On October 19, 2014, at 2:28 p.m. EDT, Mars and Comet Siding Spring were approximately 149 million miles from Earth and passed within 87,000 miles (1.5 arcminutes) of each other.
The image was created from Hubble data from the following proposals: 13936: PI: Z. Levay and the Hubble Heritage Team (STScI/AURA) and 13675: PI: J.-Y. Li (Planetary Science Institute), T. Farnham and M. Kelley (University of Maryland), N. Samarasinha (Planetary Science Institute), D. Bodewits and M. A'Hearn (University of Maryland), C. Lisse (JHU/APL), W. Delamere (Delamere Support Services), and M. Mutchler (STScI).