NASA ’s Mars Atmosphere and Volatile Evolution ( MAVEN ) mission only move into its skill phase in mid - November after slip into orbit two month sooner , but it is already prove to be worth every centime , having beamed back some exciting data . Back inDecember , the orbiter begin to reveal key features of a mountain chain of solar - driven processes that lead to the loss of the major planet ’s ambiance over sentence , which is one of the delegacy ’s primary target . Now , the cunning has mention two ratherunexpected phenomenon : a freaky gamey - altitude dust swarm that scientists are struggling to excuse , and an first light that lead deep into the atmospheric state .
Auroras , known informally as northerly or Southern visible radiation on Earth , are natural events triggered by gumptious charged atom , such as electrons and proton , slamming into the atmospheric state from above , causing excitation of natural gas in the atmosphere that subsequently do them radiate . We regularly see these in the sky above our own satellite , but this phenomenon was also observed in the Martian aura lately last twelvemonth by MAVEN ’s Imaging Ultraviolet Spectrograph ( IUVS ) .
grant to aNASA statement , for five twenty-four hours on the running up to Christmas last year , the investigation peck up a brilliant ultraviolet radiation auroral glowing sprawl across the satellite ’s northerly hemisphere , not tied to any particular place . As target out by theBBC , although Martian auroras have been notice previously by Europe ’s Mars Express space vehicle , this event caused a stir amongst scientist because it reached surprising depths in Mars ’ standard pressure — significantly deeper than those seen on our planet or anywhere else on Mars .
“ The negatron make it must be really energetic , ” Arnaud Stiepen , IUVS scientist at the University of Colorado , say in anews going .
Although scientist were surprised at the depths of the ultraviolet aurora , it realize common sense that this could pass due to the fact that Mars lost its protective magnetised field billions of long time ago , whereas Earth is still shielded by one . This means that industrious particles , which probably come from the sun , are able to directly boom into the Martian ambience and penetrate deep .
Interestingly , MAVEN also discover a second surprisal : the bearing of an unpredicted gamey - altitude dust cloud , which is tarry between 93 mile ( 150 km ) and 190 knot ( 300 kilometre ) above the Martian surface . Although it has been present the whole time MAVEN has been collecting information , scientists are still timid as to whether it is a temporary phenomenon or a long - stand feature article .
“ If the rubble originates from the atmosphere,”explainsLaila Andersson of the University of Colorado , “ this suggests we are miss some fundamental operation in the Martian atmosphere . ”
Scientists are n’t quite sure of the blood of the dust , but they have put forward a few hypotheses , such as dust wafting up from the atmosphere , debris from comet or dust leaking from Mars ’ two moons , Phobos and Deimos . While these may typify valid sources , none of the processes presently understood on Mars can explicate why the dust would look in the observed domain .
[ ViaNASAandBBC News ]
