Bakersfield Night Sky — January 21, 2017
by Nick Strobel
This was first week of the spring semester at Bakersfield College and classes are full! The week before was filled with workshops, including a two-day institute on the college GPS (Guided Pathways System) I wrote about last July, followed the next day by Opening Day that focused on the college GPS. Good stuff happening!
Great stuff happening up in the sky too with our two closest neighbors as brilliant Venus continues to close in on orange-red Mars in our evening sky in the southwest. Venus is the super-bright star in the southwest after sunset and Mars will be to the upper left of Venus. By the end of the month, they will be almost within the same field of view of typical binoculars. The first star chart below shows Venus and Mars in the evening sky at 6:30 p.m. The second star chart below shows the night sky at 10 p.m. when Orion and the bright constellations surrounding it are high in the southern sky.
In the latest round of planetary science missions approved by NASA, Venus was passed over. Two of the five proposals were about Venus. One would have looked at certain types of gases such as xenon and krypton that would tell us how Venus’s formation was different than Earth’s. That mission would have also sniffed the atmosphere for sulfur and carbon coming from possible volcanoes. Another mission would have made high-resolution radar maps of the surface above hot spots to follow up on the ESA Venus Express mission. The last NASA mission to Venus was the Magellan mission in the 1990s.
Venus was probably passed over because: there is no chance of life or detecting past life on it; its hellish conditions (surface temperature of 870ºF day and night, clouds made of sulfuric acid droplets, etc.) mean human exploration of Venus is out and there is also no way to extract resources from Venus. Arguments in favor of studying Venus include understanding how our closest neighbor became the hottest planet in the solar system (even hotter than Mercury) and what that might tell us about the habitability of rock-iron exoplanets with thick atmospheres (as well as the future habitability of Earth).
The three missions approved have to do with asteroids. Lucy will investigate the Jupiter Trojan asteroids, Psyche will explore the metallic asteroid of the same name, and NEOCam will survey the region around Earth for potentially hazardous asteroids. Missions to asteroids help us understand the origins of the planets because they are the left-over remnants of planet building and haven’t changed much at all since their formation while planets have erased their birth records. Many asteroids could be explored directly by humans (i.e., astronauts, not robots) and they could be mined for metals and water.
The asteroid Psyche is about 130 miles across and resides in the asteroid belt about three times farther out from the sun than Earth. What is so unusual about Psyche is that is composed mostly of metallic iron and nickel, like our planet’s core. Other asteroids are mostly rocky or icy bodies. Psyche might be an exposed core from an early planetesimal that lost its outer rocky mantle and crust from the numerous violent collisions that pounded all solid objects in the early solar system. Beyond its scientific value, a metal world might be an attractive source of materials. I wonder how many Star Wars fans among the Psyche team will be saying as the pictures are coming in “That’s no asteroid! That’s a …”
In honor of all those asteroid missions, especially NEOCam, the first show of the spring 2017 season at the William M Thomas Planetarium will be “Incoming!” from the California Academy of Sciences. Narrated by George Takei, “Incoming!” explores the past, present, and future of our Solar System and the landmark discoveries scientists have made sending spacecraft to visit tiny worlds. The lineup for the rest of the season is posted on the William M Thomas Planetarium’s website at www.bakersfieldcollege.edu/planetarium . Tickets can be purchased at the BC Ticket Office and online from Vallitix.
Congratulations to SpaceX for successful deployment of ten satellites at once last week and then landing their rocket on a floating platform for reuse in a future launch! Reusable rockets are what will drive down the cost of launches and the precision required for those landings is what we’ll need to land humans on Mars.
I’ll close this column with a comment about the process of science. Because I’m a science educator, I read with great interest last Sunday the column by Robert Gebelhoff about using science as a political tool. Although we have discovered much about our universe that we’re confident enough to bet our life on, there is still a lot that is unknown and tentative. Science is a human endeavor and it isn’t perfect but the process of science has built into it a way to take into account our human fallibility.
Instead of “arguing from authority”, the process of science uses peer review to double-check (triple-check, quadruple-check, etc.) our ideas and ultimately, nature will be the final judge of what’s true or not—nature has the final veto power over any of our ideas. Studies and theories based on facts are published in peer-reviewed journals for other research teams to pick apart and find the defects in the argument or method. When an idea has been tested many times by many independent groups and has withstood all those tests, then the reasonable approach is to assume that the idea is close to the truth.
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