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.