Join our SkyWatch hosts for conversation highlighting news from the world of astronomy. Listen in via your computer or MP3 player as they bring the latest discoveries down to Earth. SkyWatch also includes HubbleWatch, a round-up of news from NASA's Hubble Space Telescope.

Show 373: Voyager Reaches Edge of Solar System

January 12, 2012

Artist's conception of Voyager 1
Credit: NASA/JPL
Artist's conception of Voyager 1 Credit: NASA/JPL

NASA’s Voyager 1 is now 11 billion miles from Earth. The spacecraft has entered a new region between our Solar System and interstellar space. The data from Voyager over the past year reveals a new region where the wind of charged particles from Sun has diminished, and particles from inside the solar system seem to be “leaking” out into interstellar space.

Show 372: New Stonehenge Revelations

January 5, 2012

Scientists close in on Stonehenge's history
Credit: Edgy01 at en.wikipedia
Scientists close in on Stonehenge's history Credit: Edgy01 at en.wikipedia

Two new discoveries about Stonehenge indicate an even longer history of solar significance and a connection with a site in Wales where builders quarried stones.

Show 371: HubbleWatch for January 2012

January 4, 2012

Astronomers apply a new technique to old Hubble data to discover planets. And Hubble finds a multitude of stars arising from minute galaxies.

Show 370: Kepler finds Earth-like planets

December 29, 2011

Artist's illustration of Kepler-22b, a planet known to comfortably circle in the habitable zone of a Sun-like star.
Credit: NASA/Ames/JPL-Caltech
Artist's illustration of Kepler-22b, a planet known to comfortably circle in the habitable zone of a Sun-like star. Credit: NASA/Ames/JPL-Caltech

NASA’s Kepler mission, launched in March 2009, is observing 150,000 stars to discover planets. The ultimate goal is to discover Earth-sized planets, and in particular, Earth-sized planets in the zone around the parent star that is the right temperature for water. Over 1,000 planet candidates from Kepler have been cataloged, mostly planets larger than Earth. Now Kepler has announced the discovery of several nearly, Earth-sized planets, one right in the habitable zone. It’s a new, exciting milestone in the search for an Earth twin.

Show 365: Comet Bombardment

November 24, 2011

Artist's conception of a storm of comets around Eta Corvi
Credit: NASA/JP/ Caltech
Artist's conception of a storm of comets around Eta Corvi Credit: NASA/JP/ Caltech

Over 3 billion years ago, comets bombarded the inner solar system, scarring and cratering the Moon. The comets also struck Earth, delivering water and carbon to our planet. Crucial ingredients for life were deposited on the surface, and the first evidence for life appears shortly after this period. New data from the Spitzer Space Telescope suggests that the system around a star called Eta Corvi may be undergoing this type of event now, giving us a look at what may have happened early in the history of our solar system.

Show 363: New Planets in Old Data

November 10, 2011

The star HR 8799, home to planets, taken by Hubble in 1998.
The star HR 8799, home to planets, taken by Hubble in 1998.

Finding extrasolar planets seems to be routine these days, with a variety of telescopes using different techniques to find them. In some cases, once the planets are found, it pays to go back and see if the planets were unknowingly detected in earlier data. Recently, analysis of data taken with the Hubble Space Telescope in 1998 revealed extrasolar planets that were discovered years later by another observatory. Why bother? Well, scientists now have additional observations that show the slow movement of the planets around their parent star. Knowing the orbits of the extrasolar planets tells us a lot about those systems.

Show 362: Mission Proposed for Uranus

November 3, 2011

The seventh planet: Ready for a close-up?
Credit: NASA
The seventh planet: Ready for a close-up? Credit: NASA

In 2011, the National Research Council named a mission to Uranus as the third priority behind a Mars sample return and a Jupiter Europa Orbiter. Imaged and studied close-up only once — in 1986 by Voyager — the planet was not as striking as its neighbors Jupiter and Saturn. But we have discovered more about this unique planet that makes it worth studying more closely.

Show 360: HubbleWatch for October 2011

October 27, 2011

Astronomers discover another moon around Pluto, the smallest body to yet be found around the Kuiper Belt object. And Hubble reaches its millionth science observation while studying the atmosphere of an extrasolar planet.

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Carol Christian
& Jim O'Leary