Hi, everyone. My name is Fraser Kane. I am the publisher of universe today. And this is your weekly space hangout for October 4th, 2012.

Now, if you're watching, if you're listening to this in the astronomy cast podcast feed, I want to remind you that we record the weekly space hangout live once a week every Thursday at 10 a.m. Pacific,

one Eastern and half of six Greenwich Bean time. So if you want to watch us record live, you can always you can always join us right on Google plus. So joining, joining me this week, we've got, let's see who we got. We've got Amy Shera title from vintage space. We've got Nancy Atkinson, my co-conspirator at universe today. And we've got Nicole Galucci from CosmoQuest, aka the Noisy Astronomer.

And we've got a few topics for you guys this week. It's a very strange week. It feels like a bit of a calm before the storm. Last week was an absolute zoo of space news. And we were all sort of having to get ready for a great big press conference from NASA. And so there's one great big story that was released. And that, and there hasn't been a lot of other big news this week. So we've got a few interesting stories, but not the big news.

So, so we're going to talk about the ancient stream bed that was discovered on Mars by Curiosity. We're going to talk about the, I guess the, the square kilometer array in Australia is moving forward. We've got a strange cold layer on Venus, the most precise measurement of the universe's expansion. And happy lunch, birthday, Sputnik, 55. So, well, let's get rolling. So first we got to talk about the big, big space news, which is, which was this.

The ancient stream bed on Mars. And so last week when we did the, the week the space hangout, we didn't know that what NASA was going to be announcing. We knew they were going to be analyzing Jake, the rock. And so we thought that there was going to be some, some results from that. But in fact, there was actually some really big, big news announced. So Nancy, you covered this a bit. So what, what was the announcement?

Well, yeah, we, when we had the dash off last Thursday, I kind of figured it might be some big news because they did televised on NASA TV. But I was really surprised at this. So the Curiosity rover team said that the rover had come across a place in Gail Crater, where they said years ago, millions of years ago,

there was an angle to hip, deep water once vigorously flowed. So what they found was an ancient stream bed. And, and the gravel that was there that they found showed indications that had been worn by water. And all indications are where that the water flowed for a long time as opposed to kind of the flash water events that people have proposed in the past, which would have created the now dry waterways and gullies and other fixed features that we see on Mars today.

What they saw was what they called water transported gravel, gravel that has been worn down into small pieces by water. And that the gravel is now embedded in or kind of cemented in rock, which they called a conglomerate. And from the size of the gravel, fun by the rover, the science team was able to say that they thought the water was moving about a meter per second.

And that the water was somewhere between ankle and hip deep. Now, this, this coming from the team really amazingly early into the mission was, was really surprising. And I for one was surprised at how soon they could make this determination, especially since the rover hasn't been there all that long.

And so, but what they said is that they've really, from the orbital images, from, from high rise from the Mars Reconnaissance Orbiter, they've been able to see indications of, you know, alluvial fans and, and, and flows coming into into that crater, into Yale crater.

And so it really didn't take them long to come, come to consensus that this, you know, when they immediately, when they saw this gravelly water worn rock, they were, you know, very quickly able to come to a scientific consensus that that's what they were seeing water worn rock.

So, the area that this is, it lies to the north rim of Yale crater and, and it goes to the base of ALS Mons or Mount Sharp. And so, again, the, the abundance of channels and the gravel that they're seeing suggests that the flows continued or repeated for a long time and not just for a few years.

Yeah, I mean, I think the way that the folks at NASA described this, this is almost like if they, if Curiosity went to Mars and discovered this ancient stream bed, it would be mission accomplished, right? And they're, and they're already, this is just the first couple of months of it crawling around the surface of the planet.

So, you know, to come across, because when we've mentioned this in the past, right, that the, the goal here with Curiosity is that, you know, they're not looking for life yet, because apparently that's forbidden, but they're, but they're looking for, you know, evidence that there were conditions on Mars in ancient times that life could have existed.

So, you want water to float, liquid water to bend on the surface for a long time. You want the kinds of chemicals that would have been present with life there, an energy source, something like that, all at the same time.

And so to find this ancient river, I mean, I've, I've got a river like that near my house, you can go down and you can find these smooth rocks that have been jumbled around like in a great, big rock tumbler for a million years.

And, and that's what you see. You look at that, you look at that picture, the pictures of, of Mars.

I don't know if someone has one of those pictures. We can maybe put that up in a second, but you look at those pictures and you can see these, you know, round rocks all collected together.

It's, it's just a stunning finding. It was not at all. I was, I was completely surprised when they actually announced it in the, in the press conference.

Yeah, and, and they basically said, though, I mean, they've already moved on from this spot. It's a, it's like, okay, found that we're moving on now because they said that this actually was not a place to really find organics where they really want to go is the base of aolis mons where they've seen from orbit that there are clays, layers of clays and those are, clays are a very good preserver of carbon based organic chemicals that are, are potential.

Ingredients for life. So, basically, they found the water evidence and said, okay, found that, check that off for list and now we're going to go find organics.

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