any geomagnetic storms it creates, are more vivid auroras.

Those are something everyone can appreciate and marvel at. And you don’t need an x-ray satellite to see them.

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