Show Notes: March 19th, 2013 UTC
Title: Exploding Stars and Life on Mars?
Hosts: Jesse, Ryan, Lianne
Tonight’s episode was the 145th episode of YorkUniverse! good job team! This week in history was the anniversary of the first ever human space walk by Alexei Leonov back in 1965. Cmdr Chris Hadfield has officially taken over as the commander of the ISS. We also chatter about the origins of Cosmic Rays and a very unique supernova. Make sure you check out the Lunar Orbiter Recovery Project (links below). Thanks for listening Everyone.
This Week In Astronomy and Space History:
1. 18 March 1965: first ever human space walk by Alexei Leonov – http://en.wikipedia.org/wiki/Alexey_Leonov
He was outside the spacecraft for 12 minutes and nine seconds on 18 March 1965, connected to the craft by a 5.35-meter tether. At the end of the spacewalk, Leonov’s spacesuit had inflated in the vacuum of space to the point where he could not re-enter the airlock. He opened a valve to allow some of the suit’s pressure to bleed off, and was barely able to get back inside the capsule.
2. 18 March 1980: Vostok rocket exploded on launch pad while being refueled, killing 50
A Vostok rocket – the same type of two-stage booster used to send the Soviet astronaut Yuri Gagarin into orbit in 1961 – exploded while being fueled on the launching pad. Many Soldiers Killed: Forty-five people, mostly young Soviet soldiers, were burned to death and 5 others died later of their injuries.
3. 22 March 1997: Comet Hale-Bopp Closest Approach to Earth (1.315 AU)
It was visible to the naked eye for a record 18 months, twice as long as the previous record holder, the Great Comet of 1811
Great Hale Bopp Story: Hale chanced upon Hale–Bopp just after midnight. The comet had an apparent magnitude of 10.5 and lay near the globular cluster M70. Hale first established that there was no other deep-sky object near M70, and then consulted a directory of known comets, finding that none were known to be in this area of the sky. He emailed the Central Bureau for Astronomical Telegrams, the clearing house for astronomical discoveries.Bopp did not own a telescope. He chanced across the comet while at the eyepiece of his friend’s telescope. He checked his star maps to determine if any other deep-sky objects were known to be near M70, and found that there were none. He alerted the Central Bureau for Astronomical Telegrams through a Western Union telegram. Brian Marsden, who had run the bureau since 1968, laughed, “Nobody sends telegrams anymore. I mean, by the time that telegram got here, Alan Hale had already e-mailed us three times with updated coordinates.
4. 17 March 2011: MESSENGER enters mercury orbit, first ever to do so
It became the second mission after 1975’s Mariner 10 (launched by NASA on November 3, 1973) to reach Mercury successfully
the probe had discovered large amounts of water present in Mercury’s exosphere
MESSENGER also provided visual evidence of past volcanic activity on the surface of Mercury, as well as evidence for a liquid planetary core
And Just for fun: http://en.wikipedia.org/wiki/Family_Portrait_(MESSENGER)
1. Chris Hadfield takes command of the ISS
2 The environment at Gale Crater could have supported life: Mission Accomplished
3. ‘Curiosity Corner’ with Ryan Marciniak
Another problem is preventing the Mars rover Curiosity from resuming its science experiments. The mission’s chief scientist said Monday the rover went into safe mode again over the weekend because of a computer file error. In safe mode, activities are on hold but the rover remains in contact with Earth. Curiosity was sidelined earlier this month after a problem with its computer memory. The team had hoped to restart experiments this week when the new problem cropped up
Read more at: http://phys.org/news/2013-03-mars-rover-curiosity-problem.html#jCp
4. Comet PanSTARRS tough but fair http://apod.nasa.gov/apod/ap130318.html
5. The Vernal Equinox — 20 March 2013 at 11:02 UTC
6. Lunar Orbiter Image Recovery Project (@LunarOrbiter)
Group of volunteers seek to recover old Lunar Orbiter images, allowing us to compare the lunar surface in 1966/67 to now.
Major Topics Discussed:
1. Overwhelming proof that Cosmic Rays are indeed created by Supernovae
Cosmic Rays are not actually ‘rays’ as you may think of them. We use the word ‘ray’ typically to mean wave, or beam, of light. A Cosmic Ray would be more aptly named a Cosmic Particle, as they are actually sub-atomic particles or atomic nuclei (but mostly protons) that travelling at very high speeds. Check out the wikipedia article.
A Cosmic Ray can hit our atmosphere, which then shatters the particle/nuclei into even smaller sub-atomic particles (pions, tau particles), which then rain down on the surface of the Earth. You can create a very simple apparatus that can let you see these shattered particles, known as a ‘cloud chamber,’ For an event at York University called STAR Symposium, Lianne Manzer and others built a cloud chamber. Check out the video here.
Amazing as the phenomenon may be, astronomers were not positive where the Cosmic Rays come from. The consensus was that the protons were accelerated in the surrounding medium of a supernova, but we lacked the hard data to prove this hypothesis. In a study published in Nature on 15 February 2013, a group of astronomers using the Fermi Gamma-ray Space Telescope have confirmed that the large majority of Cosmic Rays are created by supernovae throughout our galaxy.
This was done by examining two supernova remnants and measuring their gamma ray signature (NB: in this case ‘ray’ really means light). They were able to connect the signature of pion decay. Pions are created by the Cosmic Rays acclerated by the supernova. The pions then decay with a specific gamma ray frequency. By detecting this signature, the astronomers are able to connect the observed gamma rays to highly accelerated protons near the supernova. Therefore, supernova can (and do) create Cosmic Rays!
2. Astronomers find unique supernova http://www.sciencedaily.com/releases/2013/03/130307161634.htm
A rare type 1bn supernova has exploded on the outskirts of an elliptical galaxy 780 Million light years from Earth. Only six such supernovae have ever been seen in thousands of discoveries, but what makes this particular one truly unique is its location in an area that shows no recent star formation. A potential explanation for the supernova explosion would be the collision of two old dwarf stars, increasing the mass of the merged object and eventually causing the supernova explosion. Type 1bn supernovas are characterized by the release of large amount of helium gas prior to explosion.
3. ALMA discovers Most Distant Star-forming Galaxy
Distance Calculations: http://www.astro.ucla.edu/~wright/CosmoCalc.html
See http://www.yorkuniverse.ca for overview!
Thanks for listening Everyone.
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