July 21, 2008—The European Space Agency's Venus Express creeps into closer orbit around its host planet in an artist's impression. Maneuvers began last week to steer the craft downward.

When the spacecraft settles in its new orbit on August 4, it will be within 115 miles (185 kilometers) of the planet's surface, a prime position for studying Venus's magnetic fields and ionosphere, the uppermost layer of the atmosphere.

Scientists also hope to determine the density of the Venetian atmosphere by measuring the drag exerted as the probe moves nearer to the planet.

• More Photos in the News
• Today's 15 Most Read Stories
• Free Email Newsletter: Focus on Photography