January 28th Radio Show: Galaxy Formation and Evolution

Sorry for the delay, but here is the January 28th edition of this radio show, where I continue my discussion of galaxy formation and evolution. Thank you for listening, hope you enjoy, and, as always, please email me or leave below any questions, comments, or concerns you might have.

December 31st Radio Show: Latest Astronomy News

Available here is the December 31st radio show, where I discussed most of the Astronomy news which occurred during the three weeks I was away. Hope you enjoy and, as always, please email me or leave below and questions, comments, or concerns you might have. Thank you for listening!

Description of October 29th Radio Show: Evolution of Low Mass Stars

Long available here, below is a detailed description of the October 29th edition of this radio show. On this program I talked about:

• Opening Song: Why Are Stars of Different Colors? by Tom Glazer & Dottie Evans
• News: Phoenix Mars Lander survives a dust storm that lowered its solar power intake (link), HiRISE camera on Mars Reconnaissance Orbiter sees evidence for a crater underneath the polar ice caps on Mars (link) and the Compact Reconnaissance Imaging Spectrometer sees evidence for opal on Martian surface - evidence for the presence of liquid water at some point in the past; detection of plumes of methane erupting on Martian surface may change landing location for future Mars Science Laboratory rover; both NASA and ESA having major cost overruns on next generation Mars missions; images of Mars's moon Phobos by Mars Express satellite suggests it is a rubble pile of many smaller asteroids stuck together; Cassini successfully sweeps into geysers on Saturn's moon Enceladus; radio observations of the nucleus of the Comet Tuttle suggests it consists of two objects orbiting each other very closely; new comet discovered by Rob Cardinal at University of Calgary (link); University of Western Ontario automated cameras video another meteor crashing down on Earth (link, videos); NASA launches IBEX spacecraft to study particles accelerated at the boundary of our Solar System (link); India launches its first spacecraft to the Moon, Chandrayaan-1 (link) - contains instruments built by NASA and ESA; NASA's next Lunar spacecraft, Lunar Reconnaissance Orbiter, begins testing before launch; congrats to Armadillo Aerospace for winning prizes at NASA's recent Lunar Landing Challenge; ESA hosts university challenge for Lunar Rovers; NASA tests its own future lunar rovers in Arizona and Hawaii (link); NASA and Challenger Center for Space Education host naming contest for astronaut housing prototype in Antarctica (link); waterless concrete developed to built structure on the Moon using only the lunar surface (link); ESA develops "replicators" to build future structure on Mars (link); backup computer on Hubble Space Telescope has glitch, causing spacecraft to go into safe mode (since resolved); ESA lost contact with XMM-Newton temporarily, since restored; Fermi Gamma Space Telescope (born GLAST) discovers first gamma-ray only pulsar (link); letter in Science about funding GLAST and Advanced Technology Solar Telescope; ESA satellite GOCE delayed due to rocket malfunction, cause identified; continued fighting over AMS experiment to Space Station; NASA reinstalls mirror on SOFIA observatory, scientists selected to do projects with this observatory; congrats to Kenneth Ford for becoming chairman of NASA Advisory Council Service and to Expedition 17 to the International Space Station for safe return home; Great World Wide Star Count begins.
• Wednesday Morning Astronomer (a response to this and this ESPN column): eta Carinae's bright flash not a supernova but something else, sci-fi explanations not science, I agree that launch of Chandrayaan-1 does not represent a decline in US capabilities at all.
• Calendar of upcoming Astronomy and science events in the greater Poughkeepsie and New York City area.
• Evolution of Low-Mass Stars: The definition here of low mass stars are stars born with a mass less than eight times that of the Sun, because these stars do NOT end their life in a core-collapse supernova. When these stars fuse all of their hydrogen to helium, fusion stops and they contract. As they contract, the stars core will get hot enough and dense enough to fuse helium to heavier elements. Helium fusion releases more energy than Hydrogen fusion, causing star to expand again and possibly blowing off outer layer. This results in structures called planetary nebula, and this mass loss process is poorly understood but important in understanding effect of stars on their surroundings. New observing techniques (link) being developed to better study this. Images of planetary nebula, like Cat's Eye Nebula and NGC 2371 (link) suggest process extremely complicated and variable. When Helium fusion stops, star's core begins to collapse again. In doesn't get dense or hot enough to fuse these heavier elements, but electrons in the core get close enough that their repulsion supports the core from gravity (this is called "electron degeneracy pressure"). Such an object is called a white dwarf. The internal structure of white dwarfs is poorly understood, and the best way to study it is by looking a pulsations from them. "Starquakes" in a white dwarf will change the brightness, and by studying these pulsations can learn about their structure. A new campaign to do this by the Whole Earth Telescope has begun (link). These pulsations also depend on the chemical composition of the white dwarf, and for the first time were detected from a Carbon white dwarf (link). Young white dwarfs produce a lot of ultraviolet light, which ionizes and illuminates the planetary nebula produced by the progenitor star - though in one case the white dwarf response for this has yet to be detected (link). If a white dwarf is close to another star, matter from that star will flow onto the surface of the white dwarf. This matter, as it accumulates will heat up until it is hot and dense enough to star fusion, releasing a flash of light called a "nova". XMM-Newton serendipitously observed X-ray from such a nova produced by a previously unknown white dwarf. Mass flowing from one object to another often produces radio jets - radio emission from fast moving material flowing AWAY from the central source. These jets had not been observed from a type of white dwarf system, until now. These nova explosions also believed to produce dust - the fusion creates heavier elements which, as they cool, condense to dust grains. Recent observations of a nova in 2006 suggests this might not be the case (link) for this one, though dust production has been observed in other novae (for example, this one.). If a white dwarf accumulates so much material that electron degeneracy pressure can no longer support it against gravity, it explodes in an event called a Type Ia supernova. How it explodes is currently unknown, and being simulated on lots of super-computers at the University of Chicago (link) - among other places. Additionally, it has been theorized that a white dwarf which passes to close to a black hole might be ripped apart and explode (link).
• Closing Song: Wolf 359 by The Chromatics

Thank you very much for listening. As always, any questions, comments, or concerns are deeply appreciated.

November 5th Radio Show online: Evolution of High-Mass Stars

I'm really sorry for taking so long to post this, but here is the November 5th episode of this radio show where, in addition to the usual Astronomy news and notes, I discuss the evolution of massive stars before they go supernova. Hope you enjoy!

And yes, I do owe you a detailed description of the October 29th radio show as well.

October 29th Radio Show: Evolution of Low Mass Stars

Available here (finally) is the October 29th edition of this radio show. On this program, in addition to the latest Astronomy news and calendar, I discuss the evolution of low mass stars like the Sun, from Sun-like stars to red giants and then to white dwarfs. Hope you enjoy! As always, any and all feedback is appreciated. Thanks a lot for listening.

Description of October 15th Radio Show: Star Formation, Planet Formation, and Massive Stars

Long available here, below is the detailed description of this radio show:

• News: Evidence that boundaries of sunspots play an important role in the producing the Solar wind (link); NASA's spacecraft MESSENGER completes second flyby of Mercury, images a substantial portion of Mercury's surface never observed before (link); ESA spacecraft Venus Express observes the Earth to use as a template for studying extrasolar planets; Mars Odyssey shifting orbit around Mars to better measure the spectrum of interesting regions of the Martian surface; Phoenix Mars Lander obtains new samples for study (link); asteroid collides with Earth exactly when and where as predicted; Spitzer spacecraft releases images of Comet Holmes obtained after its eruption last year, show large dust grains ejected during this event; Cassini flew by Saturn's moon Enceladus again last week to better study the plumes emanating from its surface (link), recent flyby of Saturn's moon Titan - the largest moon in the Solar system - by Cassini reveals that Titan's atmosphere can hold onto Saturn's magnetic field as it passes through (link), and Cassini images a massive cyclone at Saturn's North Pole similar to the one long seen at Saturn's South Pole (link); IBEX spacecraft to study particle accelerated at the outer boundary of the Solar System ready for launch (link); ESA has delived all of its instruments to the Indian Lunar satellite Chandrayaan-1; new crew departed for International Space Station; congrats to Dr. Ellen Ochoa, deputy director of NASA's Johnson Space Center, for being the first female recipient of the "Engineer of the Year" award given at the Hispanic Engineer National Achievement Awards Conference; research at Queen's University in UK developing a robotic system to repair satellites in space (link); ESA to test Intermediate Experiment Vehicle in 2012; NASA examines heat shield from Apollo mission to help design new lunar crew vehicle (link); NASA studying possibility of putting a large liquid mirror on the Moon; NASA issues 2008 edition of Spinoff magazine, available here.
• Wednesday Morning Astronomer (an Astronomer's response to this ESPN column): I agree that commercial rocket launches are a long, way, away from being a viable alternative. However, the lack of sunspots seen recently from the Sun isn't really a problem, and the reversal of Earth's magnetic field is going to take 100s if not 1000s of year, not occur during 2012.
• Calendar of upcoming events in the greater New York / Poughkeepsie area.
• Molecular Clouds and the Formation of Stars and Planets: Observation of a molecular cloud by astronomers in the Canary Islands discovers naphthalene, a precursor to amino acids (link); Spitzer observations of star forming region W5 show evidence for star formation being triggered by stars which just formed in the area (link); a similar process believed to be occurring in the star forming region NGC 346 located in the Small Magellanic Cloud (link); this is evidence that the Solar System was the result of a shock wave collided with its progenitor gas cloud (link); infrared survey of the Milky Way done using Spitzer space telescope detects stars in all phases of their creation - from the proto-stars created by the collapse of their natal molecular clouds to young stars blowing holes in the interstellar medium after they "turn on" (link; evidence for stars forming in the gas stripped from a galaxy as it collides with another galaxy (link); ESO's Very Large Telescope uses optical interferometry to study the structure of the disk formed by the collapse of a dense cloud of gas into a star(link); evidence for water being formed and destroyed in the outflows of material from this disk as it collapses onto the central star; chemical compositions of comets suggests that material flowed from the inner part of this disk to the outer part as our Sun formed (link 1, link 2); isotopic abundance of Oxygen in early Solar system changed during the formation of the Sun (link); asteroids in the Solar System believed to contain carbon molecules which can survive entry into the Earth's atmosphere and possibly be building blocks for life on the Earth (link); gap observed in the gas and dust disk around a young star believed to be evidence for a planet forming there (link); future telescopes believed might be able to detect disk gaps formed by planets as small as Mars (link); astronomers at University of Toronto might have made an actual picture of a planet orbiting another star (link); bizzare new exoplanet found - not sure if it is a planet or a brown dwarf (link); evidence for recent collision between two planets seen around distant star BD+20 307 (link); most massive star in Milky Way weiged in at over 110 times that of the Sun (link).

Hope you enjoyed this program and, as always, any and all feedback is appreciated. Again, thank you very much for listening.

October 15th Radio Show: Star Formation, Planet Formation, and Massive Stars

Continuing my recap of topics I discussed this summer, here is the October 15th episode of the radio show, where I discuss the latest results concerning star and planet formation, massive stars, in addition to the usual Astronomy news and calendar. I'll post a more detailed description later, but in the mean time, enjoy! Comments and concerns are always appreciated, and please leave any you have below.

October 8th Radio Show: Solar System News

Now available here is the October 8th radio show, where I quickly race through all of the recent scientific results on our Solar System plus the usual news and calendar. Hope you enjoy!

October 1st Radio Show online: Astronomy News

Finally online is the October 1st episode of this Astronomy radio show / podcast, available here. On this program, I interviewed Dr. Jeffrey Owen Katz of the Custer Institute and Observatory, as well as discuss the latest Astronomy news. Sorry it took so long to put online, and hope you enjoy! As always, please email or leave any feedback below.

Description of September 10th Radio Show: Milky Way Structure and Galaxy Formation

Already available here, below is a description of the September 10th edition of this radio show. On this program, I discussed:

• Calendar of upcoming Astronomy / science events in the greater Poughkeepsie / New York City area.
• Interview with Prof. Allyson Sheffield of Vassar College.
• News: Phoenix Mars Lander begins analysis on deepest soil sample to date (link) as well as makes some puzzling measurement regarding humidity on the Martian surface; amateur astronomers see Perseid meteor shower hit the Lunar surface; ESA's Rosetta spacecraft flies by astroid (2867) Steins - sees chain of craters, rotation, and overall diamond shape (link); Cassini detects ring arcs around two moons of Saturn (link); NASA awards contract to S.C. Jones Services, Inc. to get rid of pests at Kennedy Space Center; NASA building "Solar Ultraviolet Magnetograph Investigation" to measure the strength of the magnetic field at the outer edges of the Sun; NASA developing a new space equiptment rack for "Zero-Gravity" flights; NASA delays launch of Space Shuttle Atlantis to October 12 and launch of Space Shuttle Endeavor to November 12 due to bad weather - media viewing of equipment to be flown on Atlantis for installation on Hubble Space Telescope set for Sept. 10; launch of ESA's GOCE satellite delayed due to rocket problems; NASA to hold media briefing on September 25th on Lunar Exploration plans; mirror blank produced for Large Synoptic Survey Telescope (link); NASA produces 50th anniversary art book - information here; NASA announces new Carl Sagan postdoctoral fellowship to study extra-solar planets - information here; NASA issues a challenge to high school and college students to describe a future supersonic airliner - information here - as well as a new aeronautics competition - information here; Swift to announce new gamma-ray burst findings today; Custer Institute to host 30th annual Astronomy Jamboree and Conference October 3rd and 4th.
• Milky Way Structure and Galaxy Formation: It is currently believed that all galaxies, including the Milky Way, formed by the merging of smaller galaxies together - an this process is ongoing. If this is correct, there should be evidence for this in the Milky Way today - as discussed by Prof. Sheffield at the beginning of this show. A recent survey of satellite galaxies of the Milky Way, small galaxies which are in the process of merging into our galaxy, discovered that they all have roughly the same total mass (stars + dark matter) - regardless of how many stars they have. This implies something strong about the formation of these galaxies or the properties of dark matter - astronomers are still not sure which (link). Evidence of previous mergers is also in "streams" of stars - stars with similar orbits and chemical composition - in the halo of the Milky Way. There are many questions regarding the structure of the Milky Way - including how many spiral arms there are, since two of the spiral arms that were thought to be there have apparently disappeared (link).

Hope you enjoyed and, as always, any and all feedback is appreciated. Thank you very much for listening!

September 10th radio show: Milky Way Structure and Galaxy Formation

Finally online here is the September 10th edition of this radio show. On this program, in addition to the usual news and calendar, Prof. Allyson Sheffield of Vassar College discusses her research on the structure of the Milky Way and how it relates to the formation of galaxies. I'll post a more detailed synopsis next week, but until then, enjoy. Thank you very much for listening.

Description of August 20th radio show: Extrasolar Planets

Much detailed, for which I apologize, is a detailed description of the August 20th radio show available here. On this program, I discussed:

• News: Phoenix Mars Lander takes first photograph of a Martian dust particle using an atomic force microscope (link); Cassini spacecraft starts transmitting data from flyby over Saturn's moon Enceladus, famous for its geysers (link) - information from this flyby determines these geysers originate from fractures in its surface (link); ESA spacecraft Rosetta tracks asteroid (2867) Steins for upcoming rendezvous; NASA moves up milestones for final Hubble Space Telescope servicing mission; NASA's IBEX mission fueled and testing continues for October 5th launch; series of key tests for a components of the J-2X engine on NASA's Ares rocket (successor to the space shuttle) completed; psychologists outline personal challenges astronauts might face on longer space missions (link); NASA astronaut Greg Chamitoff on board the International Space Station answering questions on a weekly basis (link); congratulations to students at Ohio State University who successfully built and launched a balloon-born cosmic ray detector to the edge of space (link); survey of supernovae (bright flashes of light caused by either the explosion of a white dwarf or the collapse of the core of a massive star) shows that ones which are further away get dimmer slower than ones which are nearer - as expected from general relativity; PAMELA satellite which measures the ratio of positrons to electrons at high energy might (only might) have detected indirect evidence for the existence of dark matter; swimsuit used by Michael Phelps and others at Beijing Olympics to break swimming records tested at NASA's Langley Research Center (link).
• Wednesday Morning Astronomer: (an astronomer's take on the Astronomy content of Gregg Easterbrook's ESPN column "Tuesday Morning Quaterback", available here) While "smithereens" isn't very technical, it does make sense to use it in a press release. And "bizarre" is a term astronomers often use to describe what they see...
• Astronomy Calender of upcoming Astronomy and science events in the greater New York City/Poughkeepsie area.
• Extrasolar Planets: While, as discussed on August 13th, a lot of work is going into discovering new extrasolar planets, a lot of science can be done by studying known systems. One major question is what role does the chemical composition of a star play in the formation of a planet. For example, it appears that stars with a higher concentration of elements heaving than Hydrogen and Helium (which astronomers lump together as "metals") are more likely to have a planet orbiting them. A recent discovery of a planet orbiting a metal rich star that drifted away from the Hyades cluster bolsters this claim (link). Additionally, astronomers are very interested in the properties of the extrasolar planets themselves, and not just the stars they orbit. For extrasolar planets which pass between their central star and the Earth, the so-called "transiting planets", the atmospheres of these planets absorb some of the light emitted by the central star. Since atoms absorb light at particular frequencies, one can use these "absorption lines" in the spectrum to determine the chemical composition of the planet's atmosphere. Also, the width and depth of these lines gives you an estimate of the velocity and amount of this particular elements in the atmosphere. A recent analysis of the spectrum of extrasolar planet HD 209458b discovered broad Hydrogen absorption lines - implying that fast moving Hydrogen is being ejected from this planet's atmosphere. It is thought that this is the result of the solar wind from the central star interacting with this planet's atmosphere - similar to the interaction between the Sun and the Earth. Also, using this technique methane has been detected in the atmosphere of another extrasolar planet, HD 189733b - the first time this has happened. It is possible to use Solar System meteorites to estimate the properties of the Solar System when planets formed because they were also formed during this time, and have not undergone the chemical changes planets have. A recent chemical analysis of meteorites suggest that the dust cloud if which the Earth and other planets formed was denser than previously thought (link). A major goal of extrasolar planet research is to detect Earth-like planets, a method to do this is being developed by astronomers at Penn State and University of Hawaii (link). What is not known is how common a Solar System like ours is (rocky planets close to the Sun, larger gaseous planets further away) since we currently can't detect Solar Systems like our own. As a result, almost all of the other Solar Systems we known of are very different, with large gas giants orbiting close to their central star. A recent computer simulation of the formation of a solar system suggests that our Solar System is rare indeed (link, article). This affects the odds of finding extraterresterial intelligent life, which a recent analysis predicts to be quite rare (link). Last, but not least, stars are expected to swell as they age, and swallow the surrounding planets. This process might already have been observed.

Thank you for listening. Hope you enjoyed, and as always, any and all feedback is appreciated.

August 20th Radio Show Online: More on Extra-Solar Planets

Available here is the August 20th episode of this radio show. In addition to usual Astronomy news and notes, I continue discussing the latest results concerning extrasolar planets - specifically measurements of their physical properties. A more detailed description will come soon, but in the meantime, hope you enjoy!

Description of August 13th Radio Show: Planet Formation and Extrasolar Planets

Below is the detailed description of August 13th edition of this radio show, already available here. On this program, I talked about:

• News: No, Phoenix Mars Lander has not detected life of Mars, even though one of the instruments on the Phoenix Mars Lander did detect a type of salt called perchlorate - a fuel source for some micro-organisms on Earth (link); ice in Martian soil may be preventing soil samples from entering the instruments on Phoenix Mars Lander; Cassini prepares to fly within 30 miles of geysers erupting on the surface of Saturn's moon Enceladus (link), initial data already received; Hubble Space Telescope celebrates its 100,000th orbit around the Earth by taking this image of a star forming region near star cluster NGC 2074 (link); instruments on the Hubble Space Telescope slated for repair during final servicing mission to occur in October (link) - astronauts interviewed August 11th; new book on how the Hubble Space Telescope got built recently published - "The Universe in a Mirror" by Robert Zimmerman; Interstellar Boundary Explorer mission undergoing testing of science instruments prior to its October 5th launch; bizarre object discovered by Dutch school teacher Hanny van Arkel in archived images of the night sky maintained by http://www.galaxyzoo.org (link); David Dunlap Observatory in Toronto sold to a developer; NASA's Aerospace Safety Advisory Panel releases annual report, available here; NASA readjusts time table of Constellation Program - the successor to the space shuttle; NASA awards prized at General Aviation Technology Challenge (link); NASA says farewell to this year's group of high school and college aged INSPIRE interns (link to INSPIRE program); NASA awards space radiobiology grants (link); Arizona students talked with astronaut Greg Chamitoff on International Space Station on August 15th.
• "Wednesday Morning Astronomers": An astronomer's opinion on the Astronomy content in Gregg Easterbrook's weekly column on ESPN's Page 2, available here - yes, it is extremely cheesy that Doritos broadcast an ad towards a nearby star, and I also hope they aren't offended by it. I also find it extremely disturbing that a NASA press release concerning a Spitzer observation of a star similar to that of the Sun was quashed for being "alarmist."
• Calendar of upcoming astronomical and science events in the greater Poughkeepsie/New York City area.
• Planet Formation: As explained previously no this program by Dr. Aki Roberge, planets are believed to form in the gas and dust disks left behind after a star forms. The starlight from the central star has a large effect on the gas and dust in this disk, possibly driving larger icy bodies out to the solar system before gas drag causes to circulate inwards. This can lead to the formation of organic molecules and water in this "proto-planetary" disk, as was recently observed (article). Planets in this disk are expected to grow from dust grains colliding and sticking together to form pebbles, which in turn stick together to from proto-planets, which then form planets. These dust grains and pebbles scatter the light from the central star, and this scattered light has been observed from the proto-planetary disk around KH 15B binary star system. As the planet grows, it carves out a gap in the disk detectable in radio observations of the gas and dust. This has been seen around a very young star, <100000 years old, HL Tau - implying that planets form very rapidly (link), as well as around older star AB Aurigae (link).
• Extra-Solar Planets: Currently, there are three major observational techniques to detect planets around other stars - the radial velocity method, which detects the motion of the central star caused by the gravitational pull of the planet, the transit method - which detects a decrease in the light from the central star caused by the planet passing between the Earth and the star, and microlensing technique - where the gravitational field of the planet bends the light from the star such that its brightness on Earth increases very quickly. All of these techniques require monitoring the properties of many stars at once. An upcoming project to do this using the radial velocity method is MARVELS. The radial velocity method requires precision measurements of the star's spectrum since the planet's signature is a periodic change in the central frequency of spectral lines. This requires very good calibration of the spectrometer, which might be easier and 100x more sensitive thanks to a new laser standard (link). There are many transiting planet searches being conducted on the ground and from space. One such satellite, the COROT mission, has discovered a planet orbiting a Sun-like star, though at an orbit very different from the Earth's (link). NASA has also directed a spacecraft which orbits comets to look for transiting planets in it's spare time, the EPOXI mission (link). A new detector possibly capable of detecting the transit from an Earth-size planet around another star is being developed in the UK called "RISE" (link). The microlensing technique has recently been used to detect a planet just three times the size of the Earth, the smallest extra-solar planet yet. SuperWASP, a transiting planet survey, has recently detecting 10 extra-solar planets with different sizes and orbits (link). A rocky planet has been inferred around another star due to its gravitational effect on a previous detected planet in this "solar system" - it has since been detected using the radial velocity method (link), as have three other Earth-like planets (link). Small planets have also been detected around small stars like brown dwarfs (link). It has been speculated the nearest star to the Sun, Alpha Centauri, might have Earth-like planets around it (link). Last, but not least, even though planetary nebulae have nothing to do with planets, a planet has been discovered inside one (link).

Sorry for the delay in posting this. Thank you very much for listening, hope you enjoyed it, and any and all feedback will be appreciated.

Description of August 6th Radio Show: Star Formation and Brown Dwarfs

I know I already posted the August 6th radio show here, but below is a detailed description of what I actually talked about:

• Mars Phoenix Lander: The Thermal and Evolved Gas-Analyzer (TEGA) instrument detects water in sub-surface Martian ice it analyzed, mission also extended until September 30th (link); Microscopy, Electro-chemistry, and Conductivity Analyzer (MECA) instrument possibly detects perchlorate.
• News: Liquid lake discovered on Titan, believed to be full of ethane; European Space Agency (ESA) spacecraft Mars Express takes highest resolution image of Mars's moon Phobos ever (link); ESA spacecraft Rosetta starts tracking asteroid (2867) Steins in order to rendezvous with it on 5 September; book review in Nature on "The Black Hole War" by Leonard Susskind describing a debate between him and Stephen Hawking on the fate of black holes; NY Times article about new book "The Universe Mirror" by Robert Zimmerman about the challenges in getting the Hubble Space Telescope built and launched; congratulations to Mr. Enrico Saggese for being appointed head of the Italian Space Agency; congrats to Dr. Thomas B. Irvine for being appointed Deputy Associate Administrator of NASA's Aeronautics Research Mission Directorate; congratulation to the winners of NASA's first Aeronautics Scholarship competition - list of winners available here and more about this program available here; NASA unveils this webpage in honor of its 50th anniversary; NASA hosts an international meeting to discuss future lunar science missions, signs partnership agreement with University of Western Ontario; NASA's Lunar Reconnaissance Orbiter undergoes pre-launch testing at Goddard Space Flight Center; Solar Eclipse on morning of August 1 (link); NASA to broadcast highlights of its activity in HD on NASA TV.
• Calendar of upcoming Astronomy/science events in the greater New York City / Poughkeepsie Area.
• Star Formation: As described very well in an interview I did with Dr. Aki Roberge of NASA's Goddard Space Flight Center, stars form by the gravitational collapse of dense clumps (>100 of atoms per cubic cm) of material in molecular clouds, cold regions where atoms can stick together into molecules and dust grains (essentially, very large molecules with 100s of atoms stuck together). Therefore, the chemical composition of these molecular clouds are the building blocks of the chemicals we find in the Sun, Solar System, and on Earth. With radio telescopes, one can see spectral lines from these molecules, and in one molecular cloud, a primitive amino acid (acetonitrile) was discovered, while surveys for identifying other complicated molecules in molecular clouds are currently taking place (link). Miniature diamonds found inside meteorites can also form in these molecular clouds, and can be detected with the Spitzer Space Telescope. To determine how a molecular cloud breaks into dense clumps which will collapse into stars, it is important to know the distribution of material inside the molecular cloud. Since molecular clouds are extremely dense and cold, it is very hard to see into them because they absorb all the optical light behind them and don't emit much optical light of their own. However, molecular clouds scatter infrared light from stars behind them, and this scattered light can be observed, creating an effect called "cloud shine". Since denser regions scatter more light, the amount scattered light which one sees gives an estimate of the density. This approach is currently being applied to a large number of molecular clouds with ESO's New Technology Telescope and upcoming VISTA telescope. As clumps in the molecular cloud collapse into stars, these clumps can fragment, and the mass of these fragments are extremely important in determining the mass of the stars which form. Recent computer simulations by Dr. Krumholz and Prof. McKee of Princeton University suggest that, to form the most massive stars, the clump must have column density (density of material through the region, mass per unit area NOT mass per unit volumn) 1 gm / square centimeter, though this number depends on fraction of mass in elements heavier than H and He which are critical in the physics of how the gas increases in density by about a million times to become a star. Replicated this process on a computer is extremely difficult, and recently a new software code called "FEARLESS" has been developed to try and solve many of the problems (link). As the gas collapses into star, it doesn't collapse directly into a star but forms a disk of material which slowly moves inward to for the star. Recent observations of a forming star, DG Tau, has found collimated, fast moving material moving away from the central star which astronomer call a "jet". Many of these "jets" from forming star have been discovered, but the material in this one is so hot it produces X-rays that are absorbed by the material in the disk, possibly changing its chemical composition. Now, stars born at the same time, with the same mass, and out of the same material are expected to have identical properties. However, recent observations of a binary star system where one star passes in front of the other suggest that, despite having the same mass and age, they have different temperatures and radii which is extremely bizarre (link).
• Brown Dwarfs: Brown dwarfs are the least massive stars, only a few times more massive than Jupiter, and are believed to have too little mass to produce a hot core that fuses hydrogen into helium as out Sun does. As mentioned above, stars when they are form are often observed to power jets into their surroundings. Well, brown dwarfs were recently observed to do the same (link). Also, the coldest dwarf ever observed was recently detected, with a surface temperature of 350 Celsius, comparable to a pizza oven, and about 3x times colder than the surface of the Sun (link). Also, the mass and temperature of brown dwarfs orbiting each other have recently been measured, and differ from that predicted by models (link).

Sorry for the delay in posting this, and hope you enjoy. As always, any and all feedback will be very appreciated.

July 30th Radio Show online: Mercury, Saturn, and the Outer Solar System

The July 30th radio show is now online and available here. This show marked the end of our trip through the Solar System, and I discussed the latest news concerning the innermost planet in the Solar System (Mercury), as well as one of the outer ones (Saturn), and recent measurements concerning the edge of the Solar System. In detail I covered:

• News: Thank you to Home Depot for donating a new and much-needed roof to the Custer Institute and Observatory; Phoenix Mars Lander producing 3D image of surrounding area (link,3D map); NASA starts funding a GPS program for the Moon (link); NASA invites media for a demo of Lunar Surface Manipulator concept on August 1st; NASA to hold media briefing for final Hubble servicing mission September 8-9; NASA and USDA sign an agreement for the USDA to conduct research on the International Space Station; NASA develops a new webpage to show the latest satellite imagery of fires on the Earth; NASA's Kennedy Spaceflight Center hosts a program for Florida high school students to work on challenges related to returning to the Moon; 2008 General Aviation Technology Challenge to be held August 4-10 in Santa Rosa, CA; NASA's 50th Anniversary honored at EAA AirVenture 2008 air show in Oshkosh, WI July 28 - Aug 3; NASA successfully tests a parachute designed to slow down the descent of the first-stage motor from the Ares I rocket, the successor to the space shuttle; congratulations to NASA's programmers on the Data-Parallel Line Relaxation and Adaptive Modified Gerchberg-Saxton Phase Retrieval programs for winning NASA's 2007 Software of the Year award; ongoing dispute between NSF and local residents concerning the Advanced Technology Solar Telescope to be located on top of Mauna Kea; editorial in July 23rd New York Times calling for development of solar power stations in space (link); positive movie review of WALL-E in July 24th edition of Nature magazine (I concur whole-heartedly); new exhibit at Museum of History of Science in Oxford, UK on Ferdinand Verbiest - court astronomer in China in the late 1600s; Perseid Meteor shower to peak on August 12th, expected to be a good one.
• Calendar of upcoming Astronomy events in the greater Poughkeepsie / New York City area
• Mercury: The closest planet to the Sun, it is one of the least studied planets in the Solar System because it is difficult to get space craft there (it takes a lot of fuel to decelerate a space craft launched from the Earth to get so close to the Sun. A space craft launched from the Earth will stay in the Earth's orbit if it doesn't fire rockets.) However, NASA recently launched a space craft called MESSENGER to study Mercury, and while it isn't in orbit around this planet just yet, on January 14th, 2008 it did it's first flyby during which it made some measurements that revealed some exciting new information about this planet that were summarized in the July 4th, 2008 edition of Science magazine. It discovered that the smooth surface in the Caloris Region basin is likely the result of volcanic activity on Mercury - long after such volcanism was expected to end; Mercury's magnetic field is generated by an active dynamo in the core, and not the remnant of a magnetic field formed earlier that was locked into its crust as previously thought; the cooling of Mercury's core shrunk so much that is caused huge wrinkles in the crust; and made the first observations of charged particles around Mercury kicked off the surface by the Solar Wind and sunlight (link 1, link 2, link 3).
• Saturn: In my opinion, one of the most beautiful planets in the Solar System with its extensive ring system and plentiful moons, Saturn and its surroundings have been studied extensively over the passed 4 years by the recently-extended Cassini spacecraft. Recent results include a temporal and altitude temperature variation in Saturn's atmosphere over its equator likely the equivalent of seasonal variations seen on Earth; a vortex over the south pole of Saturn; a secondary aurora on Saturn resulting from charged particles produced by volcanism on its moon (link); extremely powerful lightning on Saturn the source of observed bursts of radio emission seen from this planet (link); Saturn's innermost A-ring absorbs material ejected by geysers on Enceladus; the different velocity between the dust and gas ejected by the geysers on Enceladus (dust slower, gas faster) due to dust bouncing off the walls of the fractures in the surface of Enceladus from which they are produced (link); Cassini flyby through the material ejected from Enceladus detects organic compounds (link) - leading to suggestions that their might be life on this moon (link); common black coating found on the surface of many of Saturn's icy moons; variability and fine structure in Saturn's F-ring caused by moonlets in this ring (link); discovery of partial ring system around Saturn's moon Rhea (article); Saturn's moon Titan believed to more liquid hydrocarbons on its surface than present in the Earth (link) and has a rapidly changing rotation period likely the result of an internal water ocean.
• Pluto: It might not be classified as a planet any longer, but it is still an interesting object to study. NASA launched a space craft a few years ago called New Horizons to study it in detail, and it appears that Pluto's atmosphere will still be around when it arrives.
• Edge of the Solar System: The sun resides in the Milky Way, and one edge of the Solar System is defined where the solar wind - the stream of highly energetic particles produced in the Sun's corona - is decelerated by the surrounding interstellar medium. This region is called a "termination shock", since the wind is suddenly terminated there, about both Voyager spacecraft have crossed this boundary, Voyager 2 most recently on August, 31 2007. Voyager 2 crossed this shock at a distance very different than Voyager 1, suggesting that the termination shock is dented - possibly a result of the Milky Way's magnetic field. It was also able to make measurements of the density structure, composition, and magnetic field in this region - discovering that a lot of the energy in the solar wind is transferred to interstellar material ionized by solar wind particles (link). The STEREO spacecraft has also recently discovered high energy neutral particles from this region (link).

Thanks a lot for listening, hope you enjoyed, and any and all feedback is extremely appreciated.

Solar Eclipse this Friday

This Friday, beginning at 5:20 AM the Moon will pass in front of the Sun producing a solar eclipse which can be seen from arctic Canada through Greenland, Siberia, and Mongolia, and China. The partial solar eclipse will be visible from almost all of Europe, the Middle East, India, Asia and a corner of North America. For more information on the location and time of this ecllipse, go spaceweather.com, and for more information about solar eclipses, read this article courtesy of NASA Science News.

Happy eclipse viewing!

July 23rd Radio Show: Asteroids and Jupiter

Now available here, in addition to discussing all of the Astronomy news I missed while I was at COSPAR, I also covered some interesting new results asteroids and Jupiter, its rings, and its moons. On this program, I talked about:

• Phoenix Mars Lander: The latest activity, including:
  • July 8 - Second Sample delivered to the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) laboratory (link)
  • July 9 - The robotic arm tested different methods to collect large enough samples of the icy soil discovered near the Phoenix Mars Lander for analysis in its instruments (link)
  • July 10 - First measurements of the electrical properties of the soil near the Phoenix Mars Lander were made, as were the first images of Martian soil with the atomic force microscope
  • July 15 - Trench used to get soil samples extended by about 6 inches to make getting samples easier (link)
  • July 16 - To get a sample of icy soil large enough for analysis, robotic arms begins rasping frozen layer (link)
  • July 17 - Rasping successful, sample of icy soil collected for Thermal and Evolved-Gas Analyzer (TEGA) instrument (link)
• News: UK science budget finalized, large cuts to several Astronomy programs; first observations with the Express Production Real-time e-VLBI Service (EXPReS) project which combines data from large radio telescopes across the world, including Arecibo, conducted successfully (link); Czech Republic joins European Space Agency (ESA); NASA and ESA complete joint study on what is required to support a permanent human outpost on the Moon; NASA announces winners of college student competition to design future aircraft (link,contest); Dr. Rob Strain appointed next director of Goddard Space Flight Center; EPOXI mission has begun a search for transiting extrasolar planets as it approaches a flyby of comet Hartley 2 (link) and filmed a movie of the Moon transiting the Earth (link); orbit of ESA's Venus Express modified to bring it deeper into Venus's atmosphere; ESA's Mars Express preparing for very close approaches to Mars's moon Phobos; recently launched GLAST has turned on its scientific instruments for the first time, and all appears to be well (link); hardware for final Hubble servicing mission arrives at Kennedy Space Center; calibration of ultraviolet instruments for upcoming Solar Dynamics Observatory to be done using high-altitude balloons (link); NASA and ESA issue report on what is needed to return a sample from Mars (report); new infrared detectors useful for future telescope designed to study high redshift universe developed (link); new materials being developed to protect future satellites from collisions with space junk (link); NASA developing longer-lasting, higher-altitude balloons for science / astronomy experiments.
• Calendar of upcoming Astronomy/science events in the greater Poughkeepsie, New York City area
• Asteroids: Acid rain supports meteorite interpretation of Tunguska event (link); source of most common meteorites discovered in the asteroid belt (link); the source of UFO-shaped and small binary asteroids believed to be the result of asteroids spinning faster from reflecting sunlight - the faster rotation period moves material from the poles to the equator, and in some cases the asteroids can rotate so quickly they fling material off which then coalesces into a smaller asteroid that orbits the larger one (link)
• Jupiter: Buckyballs can hold hydrogen as dense as the center of Jupiters, allowing scientist to determine (finally) the structure of Jupiter's core (link); winds in Little Red Spot in Jupiter's atmosphere observed to be getting faster (link); turbulence in Jupiter's upper atmosphere observed to continue - result of global climate change on Jupiter? (link); the three red spots observed in Jupiter's atmosphere pass near and distort each other (link,pictures); burst of low-frequency radio emission from Jupiter believed to be the result of Jupiter's rotation effected ionized particles released by volcano's on Io (link); aurora on Jupiter believed to be result of Io deflecting the path of charged particles orbiting Jupiter (link); bizarre features of Jupiter's outer rings caused by material moving in and out of Jupiter's shadow - when illuminated by sunlight, the ring material becomes ionized and feels the effect of Jupiter's magnetic field, and when it is in Jupiter's shadow it becomes neutral and no longer is affected (link); cracks on Europa's crust likely to be result of rotation poles of Europa changing - applying pressure to the icy crust through a liquid ocean underneath (link)

Thank you very much for listening. Hope you enjoyed and, as always, any and all feedback is appreciated.

July 9th radio show description

Already available here, below is the description of what I talked about on the July 9th radio show:

• News: The next sample to be tested by the Thermal and Evolved-Gas Analyzer (TEGA) on the Phoenix Mars Lander to be rich is sub-surface ice, one the ovens that comprise the TEGA has a short circuit most likely the result of all the shaking done early to get a sample in there (link); International Astronomical Union decides to call pluto-like objects "plutoids" (link); Ulysses spacecraft still functioning - fuel lines were expected to freeze on 1 July; Rosetta spacecraft en route to a rendezvous with a comet is preparing to study a rare type of asteroid; main mirror for new airplane-hosted infrared telescope SOFIA has been made; first underwater detector for high energy neutrinos coming from space, Antares, is complete (link); thanks to infusion of money from recent supplemental budget passed by Congress, Fermilab cancels layoffs; congratulations to the winners of NASA's aircraft design competition (link); European Space Agency announces an opportunity for graduate students to conduct an experiment in zero-gravity for their thesis (link); NASA considering developing a program to teach university students how to develop a satellite (link); NASA debuts website devotes for first test flight of the Ares spacecraft - the replacement of the space shuttle (link); new swimsuit being used at the Beijing olympics was tested at NASA's Langley Research Center (link); meeting from July 9-10 in Paris to discuss a mission to Mars that would return a sample to the Earth (link); NASA TV to broadcast upcoming spacewalks (sorry, already happened); European Space Agency to host an Internal Space Station Heads of Agency meeting on July 17th to discuss future activity; Swedish gym for astronauts currently being tests on the International Space Station (link); mysterious acronym on extra-solar planet website believed to hold clue to new discovery; Doritos broadcasts first advertisement into outer space (link); Slovenia signs cooperation agreement with European Space Agency; Austria has joined European Southern-Hemisphere Observatory (ESO)
• Calendar of upcoming astronomy and science events in the greater Poughkeepsie/New York City area
• Return to Moon and Mars: A lot of technological development is required for this since much of the old technological capabilities have essentially been lost, including a new generation of spacesuits (link), a new lunar module breathing system which was just tested for the first time (link), new moon buggies, which NASA has been exhibiting and inviting teams to design their own and race (link, link) with ESA have their own competition (link). Before humans can return to the Moon and establish a permanent base their, more detailed mapping of the lunar surface and subsurface needs to be completed - goal of Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) to be launched later this year. Also need a study of what is required for a moon base, which was reviewed on June 20th. High resolution radar images of Moon's South Pole - a possible place to land people and build a moon base, waere released earlier this year (link). ESA's SMART-1 also doing this (link), and NASA devloped a laser radar technique to get even finer maps of lunar surface (link). NASA to launch in 2011 a mission to measure distortions in the gravitational field of the Moon caused by mass concentration underneath craters called "GRAIL", and will look for subsurface on the Moon with LRO. Once on the surface, moon dust would be a problem for humans and rovers because it is very fine, scratchy, and sticky due to its electrical charge as a result of the Solar Wind - cause be highly carcinogenic (link). Moon dust almost derailed an Apollo 17 rover, but duct tape saved the day. When/If people return to the Moon, NASA plans on doing some Astronomy there as well, has recently issued a called for proposals (link). Moon passes through Earth's magneotail, which also charges moon dust, can cause lunar dust storms, and is a process that is bizarre and one of things NASA hopes to study when people return (link). Giant crater at bottom of Moon might hold key to understanding period or intense bombardment in early Solar System, as well as seeing meteors crashing into Moon today. Reanalysis of Apollo 12 relic yield understanding on lunar "soil", which is a collection of the remains of past meteorites to hit the lunar surface. Moon also a good place to do very low frequency radio observation of the cosmos, since no ionosphere or interference like FM radio stations to worry about(link). Might also be possible to make a giant optical mirror on the moon using moon dust (link). Sun is expected to vaporize Earth when it enters its Red Giant phase of evolution (link) - providing incentive for humanity to leave the Earth in the next billion years or so.

Thank you very much for your patience, and hope you enjoyed listening.

June 25th radio show online - GLAST

Available here is the June 25th radio show, not surprisingly devoted to the launch of the Gamma-Ray Large Area Space Telescope (GLAST) which I've been talking about and expected for the past 6 months. On this program, I covered:

• Calendar of upcoming events in the greater New York City / Poughkeepsie area
• GLAST: History of gamma-ray astronomy; many if not most of known gamma-ray sources are unidentified; GLAST significantly more sensitive and has much better angular and energy resolution than previous satellites. Has two main instruments, the Large Area Telescope (LAT) and GLAST Burst Monitor (GBM). The LAT will be used to constantly survey the gamma-ray sky (link), while the GBM is designed to detect transient events. Succesfully launched of June 11 (link), the first science observations are not expected to occur until 2 months after launch. To check out a music video summarizing the development and science of GLAST, go here.
• Interview with Dr. Charles Meegan of Marshall Space Flight Center, primary investigator of the GBM, discussing the science and technology of this instrument.
• Phoenix Mars Lander: Lots of daily updates
  • 5 June - two practice digs uncovered bright material in the soil just below the surface (link).
  • 6 June - Optical Microscope on Phoenix Mars Lander returns highest resolution images ever of Martian surface, seeing particles <1/10 the diameter of a human hair (link), first scoop of soil delivered to one of the on-board laboratories (link).
  • 7 June - soil was too clump to pass through the screen protecting the instrument, mission controllers will attempt to shake the material through(link).
  • 9 June - shaking continues, new soil sample acquired for a different instrument on the Phoenix Mars Lander (link).
  • 10 June - Mission controller tests a sprinkling technique to deliver soil to Phoenix Mars Lander which will hopefully break up the clumpy soil (link).
  • 11 June - Phoenix Mars Lander has oven full of soil, why it passed through the screen all of sudden not completely understood (link).
  • 13 June - Phoenix Mars Lander sprinkles some soil into another instrument (link).
  • 14 June - Two instruments on Phoenix Mars Lander now analyzing chemical composition, other properties of Martian soil (link).
  • 17 June - Baking of martian soil continues while robotic arm digs deeper to study the bright material uncovered on 3 June (link).
  • 18 June - Robotic arm keeps on digger, hoping to uncover more of the bright, white material first seen on 3 June (link); overload in mission housekeeping data causes some information in flash memory to be lost, not of it critical science data (link).
  • 19 June - Bright material uncovered on 3 June disappears, likely meaning that is was ice (as opposed to a bright salt-like compound) that sublimated (evaporated) after being exposed, confirming that ice below the surface on Mars is not confined to the polar regions (link, link).
  • 22 June - Phoenix Mars Lander sprinkles soil onto the Optical Microscope for a close-in image (link).

Thank you very much for listening, and hope you enjoyed this program. Please email or leave below any questions, comments or concerns you might have - any and all feedback is appreciated!