Sunday, November 30, 2008

Planetary Conjuction this weekend

This weekend, the Moon, Venus, and Jupiter will approach each other on the sky, making for a very pretty picture. Go here for more information, and hope it isn't cloudy!

Want to know when a satellite is overhead?

Personally, one of the coolest things for me in the night sky is watching satellites, like the International Space Station, because they move in the sky so quickly. Plus, they are typically very bright, so they are visible even in the New York City night sky. If you live in the US or Canada, go to this website to see what is visible, and if you live elsewhere, go here. Both website managed by spaceweather.com. Enjoy!

Friday, November 28, 2008

NASA on iTunes

As many of you probably know, NASA is working on a successor to the Space Shuttle called the Ares Rocket, its first new rocket and decades. This requires a large amount of R&D, which in turn leads to lots and lots of reports being written on progress. The latest quarterly progress report is actually available as a podcast from iTunes here. Enjoy!

Hubble Holiday Greeting Cards

Looking for the perfect greeting card to give your favorite Astronomy-lover but can't find one? Check out the cards available here for downloading and printing out.

Happy Holidays!

November 19th Radio Show: Supernovae and Gamma-Ray Bursts

Available here is the November 19th episode of this radio show, where I discuss the latest scientific discoveries related to the supernovae and gamma-rays bursts resulting from the gravitational collapse of the cores of the most massive stars which Dr. Maryam Modjaz discussed on the November 12th episode. Hope you enjoy!

Thursday, November 27, 2008

Happy Thanksgiving

Hope you are having a happy and healthy Thanksgiving.

Wednesday, November 26, 2008

Intreview with Dr. Maryam Modjaz (U.C.-Berkeley)

Available here is my interview with Dr. Maryam Modjaz of U.C.-Berkeley on core-collapse supernova, specifically how observations of the light produced in the aftermath of these explosion helps us try and determine how these stars explode. For more information of this research, check out her research webpage as well as the webpage of the PAIRTEL telescope - a robotic telescope which looks at the optical light produced in supernova explosions.

As always, if you have any questions, comments, or concerns, please email me or leave them below. Thank you for listening!

Tuesday, November 25, 2008

Watch a tool belt in orbit

Last week, during a spacewalk, an astronaut dropped a tool belt which is currently orbiting the Earth. Surprisingly enough, you can see it from the ground with binoculars or a small telescope. Go to here to learn how you can see it for yourself. Enjoy!

NASA's 16th annual Great Moonbuggy Race

Every year, NASA's Marshall Space Flight Center hosts a great moon buggy race (on the Earth). Next year's race will take place April 3-4th, and registration is open now until February 1, 2009. For more information, go here, and good luck!

New NASA Contest: Name that Mars Rover

NASA is working on building its next rover to Mars, currently called the Mars Science Laboratory, schedule for launch in 2009 (though it probably will slip until 2010). However, that name is pretty boring, and NASA and WALL-E have teamed together to sponsor a contest for you(!) to come up with a better name. Go here for contest rules and regulations, and good luck!

Monday, November 24, 2008

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

Already available here, below is a description of the November 5th episode of this radio show, which was devoted to the evolution of high mass stars - stars born with a mass more than eight times that of the Sun. On this program I talked about:

  • News: Phoenix Mars Lander hopes to extend lifespan by shutting off some instruments (link), experienced a low power fault brought on by a dust storm; MESSENGER spacecraft images more parts of Mercury never seen before (link); NASA tests prototype lunar rover in Arizona (link); congrats to University of Bremen team for winning ESA rover challenge; first hardware for test flight of NASA's new Ares I-X rocket arrives in Florida; NASA to launch space shuttle Endeavor to International Space Station on November 14th; Hubble Space Telescope servicing mission delayed to give more time to prepare data handling unit to replace the one that failed last month - Hubble now using backup and is thankfully working just fine (link); GALEX - a UV satellite - images galaxy near bright star; GREAT08 PASCAL challenge issued to scientists to figure out how to use weak gravitational lensing to study dark matter (link, by the way - they are already lots of people working on it anyway); new James Bond movie "Quantum of Solace" features scenes filmed at astronomer's guest house at ESO's Paranal Observatory; congrats to Roger Cabana who is now director of NASA's Kennedy Space Center; NASA and South Korea sign statement of intent for future cooperation; congrats to receipient of NASA's Small Business Innovations Research Projects (link); NASA awards contract to support mission controls at Goddard Space Flight Center; ESA adapts technology used for Integral satellite to detect radioactive material in airports; American astronauts vote from space on November 4th (link).
  • Wednesday Morning Astronomer (my take on the Astronomy content of this ESPN column): "Ripples in space and time" is not just fluff added to a press release, but does mean something and is a consequence of Einstein's Theory of General Relativity. And even the most diehard string theorists will says that it is a theory that needs to be proven experimentally. They just argue that it is currently the best theory out there.
  • Calendar of upcoming Astronomy/science events in the greater Poughkeepsie area
  • Evolution of High-Mass Stars: High-mass stars are able to fuse much heavier elements in their core than their lower mass brethern (all the way up to Iron, rather than just Carbon and Oxygen), but as they do so blow off their outer envelopes in powerful winds. The stars with most powerful winds are called Wolf-Rayet stars, and these are believed to be some of the most massive stars in the galaxy, with more than 100 times the mass of the Sun. A binary of such stars was just discovered in the center of the Westerlund 2 star cluster (link). The outer layers of massive stars can be so dense and hot they undergo explosive fusion. Such an event might have powered an outburst observed in 1843 for very nearby massive star eta Carinae - a more powerful outburst than had ever been observed from a star before (link). The outer layers of massive stars aren't stable, and they contract and expands - getting hotter (and looking bluer) when smaller and cooler (and looking red) when larger. They spend most of their time at the extremes, which is why the discovery of a yellow supergiant binary so exciting (link). Integral satellite discovers massive stars orbiting a neutron star or a black hole behind lots of dusts.
Hope you enjoyed and, as always, any and all feedback is greatly appreciated and wanted. Thank you for listening!

Friday, November 21, 2008

Question and Answer show

I'd really like to do a question and answer show on December 31st. In order to do that, of course, I need questions to answers. So, please, please, please, email or post below any astronomy questions you have, and I'll do my best to answer them on-air.

Thank you

Thursday, November 20, 2008

NASA restores famous Earth-rise picture

Ever see the picture of the Earth rising over the Moon's surface taken by astronauts on boards NASA's Lunar Orbiter 1 in 1966? Well, NASA has recently restored this iconic image to a much higher resolution than previously possible. To check it out, go here. Looks really awesome to me.

Happy Birthday International Space Station!

Ten years ago today, the first module that now comprises the International Space Station was launched. To learn more about this space station, go here. Enjoy!

Wednesday, November 19, 2008

November 12th Radio Show: Supernovae

Now available here is the November 12th episode of this radio show. On this program, in addition to the usual Astronomy news, Dr. Maryam Modjaz of UC-Berkeley talks about supernovae - extremely bright flashes of light believed to be the result of either the death of a white dwarf or a massive star. Hope you enjoy!

Monday, November 17, 2008

Public Lecture tomorrow (November 18th)

I'll be giving a talk tomorrow (Tuesday, November 18th) at the Indoor meeting of the Mid-Hudson Astronomical Association. The meeting stars at 7:30 PM, talk starts around 8:00 PM, and takes place in the auditorium of the Coykendall Science Building on the campus of SUNY-New Paltz. This talk is open to everyone (who don't need to be members to come). For more information, go here (directions available here). Hope you can make it!

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.

New video of meteor falling to Earth

The University of Western Ontario Meteor Group has a network of cameras which scan the sky looking for previously unknown meteorites falling onto Earth. On October 15th they saw one, and you watch the pretty incredible videos here. Enjoy!

Hubble Directly Images a Planet around another Star!

As I discussed on this radio show, all of the extrasolar planets (planets orbiting stars other than the Sun) we know of have been discovered indirectly. They weren't discovered by seeing the light they emit, but by either their gravitational effect on their central star or the gas and dust disk in which they were formed or by passing between the Earth and their host star - blocking some of the light. However, for the first time ever, Hubble has directly imaged an extrasolar planet! Go here and here for more information. This really is big.

This has long been a goal of people who study extrasolar planets (listen to this interview with Dr. Jennifer Wiseman of NASA's Goddard Space Flight Center) and it is pretty amazing it has finally been achieved.

Image of Aurora on Saturn

The Cassini spacecraft has been taking pictures of lots of aurorae on Saturn, and it might have just imaged its weirdest one yet. Go here for the very pretty picture.

Impact of Astronomy on Daily Life

I mentioned on last week's show (which I have to put online, I know), that the European Space Agency has recently used technology it developed for the Integral X-ray satellite to develop better bomb detectors at airport. This is just one of a long list of items originally developed for Astronomical use but has entered "everyday" life as well. Heck, NASA has an entire magazine devoted to spinoffs of its technology. Astronomy has also been a very important source for a lot of the basic physics which form the basis for our current understanding of the universe. Read this article for examples of how Astronomy has been vital for advancing physics.

(Thank you very much to Dr. Tom Bridgman for pointing me to this article. It is a good one.)

Friday, November 14, 2008

Cute astronomy comic

Courtesy of xkcd:



Go here for the permanent link. And no, I'm not that convinced by the paper in question. There really isn't much evidence that all of the galaxies are being pulled to one area on the sky which just happens to be far enough away from the Earth that light emitted by this object has not arrived yet. That would require that Earth is in a very special location and this is a very special time in the Universe, since a different location closer to this object would have detected it or at some later time we can detect it. The comic is very cute though.

Thursday, November 13, 2008

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.

Friday, November 7, 2008

Taurid Meteor Shower

Going on now till November 12th is the Taurid Meteor Shower, so named because the meteors appear to come from the direction of the Taurus constellation. This meteor shower is the result of the Earth passing through the debris field left by comet 2P/Encke as it orbits the Sun, and this year it is believed the Earth is passing through a dense region - making for a more spectacular shower. The best time to look is during the hours around midnight when the constellation Taurus is high in the sky, and go here for more info. Enjoy!

Thursday, November 6, 2008

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.

Tuesday, November 4, 2008

Happy Election Day

Courtesy of NASA.



If astronauts can do it from space, you can too! Seriously, if eligible, please vote - regardless of who you may support.

Monday, November 3, 2008

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.