Subj : Daily APOD Report To : All From : Ben Ritchey Date : Wed Mar 06 2019 10:08:46 Astronomy Picture of the Day Astronomy Picture of the Day Discover the cosmos! [1] Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2019 March 6 [2] A February without Sunspots Images Credit & Copyright: Alan Friedman [3] (Averted Imagination [4] ) Explanation: Where have all the sunspots gone? Last month the total number of spots that crossed our Sun was ... zero [5] . Well below of the long term monthly average, the Sun's surface has become as unusually passive this solar minimum [6] just like it did 11 years ago during the last solar minimum [7] . Such passivity is not just a visual spectacle [8] , it correlates with the Sun [9] being slightly dimmer [10] , with holes [11] in the Sun's corona [12] being more stable, and with a reduced intensity in the outflowing solar wind [13] . The reduced wind, in turn, cools and collapses Earth's outer atmosphere [14] (the thermosphere [15] ), causing reduced drag on many Earth-orbiting satellites. Pictured in inverted black & white on the left, the Sun's busy surface is shown near solar maximum [16] in 2012, in contrast to the image on the right, which shows the Sun's surface last August, already without spots (for a few days), as solar minimum [17] was setting in. Effects of this unusually static solar minimum are being studied [18] . Tomorrow's picture: cosmic jellyfish ------------------------------------------------------------------------------- < [19] | Archive [20] | Submissions [21] | Index [22] | Search [23] | Calendar [24] | RSS [25] | Education [26] | About APOD [27] | Discuss [28] | > [29] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [30] (MTU [31] ) & Jerry Bonnell [32] (UMCP [33] ) NASA Official: Phillip Newman Specific rights apply [34] . NASA Web Privacy Policy and Important Notices [35] A service of: ASD [36] at NASA [37] / GSFC [38] & Michigan Tech. U. [39] ---------- Site notes: [1] archivepix.html [2] image/1903/SunMaxMin_Friedman_1733.jpg [3] mailto: alan at greatarrow dot com [4] http://www.avertedimagination.com/ [5] http://spaceweather.com/archive.php?view=1&day=01&month=03&year=2019 [6] https://science.nasa.gov/science-news/news-articles/solar-minimum-is-coming [7] https://www.nasa.gov/topics/solarsystem/features/solar_minimum09.html [8] https://media.tenor.com/images/dc1bbc8e86816ac51e86b41ad294fa89/tenor.png [9] https://solarsystem.nasa.gov/solar-system/sun/in-depth/ [10] https://spaceweatherarchive.com/2017/12/17/the-sun-is-dimming/ [11] ap100828.html [12] ap170920.html [13] ap000318.html [14] https://science.nasa.gov/science-news/science-at-nasa/2010/15jul_thermosphere [15] https://spaceplace.nasa.gov/thermosphere/en/ [16] ap170219.html [17] https://en.wikipedia.org/wiki/Solar_minimum [18] http://parkersolarprobe.jhuapl.edu/index.php#the-sun [19] ap190305.html [20] archivepix.html [21] lib/apsubmit2015.html [22] lib/aptree.html [23] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [24] calendar/allyears.html [25] /apod.rss [26] lib/edlinks.html [27] lib/about_apod.html [28] http://asterisk.apod.com/discuss_apod.php?date=190306 [29] ap190307.html [30] http://www.phy.mtu.edu/faculty/Nemiroff.html [31] http://www.phy.mtu.edu/ [32] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [33] http://www.astro.umd.edu/ [34] lib/about_apod.html#srapply [35] https://www.nasa.gov/about/highlights/HP_Privacy.html [36] https://astrophysics.gsfc.nasa.gov/ [37] https://www.nasa.gov/ [38] https://www.nasa.gov/centers/goddard/ [39] http://www.mtu.edu/ --- Mystic BBS v1.12 A43 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .