seg 1: planetary systems outside our own
seg 2: are like distant cities
seg 3: whose lights we can see twinkling
seg 4: but whose streets we can't walk
seg 5: by studying those twinkling lights though
seg 6: we can learn
seg 7: about how stars and planets
seg 8: interact
seg 9: to form their
seg 10: own ecosystem
seg 11: and make habitats that are amenable to life
seg 12: in this image of the tokyo skyline
seg 13: i've hidden data
seg 14: from the newest planet hunting space telescope on the block
seg 15: the kepler mission can
seg 16: you see it
seg 17: there we go
seg 18: this is just a tiny part of the sky the kepler stares at
seg 19: where it searches for planets
seg 20: by measuring the light of over one hundred and fifty thousand stars
seg 21: all at once
seg 22: every half hour
seg 23: and very precisely
seg 24: and what we're looking for
seg 25: is the tiny dimming of light
seg 26: that is caused by a
seg 27: planet
seg 28: passing in front of one of these stars
seg 29: and blocking some of that starlight from getting to us
seg 30: in just over two years of operations
seg 31: we've found over one thousand two hundred
seg 32: potential
seg 33: new planetary systems around other stars
seg 34: to give you some perspective
seg 35: in the previous two decades of searching
seg 36: we had
seg 37: only known about four hundred
seg 38: prior to kepler
seg 39: when we see these little dips in the light
seg 40: we can determine a number of things
seg 41: for one thing we can determine that there's a planet
seg 42: there
seg 43: but also
seg 44: how big that planet is
seg 45: and how far it is away from its parent star
seg 46: that distance is
seg 47: really important
seg 48: because it tells us
seg 49: how much light
seg 50: the planet receives overall
seg 51: and that
seg 52: distance and knowing that amount of light is important because
seg 53: it's a little like you or i sitting around a campfire
seg 54: you want to be close enough to the campfire so that you're warm
seg 55: but not so close that you're too toasty and you get burned
seg 56: however there's more to know about your parent star
seg 57: than just how much light you receive overall
seg 58: and i'll tell you why
seg 59: this is our star
seg 60: this is our sun
seg 61: it's shown here in visible light
seg 62: that's the light that you can see with your
seg 63: own human eyes
seg 64: you'll notice that it looks pretty much like
seg 65: the
seg 66: iconic yellow ball that sun that we all draw when we're children
seg 67: but you'll notice something else
seg 68: and that's that the face of the sun
seg 69: has freckles
seg 70: these freckles
seg 71: are called sunspots
seg 72: and they are just one of the manifestations of the sun's magnetic field
seg 73: they
seg 74: also cause
seg 75: the light from the star to vary
seg 76: and we can measure this
seg 77: very very precisely with kepler
seg 78: and trace their effects
seg 79: however
seg 80: these are just the tip of the iceberg
seg 81: if we had u v eyes
seg 82: or
seg 83: x ray eyes
seg 84: we would really see
seg 85: the dynamic
seg 86: and dramatic effects
seg 87: of our
seg 88: sun's magnetic activity
seg 89: the kind of thing that happens on other stars as well
seg 90: just think even when it's cloudy outside
seg 91: these kind of events are happening in the sky above you
seg 92: all the time
seg 93: so when we want to learn
seg 94: whether a
seg 95: planet
seg 96: is habitable
seg 97: whether it might be amenable to life
seg 98: we want to know not only how much total light it receives and how warm it is
seg 99: but we want to know about its space weather
seg 100: this high
seg 101: energy radiation
seg 102: the u v and the
seg 103: x rays
seg 104: that are created by its star and that
seg 105: bathe it
seg 106: in this
seg 107: bath of high energy radiation
seg 108: and so
seg 109: we can't really look
seg 110: at planets
seg 111: around other stars
seg 112: in the same kind of detail that we can look
seg 113: at
seg 114: planets in our own solar system
seg 115: i'm showing here
seg 116: venus
seg 117: earth and mars
seg 118: three planets in our own solar system that are roughly the same size
seg 119: but only one of which
seg 120: is really a good place to live
seg 121: but what we can do
seg 122: in the meantime
seg 123: is measure the light from our stars
seg 124: and learn
seg 125: about this relationship between the planets and their parent stars
seg 126: to suss out
seg 127: clues
seg 128: about which planets might be good places to look for life in the universe
seg 129: kepler won't find a planet
seg 130: around
seg 131: every single star it looks at
seg 132: but really
seg 133: every measurement it
seg 134: makes
seg 135: is precious
seg 136: because it's teaching us
seg 137: about the relationship
seg 138: between stars and planets
seg 139: and how it's really the starlight
seg 140: that sets the stage
seg 141: for the formation of life in the universe
seg 142: while it's kepler the telescope
seg 143: the instrument that stares
seg 144: it's we
seg 145: life
seg 146: who are searching
seg 147: thank you