Show notes for Episode 187, March 5th, 2014
Hosts: Paul, Jesse
Title: Planets Near and Far
Surprisingly, it took Paul upwards of 55 min before he mentioned the southern hemisphere. Though it was probably Jesse’s fault as he brought up the Large Magellanic Cloud.
This week in space/astronomy history:
1. March 5th, 1979 – Voyager 1 makes its closest approach to the planet Jupiter at 349 000 kilometers (roughly the Moon-Earth distance). It began photographing Jupiter in January 1979, and finished in April 1979, however most of the discoveries were made in the week centred on the closest approach. A short list of discoveries made my Voyager 1: Jovian cloud vortex and movements, Jovian lightning and Aurora, the Jovian ring system, Io’s volcanism, Ganymede’s tectonic activity, Europa’s surface features, impact craters on Callisto. Voyager 2 followed on July 9th, 1979.
2. March 6th, 2009 – The Kepler Space Telescope is launched from Cape Canaveral en route to an Earth-trailing heliocentric orbit.
1. The 715 new planets of Kepler. On Wednesday February 26th, 2014, NASA released the latest from the, now defunct, Kepler Space Telescope. They have found 715 new planets around 305 different stars. About 95% of these planets are smaller than Neptune, and 100 or so are roughly Earth sized. Most interesting, four of these planets are less than 2.5x the size of Earth and orbit in their star’s habitable zone. The data presented in this new crop represents data taken from May 2009 to March 2011 and is specific to multi-planet systems. With these new planets, the total known is now over 1700. (Suggested Reading: Bad Astronomer Article. NASA Press Release, Science @ NASA article, Universe Today Article).
2. Moon occults Lambda Gemini
3. A preliminary report out regarding Astronaut Luca Parmitano’s space suit malfunction. The report indicates that Mission Control did not send the endangered Astronaut back to the airlock in a prompt enough fashion. Parmitano warned the controllers multiple times that the water accumulating in his suit was not a result of the drinking bag (the expected issue at the time). The report also indicates that drinking bags don’t leak as often as originally cited. In fact, the report says there has never been a case of a drinking bag leaking during space walk. Parmitano was sent back to the airlock 23 min after he first indicated a problem, and he was sent back alone. Further, station push for science may have made the astronauts overlook a possible leak (found in the suite on a previous space walk). (Suggested Reading: Universe Today article, Luca Parmitano Wiki, NASA termination note).
4. NASA offering free Space Systems Engineering courses. Today was the first day of a free Space Systems Engineering course offered online by NASA and the Saylor foundation. The course will run for 6 weeks and aims to give the public an understanding of the systems engineering challenges that NASA scientists and engineers do battle with every day. The course is going to culminate in a final project to design a sample return mission to Mars, the student who produces the best project will win a trip to go and see the Goddard flight centre. Anyone who is interested in how NASA projects work should sign up for the course. Today (March 5th) was the first day so you won’t be too far behind. After completion of the course, you will be able to explain the value and purpose of systems engineering, the systems engineering project life cycle, and relate the roles of systems engineers in complex space missions. You will also identify the roles and concepts of operations, requirements, and trade studies in the project lifecycle and demonstrate the ability to apply these concepts to a real NASA mission. (Suggested Reading: http://www.saylor.org/sse101/, syllabus).
5. Mapping the Large Magellanic Cloud in 3D.
distance 163000 lightyears
key rung on cosmic distance ladder
used hubble to measure actual 3D rotation of the LMC in space
all about measuring stellar motions
relatively easy to get rotation, one side of galaxy is moving away, other is moving towards
however proper motions are harder to measure, you actually have to WAIT for the stars to move measured average proper motion of 6790 over 7 years, in 22 different fields, with quasars able to measure change in position at resolution of 0.03 milliarcsecond (60 000 000 times smaller than the full moon). equivalent to watching an astronauts hair grow 5cm over the course of a year on the moon combine this with the doppler rotation to get fully 3D view
awesome because the proper motions lead to indications of interaction with SMC and MW
NOTE: Hipparcus and Gaia
(Suggested Reading: Sky and Telescope article)
Major Topics Discussed:
1. Population III stars
Population III star SMSS J031300.36-670839.3, or SM0313 for short found using the 1.35 metre SkyMapper telescope in Australia. This object some 6,000 light years from our Sun has the lowest metal abundance yet detected. It seems to be the result of an early universe low energy 60 solar mass supernova blast that expelled the outer atmosphere of its envelop while trapping most of its synthesised heavy elements in its black hole core. The implication is that the early universe may not have been as dominated by hypernova as originally suspected.
Keller et al suggest that apart from H and He, only 4 other elements exist in this tsar (Ca, Mg, Li, C). There is 15 million times less Fe in SMSS than in our Sun! The actual age of this star remains to be determined but is suspected to be of order 13 billion years old.
S. C. Keller et al. “A single low-energy, iron-poor supernova as the source of metals in the star SMSS J 031300.36-670839.3” Nature, 2014
Thanks for listening!
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