太阳黑子与光桥

太阳黑子与光桥

ByNASA中文

2023年5月17日 Sunspot with Light Bridge Image Credit & Copyright: Mark Johnston Explanation: Why would a small part of the Sun appear slightly dark? Visible is a close-up picture of sunspots, depressions on the Sun’s surface that are slightly cooler and less bright than the rest of the Sun. The Sun’s complex magnetic field creates these cool regions by inhibiting hot material from entering the spots. Sunspots can be larger than the Earth and typically last for about a week. Part of active region AR 3297 crossing the Sun in early May, the large lower sunspot is spanned by an impressive light bridge of hot and suspended solar gas. This high-resolution picture also shows clearly that the Sun’s surface is a bubbling carpet of separate cells…

太空站凌越活跃的太阳

太空站凌越活跃的太阳

ByNASA中文

2022年4月11日 A Space Station Crosses a Busy Sun Image Credit & Copyright: Wang Letian (Eyes at Night) Explanation: Typically, the International Space Station is visible only at night. Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot several times a year from many locations. The ISS is then visible only just after sunset or just before sunrise because it shines by reflected sunlight — once the ISS enters the Earth’s shadow, it will drop out of sight. The only occasion when the ISS is visible during the day is when it passes right in front of the Sun. Then, it passes so quickly that only cameras taking short exposures can visually…

斜塔与活跃红日

斜塔与活跃红日

ByNASA中文

2022年4月1日 Leaning Tower, Active Sun Image Credit & Copyright: Antonio Tartarini Explanation: The natural filter of a hazy atmosphere offered this recognizable architecture and sunset view on March 27. Dark against the solar disk, large sunspots in solar active regions 2975 and 2976 are wedged between the Duomo of Pisa and its famous Leaning Tower. Only one day later, Sun-staring spacecraft watched active region 2975 unleash a frenzy of solar flares along with two coronal mass ejections. The largest impacted the magnetosphere on March 31 triggering a geomagnetic storm and aurorae in high-latitude night skies. On March 30, active region 2975 erupted again with a powerful X-class solar flare that caused a temporary radio blackout on planet Earth. Tomorrow’s picture: a colour out of space…

AR2835：光球层上的黑子群

AR2835：光球层上的黑子群

ByNASA中文

2021年07月02日 AR2835: Islands in the Photosphere Image Credit & Copyright: Michael Teoh, Heng Ee Observatory, Penang, Malaysia Explanation: Awash in a sea of incandescent plasma and anchored in strong magnetic fields, sunspots are planet-sized dark islands in the solar photosphere, the bright surface of the Sun. Found in solar active regions, sunspots look dark only because they are slightly cooler though, with temperatures of about 4,000 kelvins compared to 6,000 kelvins for the surrounding solar surface. These sunspots lie in active region AR2835. The largest active region now crossing the Sun, AR2835 is captured in this sharp telescopic close-up from July 1 in a field of view that spans about 150,000 kilometers or over ten Earth diameters. With powerful magnetic fields, solar active regions are…