This week's research roundup looks at anti-vaccine sentiment on Twitter, theÌýdecline inÌýhigh school football participation and a global aurora that took place this month on Mars.
Twitter a hotbed of anti-vaccine sentiment, finds Â鶹Ãâ·Ñ°æÏÂÔØBoulder study
Negative sentiment about vaccines is alive and growing in social media, according to an expansive study designed to examine the prevalence and geographic clustering of online viewpoints.
High school football participation has 'peaked,' further declines likely, professor says
The number of high schoolers playing American football grew steadily from 1998 to 2009 but then began a notable decline that's likely to continue, according to Â鶹Ãâ·Ñ°æÏÂÔØBoulder Professor Roger Pielke.
MAVEN observes large solar storm that sparked global aurora on Mars
An unexpectedly strong blast from the Sun hit Mars this month, observed by NASA missions, including the Mars Atmosphere and Volatile Evolution (MAVN) spacecraft.