【Week 4】火星探險

Opportunity Mars Rover set for last missions to find water

By Jose Gregorio Zapata -November 7, 2016

NASA’s Opportunity Mars Rover is ready for the last two years of its mission after it spent the month of October studying the rich and familiar geology at the Wharton Ridge on the western rim of Endeavour Crater. The two-year extended mission that began on October 1 will drive the Opportunity down a gully carved many time ago by a fluid that could have been water. The probe should take samples and photos at the spot and send them back to operation control.

Next, Opportunity will explore the insides of the Endeavour Crater, and it will become the first probe ever to see the interior of Mars’ cavities. The probe should compare the rocks inside the crater to the dominant type of rock it found on the plains it explored before.

The ditch goes west-to-east through the rim about half a mile south of the rover’s current location. Opportunity’s Principal Investigator Steve Squyres of Cornell University believes the fluid that covers the gully was water millions of years ago.

NASA knows about fluid-covered gullies since it began watching Mars from orbit on the 1970s, but this is going to be the first mission to examine the fluid up close on the surface.  The team wants to drive Opportunity down the entire gully and onto the crater floor. The last goal of the extended mission is to compare the rocks inside Endeavour Crater with the rocks on the surface to see if there are traces of water.

The probe’s latest and probably most important expedition will begin in the Bitterroot Valley portion in the western rim of the Endeavour Crater. It is a 14 miles diameter basin that was created by a meteor impact billions of years ago.

The vessel reached the edge of the crater in 2011 after more than seven years investigating a series of smaller holes. In those places, the rover found evidence of ancient acidic water that went to underground layers and could have been on the surface before.

Excerpt from: http://theusbport.com/opportunity-mars-rover-set-for-last-missions-to-find-water/20842

Structure of the Lead:

What: Opportunity
Where: Mars
Why: to find water
When: began on October 1
How: Not given
Who: Not given

Keywords:

geology(n.) 地質學
gully(n.) 溝渠
fluid(n.) 流體
probe(n.) 探測器
crater(n.) 噴火口
orbit(n.) 軌道
trace(n.) 蹤跡
expedition(n.) 考察
basin(n.) 盆地
underground layer(n.) 地下層