Bakersfield Night Sky – November 5, 2016
By Nick Strobel
First a public service announcement: “fall back” one hour tomorrow and enjoy the extra hour of sleep tomorrow as daylight saving time ends tomorrow on Sunday, November 6. (So when does daylight savings time end again?) You only get the benefit of the extra hour of sleep if you go to bed tonight at the regular time and not an hour later.
Now that that “dad moment” is over, here’s what’s happening in space and the William M Thomas Planetarium. This Thursday, November 10, is the showing of “Supervolcanoes” about the super-powerful volcanic eruptions that can release many times more energy, lava, and ash than the 1980 Mount St Helens eruption. Fortunately, these eruptions are very rare! John Menzies will start the evening show with a tour of the night sky using the Goto Chronos star projector.
A week later on November 17, I’ll present the newest show “Incoming!” from the California Academy of Sciences. Narrated by George Takei (The original Star Trek’s “Sulu” and social media star), “Incoming!” explores the past, present, and future of our Solar System and the landmark discoveries scientists have made sending spacecraft to visit tiny worlds. These tiny worlds are the asteroids and comets that have not changed since they formed 4.6 billion years ago, so they are important for telling us how Earth and planets formed.
It is also important to study them because some of them have orbits that cross Earth’s orbit. If Earth happens to be at that crossing point when the asteroid or comet is there, we can have a very bad day or decade or millennium. The structure of the asteroid or comet will determine how we should go about deflecting such an object. If the object is stiff, then hitting it with a projectile or nearby explosion will knock it into another path. If the object is a rubble pile held loosely together, then hitting it will do as much good as shooting a bullet into a bag of sand.
One such potential bad object is the Near-Earth Object Bennu, a 500 meter diameter asteroid that has a 0.037% of hitting Earth in the late twenty-second century. The OSIRIS-REx spacecraft launched in early September will begin studying Bennu in 2018.
Tiny bits of rock and dust left behind by comets with orbits that cross Earth’s make the meteor showers. Two will be happening this month. The Taurid meteor shower comes in two batches but both are from Comet Encke. Both batches are very spread out so they overlap each other. The South Taurids appear to stream out of the southern part of Taurus and it will peak on the night of November 4/5 (see the first chart below). The waxing crescent moon will set by 10 p.m. on that night. The North Taurids appear to stream out of the northern part of Taurus and it will peak on the night of November 11/12. By that date the moon will be in a waxing gibbous phase, so it will be big and bright most of the night. Both of the Taurid meteor showers have at most about 7 meteors per hour that hit our atmosphere at 17 miles/second. The Taurids are known for producing fireballs to compensate for the smaller number per hour.
The early morning of the “Incoming!” show, November 17, will be the peak of the Leonid meteor shower. These dust bits from Comet 55P/Tempel-Tuttle appear to stream out of the head part of Leo. The dust stream for the Leonids is much narrower than the Taurids so the Leonid peak is sharper. Unfortunately, this year we’ll have the waning gibbous moon to contend with for most of the night. At best the Leonids will produce about 10 to 15 meteors per hour but most of them are going to be washed out by the bright moon.
In the early evening sky, brilliant Venus lights up the southwestern sky after sunset. It will set about two hours after the sun sets. Higher up in the south-southwest shortly after sunset is the orange-red planet Mars. Tonight a waxing crescent moon will hang up and to the right of Mars as shown in the second chart below. We have pulled well ahead of Mars in our faster orbit, so Mars continues to grow slightly fainter throughout the month. Mars will drift eastward from the stars of Sagittarius to the dimmer stars of Capricornus. Its eastward motion among the stars will mean that Mars will set at the same time every night this month, or about 10:30 p.m.
Mars’s planetary defense system claimed another spacecraft. The ESA Schiaparelli lander appears to have stopped firing its braking rockets much too soon while still about 2 miles above the surface. From that height it would have hit the surface at almost 190 mph and exploded to make a crater a few meters across. Schiaparelli was testing landing equipment that will be used for ESA’s ExoMars rover in 2020. Hopefully, the engineers will find out how to fix the complex landing system by the 2020 launch date or they will have to wait 26 months for the next launch window. NASA will also have a rover landing in 2020. Let’s hope the martians will find our political scene a bit saner then so they won’t be so upset and try to keep the Terran aliens out.
The Schiaparelli lander hitched a ride with the ExoMars Trace Gas Orbiter that entered orbit properly and is now in an extremely elliptical orbit that varies from 190 to 60,000 miles from Mars’s surface. Eventually, the orbit will be circularized and its four instruments will study the gases that make up less than one percent of Mars’s already thin atmosphere. The trace gases could be the signatures of active biological or geological processes in the present or in the past.
In the early morning sky, Jupiter is now visible as the bright star low in the east shortly before sunrise. It rises about two-and-a-half hours before sunrise.
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