BBC Homepage World Service Education
BBC Homepagelow graphics version | feedback | help
BBC News Online
 You are in: Sci/Tech
Front Page 
UK Politics 
Talking Point 
In Depth 

Monday, 23 October, 2000, 17:37 GMT 18:37 UK
New view of giant Martian volcano
Olympus Mons, the largest volcano in the Solar System
By BBC News Online science editor Dr David Whitehouse

Laser beams bounced off the surface of Mars have produced a unique view of the largest volcano in the Solar System.

Olympus Mons is 27 km (17 miles) tall, three times the height of Mount Everest, and twenty times wider than it is high.

Looking down from Viking
Images mapped by the Mars Global Surveyor spacecraft have enabled a profile of the Martian volcano to be produced with unprecedented accuracy.

Astronomers say it is raising many questions about the still poorly understood, extinct volcano.

Mars mission

Since it started its mapping mission around Mars in 1998, the Mars Global Surveyor has sent back thousands of high quality images.

It has also scanned the surface of the planet using Mola (Mars Orbiter Laser Altimeter), which beams an infrared laser pulse towards the surface of the Red Planet 10 times a second. Mola then measures how long it takes for a reflection to return to the spacecraft.

A profile of the surface can be obtained to an accuracy of 37 cm (15 inches) with this data. The measurements have been used to construct a precise topographical map of Mars with many applications in geophysics, geology and atmospheric circulation.

The volcano data have been merged with an image of Olympus Mons taken by the Viking Orbiter spacecraft of the 1970s and vertically exaggerated by a factor of 10.

Astronomers say that Mola's data are giving them a new view of the volcano. It shows that Olympus Mons sits off to the west of the main Tharsis rise rather than on its western flank as was thought.

The topography also clearly shows the relationship between the scarp of the Olympus Mons, unique on Mars, and structures produced by the collapse of the flanks of the volcano.

Search BBC News Online

Advanced search options
Launch console
See also:

17 Jan 00 | Sci/Tech
Nasa ends search for Mars probe
31 Jan 00 | Sci/Tech
New Mars meteorite found
12 Feb 00 | Sci/Tech
Happy Valentine's from Mars
11 Apr 00 | Sci/Tech
Martian mysteries at poles
21 Jun 00 | Sci/Tech
Water 'found on Mars'
Internet links:

The BBC is not responsible for the content of external internet sites

Links to more Sci/Tech stories are at the foot of the page.

E-mail this story to a friend

Links to more Sci/Tech stories