Some June Post-Its

Hey, everyone! I hope you’ve had a great weekend. With fireworks going off in the distance from one nearby fair or another, it seems like now would be a great time to wish a happy birthday to Charles Messier, who would have turned 199 years old today. M. Messier was a French astronomer and comet hunter who cataloged 110 deep sky objects that weren’t comets. If you’ve ever wondered, he’s the Messier of such hits as Messier 31 (the Andromeda Galaxy), Messier 42 (the Orion Nebula), and Messier 45 (the Pleiades cluster).

It’s been a pretty busy week in the skies, and for me here at my desk. I’ve been tied up with a lot of the comings and goings of the moon and planets, and some other non-Sky Watch things. So, it’s time time again. In no real order, here’s some things I’ve scribbled on Post-Its and stuck to my notebook:

  • A couple of weeks ago, NASA’s Juno probe to Jupiter crossed the point on its trip there where Jupiter becomes the most dominant gravitational force around. This is all part of the process for our ceiling fan-shaped friend as it gets nearer and nearer to Jupiter. On July 4, with the fireworks and the hot dogs, Juno will enter a polar orbit around Jupiter where it’ll spend its time trying to figure out how its incredibly strong magnetic field — the second strongest in the solar system — works, what makes its clouds tick, and how much water there is inside it (they think there could be quite a bit; it’s a big planet), among other things. This will be the first time any probe from Earth will see Jupiter’s polar regions close up. It’ll also get closer than any other human-made thing has ever gotten to the most giantific planet, only 3500 miles from the cloud tops. Voyager 1, in March of 1979, came within 128,500 miles. As of this past Friday, June 24, Juno was about 5.5 million miles from Jupiter, and closing. I was too young to remember when the Voyagers got the Jupiter, and I loved seeing what came back from the Galileo probe in the 1990s. I can’t wait for the news from this one to start coming in.
  • Speaking of far-flung, rocket-powered <radio voice> computers of awesomeness </radio voice>, NASA’s New Horizons probe, which zipped through the Pluto system last July 14 (2015), has returned photos of a Super Grand Canyon on Charon, Pluto’s largest moon. The Argo Chasma is about 430 miles long, and five and a half miles deep. The Grand Canyon in Arizona is about a mile deep and 280 miles long. Looking up at the scoreboard, New Horizons is now about 2.8 astronomical units (AU) from the Sun. An AU represents the average Earth-Sun distance, about 92.9 million miles, so Pluto is about 270 million miles past Pluto on its way to Kuiper Belt object 2014 MU69. This puts it about 35 AU from Earth; that’s about three and a quarter billion miles. Radio signals take over 9.5 hours to get to it. That’s 19 hours round-trip.
  • It’s a while ago now, but remember back in February of this year, when it was announced that the LIGO observatories had, for the first time, detected the gravitational waves from two colliding black holes billions of light years away. This proved Einstein right, again, and is easily short-list-for-a-Nobel-Prize stuff. Well, LIGO’s at it again. It was announced earlier this month that LIGO picked up gravitational waves from another set of colliding black holes, these 1.4 billion light years away. That’s…. a hundr… carry the six… really, really far away at 6 trillion miles to the light year. As part of his general theory of relativity, Albert Einstein predicted that the movement of very massive objects could cause shifts in the shape spacetime; ripples, waves, in the very fabric of space itself. These gravitational waves are those ripples, proof that he got it right. When they reach Earth, they change the shape of space enough to affect the distance between the detectors at LIGO. The computers there can then observe this change. Incredible, incredible, incredible.
  • Huh… New Horizons did its thing on Bastille Day last year, and Juno will do its on Independence Day this year.
  • And, finally, for now, NASA has announced that astronomers using its Kepler observatory has found the largest planet yet that is orbiting two stars– a circumbinary planet. I like that word. This planet is like Tattooine in the Star Wars movies. The planet, Kepler-1647b, is 3700 light years off in the constellation Cygnus, the swan. The two stars it orbits are a lot like the Sun. One’s a bit bigger, one a bit smaller. Pretty cool. It’s always exciting to see the things Kepler keeps discovering. We’re getting closer and closer to something huge.

That’s it for now. Thanks for reading. I know this was a long one. Clear skies, everyone!

Artist’s concept of Juno approaching Jupiter (from NASA)

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