Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured above are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict. Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example. Of course rocks and ice bits of much smaller size strike the Earth every day, usually pose no danger, and sometimes creating memorable fireball and meteor displays.
This is a closeup image of the Aerojet Rocketdyne RS-68A engine (center engine) and four (two on each side) Orbital ATK GEM-60 solid rocket motors that power United Launch Alliance's Delta IV Medium+ (5,4) rocket. This past Saturday, this Delta IV launched the 9th Wideband Global SATCOM satellite (WGS-9) for the USAF.I shoot for AmericaSpace as a launch photographer; before most launches from Cape Canaveral, other members of the media and I are escorted to the launchpads on Cape Canaveral Air Force Station to setup "remote" cameras. (I'm not credentialed for all of them--long story.)This image was taken with a Nikon D3300, Nikon 55-300mm f/4.5-5.6 lens (at 80mm) and was the shot was triggered by a Vela Pop sound trigger, as I watched the launch from ~2.5 miles away; the sound would kill anyone this close. The camera was about 300ft from the rocket, its tripod was staked down using tent stakes, and there was a plastic bag around the camera to protect it from weather and the rocket itself.Settings: 1/4000 f/13 ISO 100 - many other photographers have successfully executed these shots in the past, and I used their EXIF data as reference, but I opted to underexposed even further to properly expose the extremely bright exhaust. The D3300 has surprisingly good dynamic range and I was able to pull up the shadows in LR.I've been taking rocket launch images for about two years and have had up-close access for about a year, but this is probably my favorite shot I've ever taken.Thanks for viewing; feel free to ask anything about the setup or the launch!Personal stuff below Instagram: @johnkrausphotos - I'm doing the 365 day daily photo challenge after completing it last year. No missed days; feel free to follow for daily content WebsiteFlickr, which hosts solely my daily photo images from this year.