An artist’s rendering of Mars four billion years ago (M. Kornmesser / ESO)
Earlier this month, research from the MAVEN spacecraft taught us a little bit about how Mars once had an atmosphere that was stripped away by powerful solar activity. The idea was sparked by evidence that Mars was once warm enough to have entire oceans on its surface before becoming the dusty brownish red marble we know today. The planet’s former thick atmosphere was likely lost thanks to strong bursts of particles known as solar wind, battering Mars with hot plumes of plasma and taking away oxygen at a rate ten times faster than Earth under the same conditions.
“When we look at ancient Mars we see a different type of surface, one that had valleys that look like they were carved by water, lakes that were standing for long periods of time,” said Bruce Jakosky, the principal investigator at the University of Colorado’s Laboratory for Atmospheric and Space Physics. “The climate must’ve been very different, warmer and wetter, and the atmosphere must’ve been thicker at that time in order to sustain a warmer climate. So what happened to the carbon dioxide from that early atmosphere? What happened to the water on early Mars?”
Of course, all of this was billions of years ago, and it led people to start asking if Earth will endure the same fate over time. While our planet has its protective magnetic shield now, scientists believe the pre-solar flare Mars looked much like our own home. This theory that Earth could also lose its water through evaporation would take approximately 4 billion years to carry out. “If it did happen, it’s hard to imagine that water would survive anywhere on Earth—no lakes, rivers, glaciers,” says Paul Renne, the director of Berkeley Geochronology Center. “This would presumably mean 100 percent extinction of biota.” But in those 4 billion years, it’s also expected that the sun will have swelled up to more than 100 times its size today. With that the Earth’s oceans will boil up before the sun engulfs it. So either outcome leaves no room for a thriving ocean or any people to enjoy it.
We’ll just have to wait 4 billion years and see.
