When Mars was young, the planet was much warmer and wetter than it is today, with a fairly thick atmosphere. Most of that atmosphere leaked away into space. And scientists are still trying to understand how that happened.

They should learn more from twin spacecraft that are scheduled to launch soon. The mission is called Escapade, while the individual craft are designated Blue and Gold. If they launch on time, they’ll enter orbit around Mars a year from now.

The probes will study the weak Martian magnetic field and how it interacts with the solar wind – a “breeze” of charged particles from the Sun.

Because Martian gravity is much weaker than Earth’s gravity, molecules in its early atmosphere drifted to the top of the atmosphere. There, radiation from the Sun split the molecules apart. The solar wind then carried off some of the residue. Over the eons, that depleted the atmosphere. Today, it’s less than one percent as thick as Earth’s.

Many of the details of that process are unclear. The Escapade probes will monitor that process from different perspectives, offering a 3-D view of what’s going on. That should help scientists fill in the blanks – providing a much better understanding of how Mars lost its air.

Mars perches close to the Moon early tomorrow. They climb into view by 1 or 1:30 a.m., and stand high in the sky at first light. Mars looks like a bright orange star to the lower right of the Moon.

Script by Damond Benningfield

NOTE: Since this program was recorded NASA has delayed the launch of Escapade until at least 2025.