Watch Japan launch a bold sample-return mission to Mars moon Phobos today

Japan will launch an epic mission to Mars today (Oct.

19), and you can watch the action live.

The Martian Moons eXploration ( MMX ) mission is scheduled to lift off atop an H3 rocket from Japan's Tanegashima Space Center today at 3:41 p.m.

EDT (1941 GMT; 4:41 a.m. on Oct.

20 local Japan time).

You can watch it live via the Japan Aerospace Exploration Agency (JAXA).

Coverage will begin at 2:45 p.m.

EDT (1845 GMT).

An artist’s concept of JAXA’s MMX spacecraft during its Mars orbit insertion.

The Martian moon Phobos, which MMX will explore and sample, is in the background. (Image credit: JAXA) As its full name suggests, MMX will focus on Mars ' two moons, Phobos and Deimos .

They're both tiny compared to Earth's own moon; Phobos is just 14 miles (22 kilometers) wide, and Deimos is even smaller, with a diameter of about 8 miles (13 km).

They're also quite mysterious.

While astronomers have a pretty clear understanding of our own moon's birth — it coalesced from material blasted into space when a Mars-sized planet slammed into Earth long ago — there's no consensus about Phobos and Deimos' origin story.

The duo "may be the remains of a massive impact on Mars that sent material into orbit around the planet, or they could be ancient asteroids that were captured by Mars' gravity billions of years ago," Tom Statler, MMX program executive and program scientist at NASA Headquarters, said in an Oct.