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When astronomers go on a scavenger hunt for cool things around the solar system, the grand prize they hope to find is liquid water. Sure, scientists think that it may be possible to have some  kind of life that uses other substances like liquid methane, but we know that it's definitely possible with liquid water.

So last week, when a group of scientists from Germany and the U.S announced that they'd found evidence of a vast subsurface ocean on Jupiter's moon Ganymede, it was kind of a big deal. But it wasn't the first time that scientists suspected there was water beneath the moon's icy surface.

Back in the 1970s, scientists predicted that there could be back in the s and has predicted that there could be a whole lotta water sitting under there, but that was just based on models and simulations.

In 2002 researchers speculated there is water beneath the main service based on measurements of its magnetic field taken by the probe Galileo. But it still wasn't quite enough for the scientific community to agree that yes, Ganymede definitely has a lot of water... until now.

The new research uses Hubble's Space Telescope imaging spectrograph to study the moon's auroras, the bands of light near the poles created by interactions between the electrically charged solar wind and particles in the moon's atmosphere. Where those bands end up has a lot to do with the moon's magnetic fields because electric and magnetic fields are two parts of the same force. Jupiter, never a planet to do anything halfway, generates a huge magnetic field strong enough to influence the pattern of auroras on Ganymede.

In fact, its super strong field should cause the auroras to rock back and forth about six degrees every ten hours. But the researchers were able to prove that the bands of light were only moving about two degrees, meaning that something was messing with the moon's magnetic field. In this case it turned out to be a second magnetic field on Ganymede created by the interaction of Jupiter's magnetism with a giant salty electrically conductive ocean.

By the scientist's calculations the ocean is about a hundred kilometers deep and if they're right about how expansive it is, than Ganymede contains more water than all of Earth's oceans put together. Ganymede may be bigger than Mercury but that's still a lot of water for one moon to hold. And now that scientists have developed this new method for finding water, studies of other moons might use the same aurora tracking technique to detect liquid water and who knows what else.

In other news, if you don't happen to have a multi-billion dollar space telescope at your disposal and you're just into watching the night skies yourself, well then NASA wants you. With the proliferation of the worldwide data sharing tool we affectionately call the Internet space agencies have begun to embrace citizen science. Harnessing the smarts and curiosity of ordinary people around the world.

recently professional astronomers have called upon this crowd sourcing power to help them scan the night skies and identify possible threats. With as many observatories online as there are at any given time, there are so many pictures being taken of the night sky that it's impossible for all the little objects in them to be analyzed by people. So the images are fed into a computer program that uses algorithms to figure out what all the different colorful pixels mean. Using information like what area of the sky a picture was taken in, the program can track known objects and also identify new ones like near-earth asteroids.

And when it comes to tracking asteroids the fact is, our programs haven't been very good. According to NASA's own estimates they've only been accurate eighty to ninety percent of the time. Which seems pretty good, but when you're talking about finding giant space rocks that want to punch earth in the face you really want to get as close to one-hundred percent as possible.

So NASA and asteroid mining firm Planetary Resources figured they should start building a new asteroid tracking program from scratch. That's why they launched the "Asteroid Data Hunter Challenge". A competition that offered fifty-five thousand US dollars in prizes to anyone who could come up with new and better algorithms for a new Asteroid detecting program.

The winning algorithm, announced last week, was both more sensitive and produced fewer false positives than the old program. Overall, it proved to be fifteen percent better at finding asteroids. So NASA and Planetary Resources have turned the winning bit of code into software appropriately called "Asteroid Data Hunter" which you can now use yourself to help save Earth from total destruction!

Or just to discover new but harmless asteroids, which is pretty awesome too.

All you have to do is upload images from your telescope and the program does the rest. Identifying the objects in the image and listing them for you. Then it automatically shares that data with the rest of the world.

You can download the program for free from the link in the description below. So get observing, and let us know what you discover! In the meantime, thanks for joining me for SciShow Space News.

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