MRO MARCI Weather Report for the week of
13 April 2009 – 19 April 2009

Martian weather between 13 April 2009 and 19 April 2009:

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.

The past week on Mars consisted of notably less storm activity than observed over the last few weeks. Water ice clouds occurred in the northern mid-latitudes, particularly in Tempe and Acidalia. Dust activity occurred in Hellas and Argyre and along the seasonal south polar cap edge (particularly in Terra Cimmeria), but nothing as remarkable as some of the recent dust storms. A dust haze was still present in the atmosphere, leading to murky skies across much of the planet, including over both the Spirit and Opportunity rovers. Only the southern high latitudes and high elevation areas such as Olympus Mons and the Tharsis volcanoes experienced dust-free skies, although water ice clouds persisted over Arsia throughout the week.

This week’s MARCI “movie” can be downloaded HERE (9.2 MB .mov file).

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.