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Notes on video lecture:
The Milky Way and Its Black Hole
Choose from these words to fill the blanks below:
16, Moon, Selenological, 375, outside, heavier, million, 12, Centauri, massive, black, quickly, 1500, heavy, staggering, 28, minutes, time, seconds, mirror, Minerva, past, 2007, lag, four, 384, flashes, gas, JAXA
as you look far away in the universe, you are looking into the         
International Space Station
only very recent that humans have developed technology to have a station                the earth
floating above the Earth at an altitude of        kilometers
the diameter of the Earth is     ,000 kilometers
suggests that moving out away from the Earth is not a very easy thing to do
travel to the moon
      ,400 kilometers
nickname for SELENE (                           and Engineering Explorer)
launched on September 14,         
went to the other side of the moon
took pictures of Earth rise
because distances are so large in space, we use          to describe how far away objects are
light takes 1.3 seconds to reach the         
Moon is 1.3 light-seconds away
the Apollo astronauts put a              on the Moon
we can shoot a laser to it and it returns 2.6                later
1.5 10^8 kilometers away
8.3 light-               away
an unmanned spacecraft developed by the Japan Aerospace Exploration Agency (        ) which returned a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis
20 light-minutes away from the Earth (more than two times the distance to the Sun)
the command sent to the probe to deploy the                lander arrived to late, since it took 20 minutes to get there
there is a 40-minute        for making decisions of how the probe should interact with its environment
it had to decide as much as it could on its own
         light-hours away
human-made object that is the farthest from Earth
    -light-hours away
we are still communicating with it
closest star
4.2 light-years
Voyager will have to travel for over 10,000 years to get to Proxima Centauri
Milky Way galaxy
we are in a galaxy which is a disc and when we look at the Milky Way we see the disc from the inside
we are     ,000 light-years away from the center of the galaxy
it's only          light-years thick
our solar system is revolving around the center of the our galaxy
at a speed of 220 km/s
something is pulling us to the center of the galaxy
we know this to be a            hole
with infrared light we can see through the dust and debris in space to see the motion of stars at the center of the galaxy
something is pulling a star, and after it passes through, it speeds on               
it takes 20 years for a star to orbit around this very            object
by studying the motion of these stars, you can determine how                the object is
the answer is                     : the object in the middle of the Milky Way galaxy is four million times heavier than our Sun
nothing can be that heavy except for a black hole
black hole at center of the Milky Way
four                times our solar mass
other galaxies have                black holes
it can consume objects including        around it
even the speed of light is not enough to escape the force of gravity from the black hole
just before gas enters the black hole, it                in light
The Milky Way and Its Black Hole