Comets and Asteroids and TNOs: Oh My!

Show notes for Episode 191, March 31, 2014
Hosts: Paul, Julie, Jen
Title: Comets and asteroids and TNOs: Oh My!

Tonight’s show featured a wealth of observational projects from Messier Marathons through to lunar eclipses and lunar occultations.  The outer solar system was featured with Centaur’s with rings not to mention far flung Kuiper Belt objects spanning the gap between the Kuiper Belt and the Oort Cloud.  A new segment debuted: Observatory Astro Log, featuring brief appearances by a member of the York Observatory Team.

This week in space/astronomy history:
1. March 25, 1655: Christiaan Huygens discovers Titan, moon of Saturn. Titan is the largest moon of Saturn and is the second-largest moon in the solar system. It has a dense atmosphere where lots of interesting chemistry happens. There is evidence for it having stable bodies of liquid on its surface (liquid methane).
2. March 25 1996: Comet Hyakutake closest approach to Earth.  Bright and fast moving, this was a spectacular object easily visible without any optical aid.
3. April 1 1997: Comet Hale-Bopp’s closest approach to Sun

The Observatory Log Book, hosted by Jen Zomederis
– AstroCATS – Astronomy Telescope Show May 3rd and 4th. (Tickets)
– Observatory Calendars available for a $10 donation.  Send a request to observe@yorku.ca and we will drop one in the mail!
– PV & OPV hours change as of April.  Check out yorkobservatory.com for all the details.

News:
1. Lunar Eclipse on April 15th, the first of a tetrad of eclipses, 4 total lunar eclipses in a row all visible from North America!  For This month’s eclipse,  1:58 AM is when the partial phase of the eclipse begins with totality starting at 3:06 AM EDT.  The next 3 total eclipses are October 8 2014, April 4 2015 and September 28 2015. http://science.nasa.gov/science-news/science-at-nasa/2014/27mar_tetrad/
2. Ringed asteroid: The asteroid Chariklo has two dense, narrow rings. It’s the smallest body in our solar system by far to be found with rings (the others being the gas giant planets). Chariklo is the largest of the asteroids known as Centaurs, which orbit the Sun between Jupiter and Neptune. Chariklo’s orbit is between Saturn and Uranus. The rings were discovered when the asteroid occulted a star (UCAC4 248-108672). Observations were made from 7 different observatories in South America. The rings were likely the result of an earlier collision and their configuration indicates they are either very young or that they are affected by yet-to-be-discovered small moons of the asteroid. Suggested reading ESO media release,
3. Sedna-like body discovered: 2012VP113 (nick-named Biden) is only the second object of its kind to be discovered. The first was Sedna, discovered in 2003. Both pretty far from the Sun and have highly elliptical orbits (perihelion of 76 AU for Sedna and 80 AU for 2012VP113). The solar system can be divided into 3 regions: the inner, rocky planets and asteroids (0.39 – 4.2 AU from the Sun), the gas giants (5 – 30 AU) and the Kuiper belt objects (30 – 50 AU). Sedna and “Biden” would be a part of the inner Oort cloud, the outermost grouping of objects in our solar system and the place comets come from. These objects could be the link between the Kuiper belt and the hypothesized outer Oort cloud about 10 000 AU from the Sun. There are two main models for the formation of the inner Oort cloud, as we discover more objects like Sedna and Biden, we will be able to determine which is the more likely to have happened. Suggested reading Discovery article
4. Global Astronomy Month (April is starting off with an online Messier Marathon  Check out astrowebtv.org starting from 1800 hours UT April 1 to catch all of the action, both telescopic and commentary!  Messier marathons are an exciting opportunity to see wealth of diverse non-stellar objects first found by Charles Messier over 200 years ago.  Not for the faint of heart, these marathons can result in all 110 objects being observed in one night.  It is a lot of work but a lot of fun!
5. Lunar occultations this Thursday April 3 with the Moon traversing through the Hyades star cluster.  The advancing dark limb of the Moon will occult a series of 4th and 5th magnitude stars in teh late evening (EDT).  As with all occultation measurements, accurate timing of such events can yield useful positional data on the star or the Moon and can potentially detect heretofore unknown companions.  skyandtelescope.com
6. Planet roundup for the night sky.  From the gas giants Jupiter and Saturn adorning the evening sky to the terrestrial worlds Mars (evening) and Venus (morning) there is no shortage of planets (shining with steady untwinkling light) visible to the naked eye.
7. Cosmos wrap up from last night.  Delighted to see more astronomers from history making their way into the narrative of the show.  John and William Herschel for example.  We enjoyed the discussion and description of the relationship between distance and time.  We also appreciated the tribute to Carl Sagan towards teh end and the role he played in influencing Tyson when he was just embarking onto his astronomy career.

Thanks for listening!

-YorkUniverse Team

__________

YorkUniverse is a co-production of Astronomy.FM and the York University Astronomical Observatory. For more information on us, check out the following links:

webpage: www.yorkuniverse.com

twitter: @YorkUniverse

AFM page: astronomy.fm/yorkuniverse

Observatory webpage: www.yorkobservatory.com

Observatory twitter: @YorkObservatory

The Matt, Pat, and Paul Travelling Universe Show!

Show notes for Episode 190, March 24th 2014
Hosts: Paul, Pat, Matt (Guest)
Title: The Matt, Pat and Paul Traveling universe show!

Tonight’s show will feature some local devastation (on Jupiter from comet SL9) not to mention a quick summary of the changing appearance of nearly planets (gullies on Mars, volcanoes on Venus).  However, the real excitement is way back in the past with Matt Johnson (YorkU and Perimeter Institute) as we examine in some detail the announcement of the detection of B-mode polarization and its implications for inflation in the early universe and the Big Bang cosmology.

This week in space/astronomy history:
1. Comet Shoemaker Levy 9 March 24 1993 discovery.  It was a “rubble train” at this point, the most unusual comet that either Eugene (or Carolyn) Shoemaker or David Levy had ever seen.  Tidally disrupted by Jupiter in 1992, Comet SL9 (formerly D/1993 F2) would rain rocks into the Jovian atmosphere in a spectacular manner in July 1994.
2. March 24 1975 marked the end of the Mariner 10 mission, first mission to extensively map the planet Mercury.  A lack of onboard fuel to allow teh spacecraft to orient its radio antenna towards Earth finally closed off the scientific flow from Mariner 10.
3. Mercury RD-BD unmanned Mercury flight that COULD have flown Alan Shepard into a sub-orbital flight prior to Yuri Gagarin’s flight of April 12 1961.  However, the mission remained unmanned and flew successfully.
4. Birthday shoutout to Joseph Hooton Taylor, born March 29 1941.  Nobel Prize for work on pulsars, shared with Russell Hulse in 1980.  taylor is synonymous with pulsar research and the uses pulsars (rotating neutron stars) have in testing aspects of teh theory of relativity.
5. Christian Huygens discovered the largest moon of Saturn,  Titan in March 25 1655.

Guest:  Matt Johnson (of York University and the Perimeter Institute) will discuss with the YorkUniverse Team the announcement last Monday March 17 2014 of the B-mode polarization detection and its implications for the Inflation model of the Big Bang cosmology.
Matt intro:

  • Bachelor’s in Liberal Arts (Physics specialization) at Evergreen State College, Olympia Washington USA

  • PhD Physics at UC Santa Cruz

  • Postdoc at CalTech

  • Postdoc at Perimeter Institute

  • Assistant Professor at York University and Associate Faculty Member at Perimeter

Large gravitational wave signal in the CMBR is good news!  Other existing (and planned) instruments can check if it’s real, and if so, study it in detail to gain new information about inflation. Will the B-mode polarization be found at other wavelengths?  If not, does this suggest the interpretation of gravity waves as the cause of the B mode polarization needs to be revisited or indeed discarded?  Pat is suggesting that new observations will cast doubt on the current interpretation of the B mode observations.  A $10 bet is “on” with Matt!  Stay tuned.

News:
1. Active volcanoes on Venus?  New data from ESA’s Venus Express suggests that 3 recent volcanic eruptions may have occurred.  While the notion of Venusian volcanism dates back to the Pioneer Venus days of the late 1970s, no definitive proof has yet been established.  venus is tough to observe even with orbiting spaceprobes.  Smrekar et al from JPL have measured 3 “hot spots” on the Venusian surface that they conclude are very recent.  While the article is soon to be published in Nature, the  data from Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), is very suggestive of three eruptions last year.  Sulphur dioxide measurements are often cited as evidence of such eruptions but that is not considered definitive.
2. Next crew to launch to the ISS March 25, 5:17 PM EDT.  Expedition 39, despite the ongoing crisis in Ukraine seems to be business as usual with 2 Russian and 1 NASA astronaut.
3. Very few observations of the Regulus Occultation by 163 Erigone from March 19-20.  It would appear that almost the entire observation path was clouded out.  A real disappointment to the IOTA team members not to mention those of us planning to witness this once in a lifetime “disappearance’ of one of the brightest stars in the night sky.

Major Topics Discussed:

1. New gully on Mars (but probably not from water):
http://www.universetoday.com/110483/new-gully-appears-on-mars-but-its-likely-not-due-to-water/#more-110483
Images from NASA’s Mars Reconnaissance Orbiter show a new channel in the southern hemisphere region of Terra Siernum that appeared between November 2010 and May 2013.
The pair of images that shows material at the base of a gully broke out of an older route and eroded a new channel.
This particular feature is likely not due to water.
“Before-and-after HiRISE pairs of similar activity at other sites demonstrate that this type of activity generally occurs in winter, at temperatures so cold that carbon dioxide, rather than water, is likely to play the key role,” the agency said.
Last week, the agency also announced that MRO recovered from an unplanned computer swap that put the spacecraft into safe mode. Incidents of this nature have happened four times before, the agency noted.

2. 360-degree Milky Way panorama from Spitzer:
http://www.universetoday.com/110525/360-degrees-of-milky-way-at-your-fingertips/#more-110525
More than 2 million infrared photos taken by NASA’s Spitzer Space Telescope were jigsawed into a 20-gigapixel click-and-zoom mosaic.
Named GLIMPSE360 (Galactic Legacy Mid-Plane Survey Extraordinaire project), the deep infrared survey captures only about 3% of the sky, but because it focuses on the plane of the Milky Way, where stars are most highly concentrated, it shows more than half of all the galaxy’s 300 billion suns.
In this mosaic you can see jets from young stars, bubbles blown around massive stars, and emission nebulae lit up by the light from stars.
Unlike visual light, infrared light is not stopped by dust, and thus is used by astronomers to view structures in the plane of our galaxy that are obscured in the optical.
http://www.spitzer.caltech.edu/glimpse360/

 

Thanks for listening!
-YorkUniverse Team
_________
YorkUniverse is a co-production of Astronomy.FM and the York University Astronomical Observatory. For more information on us, check out the following links:
webpage: www.yorkuniverse.com
twitter: @YorkUniverse
AFM page: astronomy.fm/yorkuniverse
Observatory webpage: www.yorkobservatory.com
Observatory twitter: @YorkObservatory

The Sequester Walks The Planck: Mar 26 2013

Show Notes: March 26th, 2013 UTC

Hosts: Paul, Jesse, Lianne
Title: The Sequester Walks The Planck

A little extra time on the show tonight allowed us to pontificate on the political strife in the United States. The sequestration has caused a massive amount of public funding cuts, including NASA public outreach and education. Of course the Planck Telescope delivers its news that Universe is slightly older than we once thought. Paul, ‘the dean,’ gripes over his failing Aussie cricket team (but mostly off-air). Astronomy Night in Canada starts with York Universe, thanks for listening! See our show notes and podcast below.

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