91制片厂

Researchers at the find that 鈥渟peed bumps鈥� in space, which can slow down satellites orbiting closer to Earth, are more complex than originally thought.

鈥淲e knew these satellites were hitting 鈥渟peed bumps,鈥澨齩r 鈥渦pswellings,鈥澨齱hich cause them to slow down and drop in altitude,鈥� explains Marc Lessard, a physicist at 91制片厂. 鈥淏ut on this mission, we were able to unlock some of the mystery around why this happens by discovering that the bumps are much more complicated and structured.鈥�

In听the , published in AGU鈥檚 journal Geophysical Research Letters, scientists outline their observations during the Rocket Experiment for Neutral Upwelling 2 or RENU2 mission, finding that a type of high-altitude auroras, or northern lights, are responsible at least in part for moving pockets of air high into the atmosphere where they can cause drag on passing satellites, similar to driving a car into a strong headwind. These auroras, viewed from the in Norway, were not the typical bright ribbons of light seen in the night skies in Earth鈥檚 high latitudes. Known as Poleward Moving Auroral Forms, these auroras were less energetic, dim and distant.

鈥淵ou can think of the satellites traveling through air pockets or bubbles similar to those in a lava lamp as opposed to a smooth wave.鈥�

Scientists had long suspected that the aurora may be instigating the upwelling events affecting the lower altitude satellites because when they were flying through the aurora, they would encounter 鈥渟pace speed bumps鈥� caused by the heating up of the very high-altitude thermosphere. But since they occur at such high altitudes, these lower-energy auroras transfer more of their energy to the thin atmosphere at 250-400 kilometers (150-250 miles) above the ground and produce more interesting effects than more familiar aurora, which sparkle at closer to 100 kilometers (60 miles) up.

鈥淵ou can think of the satellites traveling through air pockets or bubbles similar to those in a lava lamp as opposed to a smooth wave,鈥� said Lessard.

When early space programs first put satellites into orbit, they noticed the degradation of the satellites鈥� orbits when the sun was active. The problem is, when the extra drag slows down the satellites, they move closer to Earth. Without extra fuel to boost them back up, they will eventually fall back to Earth.

These specific satellites that orbit in this area closer to Earth are important because they do everything from take pictures of the Earth to help provide up-to-date information for climate monitoring, crop yields, urban planning, disaster response and even military intelligence.

Funding for this research was provided by the .