Gadgetory

I'm Sheena reporter Kara Tsuboi at NASA's Ames Research Center in California's Silicon Valley i'm joined by jack lissauer a planetary scientist for nasa and we are here to talk about NASA's ongoing mission with the messenger to explore mercury they are circling mercury right now as we speak and tell chef what they're hoping to find from this mission well two spacecraft they've been visits to mercury by one spacecraft back in the 1970s cold mariner 10 okay and that went by three times but it would always photographed mercury in the same part of its orbit and when the same part of the planet was left so it ended up taking pictures of a little under half the surface now messenger went by once in January of this year at a photograph some of the parts that mariner 10 saw and a few new parts this visit season a different side of mercury and we're going to see a lot of parts of mercury that have never been imaged by a sprayed spacecraft previously what kind of images are we expecting to see what is the terrain like on Mercury well mercury has a lot of craters but there have been other geological processes the planet seems to have shrunk over the history of the solar system and things have fallen down things have been pushed up as a result of this and there are geological features in addition to just the craters that are saved moreover there's evidence of previous volcanism in the long long past and this leaves its sign on mercury what does Mercury's significance as a planet in our solar system well mercury is the planet that's closest to the Sun class and it's the smallest of the eight major planets it's also the planet that is has the most dense material its may up substantially of iron and nickel in its core it scores a larger fraction of its size than the core of any other planet and we believe that what happened was mercury was once larger and it got hit by something and that's something knocked off about say twenty percent of Mercury's mass and it was lighter material the parts that were in the crust in the mantle now something like that happened at a smaller scale in the case of the earth material was knocked off earth and some of that went into orbit and that formed Earth's moon but because earth is a bigger planet it didn't lose a lot of materials mercury lost a lot of material because it's smaller it has less gravity and it orbits closer to the Sun so things tend to hit it at a faster velocity now if there has been a real gap in exploration of mercury between the I don't know some 20-odd years why has there been such a gap in the exploration of mercury well that's a good question and the reason is mercury is actually very difficult to get to you might think that mercury it's closer to the Sun you just fall in well we're going around the Sun we're not falling in and you send a spacecraft out it's going around the Sun like Earth and you've got to get it going around the Sun much less rapidly sir and the way to do that the best way to do that is actually slow it down a little bit get it to have an orbit which crosses Venus use the gravity of Venus to bring it near mercury and that was done back in night the 1970s with Mariner 10 and it was done again we have met the messenger spacecraft what kind of spacecraft is messenger well messenger is a small spacecraft it has various instruments the most interesting ones are cameras and a laser we will be useful when messenger goes into orbit around mercury in 2011 to get the heights of the surface to see how the big the mountains are how deep the craters are when these scarfs that formed by Mercury's contraction will get also information on the magnetic field of mercury that was a big surprise of the mariner 10 mission to find that mercury has a significant magnetic field now it's nowhere near as much as Earth Mercury's a much smaller planet but this was our first indication that that core of mercury wasn't all solid like he was first believed but had some liquid on it it was just recently confirmed that the outer part of Mercury's core is liquid and mercury is generating a magnetic field in the same way that Earth is and that's different from any of the other planets in our solar system so does that mean possible signs of life or extinct I think mercury is a little bit too hot on most of its surface and it also has virtually no atmosphere but it may help us understand how earth got its magnetic field how r magnetic field changes with and that has effects on life and it has effects on life unpossible other planets outside our solar system how common magnetic fields like the Earth's are but of course it sends back a stunning photos of a planet that we don't normally get to see much of oh yes we're getting these first hints of what's going on and we're also testing out the instruments knowing how to deal with data so when it goes into orbit they can plan what to do when it goes into orbit they can analyze the data more quickly so these flybys well their primary reason is to change messengers orbit they have significant secondary scientific benefits absolutely well good to see a lesser known planet get some love finally and we look forward to the images that it sends back excellent I'm looking forward with you thank you so much NASA planetary scientist Jack lissauer I'm seen a reporter Kara Tsuboi reporting from NASA's Ames Research Center in the heart of Silicon Valley you