Dr. Carly Howett – TRANSCRIPT
What’s the worst thing you can see from a spacecraft that’s 3 billion miles away from you? Well, in my experience, it’s this. If you don’t know what this means, then consider yourself to be lucky.
It’s the blue screen of death, and it basically means your computer is in some trouble. New Horizons saw this just ten days before this spacecraft was due to encounter Pluto. But what was it doing there? Why did we send a spacecraft all of that way? Well, this little space robot had very important mission. It was to complete humankind’s first reconnaissance of our Solar System, and this was important, because we thought by understanding Pluto better, we would understand our outer Solar System better, which would tell us more about how our whole Solar System both formed and evolved.
We tried looking at Pluto from the Earth, from telescopes we have available to us now, and this was the image that we constructed. It’s kind of blotchy. And this looks especially bad if you compare it to the images we have of other planets. Compare it to this image of Mars or Saturn. So, they tackle image. Well, Pluto looks kind of sad and blotchy. And it’s not that we’re just – rubbish – pulling together HST images.
This is a very hard thing to do because Pluto is about the same size as Russia, but it’s located 3 billion miles away from us. To put that into a different context, that’s like trying to understand the markings of a soccer ball that’s 40 miles away from you, or the back row of this audience trying to see what the color of that single hair of my head is like. It’s a tough thing to do. We had a spacecraft, and we knew we needed to get it there, but how do you do that?
We have some options.
You can be fast, and we were fast. We built a light spacecraft, and we put it on top of a very quick rocket. We lit the fuse and stood well back. By the time New Horizons was at Pluto, we were going 32,000 miles an hour. If this spacecraft was going around the Earth, it would do so in just 40 minutes. It’s pretty speedy. You could be smart. We’re scientists. We were smart. We launched the spacecraft in such a way that it went past Jupiter and in doing so, this enormous planet gave us a kick and that sped us up, cutting three years off of our journey time.
And patient. Well, there’s no getting around that. If you’re going to send a spacecraft all that way up to Pluto, you have to be willing to wait a little while. So, we waited. One, two, three, four, five, six, seven, eight, nine long years for this spacecraft to reach Pluto, which brings us back to the beginning of our story.
Bam! A blue screen of death. Now, it wasn’t really the blue screen of death because we weren’t running Windows XP. But it was this spacecraft equivalent, and that’s known as safe mode. So, what happens is the spacecraft thinks it’s in danger, and it closes down all non essential systems and it calls home. So, now, A: we’re not taking any data just 10 days before we explore a new world – seems like a bad idea – and B: we have a very limited time to coax this spacecraft back into working order. Now, this would be a hard thing to do normally, but New Horizons is just 3 billion miles away from us, so every command that we send it takes four and a half hours to reach the spacecraft and everything it wants to tell us, takes four and a half hours to reach us.
Imagine trying to debug the blue screen of death when every command takes nine hours. But, this isn’t a first time we’ve operated a spacecraft, and it’s not even the first time we’ve operated New Horizons, and we had a trick up our sleeve. The main one was in the form of a module, a simulator, located here on Earth where we could test different ideas, different commands that would solve this problem. And so, four days later, not a lot of sleep and a lot of time, we uploaded this command and New Horizons was back on track, just six days before our encounter with Pluto. And, boy, are we glad we were, because we went from this to this.
So, earthlings, I’d like to introduce you to Pluto. You don’t have to be a well trained geologist to see that this planet is full of crazy terrains. One of the first things that struck us is this crazy shape on its surface. There’s a shape of a heart. Can you see it? All right, those who can’t, I’ll give you a clue.
Now, this is weird because we don’t see heart shapes in our Solar System. We’ve been to a lot of places, and we don’t see them; they’re not there. We see lakes of methane on Titan. We see a storm on Saturn’s north pole. It’s a hurricane, but it’s shaped like a hexagon. And little Io has volcanoes that erupt directly into space. But no hearts. And yet, here it is, a giant, whacking, ginormous heart right in the middle of Pluto. If that wasn’t weird enough, this heart is very, very smooth in places, which is strange because everywhere in our Solar System is bombarded by meteorites. It’s just a fact of life.
And meteorites create impact craters. If we compare Pluto to one of Saturn’s moons, called Rhea, and they’re about the same size, so the comparison isn’t that crazy, you can see just how smooth some of these heart regions are. So, that’s telling us that something’s happening here to eradicate, to erase those craters. And geologists think that recently – and you have to be careful with that word when it comes to geology because it doesn’t mean the time between breakfast and dinner like you or I might talk about; it actually can mean anything up to 100 million years to current times – but recently, geologically speaking, this region was active, and we don’t really know what form that activity took. Maybe the surface ices here are very soft.
So, creating an impact crater here is a lot like trying to punch a hole in jello. It’s just never going to work. Or maybe the ices here are more likely than the their surroundings to sublimate away. Now, that means when an ice goes directly into a gas, and we see that all the time in Colorado; our snow doesn’t melt like elsewhere. So, maybe creating an impact crater in this region is a lot like making a footprint in the Colorado snow.
It was never destined to stand the test of time. Now, there’s a lot in this image that I could tell you about. These are one of my favorites. These are mountains, mountains on Pluto. We know that they’re mountains because you can see their shadows are very long.
And we know they’re actually a lot like our own Rocky Mountains. They stand about three miles above the surface, and they’re very new because they’re sharp and pointy still. But unlike our own rocky Rocky Mountains, these are made of water ice. See, Pluto simply isn’t heavy enough for these to be made of rock. And we see other ices on Pluto’s surface; we see nitrogen and methane ice.
But at the Pluto’s conditions, these ices are too soft, they would crumble under the weight of that mountain. But at Pluto’s temperature, water ice is funny, and it’s incredibly hard, and it could do things that would be impossible here on Earth, like form mountains. So, in case you’re wondering, with the right gear, you could totally ski on Pluto.
Now, it wasn’t just Pluto that we looked at. New Horizons explored the entire Pluto system. Did you know that Pluto has a moon called Charon that’s almost the same size as Pluto? This is Charon. It has a weird red spot on its north pole that’s coincident with a crater, and we don’t know if the two things are connected. Pluto also has a series of small moons, one of which is called Nix. This is Nix. We’ve been studying Nix for a long time, and we’d only have seen it as a small speck of light.
So, imagine our surprise and slight confusion when we finally resolved this object, only to find that it looked like potato that had been kissed. And we have no idea how you get a kiss mark on a small moon. I couldn’t leave you without touching on only one more image of Pluto, and this is an image that was downlinked this week. As a scientist, I want to spend my career analyzing this image, because there are so many complex things going on to create this image. But as a human being I wonder at its beauty.
Was Pluto worth the wait? I’ll let you decide, but I sure know what I think. Thank you.
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