Presentation on theme: "ACTIVITY ON THE SUN: Prominences Sunspots Solar Flares CME’s – Coronal Mass Ejections Solar Wind Space Weather."— Presentation transcript:
ACTIVITY ON THE SUN: Prominences Sunspots Solar Flares CME’s – Coronal Mass Ejections Solar Wind Space Weather
Prominences: Prominences are clouds of gas forming above sunspots that follow the magnetic field line loops. So-called “quiet”ones form in the corona. (about 40,000 kilometers above the surface) Quiet prominences last several days to several weeks. “Surge” prominences lasting up to a few hours shoot gas up to 300,000 kilometers above the photosphere.
Sunspots: Sunspots are areas on the sun with strong magnetic fields. The solar magnetic field is responsible for the sunspot cycle. Alternating every 11 years between solar maximum (11 years) and solar minimum (11years) – making one entire cycle 22 years long. –Most sunspots form in groups around the solar equator.
“Galileo discovered that the Sun's surface is sprinkled with small dark regions called sunspots.” “Sunspots are cooler regions on the photosphere. Since they are 1000--1500 K cooler than the rest of the photosphere, they do not emit as much light and appear darker.” “They can last a few days to a few months.”
Sunspots: “Galileo used the longer-lasting sunspots to map the rotation patterns of the Sun. Because the Sun is gaseous, not all parts of it rotate at the the same rate.” “The solar equator rotates once every 25 days, while regions at 30° above and below the equator take 26.5 days to rotate and regions at 60° from the equator take up to 30 days to rotate.”
Solar Flares: “Solar Flare eruptions are larger than prominences. Solar Flares will last only a few minutes to a few hours.” “A lot of ionized material is ejected in a flare. Unlike the material in prominences, the solar flare material moves with enough energy to escape the Sun's gravity.” “When this burst of ions reaches the Earth, it interferes with radio communication.”
Solar Flares: “Sometimes a solar flare will cause voltage pulses or surges in power and telephone lines. Brownouts or blackouts may result.” “Humans traveling outside the protection of the Earth's magnetic field will need to have shielding from the powerful ions in a flare.”
CME’s – Coronal Mass Ejections: CME’s are much like Solar Flares CME’s and Solar Flares are the biggest explosions in our solar system
CME’s Continued: CME’s and Solar Flares have the power of about 100 billion Hydrogen Bombs! Some CME speeds can be 2 million miles a second – faster than the solar wind. And releases 220 billion pounds of material from the sun.
Solar Wind Continued: Solar Wind is the cause of ‘space weather’. Solar Wind is charged particles, such as electrons and protons, called plasma, coming out of the Sun in all directions at very high speeds -- an average of about 400 km/sec, almost a million mph!.
Solar Wind Continued: “[Solar Wind] is responsible for the anti-sunward tails of comets and the shape of the magnetic fields around the planets.”magnetic fields Particles from the solar wind can get trapped near the north or south poles of planetary magnetic fields causing auroras.
Space Weather: “Major solar activity is a very serious concern in space flight.” “Communications may be disrupted. Large solar disturbances heat the upper atmosphere, causing it to expand and create increased drag on spacecraft in low orbits, shortening their orbital lifetime.” “Spacecraft could potentially tumble and burn up in the atmosphere.” Also, radiation exposure to astronauts is also seriously increased and of high risk!
Space Weather Continued: “Radiation sickness can result when humans are outside the protective magnetosphere of the Earth, as in missions to the moon and to Mars.”magnetosphere “NASA Monitors astronaut's exposure to radiation” “High-energy solar protons can produce increased radiation in the atmosphere at altitudes where supersonic aircraft fly. This is especially true for flights over the north and south magnetic poles, areas unprotected by the Earth's magnetic field, where the radiation has direct access to the atmosphere.”protons
Space Weather: “To reduce the risk to aircraft, crews and passengers, routine forecasts and alerts are sent through the Federal Aviation Administration so that a flight in potential danger can consider what course of action to take to minimize radiation exposure.” “The National Oceanic and Atmospheric Administration (NOAA) Space Environment Center (SEC) forecasts high-speed solar wind advisories.”National Oceanic and Atmospheric Administration (NOAA) Space Environment Center (SEC)