CAPE CANAVERAL, Fla. — A NASA probe is scheduled to launch to Mars today, Nov. 18, and you can watch it live online.

The space agency's Mars Atmosphere and Volatile Evolution spacecraft (MAVEN) is scheduled to launch atop its Atlas 5 rocket at 1:28 p.m. EST (1828 GMT) from here at Cape Canaveral Air Force Station. You can watch the launch live on SPACE.com via NASA TV, beginning at 11 a.m. EST (1600 GMT).

The  $671 million MAVEN will investigate the atmosphere of Mars in order to understand what could have happened to the planet in the past. Scientists think that ancient Mars had a thick atmosphere that supported liquid water, however, at some point in the planet's past, that changed and Mars morphed into the cold desert it is now. Mars' atmosphere is now about 1 percent as thick as that of Earth's. [NASA's MAVEN Mission to Mars (Photos)]

"We really do believe that at one time Mars was a planet that was not much unlike Earth is today," NASA chief Charlie Bolden told reporters Sunday, Nov. 17. "We want to know what happened. What happened to its atmosphere? Did it get scraped off or what? So MAVEN is going to help us understand the interaction of the sun with the Martian atmosphere."

While MAVEN — the 10th Mars probe launched by NASA — travels to Mars, the probe will be able to measure the environment it encounters during its trip, scientists working with the probe have said.

Once MAVEN completes its 10-month journey to Mars, it will join three other active probes in orbit around the Red Planet. NASA's Mars Reconnaissance Orbiter, Mars Odyssey and the European Space Agency's Mars Express are all studying Mars from above the planet.

NASA's Mars rover Curiosity and the Opportunity rover are still actively investigating Mars from the surface, and MAVEN has the ability to help them with their missions. The new probe has the ability to act as a relay point between Earth and the rovers on Mars in much the same way as the Mars Reconnaissance Orbiter and Mars Odyssey do today. MAVEN's relay system will act as a backup communications system for the rovers.

The Indian space agency launched its first Mars-bound probe earlier this month. The Mangalyaan spacecraft left Earth on Nov. 5 and is scheduled to arrive in orbit around the Red Planet on Sept. 24, 2014, two days after MAVEN is expected to arrive.

NASA centers around the country are holding viewing events for the launch today. Facilities associated with NASA in Washington, Maryland, Mississippi, Alabama and West Virginia will all host special events in honor of the launch. For a full list, visit NASA's MAVEN website.

Visit SPACE.com for the latest MAVEN news, photos and videos. You can also follow MAVEN coverage through the Mission Status Center at SPACE.com's partner, Spaceflight Now.

Follow Miriam Kramer @mirikramer and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on SPACE.com.

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This story was originally written for SPACE.com and was republished with permission here. Copyright 2013 SPACE.com, a TechMediaNetwork company.