GALLERY t JUPITER AND ITS ENTOURAGE Damian Peach Jupiter's ever-changing Great Red Spot (see page 52) transits the planet's central meridian. The Galilean moons Ganymede (far left), Io (left), and Europa (lower right) each display mottled surface details in this high-resolution image. DETAILS: ASA RC-1000 telescope with ZWO ASI290MM video camera. Stack of multiple video frames captured on August 5th at 3:57 UT through RGB filters. q SUNSET IN TUSCANY Marco Meniero Two elusive green flashes (caused by differential refraction in the atmosphere) are seen by the arch of Meloria Tower in Tuscany, Italy, at sunset on July 20th. DETAILS: Canon EOS-1D X Mark II with 400-mm EF DO IS II USM lens. Composite of five images taken at ISO 200. Gallery showcases the finest astronomical images that our readers submit to us. Send your best shots to gallery@skyandtelescope.org. See skyandtelescope.org/aboutsky/guidelines. Visit skyandtelescope.org/gallery for more of our readers' astrophotos. 78 NOVEMBER 2021 * SKY & TELESCOPEhttp://www.skyandtelescope.org/aboutsky/guidelines http://www.skyandtelescope.org/gallery