ASTRONOMY. o\ 



The inner satellite is intrinsically the brighter, and the 

 outer one has been seen with the 9.6-inch Munich equatorial 

 at Washington. The most remarkable point of this im- 

 portant discovery is the short period of the inner satellite, 

 which is only one third as long as that of Mimas, the in- 

 nermost satellite of Saturn, hitherto the object having the 

 shortest period in the solar system. 



Apart from the physical interest of these brilliant discov- 

 eries, these satellites will furnish an accurate determination 

 of the mass of Mars. From the observations of the first 

 nine days this mass appears to be -g-oWoinT- The discus- 

 sion of all the observations will change this somewhat. 



A curious fact about the relative visibility of these satel- 

 lites in various European telescopes is noticed elsewhere. 

 Photometric measures of the satellites of Mars have been 

 made by Professor Pickering and Mr. S. C. Chandler. 



The series of observations made by Professor Hall on the 

 moons of Mars ended October 31, the planet having re- 

 ceded to a distance at which they become invisible, even 

 with the 26-inch refractor. Not until 1879 will there be 

 any opportunity to see them again, and that will not give 

 nearly so good a view as the past season. Professor Hall 

 has secured fifty-one observations of the outer (Deirmis) and 

 forty-six of the inner satellite (Phobus). 



A passage in the 15th book of the "Iliad," where Ares 



is preparing to descend to the earth, has suggested these 



names for the two satellites of Mars, which names, it is 



understood, Professor Hall has approved : 



" n Qfi <pdro iccti p 'iTnrovg KeXero Ae7/^ov re fyofiov re 

 Ztvyvvptv " 



which Pope renders 



"With that he gives command to Fear and Flight 

 To join his rapid coursers for the fight." 



Deimus and Phobus are the names adopted. 



Todd, of Adelaide, Australia, has made an important 

 series of observations of the phenomena of Jupiter's sat- 

 ellites. Besides the record of the times of the phenom- 

 ena, notes on the physical appearances of Jupiter and the 

 satellites are given. " On one or two occasions when a 

 satellite has been on the point of occultation it has ap- 

 peared as if seen through the edge of the planet, as if the 



