Bakersfield Night Sky – May 2, 2015
By Nick Strobel
Last week NASA celebrated the 25th anniversary of the launch of the Hubble Space Telescope. There is a very nice 30-minute documentary on the NASA homepage(www.nasa.gov) about the history of Hubble's development, its construction, service missions, and the connection to our society and culture. I remember in graduate school wondering if it was ever going to launch. With all of the delays my fellow grad students had a sort of gallows humor about the delays, likening the chance of it launching in the same way a Bakersfield resident would expect a snowstorm in July. However, when it launched, we were ecstatic!
Then came the crushing disappointment of its blurry vision. While its clarity was better than from any ground-based telescope, it was not as clear as it needed to be to do the promised research. Frustration and gallows humor returned to the graduate student offices. The main mirror's curvature was off by just 1/50th the width of a human hair over the 94 inches of mirror to make a defect called "spherical aberration". It turned out the aberration was a textbook "perfect" defect that could be partially corrected for with computer processing of the images and later completely fixed with corrective optics.
The fix was possible because the orbiting observatory was designed to be repaired and upgraded throughout its lifetime. No other space observatory has that capability, so once the other space observatories exhaust their supplies or have an electronic failure, the mission is done. After the first Hubble servicing mission in 1993, the results in the following years captured our imaginations. When I interviewed for the astronomy position at Bakersfield College, the image of the "Pillars of Creation" in the Eagle Nebula was on the front cover of the Bakersfield Californian.
Hubble was serviced five more times. The last one was after its designed lifetime but the Hubble Space Telescope had become the "people's telescope" and the groundswell of support for Hubble convinced NASA to upgrade it one last time in 2009. The upgrade should keep Hubble going until 2020.
Goodness, that's only five years away! Hubble's "successor" will be the James Webb Space Telescope ("JWST" for short) that is expected to launch in 2018. JWST will be much larger than Hubble and it will observe in the infrared instead of the visible band our eyes can detect. What concerns me most is that it will be placed too far from Earth for servicing. There are a lot of new innovative things going into the deployment of the telescope, any of which could end the mission if they don't work correctly. This multi-billion telescope has to work right the first time. However, the new innovative systems that had to work to get the Curiosity rover to a safe landing on Mars and the Rosetta mission to Comet 67P/C-G prove that today's engineers and scientists have the know-how to make it work given the time and funding to test and re-test the systems again and again before launch.
Speaking of the Rosetta mission, the Rosetta Comet Campaign needs the help of amateur astronomers to share and contribute observations as the comet nears the Sun this summer. Photos, brightness estimates, maps, spectra, sketches, verbal descriptions, etc. are all needed. Ground-based observations provide a big picture perspective to complement the up-close measurements from Rosetta. Amateur astronomers are not tied to a highly competitive schedule of a large observatory that professional astronomers have to contend with. Because of this, amateur astronomers are often the first to report new things happening to a comet or other object out in space. See http://rosetta.jpl.nasa.gov/rosetta-ground-based-campaign for how to help.
Comet 67P/C-G is becoming more active as it nears the Sun and warms up. The Rosetta team was able to spot a jet turning on. The Rosetta team was able to use the magnetometers on both the Rosetta orbiter and Philae lander to determine the trajectory of the Philae lander during its multiple bounces and have narrowed the possible final resting location to within an area 30 by 50 meters on the surface. Still unknown is the exact orientation of the lander and the features all around the lander to know if the increasing sunlight will be enough to warm up the electronics and charge the battery back up to re-establish contact. The Rosetta orbiter continues to listen for a signal from Philae.
The Dawn spacecraft orbiting the asteroid-dwarf planet Ceres is now in the first of its science orbits, 8400 miles above Ceres. The two bright spots seen in one of the craters continue to be mysterious. Dawn will probably have to get to one of its lower orbits before the cameras and other instruments have the resolution to figure them out. However, the Dawn team welcomes your vote on what they could be on their "What's the spot on World Ceres?" webpage. Just click one of the icons to cast your vote. Choices include: volcano, geyser, bright rock, ice, salt deposit, and "other".
Later this month, on Saturday, May 23rd, the Kern Astronomical Society will have their telescopes set up at Panorama Park across from where Linden Ave meets Panorama Drive. The Moon and planets will be bright targets to see along with beautiful star clusters and nebulae. Observing will start soon after sunset and go to about 10 PM, depending on foot traffic.
Mercury is now making an appearance in our early evening sky. It is low in the west-northwest between the Pleiades star cluster at the shoulder of Taurus and Aldebaran, the orange star at the eye of Taurus. Further above is super-bright Venus between the tips of Taurus' horns. High up in the southwest is bright Jupiter. The first star chart below shows the sky at 9 PM. Though Mercury is still above the horizon and the sky is dark by then, you'll probably need to look for Mercury a bit earlier in the evening so that Mercury is above the brown haze layer we have in the dusty-smoggy Bakersfield sky.
A Waxing Gibbous Moon will rise shortly before sunset but it is over in Virgo in the southeast, so it won't wash out Mercury on the opposite end of the sky. The Moon will be at Full Phase on Sunday. By about 9:30 PM you should be able to see Saturn rising up in the east at the head of Scorpius. On Monday, the gibbous moon will be next to Saturn but Saturn should be bright enough to see in the glare of the moonlight. By the time of the KAS public star party, Saturn will be rising at sunset, so it should be on the list of objects to check out in the KAS telescopes. The rings have opened up quite a bit, so they'll be easy to see in the KAS telescopes. The opening up of the rings is also why Saturn is appearing so bright in our sky. In fact, Saturn is the brightest it has been for eight years. The second star chart below shows the location of Saturn at 11 PM.
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