Life,
The Universe, And Everything * *from The
Hitchhiker’s Guide to the Galaxy series of novels,
used with permission of Douglas Adams.
April 2007 Issue
Worlds With Multiple Suns By Jenny Shih
When we think of extra solar systems, we tend to think of systems similar to our own solar system. However, it turns out that more than half of stars are part of a multiple star system. So in the search for extrasolar planets, we have to ask how likely it is to find planets around these multiple star systems.
Theorists have long wondered if solar systems can form around stars with one or more companions given the complex gravitational situation. In new computer modeling efforts, Alan Boss at Carnegie Institution’s Department of Terrestrial Magnetism (DTM) and colleagues determined that gas-giant planets like Jupiter can indeed form in binary star systems in much the same way that planets form around single stars such as the Sun. The new theoretical model by Boss’ team shows that if the gravitational force from one star in a double star system is weaker than the other, then gas-giant planets can form in much the same way as they do around single stars. In these theoretical systems, the whirling disks of dust and gas that form the starting material for planets could remain cool enough to grow into solid cores and form gas planets with masses thousands of times that of Earth. After the formation of these gas giants, the model also predicts formation of terrestrial planets like Earth. Since binary star systems are more like the rule in our galaxy instead of the exception, the predictions of this new model increases the likelihood of finding another Earth-like, life-supporting planet out there.
Observations have also confirmed the possibility of planet formation around multiple star systems. In the 207th meeting of the American Astronomical Society, a doctoral student, Deepak Raghavan, from Georgia State University presented his study which confirmed that 29 planet-harboring star systems also contained a second star; three actually had two companions and were triple star systems. David Trilling from University of Arizona and his team looked for disks in 69 binary systems between 50 and 200 light-years away from Earth. All the stars are more massive and younger than our middle-aged Sun. The researchers found that about 40 percent of the binary systems they looked at had disks that can later form planets. This frequency is a bit higher than that for a comparable sample of single stars and suggests planets are at least as common around binary stars as they are around single stars.
Researchers in this field say that the new findings are exciting and encouraging. Now with our new understanding of the multiple star systems, the likelihood of finding a habitable planet around a distant star is greatly increased.
December 2006 Issue
Cosmic Rays and Life on Earth By Jenny Shih
Although the conditions for life on Earth are mostly influenced by changes within the solar system, recent discoveries had shown that the blooming of life on Earth may be related to the formation of stars far out in our Galaxy.
Some 2.4 billion years ago was the stellar baby boom period of our Milky Way Galaxy. Scientists have discovered that the biggest fluctuation in productivity of life coincides with this period of star formation. The evidence is the abundance of Carbon 13 in rocks that formed around 2.4 billions years ago. When algae and bacteria were growing in the oceans, they took in carbon-12, so the ocean had an abundance of carbon-13. Many sea creatures use carbon-13 to make their shells. If there is a lot of carbon-13 stored in rocks, it means life was booming.
According to one theory, when a star explodes far away in the Milky Way, cosmic rays penetrate through the Earth’s atmosphere and produce ions and free electrons. The released electrons act as catalysts and accelerate the formation of small clusters of sulfuric acid and water molecules, which are the building blocks of clouds. When there were more stellar formation, more cosmic rays bombarded Earth and leads to increase in cloud formation. The clouds reflected sunlight and kept the planet relatively cool.
Contrary to popular belief, cold and icy weather does not lead to low productivity. Data shows that during this cool period, biological productivity oscillates between very low and very high. Researchers suggest that this is because the winds are stronger during the icy epochs. The stronger winds stir up the ocean and improved nutrient supply.
When an organism in the ocean dies, it sinks to the bottom of the ocean and decomposes. Therefore most nutrients are concentrated at the bottom of the ocean. However, many basic life forms in the ocean live on the surface where photosynthesis can take place. They obtain the nutrients they need when the ocean water mixes vertically and the bottom water, along with the nutrients, is brought up to the surface. But the surface water, which is warmer and less salty, is less dense than the bottom water. This makes it harder for bottom water to rise up to the surface. External forces are needed to drive the vertical mixing of water, and wind is one of the good driving forces. Therefore when the wind is stronger during the cold periods, more nutrients are brought up to the ocean surface and biological productivity is higher.
“The odds are 10,000-to-1 against this unexpected link between cosmic rays and the variable state of the biosphere being just a coincidence, and it offers a new perspective on the connection between the evolution of the Milky Way and the entire history of life over the last 4 billion years,” said study author Henrik Svensmark of the Danish National Space Center.
Search for Another Earth By Jenny Shih
Driven by the desire to know the world beyond ours, many efforts had been made to search for other habitable planets in the universe. Today, a little less than 200 extra-solar planets are known around nearby stars. However, though planets in other solar systems are not hard to find, it is a challenge to find a planet that has the potential to support life.
First, to be habitable, the planet needs to have water. It cannot be too close to the host star or else the water will boil away. However, if the planet is too far it’ll become a block of ice. Also, it needs to have a nearly circular orbit to ensure a stable, habitable climate throughout the year. A highly eccentric orbit will cause the planet to have extreme climate variations unsuitable for life. Earth, for example, is kept in this circular orbit by Jupiter’s gravitational force.
Then, the planet needs to have a strong magnetic field to protect it from the deadly radiation from the host star and elsewhere in the cosmos. Mars, for example is a planet with weak magnetic field and thus has little protection from deadly energetic particles.
Other than protection from radiation, the planet also needs to be shielded from objects in space that can constantly bombard the planet. Jupiter serves this purpose for Planet Earth. Its strong gravity sucked in a lot of space rocks in our vicinity and sparing Earth from many catastrophic collisions.
The existence of extraterrestrial life is not limited to planets. Possible candidates also include moons orbiting giant gas planets similar to our Jupiter. The closest planet beyond our solar system known orbits around Epsilon Eridani, a young star 10.5 light years away. A study team member, Fritz Benedict at University of Texas, said that if moons orbit this planet, they might have temperature similar to the Earth’s and possibly liquid water.
To study these extrasolar objects, which are light years away and obscured by the brightness of their host stars, in detail, requires better instruments than ones that we currently have. It would require launching large telescopes into space. Possible future missions include ESA’s Darwin Telescope Array and NASA’s Terrestrial Planet Finder (TPF). ESA’s Darwin Telescope Array would use infrared wavelengths, instead of optical wavelengths, to search for Earth like planets around some 300 stars within 50 light years of Earth. NASA’s TPF would use an array of telescopes orbiting the Earth in formation to generate planetary pictures 100 times more detailed than those the Hubble Space Telescope could take. It would also be able to eliminate bright starlight through interference of light waves for a better view of the planets.
Source: www.space.com
October 2002 Issue
Message from the Founders Laurel Methot & Jason Finley
This will be the UCLA AstroBiology Society's fourth year of
existence. What began as an ambitious idea seeded in our minds in our
freshman year by the GE70 Cluster class, "Evolution of the Cosmos and
Life," has grown into a thriving and ground-breaking student
organization. As we foresaw our eventual graduation and departure from
UCLA, we often wondered about the fate of ABS. However, as the years
progressed we saw a number of bright, enthusiastic, and dedicated
students attracted to the organization and were glad to recruit them as
officers. The ABS officers have proven themselves visionary as well as
capable, and have given us much hope that ABS wil continue to thrive
after we leave. And so, in our fifth and final year as undergraduates
at UCLA, we have stepped down as co-presidents and handed the
leadership of ABS to our fellow officers. Thus we are pleased introduce
the 2002-2003 ABS Officer Body.
Co-President - Geoff Robertson
Co-President - Dan Fingal
Co-Vice-President - Evan Cholfin
Co-Vice-President - Cynthia Aguilar
Historian & Secretary - Lila Farrington
Co-Treasurer - Dorel Ibarra
Co-Treasurer - Toni Lee
Publicity Coordinator - Dieu Trinh Le
Publication Journalists - Robert Conkey, Jon Young, Katy Tschann-Grimm,
Todd Huffman
Pathfinder Group Director - Sabrina Mayerberger
Pathfinder Group Researchers - Cynthia Aguilar, Lila Farrington, Kyoo
Hyung Choe
Co-Founder - Laurel Methot
Co-Founder - Jason Finley
The officers page can be found here.
There are several positions currently available, see the list here.
The Earth has 3 Moons??
By Robert Conkey
Staff writer
On September third, amateur astronomer Bill Yeung found what
very well could be an additional moon orbiting the Earth. Up to this
point there have been two known objects orbiting our planet: first, the
moon, and a second, little-known satellite that was discovered in 1986
called Cruithne. Cruithne, pronounced “croo-een-ya” is a small asteroid
that takes a strange horseshoe-shaped path around both the Earth and
Sun. At its closest orbit it is 9 million miles away from our planet,
or about one tenth of our distance from the sun. The third, newest
object, officially labeled “J002E3,” is calculated to have entered
orbit in either march or april of this year, according to Paul Chodas
of the American space agency's Jet Propulsion Laboratory in California.
Jason Finley is a co-founder and dedicated ex-co-president of
ABS. It is he and Laurel Methot that have created this student group
from scratch, and the 1999 Bioastronomy conference was what could
represent its very beginnings. As Jason notes, this conference was a
great landmark for ABS, and the contrast between the idea that ABS was
in ‘99 and the established group it is now is impressive indeed. The
following is Jason’s first-hand report on ABS’s second Bioastronomy
conference:
Beyond the gentle womb of our atmosphere space vehicles face a
tough and unforgiving cosmos. Oscillations between extreme heat and
cold coupled with high levels of background radiations threaten the
computing systems that handle the sensitive computation of guidance,
communication and many other critical tasks. Traditionally NASA and
other space going organizations have relied on redundant systems to
protect against computer malfunctions, having several of each computer
to be brought online when one fails. This crude method may be replaced
by self evolvable hardware, electronic circuits capable of
reconfiguring themselves to adapt to damage or to optimize itself for
its mission.
UCLA Involvement in the Particle
Accelerator That Will Revolutionize Our View of the Atom and the Early
Universe
By Katy Tschann-Grimm
Staff Writer
One of the fundamental questions of science has always been
"What is matter made of?" Physicists continue to search for a more
complete answer to this question at the CERN Laboratory for Particle
Physics in Geneva, Switzerland, the largest particle physics research
center in the world. I talked to Professor Bob Cousins about the
research that UCLA is involved in at CERN.
UCLA’s Professor Bruce Runnegar Named
Next Director of NASA’s Astrobiology Institute
By Kathleen Burton
NASA Ames Research Center Public Affairs Office
Dr. Bruce Runnegar, a professor in the UCLA Department of
Earth and Space Sciences and the Institute of Geophysics and Planetary
Physics (IGPP), was selected September 6 as the next director of NASA’s
Astrobiology Institute (NAI). For the past four years Dr. Runnegar has
been the director of the IGPP Center for Astrobiology, one of the
eleven lead teams of the NAI.
*Astrobiology Student Research Program (ABSRP)*
Presently, we are working to provide undergraduates with a direct
filter into the labs of NAI-affiliated researchers at UCLA. This will
give students an opportunity to have hands on experience in fields they
may be interested in pursuing as future Astrobiologists. More
information and an application are currently available here: http://www.studentgroups.ucla.edu/abs/absrp.htm
*ABS Pathfinder Group*
The ABS Pathfinder Group is continuing to work with the NASA
Astrobiology Institute’s Education and Public Outreach program to
contribute research to the NAI Pathfinder project, which aims to
produce a tool for students of all ages to find paths toward becoming
Astrobiologists.
*Pathfinder Group Expedition Project*
Starting this winter, Pathfinder Group members will visit high schools
in the Los Angeles area to present “Astrobiology: Part of your Future?”
– a presentation intended to make Astrobiology a new career option in
the minds of prospective college students.
*Space 101*
We are currently working with the Space Frontier Foundation to put on a
weekend-long space settlement design competition for high school
students. At this point we are trying to secure facilities for this
event to be held in Winter quarter.
QUESTION:
Would the indisputable discovery of intelligent life beyond earth
change the way you view life and the universe?
Questions, comments, ideas for stories, or would you like to
submit something for the newsletter? Just email absoc@ucla.edu
