NASA started its final design and construction phase of the Mars 2020 rover last July. The rover is intended to hunt for signs of ancient life on the Red Planet after touching down in February 2021, exploring for at least two years.
Since this rover will be focused on gathering samples of rocks and dirt to potentially send back to Earth, scientists are looking for places that will offer a wide variety of these things. In other words, scientists have to choose and choose wisely about where they send the rover.
They've been working on it. The original 30 options were whittled down to just eight as of last July. And now NASA scientists have it down to three choices: an ancient lake, what used to be a volcanic hotbed, or a section of land that was once the site of a hot spring. All sound pretty cool.
The Mars 2020 rover might go to Jezero Crater, an ancient lakebed where microbial life may have developed at one point. The river delta's structure indicates, according to NASA scientists, that the area has filled with water and then been drained at least twice over the course of a very long time. A closer look at this planet might end up providing evidence there actually has been life on Mars in the past.
If NASA scientists aren't feeling the Jezero Crater, they could decide to send the Mars 2020 rover to the Columbia Hills, a spot nestled in the Guzev Crater.
Back in 2004, the Spirit rover started exploring the Guzev Crater, a crater that could easily hold all of Connecticut. While the Spirit rover was checking out the area, it came across the Columbia Hills, an area that showed evidence mineral springs had once flowed there.
In fact, all three of the possible locations used to have water on them, an important factor since part of the Mars 2020 rover's mission will be focused on looking for the “chemical or mineral signs of past life” that might help scientists understand just how inhabitable Mars once was.
These spots are also all good places because NASA expected that the rover will be able to move around easily to do all the tasks scientists want it to do.
Not everyone is thrilled by the final three choices. Some scientists say that it's a waste of time to even consider going back to Columbia Hills, since the Spirit rover has already explored it, according to Nature. However, supporters of that option insist there's more to learn from the site.
We won't know which spot will be the focus of the Mars 2020 rover for a while, though. The decision will be made about a year or two before the rover is launched on top of an Atlas V rocket in 2020.
Then, once the Mars 2020 rover actually reaches the planet (some 142 million miles later), it will bag up a bunch of samples and leave them there. There's still no actual official plan for how these samples will subsequently be transported back to Earth either. Expect to wait even longer to find out how that is going to happen.