How Recently Did Mars Have Liquid Water?

Science is very hard. You think you know something, you think you've got things all figured out, but then you get some more information, and that previous assumption just goes flying out the window. Case in point: last year, I wrote about how the MAVEN space probe had studied the Martian atmosphere and determined that the pleasant Mars with a substantial atmosphere and abundant liquid water was gone nearly 4 billion years ago, and for most of Mars' history, it's looked pretty much the same as it does now. It was simple, it was elegant, and while it wasn't really good news, it fit the data we had.

You can probably see where this is going. As it turns out, there are valleys and basins on the Martian surface that were formed by liquid water, but formed a billion years after the Martian atmosphere was lost to space, and the planet's surface became too cold to host liquid water. We're not talking about an insignificant amount of water either, there was enough water in one of these lakes to fill Lake Erie and Ontario with water to spare. The valleys running into these basins are not as complex as the older river valleys, indicating a slower flow. This probably indicates the lakes were filled not with rain, but with runoff from fallen snow.

This is obviously a bit of great news. If water could stay liquid on the Martian surface 2 billion years ago, that means that it was potentially habitable for the same amount of time. That is a much longer timeframe then we previously thought. 500 million years is not a huge amount of time for life to evolve, but 2 billion years is a lot more generous. Of course, it also raises into question the findings of MAVEN. Was the atmosphere gone by that point? Where did all the snow come from? Mars just got a lot more interesting.

Concert Review: Bruce Springsteen at Nationals Park

On September 1st, I went down to Nationals Park in Washington, D.C. to see Bruce Springsteen and the E Street Band play. I haven't been to a huge number of concerts in my life, but I can safely say that this was by far the best I've ever been to. I don't know much else to say about it, other than it was an absolutely incredible experience, and I would recommend his shows to anyone with even a passing interest in live music. The show ran for 3 hours and 45 minutes and there were no breaks at all, not even a lengthy anecdote or two. There just isn't an experience quite like a Bruce Springsteen concert.

Anyway, here's a couple of pictures from the show. I was literally in the last row of the stadium, so the quality isn't great, but there wasn't any problem with sound. It took the better part of a day for my hearing to recover completely.

Like I said, I was very far away from the stage.

I was hoping to hear "Atlantic City" and "Thunder Road", but realistically, if I were to grade the performance, that would only bring it down to a 9.9 out of 10. There was a lot from "Born in the U.S.A", though oddly, no "Born in the U.S.A.". Also, there wasn't much from "The River", which I thought was a little odd since this was the River Tour. They've been doing the whole album for a while now, I guess it was time for a bit of variation. Anyway, here's the setlist from the evening

New York City Serenade
Summertime Blues
Sherry Darling
No Surrender
Growin' Up
It's Hard to be a Saint in the City
Does This Bus Stop at 82nd Street?
Spirit in the Night
Lost in the Flood
Kitty's Back
Incident on 57th Street
Rosalita (Come Out Tonight)
Night
Trapped
Better Days
The Promised Land
American Skin (41 Shots)
Hungry Heart
Out in the Street
Darlington County
Working on the Highway
Downbound Train
I'm On Fire
Because the Night
The Rising
Badlands
Secret Garden
Jungleland
Born to Run
Seven Nights to Rock
Dancing in the Dark
Tenth Avenue Freeze-Out
Shout
Bobby Jean