Night Sky by Tre Gibbs, LAAS - June 2017
By Tre Gibbs, LAAS
On Tuesday, June 20th at 9:15pm Summer returns to the northern hemisphere. For a couple of weeks before this and a couple of weeks after, the sun will rise and set at their furthest northern points on the horizon. As a result, the sun’s path across the sky will be the highest – or most furthest north - for the entire year. As you probably know, Earth is tilted. It’s axis is about 24 degrees off of what would be considered straight up and down. As Earth orbits the sun, it’s axis just happens to point to the same spot in space, a star about 433 light years away, “Polaris”, which is Latin for “pole star”, since Earth’s North Pole points to it – hence it’s more popular name, “The North Star”. As Earth continues it’s orbit around the sun, there are times when the northern hemisphere is tilted toward the sun and times when it’s tilted away from the sun. The Summer Solstice is the time when we in the northern hemisphere, or the top half of Earth, are tilted toward the sun. That’s why, in summer, the sun appears high in our daytime sky as opposed to winter, when the northern hemisphere is tilted AWAY from the sun, and therefor appears much lower in our daytime sky. However, after this day, and as the sun continues it’s journey around the sun, the days slowly begin to get shorter, although it’s not very noticeable until sometime in mid to late July.
Saturn is back! By mid month, Saturn rises in the east-southeast just as the sun sets in the northwest. Spotting Venus, Mars and Jupiter is pretty easy since they are some of the brightest, non-twinkling objects in the sky. Saturn, however, is different. Due to the fact that it’s so far away, Saturn looks more like one of the countless distant stars in the night sky. Only it’s not - one look through a small telescope or a good pair of binoculars will reveal a hint of its magnificent ring system. To find Saturn, wait until the night of June 9th. This month’s “Full Strawberry Moon” will rise along with Saturn, but just to the left of the quintessential gas giant. The two will travel the night sky together until dawn, though the moon will be continuously inching it’s way east of and away from Saturn. This becomes evident the following evening, when, onJune 10th, the moon trails Saturn almost an hour later.
Look for bright Jupiter high in the south at sunset this month, but slowly moving further westward as the month progresses. Jupiter is larger than Saturn but also much closer to Earth than it’s ringed neighbor, which is why it appears so bright in our evening skies.
So that’s it for this month. Enjoy the return of both Summer and Saturn – and if you get a chance, Google NASA’s Cassini mission, which has been exploring Saturn since it’s arrival in 2004. The mission endsSeptember 15th, 2017 as the Cassini spacecraft is running out of fuel and will do 22 consecutive dives between Saturn and it’s rings, and then, in a grand finale, it will dive into the surface of Saturn, becoming part of the planet itself.
