Researchers at the European Space Agency noticed a plume of dust on two separate dates while reviewing Hubble images, but coming from the same general location. Dust plumes aren’t entirely unheard of on Mars, but none were ever this big, at more than 250-kilometers (155-miles) high. The strange thing is that no one really know why these dust plumes are happening, as previous plumes have never exceeded 100-kilometers (62-miles) high. For the record, Mars has experienced planet-wide dust storms that can last for up to a year, and the reason for the longevity of these storms is that the dust is so light it stays airborne for a very long time once picked up. However, a dust storm and a localized dust plume are two very different things. Click here to view the first image in today’s viral picture gallery. Continue reading to see the five most popular viral videos of today.