MRO MARCI Weather Report for the week of
14 April 2008 – 20 April 2008

Martian Weather Between 14 April 2008 and 20 April 2008:

The MARCI acquires a global view of the red planet and its weather patterns every day. Please click and play the Quicktime movie (.mov file) to see how the weather on Mars changed during this time.

As of the past week, the seasonal north polar cap edge had retreated to about 70 degrees north latitude. Water vapor released from the north polar cap was transported southward by the general circulation to the northern tropics, where it formed into clouds as part of the aphelion (equatorial) cloud belt. Water ice clouds were also observed over the major shield volcanoes and in the southern mid-latitudes. Hellas and Argyre remained rather hazy due to these clouds. A number of local dust storms were observed west of Argyre basin and more sporadically throughout the rest of the southern mid-latitudes. One dust storm of note occurred mid-week along the north polar cap edge, lifting dust onto the perennial cap. This storm abated within a couple days. The two MER rover sites (Gusev Crater and Meridiani Planum) continued to experience scattered water ice cloud cover throughout the week, but remained free of any afternoon dust storm activity.

Earlier Mars Weather Reports are available HERE.

About the Quicktime Movie:
The movie (a .mov file that you can click and play, above) was generated from images obtained by the Mars Color Imager (MARCI) onboard the Mars Reconnaissance Orbiter (MRO). During a nominal operational week, a total of about 273 MARCI images, taken in three of the camera’s seven color filter bands (420, 550, and 600 nanometer wavelengths), are map projected and mosaiced together to produce seven false-color daily global maps. These maps are then projected onto a sphere with north at the top and east to the right and with the mid-afternoon vantage point of an observer in the orbital plane (the imaginary plane that the planet draws out as it circles the Sun). Black areas in the movie are the result of data drops or high angle roll maneuvers by the spacecraft that limit the camera’s view of the planet. Equally-spaced blurry areas that run from south-to-north (bottom-to-top) result from the high off-nadir viewing geometry, a product of the spacecraft’s low-orbit, 250 km x 316 km (155 miles x 196 miles). The movie is rendered at a lower resolution than the intrinsic 1–2 km nadir resolution that the MARCI provides, so that it is practical to view and share via the Internet. The small white circles on these images of Mars indicate the locations of the two Mars Exploration Rovers, Opportunity (on Meridiani Planum) and Spirit (in Gusev Crater). Other locations on Mars referenced in the weather report can be found by referring to the map below. Note that the still image of Mars depicted at the top of this page is a single frame from the Quicktime movie.

Malin Space Science Systems, Inc., San Diego, California, U.S.A.