Can you spot the Differences?
These facts may help you understand why things are a 'changin on this neighboring world.
1) In June 2001, Mars was closer to us, and in fact ended up being the closest it has been in 1000's of year in 2003.
2) It was also tilted
more face on in 2001. In May 2016 it is tipped with the north pole slightly toward us.
3) Cloud structures on a daily schedule change just like on Earth.
4) Illumination (from the sun) and filter selection adds to the differing images.
June 2001 WFPC Image of Mars: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Acknowledgment: J. Bell (Cornell U.), P. James (U. Toledo), M. Wolff (SSI), A. Lubenow (STScI), J. Neubert (MIT/Cornell)
May 2016 WFC3 Image of Mars: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute)
Heritage wishes to thank Mike Wolff (Space Science Institute), Jim Bell III (ASU), and Greg Bacon (STScI) for their invaluable help. We also wish to thank the STScI directorate for granting us a Director's Discretionary orbit to image Mars during this opposition.
When taking the observations for the 2016 Mars Opposition, the Hubble Heritage team took 26 exposures of Mars throughout one HST orbit. We repeated through four desired filters that would be used to create our color composite, and adjusted exposure times in case a particularly bright feature such as clouds or dust would saturate in our already short observations.
In 13 of the 26 frames, Mars' moon Phobos can be seen peeking out from behind the lower left limb of the planet. In order to see the moon, which is many times fainter Mars has been overexposed in these frames. Other artifacts that move in random directions are also visible. The final frame of the looping movie shows all images stacked. The colors are just to make things interesting.