Astron

High Resolution Imaging Science Experiment is a camera on board the Mars Reconnaissance Orbiter . The 65 kg (143 lb), $40 million USD instrument was built under the direction of the University of Arizona 's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp. It consists of a 0.5 m (19.7 in) aperture reflecting telescope , the largest so far of any deep space mission, which allows it to take pictures of Mars with resolutions of 0.3 m/pixel (about 1 foot), resolving objects below a meter across. HiRISE has imaged Mars landers on the surface, including the ongoing Curiosity and Opportunity rover missions . [1] https://en.wikipedia.org/wiki/HiRISE   Portal   http://www.uahirise.org/  

Comparative planetary science or comparative planetology is a branch of space science and planetary science in which different natural processes and systems are studied by their effects and phenomena on and between multiple bodies . The planetary processes in question include geology, hydrology, atmospheric physics, and interactions such as impact cratering, space weathering, and magnetospheric physics in the solar wind, and possibly biology, via astrobiology . Comparison of multiple bodies assists the researcher, if for no other reason than the Earth is far more accessible than any other body. Those distant bodies may then be evaluated in the context of processes already characterized on Earth. Conversely, other bodies (including extrasolar ones ) may provide additional examples, edge cases, and counterexamples to earthbound processes; without a greater context, studying these phenomena in relation to Earth alone may result in low sample sizes and observational biases.