... is now online. This was an "all-news", trying to wrap up the latest results on the calendar year. I'll post a synopsis shortly and, as always, please leave comments and/or questions below. Hope you enjoy, and Happy New Year!
Wednesday, December 26, 2007
.. which was the United States's entry into the Space Race, occurs on 2008 January 31, and to commemorate the event Jet Propulsion Lab (JPL) will be hosting a conference on this event for educators, museum staff, and high school students this January 26 & 27 in Pasadena, CA. Registration by January 22 is required, and there is a registration fee of $40. If interested, send a check payable to Jet Propulsion Laboratory, as well as your name, citizenship, title, school/organization, subjects taught, grades taught, address, state, zip code, and contact info for last minute changes (email or phone) to:
History Educator Conference
Attn: Trisha Wheeler
Mail Stop 180-109
Jet Propulsion Laboratory
4800 Oak Grove Drive
Pasadena, CA 911109
If any one goes, I'd be very interested in hearing what was discussed.
Posted by You'd Prefer an Astronaut at 7:08 PM
Every year, Science Magazine publishes their list of the top 10 science breakthroughs of the year, and this year only one Astronomy results made the list - the assertion from Pierre Auger that the arrival directions of the highest energy particles in space are correlated with the position of active galactic nuclei, supermassive black holes in the centers of galaxies which are accreting ("eating") a lot of material (several fractions of the weight of the sun per year or more). What do you think this was the most interesting result of the year? I put up a poll with some of my favorites, though I have to admit I am heavily biased by my research interests (supernova explosions, neutron stars, that sort of thing). What were yours? Please list what interested you the most below.
Thanks a lot, and happy holidays.
Posted by You'd Prefer an Astronaut at 6:38 PM
Tuesday, December 25, 2007
... is finally online. Sorry for the delay, but it is the holiday season... On this program, I discussed:
- News: Congratulations to the Custer Institute and Observatory in Southold, Long Island for being chosen as a recipient of a Fund for Astrophysical Research grant, to be used to purchase optical equiptment to start a search for extrasolar planets and supernovae (if interested in helping, please contact Donna L. McCormick) as well as Cal Tech and the UC system for being awarded $200 million dollars to start designing the Thirty Meter Telescope; new software package called Montage designed to combine images of the sky from different sources, wavebands, etc.; initial data from the largest yet digital survey of the Milky Way (called IPHAS) is released; NASA diverts Epoxi mission to Comet Hartley 2 since initial target, Comet Boethin, disappeared; NASA's GLAST satellite arrives at Naval Research Laboratory for final round of pre-launch testing; new international task forces called IMARS is formed to determine the best way to return samples from Mars to Earth; NASA announces plans to select next major Solar System mission soon.
- Solar System
- Sun: SOHO sees evidence for the next solar cycle beginning.
- Earth: NASA's AIM satellite releases initial results concerning "night-shining" clouds; THEMIS releases new measurements of Northern Lights.
- Mars: Made its closest approach to the Earth for this year; Mars Reconnaisance Orbiter detects "lace" and "lizard skin" terrain on Mars, likely from vents of carbon-dioxide gas forcing through the icy surface; Mars Rover Spirit discovers a rock composed of silica-rich rock believed to form naturally only in hot springs or volcanic vents, implying Mars used to be much warmer; organic material and molecules dicovered on meteorite Allan Hills 84001 which is believed to have come from Mars.
- Jupiter: New strategies discusses to probe under the ice shell on Jupiter's moon Europa.
- Saturn: Small moons Pan and Daphnis around Saturn show evidence of sweeping up ring material, getting larger in the process; rings around Saturn appear to have different ages, with material being recycled between them; current of charged particles detected around Saturn in a ring, which appears to be rotating with Saturn and changing in size and shape on short timescales.
- Outer Solar System: Voyager 2 crosses "heliosheath," where the Solar wind is decelerated by the interstellar medium - the material between stars that fills most of the volume of the Milky Way, at a much closer distance that Voyager 1, implying the solar system is "squashed."
- Wednesday Morning Astronomer: My weekly discussion on the "A Cosmic Thought" section of the Tuesday Morning Quaterback article written by Gregg Easterbrook.
- Calendar of Events in the New York area
- Interview with Michael Bank of the Mid-Hudson Astronomical Association on amateur astronomy in the mid-Hudson / Poughkeepsie region.
Posted by You'd Prefer an Astronaut at 2:05 PM
Friday, December 21, 2007
Senior Research Scientist at Columbia University, on laboratory astrophysics is finally online and available here. Laboratory astrophysics, the field of replicating astronomical systems on Earth and making measurements, is extremely important and very underappreciated - especially among professionial astronomers, so I encourage all of you to listen. If you want learn more about this work, check out Dr. Savin's personal webpage, as well as an article in Sky & Telescope (in PDF format) he co-authored on the subject.
As always, please leave questions and comments below, and hope you enjoy.
Happy Holidays -- Yosi
Posted by You'd Prefer an Astronaut at 5:13 PM
Tuesday, December 18, 2007
Unfortunately, I wasn't unable to record this show (CD-R malfunction) so I can't post it. There was lots of research results released last week, but I just focused on news and new results concerning the Sun:
- News: Congrats to Alexander Sharpe, Joshua Leviton, and Alistair McGregor for winning the Cassini "Scientist for a Day" competition, Prof. Geoff Marcy of UC-Berkeley for being chosen to deliver the annual John N. Bahcall Public Lecture at the Smithosonian Air & Space Museum, and Prof. Hinz, Dr. Kuchner, and Dr. Serabyn for being awarded time on the Keck inteferometer to study the disks left behind around stars after they form; design for the optical telescope system on the upcoming James Webb Space Telescope passes its preliminary design review; NASA announces plan to use a series of high altitude balloons called BARREL to study Van Allen belts and a new mission to the Moon called GRAIL to measure its gravitational field.
- Sun: The 7 December 2007 edition of Science was devoted to initial results of the Hinode satellite (for more information on this mission, go here) which studies X-ray emission from the Sun. One very puzzling aspect of the Sun and other similar stars is that the outermost layers, called the chromosphere and the corona, are significantly hotter than the photosphere, which is the region of the Sun where most of the visible light we see originates. Before I discuss the new results on this region, I want to first briefly describe the current best picture of what goes on inside the Sun. The Sun is quite a complicated object, with an extremely hot and dense center where fusion takes places (for example, "hydrogen turning into helium" as quoted in the song which I being many shows). These fusion reactions releases energy in the form of light. However, the region of the Sun that is hot and dense enough to sustain fusion reactions is nowhere near the size of the entire Sun, and how this energy goes from the inner center to the outer regions is quite complicated. In the region of the Sun just around the Hydrogen burning core, this energy radiates outward. However, this radiative region does not reach the surface, and this radiative core is surrounded by a convective envelope - meaning that gas heated by the radiative core rises up, and as it rises it cools, causing it to fall and get heated again, just as happens on the Earth from solar heating and similar to steam from a boiling kettle. This process of hot gas rising/cool gas falling is actually a very efficient method of getting the energy from the hot interior to the outer regions of the Sun, and most of the optical light we see from the Sun is from the top level of this convective layer called the photosphere. (The name "photosphere" is just a contraction of photon sphere, ie. the sphere where the photons - light - we see come from). However, it was discovered that outside this photosphere, where a large fraction of the energy generated by the fusion reactions in the center of the Sun escapes in the form of sunlight and travels into space, are hotter layers called the chromosphere and corona which are responsible for the solar wind, solar fares, coronal mass ejections, etc. Why? Well, since most of the light produced in these regions of the Sun is emitted in the X-ray band, not optical, to figure this out one needs high-resolution and sensitive X-ray observations of these regions, which Hinode was designed to provide. Astronomers had long suspected that the magnetic field generated in the convective layers of the Sun (all the gas in the Sun is ionized, meaning that it is in the form of electrons and atomic nuclei - mostly protons, and moving ions can produce electric and magnetic fields) was responsible, specifically through magnetic field generates by different patches of moving gas in the Sun interacting through each other. This speculation was believed to by confirmed by Hinode observations which detected a lot of "X-ray jets", X-ray emission produced by fast moving material believed to be created when these magnetic fields overlap, many more than had been detected before, which occur often enough and produce enough energy to explain most of the solar wind and coronal mass ejections. This just one of the many exciting results this satellite announced, and I encourage all of you to check out the Science issue
- Interview: with Dr. Daniel Savin of the Columbia Astrophysics Laboratory (Columbia University) on the field of Laboratory Astrophysics.
Posted by You'd Prefer an Astronaut at 2:34 PM
Tuesday, December 11, 2007
... is finally online, now that I have a nice friendly place to put it, and is available here. This was also an all-news-and-views show, and on this program I covered:
- News: JPL announces new version of PlanetQuest, a database with information on extra-solar planets; new NASA competition for high school and college students on aeronautics (good luck!); European Space Agency (ESA) announces a new program for recently graduated students interested in a career in the space industry, extension of Integral and XMM missions until 12/31/2012.
- Solar System: Solar flares possible accelerate electrons in "magnetic islands"; first results from the Venus Explorer mission are released, including detection of lightning and evidence that the solar wind is at least partially responsible for deficiency of water in its atmosphere; Mars Express marks 5000 orbits around Mars; Cassini detects complex hydrocarbons in atmospher of Titan, Saturn's largest moon; Voyager 2 expected to reach the "termination shock" where the Solar Wind collides with the interstellar medium soon.
- Milky Way: "Santa-shaped" cloud of very hot gas detected in Orion Nebula; giant jets (very fast, narrow, columns of outflowing material) detected around forming star L1157; evidence for planets forming around very young star UX Tau A; discovery of young, fast moving white dwarfs in globular star cluster NGC 6397 - origin of these velocities still a mystery; discovery that neutron star RX J0822-4300 is moving with a velocity >3 million miles an hour - extremely fast and extremely puzzling.
- Calendar of Astronomy events in the greater New York Area
- Cosmology: Unfortunately, I didn't get a chance to do this news item the justice it deserves, but simulations suggest that the interaction between massive stars and their environment can smooth out the density of dark matter in the center of dwarf galaxies, which could explain why the observed density of matter in these galaxies is a lot smoother than previously predicted by Cold Dark Matter models, which are the currently favored model for solving the "missing mass" problem (that when one uses the velocity of stars/galaxies to estimate the mass of a galaxy/galaxy cluster, the required mass is much higher than can be explained by the mass of all the observed stars/galaxies).
Posted by You'd Prefer an Astronaut at 3:58 PM
I hope. All of the interviews and radio shows which were previously available have been moved to a new site, and I believe I have updated all of the links here. Please let me know if you have any problems downloading material or, if any of you subscribe to this site via podcast servers, they have problems as well.
Thanks a lot, and don't forget to tune into tomorrow's show - special Dr. Daniel Savin of Columbia Astrophysical Laboratory (Columbia University) will be on to talk about laboratory astrophysics, an extremely important yet very under-appreciated field of astronomy (don't worry, I'll post this show and interview online as well) -- Yosi
Posted by You'd Prefer an Astronaut at 3:54 PM
Monday, December 10, 2007
... for any broken links below and not putting last week's show online yet, but I just learned that I lost the space I had from my previous institution which was hosting all of this material. Don't fear, since I hope to get everything back online tomorrow. Thank you for your patience -- Yosi
Posted by You'd Prefer an Astronaut at 6:42 PM
Saturday, December 8, 2007
Monday, December 3, 2007
... is finally online here. Since there was no show on 11/21, this was an "all-news" program. On this program:
- News: United Kingdom withdraws from Gemini Observatory, Thailand begins construction on a new optical observatory, Sloan Digital Sky Survey celebrates 5 years of operation, first HDTV "Earth Rise" taken by Japan's Selene mission, NASA announces success test of parachute system for next generation Moon rocket.
- Solar System: NASA extends SORCE satellite which studies the Sun's effect on the Earth's climate, similar chemical composition of Earth and Moon result of mixing between debris disk which formed the Moon and magma ocean which covered the Earth, Spitzer observations of nearby stars suggests Moon-like objects rare in other Solar Systems, Hubble observes core of Comet 17P/Holmes which is now bigger than the Sun, Mars doubles in brightness due to its polar caps now facing the Earth, evidence for a magma ocean covering surface of Mars for a long time in early Solar System.
- Milky Way: Evidence for rocky planets forming around stars in the Pleiades Star Cluster, discovery of white dwarfs with Carbon atmospheres,
- Extragalactic / Cosmology (1): Most luminous supernova to date SN 2006gy possible result of two stars colliding, merging, and then blowing up or result of a collision between shells of material expelled from surface of the star.
- Extragalactic / Cosmology (2): Detection of acidic molecular clouds in other galaxies, NASA's GALEX satellite finds evidence for spiral galaxies transitioning to elliptical galaxies, a lot of the "missing baryons" (missing normal matter) might not be in the form of hot gas between galaxies after all, supporters of modified Newtonian Dynamics (MOND) claim that this model can also explain the Bullet Cluster.
Posted by You'd Prefer an Astronaut at 3:57 PM