Yesterday, the sun emitted a massive solar flare toward earth which could interrupt GPS and other satellite communications.  It also has the potential to cause scattered radio communication blackouts.

NASA, the U.S. space agency, reports the sun emitted an x6.9 solar flare, the largest solar event so far in the sun’s current weather cycle. It was measured by the NOAA GOES satellite on Aug. 9, 2011 at 0748 UTC.

Thanks to the earth’s atmosphere and magnetic field, these tremendous bursts of radiation can’t harm us humans on the ground.

But, for humans traveling in space, the sun’s proton radiation could be dangerous and potentially fatal if they’re not properly protected.

Along with the flare, this solar event also produced something called a coronal mass ejection (CME), another sun-based phenomenon that sends solar particles into space.

Since this particular CME was not headed toward earth, no effects are expected here.

Classifying Solar Flares and Associated Phenomena

The sun, just like earth, has its own weather systems. And, just like on earth, there can be some wild weather.

The sun has an 11-year solar weather cycle which is currently headed for an event called the solar maximum. That’s a period when the sun experiences the greatest amount of activity.

Scientists predict the sun will reach its solar maximum in 2013.

As the sun continues its cycle toward its solar maximum, the number of solar events is expected to rise.

Among these sun-based weather events are solar flares, which are huge explosions on the sun that shoot energy, light and high speed particles into space.

As I mentioned, another of the sun’s weather events associated with the solar flares is a CME. These solar magnetic storms explode from active regions on the sun’s surface releasing massive bursts of solar wind, light and magnetic energy into space.

To keep tabs on them, scientists have developed a unique classification system for solar flares.

This system, which is often compared to the Richter scale – the system that measures the strength of earthquakes – classifies solar flares according to their strength.

The smallest flares are called A-Class, followed by B, C, M and X-Class, the largest, most powerful solar flares.

Each letter progression represents a tenfold increase in the flare’s energy output. The flare is further defined, within the letter class, on a scale of 1 to 9.

Of course, the impact and effect of the classifications of solar flares varies.

C-class and smaller flares don’t have much of an effect on earth, because they’re too weak to reach us.

Next are the M-class flares, which can cause brief radio/communications blackouts at our planet’s poles. They can also trigger minor radiation storms which could endanger astronauts outside of earth’s protective atmosphere and magnetic fields.

This brings us to the strongest classification of solar flares, the X-class flare.

Although X is the highest of the current classification of solar flare, believe it or not, scientists have observed and identified flares that are more than 10 times the power of a class-X1 solar flare.

X-class flares can and have gone higher than X9.

According to NASA, the most powerful flare observed and measured with modern methods occurred in 2003, during the last solar maximum.

That flare was so powerful, that it wound up overloading the sensors measuring it. (By the way those sensors cut out at the X28 level!)

According to scientists, the really big X-class solar flares are the largest explosions within our solar system. As a result, they’re the most exciting to watch.

While they may be fun to observe, these X-Class flares and the associated corona mass ejections, should they be toward the earth, can create a series of lengthy radiation storms. Those disturbances can cause harm to satellites, various communications systems, and even our power grids.

A series of X-class flares, which took place on Dec. 5 and Dec. 6, 2006, caused a CME that interfered with GPS signals picked up by ground-based receivers.

Agencies such as NASA, the National Oceanic and Atmospheric Administration (NOAA) and the US Air Force Weather Agency (AFWA) constantly monitor the sun’s activities and watch for those X-class flares and magnetic storms.

Scientists say that, with a bit of advance warning, various equipment and technology located both in space and here on earth can be protected from the most serious effects of these solar events.

Space Missions to Study the Sun

Over the years NASA has undertaken a number of missions to study the sun and its relationship with Earth and the entire solar system.

One of NASA’s first solar missions was the Interplanetary Monitoring Platform, or IMP.

IMP-8, also called Explorer 50, the last of the IMP series of spacecraft was launched into Earth orbit on October 25, 1973 as a part of NASA’s Sun-Earth Connection research program.

The IMP-8’s mission was to measure the magnetic fields, plasmas, and cosmic rays of the Earth’s magnetotail and magnetosheath and the solar wind nearest earth.

The latest NASA spacecraft deployed for observation and study of the Sun is The Solar Dynamics Observatory or (SDO).

Launched from Cape Canaveral, Florida on February 11, 2010, the SDO is first mission and what NASA describes as its crown jewel in a fleet of missions to study the sun.

NASA says that the mission of the Solar Dynamics Observatory mission is a major part of its Living With a Star (LWS) science program.

The SDO is studying just how solar activity is created and how space weather results from that activity.

A number of sophisticated instruments aboard the SDO are measuring the sun’s interior, its magnetic field, the plasma of the solar corona, and its irradiance or power of its electromagnetic radiation.

Among the numerous future missions NASA is planning as it continues its study of the sun is the Interface Region Imaging Spectrograph, also known as IRIS. This mission, currently under development, is hoped to be launched in December 2012.

Scientists working on this mission say that the primary goal of IRIS is to understand how the solar atmosphere is energized.

The investigation that will be undertaken by the IRIS mission will combine advanced numerical modeling with a high resolution UV imaging spectrograph and will focus on three significant themes regarding solar and plasma physics, space weather, and astrophysics.

And a bit further down the road is the European Space Agency and NASA’s joint mission called Heliophysical Explorers (HELEX).

This proposed program combines ESA’s Solar Orbiter with NASA’s Solar Sentinels mission.

The Solar Orbiter will make it possible to study the Sun from a distance closer than any spacecraft previously has, and will provide images and measurements in unprecedented resolution and detail.

NASA’s Solar Sentinels is a mission that plans to study the Sun during its Solar Maximum.

The program includes the launch of six spacecraft which will then separate into three groups.

The Solar Sentinels mission will help scientists understand the acceleration and transit of solar energetic particles as well the initiation and evolution of coronal mass ejections (CMEs) and interplanetary shocks in the inner heliosphere – the region of space around the sun where its influence is insignificant and where interstellar space is said to begin.