Where to land on Mars

You can fly over the canyons of Mars

By Dr David Whitehouse BBC News Online science editor

A Nasa website for scientists to help them chose potential landing sites on Mars is becoming a great hit with the public as well.

Scientists preparing for Nasa's next Mars mission, the twin Mars Exploration Rovers scheduled for launch in June and July 2003, have created Marsoweb to enable them to view more than 44,000 high-resolution images of the red planet.

Mars provides a wealth of exciting landing sites, but most of them present surface hazards to the current generation of landers.

The images combine all the available data about the surface of Mars allowing researchers to fly through its canyons and valleys or over its volcanoes and desert dunes.

'Easy to be overwhelmed'

All the data you need to touch down

"We created this Web site to make sure that future Mars lander projects can benefit fully from all the available remote-sensing data to allow them to select the best landing sites," says Geoffrey Briggs, scientific director of CMEX, the Center for Mars Exploration.

CMEX project leader Virginia Gulick says, "By pulling everything together and adding advanced visualisation and analysis tools, we've enabled people to focus on studying the candidate sites and not lose time worrying about how to display, manipulate and compare all the relevant, but disparate, data sets."

"More than 100 sites on Mars have been considered by dozens of planetary scientists who are involved in analysing candidate landing sites," says researcher Glenn Deardorff.

"Marsoweb provides a resource for them to increase their productivity as they wade through the available data," he adds.

New perspective

The flanks of a Martian volcano

The goal of the Mars Exploration Rover mission is to find out about Mars' geologic and climatic history which are closely tied to the history of water on the red planet and to the possibility that life may have evolved there.

Orbital images reveal many regions that evidently have been shaped by water and the Thermal Emission Spectrometer on the Global Surveyor spacecraft has identified a region where the mineral hematite, an iron oxide sometimes formed in the presence of water, is abundant.

Marsoweb includes an interactive feature developed by Deardorff that allows scientists to view Mars' surface in perspective and from any angle to help assess prospective landing sites.

This Marsoweb software allows 3-D imaging of the surface of Mars. Users can enjoy zooming through the canyons and valleys of Mars or over its volcanoes and desert dunes.

In addition to its use by the science community, Deardorff says Marsoweb also has proven popular with the general public.

"It's also becoming an effective public outreach vehicle for people wanting to know more about Mars," he says.

"Since its inception Marsoweb has been viewed by more than 44,000 distinct users, resulting in more than 1,880,000 hits," he adds.