Bakersfield Night Sky - May 4, 2013

By Nick Strobel

In less than two weeks three teams of young scientists and engineers from Bakersfield College will be traveling to Bozeman, Montana to compete against other college and university teams from across the nation in the National Student Solar Spectrograph Competition. Student teams design, build, and test optical instruments to answer questions about the Sun or use sunlight to investigate some science question about the Earth. One of the three teams from Bakersfield College is using their spectrometer to measure the amount of surface-level ozone, one of the common pollutants in our Bakersfield area air that contributes to asthma and other respiratory problems. Ozone way up high in the stratosphere is the "good ozone" because it blocks much of the ultraviolet light from the Sun from reaching the Earth's surface. Without the ozone layer in the stratosphere, multi-cellular life on the Earth's surface would not be possible and a lot of the water molecules would be broken apart---yes, that stratospheric ozone is definitely "good ozone" but we don't want it down where we breathe because of its nasty effects on our lungs. The team measuring ozone will compare the amount of ozone above Bakersfield with that above Bozeman and later with other parts of California.

Although at first glance it looks like the National Student Solar Spectrograph Competition has a narrow goal of spectroscopy of the Sun, the real goal is to train future scientists and engineers in how to solve problems as a team by working on a real-world science question. Most of the students who participate will probably not go into space science but the experience gained and techniques developed from the competition will be invaluable in whatever future science and engineering problems we'll need them to solve for us. Reading any newspaper shows that we're certainly going to need a lot of home-grown expertise in STEM fields for the future challenges in this county and state and, heck, in our inter-connected world.

This is the first year that Bakersfield College will participate in the competition and we're sending not just one team but three teams. The three teams have received NASA mini-grants to build the spectrographs within the set budget of the mini-grant but the students are going to need your help with travel/lodging costs to the competion judging event in May. At least one of the student teams needs to raise their own money to go to the competition as they are not eligible for special program funding of their travel and lodging costs (over $1900 for a team of 4). If you or your company would like to encourage these future Bakersfield scientists and engineers, please contact the Bakersfield College Foundation with whatever financial help you would like to provide (it'll even be tax-deductible).

Early the previous week I was interviewed by Miles Muzio for a special report he's creating about Comet ISON (C/2012 S1). I have had other people ask me about it, so I guess the media has done a good job in getting the word out about a possibly great show in November and December by Comet ISON. Comet ISON C/2012 S1 was discovered in late September 2012 by two Russian comet hunters in the International Scientific Optical Network (ISON). Comet ISON is coming from a very distant reservoir of comets called the Oort Cloud that exists thousands to tens of thousands times farther out from the Sun than Pluto. Sometime in the distant past Comet ISON got a nudge from a passing star that sent it towards the Sun. After taking many thousands of years to travel from the Oort Cloud, it will pass through the inner solar system in only a few months.

Comet ISON passes within 6.73 million miles of Mars on October 1st so the Mars orbiters and rovers will take a break from looking down at Mars' surface to look at the comet from their vantage point. At that time Comet ISON will be too dim to see from the Earth without a telescope. By mid-November it may be barely bright enough to see without a telescope under very dark skies (away from the city) low in the east-southeast in the pre-dawn sky. By then it is moving very fast---it will pass by Mercury on November 19-20 at which point it may be bright enough to just barely see in our Bakersfield pre-dawn sky in the east-southeast. On November 28th, Comet ISON will pass just 1.1 million miles of the Sun's center but because the Sun is so large, it will be just 680,000 miles from its surface. Because of this close distance to the Sun, Comet ISON is a "sungrazing comet" and it might not survive the heat, breaking apart as many sungrazers do. The pre-dawn nights before and after that closest Sun approach, Comet ISON should be easily visible from even the center of Bakersfield. For a brief time around that closest approach, ISON might even be bright enough to be seen during the day. HOWEVER, it will be very close to the Sun which is over a million times brighter (bright enough to permanently blind you), so you would have to be very careful about blocking the Sun to try to see the comet less than a thumb width at arm's length from the Sun. For those nights around closest approach, Comet ISON's tail may stretch across a quarter to a third of our sky! Before November 28th the tail will point southeast and after that date, it will point northeast.

In December the comet will climb up away from the Sun in our northeastern pre-dawn sky. For the first couple of weeks of December it should be bright enough to see without binoculars. On December 26th the comet will pass closest to the Earth but at a nice safe distance of 39.9 million miles. At that time you will need binoculars to see it from Bakersfield but those far from city lights might be able to see it without any aid. Our last interaction with Comet ISON may be a meteor shower on the few nights around January 12, 2014 as the Earth passes through the trail of dust debris left behind by the comet. One possible result of passing through that particular debris field though may be the creation of noctilucent clouds that float more than 50 miles above the Earth's poles. They glow an electric-blue and are seen only after sunset by those north of the Washington state border. The noctilucent clouds might be seeded by space dust. For more on this, see the Science@NASA report for April 19, 2013.

I'm a bit skeptical of claims that Comet ISON will be as bright as the Full Moon. Yes, it should get bright but Full Moon brightness is a bit too much hype. Even if it did get that bright, it would do so when it is right next to that very bright Sun. Also note that I've been tentative in my descriptions of what will happen, using words like "possibly", "might", "may", etc. Comets are very hard to predict, especially those coming into the inner solar system from the Oort Cloud because we have no prior history of that particular "dirty iceberg" to know how it will behave. Each comet has a unique structure of how the volatile materials such as water and carbon dioxide are mixed in with the dust, dirt, and rock materials all packed in a frozen chunk a few miles across to a few tens of miles across (Comet ISON is roughly 3 miles across). A comet is quite fragile---you could easily break off a piece of a comet with your bare hands. It is also quite dark, darker than charcoal. Comets only get bright when their volatile material heats up close to the Sun and vaporize to make an atmosphere. The comet atmosphere can get charged and glow to brighten the comet. The vaporization of volatiles in the comet can release the dust which is great at reflecting sunlight, further brightening the comet.

Most of the comets coming in from the Oort Cloud will brighten up substantially while still at Jupiter or Saturn's distance as their volatiles near the surface get vaporized and die down closer in as the darker dust and dirt layers shield the volatiles under them. Many comets getting close to the Sun will either break up as Comet Elenin did in late 2011. Elenin was a comet the 2012 doomsayers latched onto as a world-destroyer until it so inconveniently disintegrated. (It wasn't ever going to get closer than 21.5 million miles from the Earth but that was another inconvenient truth ignored. Sigh!) What will Comet ISON do? We'll just have to wait and see. Comet ISON will be whipped around the Sun so fast that it (or its remnants) will escape the solar system entirely. I've covered all of the key facts about Comet ISON's appearance in our sky later this year but if you want to learn more about this comet or comets in general, see the comet section of Astronomy Notes (look in chapter 10).

Closer to home and the present, Saturn is taking over the evening sky from the other large planet Jupiter. Jupiter is low in the southwest after sunset, setting a little over two hours after the Sun does tonight and less than an hour after sunset by month's end. At the end of May, Jupiter will make an interesting dance with Venus and Mercury low in the west just after sunset but that will be in my next column. Saturn is just coming off from opposition at the end of April, so it is rising as the Sun is setting and it will be up all night long. The attached star chart shows the evening sky at 10 PM. About halfway up in the east-southeastern sky you will see an elongated right triangle of brighter stars tipped up by about 45 degrees with the long end pointed toward the left (north). The lowest point of the triangle will be Saturn about a third of the way up in the sky and the upper right point about halfway up in the sky will be Spica in Virgo just slightly dimmer than Saturn. About two-thirds of the way up in the sky at the upper left point of the stretched out triangle will be bright Arcturus at the end of the kite-shaped Bootes. Arcturus will be the brightest point of the triangle. Saturn is moving retrograde (backward) toward Spica for the next couple of months. The Eta Aquariid meteor shower should have its peak early tomorrow morning (May 5th pre-dawn) but those farther south of the U.S. will have a better view. The radiant of the Eta Aquariid's is still pretty low in the sky for us as the early morning twilight begins to brighten the sky. A star chart for the early morning sky with the radiant marked on it is posted in the Night Sky section of the William M Thomas Planetarium website.

Saturn will be a nice sight through the KAS telescopes at their monthly public star parties this spring and summer. May 18th is their next one at Russo's Books in The MarketPlace. They'll have telescopes set up near Russo's Books from dusk to about 10 PM depending on foot traffic. On May 18th, Saturn will rise earlier than it does tonight so by 9 PM it will already be up around a third of the way up in the sky. The rings will be opened up by quite a bit, being their most open since 2006, so they should be quite impressive at the monthly public star parties. The Hercules Cluster (M13), a nice jewel of a globular cluster about 25,000 light years away, will be another thing to see through the telescopes. It is at the right edge of the Keystone part of Hercules as shown in the attached star chart. Enjoy! The other dates will be the Saturday closest to the First Quarter Moon. Tonight the Moon is in a thin Waning Crescent phase rising up at around 4:15 AM and it will be at New Moon on May 9th.

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. Visit the Dark Sky International website for more info.