Sun, Earth, Mars
This schematic depicts the relative positions of the Sun, Earth and Mars at the time of the observation on July 4, 2001. Chandra was scheduled to observe Mars when it was only 70 million kilometers from Earth, and also near the point in its orbit when it is closest to the Sun. (Not to scale)
(Schematic: NASA/NASA/CXC/M.Weiss)

Hubble Optical (26 June 2001)
Frosty white water ice clouds and swirling orange dust storms above a vivid rusty landscape reveal Mars as a dynamic planet in this sharp image. The Earth-orbiting Hubble telescope snapped this picture on June 26, when Mars was approximately 43 million miles (68 million km) from Earth -- its closest approach to our planet since 1988. The disk of Mars was fully illuminated as seen from Earth because Mars was exactly opposite the Sun. Hubble can see details as small as 10 miles (16 km) across. Especially striking is the large amount of seasonal dust storm activity seen in this image. One large storm system is churning high above the northern polar cap [top of image], and a smaller dust storm cloud can be seen nearby. Another large duststorm is spilling out of the giant Hellas impact basin in the Southern Hemisphere [lower right].
(Credit: NASA, J.Bell (Cornell), M.Wolff (SSI) and The Hubble Heritage Team (STScI/AURA))

Hubble Optical (04 Sept 2001)
When Hubble photographed Mars on September 4, 2001, a global dust storm had been raging across the planet for nearly two months, obscuring all surface features. The fine airborne dust blocks a significant amount of sunlight from reaching the Martian surface. This picture was taken when Mars was 60 million miles from Earth.

(Credit: NASA, J.Bell (Cornell), M.Wolff (SSI) and The Hubble Heritage Team (STScI/AURA))

More Information: http://hubblesite.org/newscenter/newsdesk/archive/releases/2001/31/

Chandra X-ray (orange color scheme)
This remarkable Chandra image gave scientists their first look at X-rays from Mars. In the sparse upper atmosphere of Mars, about 120 (75 miles) kilometers above its surface, the observed X-rays are produced by fluorescent radiation from oxygen atoms.
(Credit: NASA/CXC/MPE/K.Dennerl et al.)

Chandra X-ray Image with Scale Bar
Scale bar = 30 arcsec
Credit: NASA/CXC/MPE/K.Dennerl et al.