Largest sunspot in years spotted

NASA`s Solar Dynamics Observatory (SDO) satellite has spotted what astronomers say is one of the largest sunspots to have appeared on the Sun in years.

Last Updated: Nov 06, 2011, 16:21 PM IST

Washington: NASA`s Solar Dynamics Observatory (SDO) satellite has spotted what astronomers say is one of the largest sunspots to have appeared on the Sun in years and is
likely to shoot solar flares towards the Earth by next week.

The massive sunspot, called AR1339, has been estimated to be about 80,000km long and 40,000km wide -- almost eight times as big as the Earth, SpaceWeather.com reported.

The spacecraft`s photos of the giant sunspot, spotted on November 3, show the solar region as it comes into view on the northeastern edge, or limb, of the Sun.

The sunspot behemoth isn`t yet facing our planet, but is expected to shoot an X-Class solar flare towards us when it will move in Earth`s direction next week, astronomers said.

X-class solar flares on low scales are not too dangerous for the planet, but if one of these sunspots shoots a high end X-class number toward us, it could put most of the modern
society world into the dark ages.

The sunspot is actually a group of nearby darkened spots on the Sun, some of which are individually wider than planet Earth. It appears when intense magnetic activity ramps up on the sun, blocking the flow of heat through the process of convection, which causes areas of the sun`s surface to cool down. These isolated areas then appear dimmer than the
surrounding area, creating a dark spot, LiveScience reported.

The intense magnetic activity around sunspots can often cause solar flares, which are large releases of energy that can actually brighten up the Sun. Flares are also accompanied by flows of charged particles out into space, called coronal mass ejections, which can wreak havoc on satellites and power grids on Earth if they head our way.

The National Oceanic and Atmospheric Administration (NOAA) has predicted a 50 per cent chance of medium-class M solar flares over the next 24 hours due to this sunspot.

As the sunspot turns towards the Earth in the coming days, we may be in for a greater chance of these ejections, the scientists said.

PTI