Biggest solar X-Ray flare on record

At 21:51 UT, Monday 2 April 2001, solar active region 9393 unleashed a major solar flare. It appears to be the biggest X-ray flare on record, most likely bigger than the one on 16 August 1989, and definitely more powerful that the famous 6 March 1989 flare which was related to the disruption of the power grids in Canada. The big explosion, which took place near the Sun's northwest limb, hurled a coronal mass ejection (CME) into space - at a whopping speed of roughly 7.2 million km/h - but not directly towards Earth.

Source: SOHO (Solar and Heliospheric Observatory)

It was a quiet day on the Sun in September of 2000. This image from NASA's sun-observing TRACE spacecraft shows, however, that even during "off days" the Sun's surface is a busy place. Shown in ultraviolet light, the relatively cool dark regions have temperatures of thousands of degrees.

A large sunspot group is visible as the bright area near the horizon. The bright glowing gas flowing around the sunspots has a temperature of over one million degrees Celsius (1.8 million degrees Fahrenheit). The high temperatures are thought to be related to the rapidly changing magnetic field loops that channel solar plasma.

Source: Astronomy Picture of the day Credit: TRACE Project, NASA

In this unusual image, NASA's Hubble Space Telescope captures a rare view of the celestial equivalent of a geode -- a gas cavity carved by the stellar wind and intense ultraviolet radiation from a hot young star.

Real geodes are baseball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter "celestial geode" the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior.

Source: NASA Image of the Day Credit: NASA, ESA, Y. Nazé (University of Liège, Belgium) and Y.-H. Chu (University of Illinois, Urbana)

On a rare foggy night, mysterious laser beams seem to play across the MAGIC telescope at Roque de los Muchachos on the Canary Island of La Palma. The lasers are actually part of a system designed to automatically adjust the focusing of the innovative, seventeen meter wide, multi-mirrored instrument.

The MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescope itself is intended to detect gamma rays - photons with over 100 billion times the energy of visible light. As the gamma rays impact the upper atmosphere they produce air showers of high-energy particles.

Source: Astronomy Picture of the day Credit: Robert Wagner (MPI), MAGIC Telescope Project

Sunrise

Source: National Oceanic & Atmospheric Administration Photo Library, Historic National Weather Service Collection, Weather Wonders, Sun Phenomena

Image ID wea00173 Credit: U. S. Department of Agriculture

Towering cumulus clouds

Source: National Oceanic & Atmospheric Administration Photo Library, Historic National Weather Service Collection, Weather Wonders, Clouds

Image ID wea00084