#15ICY HIGHWAYS Ridges and fractures crisscross the frozen facade of this sphere. Some parts of the crust appear to have broken up, like sea ice in spring, and rafted to new positions. While this object is only about one-fourth Earth's diameter, scientists think it might contain as much as two times the water in all our planet's oceans combined. #16CELESTIAL BUTTERFLY Resembling a fossil insect with outstretched wings, this rayed crater is named in honor of Armenian painter Hakob Hovnatanian. The crater's oval shape and the rays' pattern imply the object that created this hole struck at a highly oblique angle. The whiteness of the rays suggests the impact was comparatively recent. #17 NEXT-DOOR NEIGHBORS No doubt you recognize the two spheres seen here, but can you guess from which solar system body the photo was taken? It was shot on October 3, 2007, from a distance of 142 million km. With a scale of 142 km per pixel, the image displays a phase angle of 98°, which is why Earth and the Moon are each less than half illuminated. HOW'D YOU DO? Your correct answers: 17: Planetary Scientist 13-16: NASA Devotee 9-12: Space Lover 5-8: Casual Skygazer 0-4: Astro Novice sk yand tele scope .o r g * JUNE 2022 29 ANSWER KEY: #1: TITAN (CASSINI); #2: PHOBOS (MRO); #3: MIMAS (CASSINI); #4: MOON (LRO); #5: MARS (MRO); #6: PLUTO (NEW HORIZONS); #7: VENUS (MAGELLAN); #8: ENCELADUS (CASSINI); #9: GANYMEDE (GALILEO); #10: IO (GALILEO); #11: JUPITER (JUNO); #12: BENNU (OSIRIS-REX); #13: SATURN (CASSINI); #14: COMET 67P/CHURYUMOVGERASIMENKO (ROSETTA); #15: EUROPA (GALILEO); #16: MERCURY (MESSENGER); #17: FROM MARS (MRO) #15: NASA / JPL / UNIVERSITY OF ARIZONA; #16: NASA / JHUAPL / CARNEGIE INSTITUTION OF WASHINGTON; #17: NASA / JPL / UNIVERSITY OF ARIZONAhttp://www.skyandtelescope.com