04Jun2012

Sunspots from modern day and from 65 years ago, with planet sizes for comparison. Read more: http://www.universetoday.com/95232/how-big-are-sunspots/#ixzz1xCEE6sru

The short answer? Really big. The long answer? Really, really big. The image above shows sunspot regions in comparison with the sizes of Earth and Jupiter, demonstrating the sheer enormity of these solar features.

Sunspots are regions where the Sun’s internal magnetic fields rise up through its surface layers, preventing convection from taking place and creating cooler, optically darker areas. They often occur in pairs or clusters, with individual spots corresponding to the opposite polar ends of magnetic lines.

The image on the left was acquired by NASA’s Solar Dynamics Observatory on May 11, 2012, showing Active Region 11476. The one on the right comes courtesy of the Carnegie Institution of Washington, and shows the largest sunspot ever captured on film, AR 14886. It was nearly the diameter of Jupiter — 88,846 miles (142,984 km)!

“The largest sunspots tend to occur after solar maximum and the larger sunspots tend to last longer as well,” writes SDO project scientist Dean Pesnell on the SDO is GO blog. “As we move through solar maximum in the northern hemisphere and look to the south to pick up the slack there should be plenty of sunspots to watch rotate by SDO.”

Sunspots are associated with solar flares and CMEs, which can send solar storms our way and negatively affect satellite operation and impact communications and sensitive electronics here on Earth. As we approach the peak of the current solar maximum cycle, it’s important to keep an eye — or a Solar Dynamics Observatory! — on the increasing activity of our home star. Source: Universe Today

 

 Is Earth’s technology Safe From The Sun’s Fiery Flare-Ups?

The subject of monstrous solar flares and the the CMEs (coronal mass ejections) returns over and over again in news worldwide. An enormous sunspot unleashed a powerful solar flare late Wednesday (May 16), triggering a radiation storm intense enough to interfere with some satellites orbiting Earth, according to space weather experts.

However, in terms of power grids and satellites, it’s not the flares that the experts have to worry about, but the CMEs. There is a risk that one day, they can wipe out all of our electronic civilization. Solar storms can disrupt communication, and navigational equipment, damage satellites, and even cause blackouts by damaging power plants and electrical grid components.

They can also bring additional radiation around the north and south poles; and this, in turn forces airlines to reroute their flights. The Sun’s abnormal behavior is a cause for concern even we all know that activity near the Sun’s surface rises and falls through an 11-year cycle that is due to peak in 2013 or 2014.

Some solar flares result in CMEs (coronal mass ejections), a huge bubble of charged particles rushing towards Earth at tremendous speeds up to millions of kilometres per hour. Did you know that an average solar flare or CME releases, only in two hours (!), enough energy to power the United States for 10,000 years. 

Dramatic flare: hot gas erupts 62,000 miles high during a July 2000 solar storm. (Photo: NASA)

It’s comforting that our planet’s magnetic field protects it from the constant attacks of high-energy particles from the Sun and elsewhere as well.

However, the solar storms that mark the arrival of CMEs can cause significant problems by affecting the Earth’s surface and causing current spikes in power grids or disrupting navigation devices.

The problem is that even up to the last minute, it is unclear how big these effects on Earth can be! The reason is that it depends on the magnetic alignment of the material within the coronal mass ejection, which, in turn – is very difficult to predict. For now, we can still sufficiently protect us but sometimes bad things happen.

 

In 1989 a solar storm affected the Salem Pressurized Water Reactor, PWR in New Jersey. The 1,160 MWe Salem-1 nuclear power plant is located on an artificial island at the mouth of the Delaware River along with two other nuclear units.

The solar storm induced a large current into the PJM 500-kV transmission system, which damaged the Salem Unit 1 step-up transformer, resulting in a large melted mass of copper and copper shot. The transformer’s winding insulation confined the damage; the plant operators discovered the damage after the storm.

The transformer had to be replaced at a cost of millions of dollars. Unfortunately, storms 10 times worse than the 1989 event can occur. The most damaging emissions from solar storms travel slowly enough to be detected by sun-watching satellites, well before the particles strike the Earth’s atmosphere, giving approximately 20 hours of warning time to take the indispensable precautions.

For example, power companies can protect valuable transformers by taking them offline before the storm strikes. That would produce local blackouts, but they would not last for long.

So, we can contemplate the benign effects like beautiful auroras but at the same time we should fear the consequences of the sun’s solar flares interfering with our high-tech. Senior space agency scientists believe the Earth will be hit with unprecedented levels of magnetic energy from solar flares in 2012 and around 2013, so think about it! Source: Message from Eagle

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