It's one small step for — no, scratch that. It's one giant step for the Mars rover Opportunity, which is about to set out on a two-year, seven-mile mission to the largest Martian crater ever investigated. Opportunity is wobbling along with some minor damage to its right front wheel and can only travel about 110 yards per day. Scientists at NASA's Jet Propulsion Laboratory say the rover may never even make it to its destination. But there are enticing possibilities if it does.

Today marks the 50th anniversary of the legislation that launched NASA and, subsequently, the human race into the great beyond. But have we really pushed our boundaries as far as space exploration can go? Or is NASA suffering a mid-life crisis?

It's the 50th anniversary of a great proxy battle fought in outer space. In 1958, President Eisenhower created NASA so the United States could compete with the USSR in space technology. Today, there’s a new space race on — between China and America. The finish line, 50 years later, is still the moon.

Guest: Heidi Hammel, Space Science Institute

Dark matter, one of cosmology’s most curious mysteries, has yet to be seen. But theorists have good reason to believe that it exists, and that galaxies, stars, and planets could never have formed without the gravitational attraction that dark matter exerts.

This was a busy week for space news watchers. The GLAST gamma-ray space observatory blasted off, the International Astronomical Union dubbed dwarf planets "plutoids" in honor of the once-planet Pluto, and the Phoenix Mars Lander scooped up Martian dirt. The Takeaway goes behind these headlines with astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium and host of NOVA ScienceNOW.

The Phoenix Mars Lander launched Aug. 4, 2007, in a quest to find life on Mars. After a 10-month journey, the lander successfully touched down on the planet's northern polar surface last night. CNN's technology and environment correspondent Miles O'Brien has been at NASA's Jet Propulsion Laboratory since Friday. He joins us live from Pasadena, Calif.

Pictured: The Phoenix Lander's Delta 2 launch vehicle taking off; an artist's rendering of the lander itself, and one of the very first images sent back from the lander this morning after its successful touchdown last night.

For the first time, scientists have witnessed the birth of a supernova. Heidi Hammel with the Space Science Institute tells us more.

On the left: 'Before' images show a previously known supernova, SN 2007uy, in galaxy NGC 2770.

On the right: An X-ray image taken on January 9, 2008, captures a moment of a 5-minute-long burst, indicating the creation of a new supernova, SN 2008D. The exploded star became visible to regular photography a few days later.

Image credit: NASA/Swift Science Team/Stefan Immler