Asteroid Florence (3122) at it’s Close Approach to Earth

Mike Olason
Location of photo
Denver Colorado
Date/Time of photo
1 September 2017, 0900UT
11" SCT f/6.4 and STF-8300M CCD Camera, 1" Refractor f/4 and ST-402ME CCD Camera
Several images of Asteroid Florence at it's close approach to Earth in the early Denver morning of 1 September 2017 when it was about 4.4 Million Miles from Earth. The 2.7 mile wide asteroid was about magnitude 8.7 moving at almost 1/2 degree per hour across the night skies of Denver. These images were taken through holes in a mostly cloudy sky.
Astronomy Pictures: Sky & Telescope's Online Gallery, Meteor, Comet & Asteroid Pictures
Mike Olason

About Mike Olason

I started imaging comets in 1994 with an ST-5 CCD Camera and an 11" SC Telescope. Since then the CCD cameras have changed (ST-7, ST-402ME and STF-8300M), but I am still using the 11" SC Telescope. Naturally I have used a lot of smaller telescopes to obtain larger fields of view. I live south of Denver at an elevation of 6150 feet which allows me to image comets down to almost magnitude 21 on a perfect night. Unfortunately ChemTrails have turned Denver cloudy and dry. I use the camera software CCDOps to process my images. All I do to each image is dark subtraction and flat field, stack images as required to show faint comets, contrast/bright adjust the final image and maybe use a median filter to reduce the image noise. The result is an image that reflects reality and will never win any picture of the day award. If you would like to use my images for a project or ask a question send me an email to "".
All comments must follow the Sky & Telescope Terms of Use and will be moderated prior to posting. Please be civil in your comments. Sky & Telescope reserves the right to use the comments we receive, in whole or in part, and to use the commenter’s username, in any medium. See also the Terms of Use and Privacy Policy.