Researchers have made an incredible find . The Earth ’s outer atmosphere extends much further than expect , stretching to 630,000 kilometers ( 391 000 miles ) , which is roughly 50 times the diameter of our planet . patently , you’re able to not breath there as the atmosphere becomes more tenuous the further from Earth ’s aerofoil you are , but this finding has important implications for space travel and space lookout station .
The findings , report in theJournal of Geophysical Research : Space Physics , were possible thanks to ten of observation from the ESA / NASA Solar and Heliospheric Observatory ( SOHO ) . The observations were actually made decades ago , and can only be done at certain time of the year .
" The Moon fly through Earth ’s ambiance , " lead author Igor Baliukin , from Russia ’s Space Research Institute , said in astatement . " We were not aware of it until we scatter off observation made over two decades ago by the SOHO space vehicle . "
The information show that the Earth ’s exosphere is slightly denser than interplanetary space for a significant distance . At the Moon distance , on average 384,000 kilometre ( 239,000 miles ) aside , there are only 0.2 speck per cubic centimeter . At 60,000 kilometers ( 37,000 miles ) from Earth , there are still 70 hydrogen atoms per three-dimensional centimetre and the tightness only cut down down to less than 1 atom per three-dimensional centimeters at over four times that aloofness . Despite the low density , the atomic number 1 interact with sunlight , ultraviolet ray in particular . This emission is what allowed researchers to study the so - called geocorona .
This UV glow or the presence of this debase hydrogen poses no threat to future astronaut on mission around the Moon , but it will need to be direct into story if we apply near - lunar observatories . Apollo 16 astronauts used the first scope on the Moon in 1972 and unknowingly took the first impression of the geocorona .
" At that time , the astronauts on the lunar surface did not love that they were actually embedded in the outskirt of the geocorona , " explicate Jean - Loup Bertaux , co - author and former principal investigator of SWAN , the cat’s-paw used by SOHO to detect the geocorona .
The finding might have crucial consequences for exoplanet inquiry , too . A UV glow from H in a planet ’s exosphere advise the presence of water supply vapor closer to the surface . This is the instance for Venus , Earth , and Mars . Detecting this signature around a planet in another star system can tell us about a potential water source there .
