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Base sky map, as ever, is from: neave.com/planetarium/
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…by Anura Guruge
Yes, earlier in the month it was Venus that was close to the Moon.
Now it is Jupiter, because they all move about — nothing stays still up there.
Venus is still around and visible in the Southwest sky, very close to the horizon, but setting BELOW the horizon by 7:30 pm. 5:30 pm, directly SW, is a good time to see Venus.
Enjoy Jupiter. It was spectacular last night — beautiful opposite conjunction with the full Moon. Today it will be above the Moon. While you are at it take a gander at Orion and soak in its grandeur.
…by Anura Guruge
Jupiter, given that it is invariably higher in the sky, will most likely be the bright object that first arouses your curiosity and awe.
If it is later in the night you might see a very bright, burning WHITE star, close to the tree line, maybe even glimpsed through the trees in the East. That would be Sirius, the Dog Star — the brightest star in the night sky. It is actually brighter than Jupiter. This serious brightness of Sirius is due to two factors: it is relatively nearby and it is big — twice as big as the Sun. It is 8.6 light years away. So what we are seeing now, in December 2012, is what Sirius was doing 8 years 7 months ago.
Many never think about this. Light thought it travels fast, still has a speed limit. So if an object is far away, it does take time before light from that object gets to us. Even Sun light takes 8.3 minutes to reach us. The light from Jupiter (i.e., sunlight reflected off Jupiter’s gaseous, yellowish atmosphere) takes nearly 35 minutes to reach us. So in reality when we look up and see Jupiter, we are not actually seeing Jupiter in ‘real time’. We are seeing Jupiter as it was 34.9 minutes ago. Think about that. You can have fun pondering this. ‘Rigel‘, the bright white star that makes up the leg of Orion, is ~860 light years away. So what we are seeing is light that left Rigel 860 years ago. For all we know Rigel could have exploded — supernovaed. It would be 860 years before we would see it.
So the next time you look up at the night sky remember that much of what you are seeing is in time lapse. Light that was there sometime before.
…by Anura Guruge
If you were curious, or if the kids were asking, what you are most likely seeing is Jupiter. Other than the Moon, it is the brightest object currently in the night sky, over NH. It is hard to miss. Given its brightness it appears in the sky quite early — even at dusk. It rises in the East, moves a bit to the South but then continues across the sky, right through the night, to set in the West. Its position, at a specific time each night, say 11 pm, will change slightly — typically further to the West. This has to do with the relative orbits of us and Jupiter.
Jupiter, right now, is about as close as it ever gets to Earth. So it is atypically bright. I take out the dogs for their last little jaunt for the day around 10:45 pm each night. In the winter, if there are no clouds, I search out Jupiter. It always uplifts me.
Saturn, Venus and Mercury are also visible this month — but in the morning. So, I won’t see those.
We might also get some meteor showers this month.
If you don’t already have a favorite site for checking out the night sky, try this. It is accurate and easy enough to use. IF I ever get enough time I will do more posts on the night sky because astronomy happens to be another of my interests. More on that later. Enjoy.