Bakersfield Night Sky – September 5, 2015
By Nick Strobel
The fall schedule of public evening shows at the William M Thomas Planetarium is now posted on the Planetarium's homepage. Each show begins with a live tour of the sky using the Goto Chronos star projector followed by an all-dome film using the SciDome system. The first show of the season will be "Ice Worlds" on September 17th followed by "Earthquake: Evidence of a Restless Planet" on October 1st. Tickets for both shows are now available from the BC Ticket Office and from Vallitix.
With the Pluto-Charon double dwarf planet system in its rear view mirror, the New Horizons spacecraft is now heading outward towards its next target in the Kuiper Belt. Up to last week we weren't sure what that next target would be. The next place for New Horizons to explore will be a small Kuiper Belt object known as 2014 MU69 that orbits nearly a billion miles beyond Pluto.
2014 MU69 is probably slightly less than 30 miles across based on its measured brightness and a reasonable assumption of its reflectivity. Something of this size is very likely a well preserved, deep-freeze sample of the outer solar system at its birth 4.6 billion years ago. New Horizons should reach 2014 MU69 in early January 2019. By the way, the "2014" in its name means it was discovered just a year ago, a "just-in-time" discovery!
New Horizons will continue beaming back data from its historic encounter with Pluto and Charon over the next year, so there will continue to be discoveries made as we get all of the data. More surprises to come I'm sure and hopefully more insights into how Pluto could have remained such a geologically active world despite its small size and not being next to a large planet for gravitational tidal flexing to heat it up.
In late October and early November, New Horizons will execute a set of four maneuvers to get itself on the path to 2014 MU69. If NASA had waited until later to make the decision of where to send New Horizons next, the spacecraft would have had to use up a lot more rocket fuel to get itself positioned. Advanced planning now means much less effort farther on down the road. Works for spacecraft and works for college students mapping out their education plans but I digress...
Not as much advance planning is needed for the two major September events happening in our part of the country. The first is the Dark Sky Festival at Sequoia National Park the weekend of September 11th-13th and the second is the Kern Astronomical Society free public star party for the total lunar eclipse on SUNDAY, September 27th.
If the Rough Fire doesn't spread much further south or the smoke doesn't ruin the skies, then the Sequoia Natural History Association will introduce thousands of visitors from all over the world to the famously dark skies of the national park. The local astronomy club, the Kern Astronomical Society, will be providing the telescopes for viewing the Sun during the day (with proper solar filters, of course) and for viewing the stars, clusters, nebulae, and galaxies at night. Events during the day will include a talk by NASA astronaut, Robert L Behnken, who is one of the four astronauts training for the first US commercial space flight and a talk by NASA Systems Engineer Nagin Cox who has worked on the Mars Curiosity rover mission and is working on future Mars missions such as the Mars InSight mission that will probe Mars's deep interior.
Other events include kids' activities, model rocket building , special Crystal Cave tours, nature walks, photography presentations, musical performances, and more. The list of events is posted at Dark Sky Festival website at www.sequoiahistory.org/darksky . The skies of Sequoia and Kings National Parks are truly dark and there will be no Moon to worry about, so you'll be able to see thousands of stars and the Milky Way. The cost to attend the Dark Sky Festival is just the park entrance fee.
The Kern Astronomical Society will be moving the date of its monthly free public star party at Panorama Bluff Park to Sunday, September 27th because of the total lunar eclipse. The full Moon will be exactly in the ecliptic (the eclipse plane which is the plane of the Earth's orbit around the Sun), so the full Moon will pass through the umbra of the Earth's shadow.
This total lunar eclipse is very conveniently timed---in the evening after sunset. When the Moon rises for us, it will already be partially in the Earth's umbra. Totality begins at 7:11 PM and the Moon may be just above the mountains in the east by then, depending on how close you are to them. Totality lasts until 8:23 PM when the Moon will be about 20 degrees above the eastern horizon, or about the width of your outstretched fingers held at arm's length. The partial eclipse will end at 9:27 PM when the Moon is about halfway up in the southeastern sky.
Depending on the dustiness of the air worldwide, the color of the eclipsed Moon will either a dark brown to coppery yellow or something in between. Sunlight passing through the Earth's atmosphere refracts, or bends, around the solid part of the Earth, so some light still reaches the Moon. If the Earth didn't have an atmosphere, then the Moon would be completely dark. (That and there would be no people to enjoy the show.) The shorter wavelength bluer colors in the sunlight are scattered away, so they don't reach the Moon during the eclipse.
In tonight's sky, Saturn is pretty much the lone planet in the evening sky. Although Mercury is also in the evening sky, its appearance is brief, setting about 50 minutes after sunset and binoculars are needed to pick it out through our haze layer. Saturn will be the bright "star" to the right of Scorpius in the southwest at the time the sky is truly dark. Saturn will be at the same altitude above the southwest horizon as orange-red heart of Scorpius, Antares, with Antares on the left and yellowish Saturn on the right.
By 9 PM, the bright star, Vega, will be almost exactly at zenith. Vega is one of the three bright points of the Summer Triangle with Deneb and Altair at the other two points. Altair will be the lower one in the southern sky. See the second chart below for the view of the evening sky.
The early morning sky will be the more interesting sight for September (except for the total lunar eclipse, of course). The two closest planets to our home planet will be well-placed in the eastern sky before sunrise. Venus will be the super-bright "star" you see in the pre-dawn sky. Dimmer orange-red Mars will be to the left of Venus, about a fist width at arm's length as shown in the first star chart below. Over the following pre-dawn mornings, Venus will climb up higher in the sky away from slower Mars. In the early morning sky you'll also see a Waning Crescent Moon get thinner over succeeding mornings as it drops down closer to the horizon, passing between Mars and Venus on September 10th. The following morning a very thin crescent Moon will be to the right of Regulus at the bottom of the Sickle part of Leo but it may too faint to see through the haze layer and the pre-dawn twilight.
Want to see more of the stars at night and save energy? Shield your lights so that the light only goes down toward the ground. See www.darksky.org for how.
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com