May 2007

Brown Dwarf or Planet: The Case of XO-3b

May 31, 2007

Odd planets seem to be sprouting in our data like mushrooms. Take the case of XO-3b. It’s got the mass of thirteen Jupiters but orbits its star in less than four days, making it the largest, most massive planet ever found in such a tight orbit. But XO-3b also seizes the attention because its orbit [...]

Read the full article →

An Asteroid Strike in North America?

May 30, 2007

Earth’s geological history could have a lot to say about our future in space. Every time we investigate a huge crater like Chicxulub, the Yucatan impact site that may have played a role in the demise of the dinosaurs, we’re reminded that the Solar System is an active and dangerous place. And the evidence multiplies. [...]

Read the full article →

28 New Exoplanets Announced

May 29, 2007

What better indication of the success of our planet hunting efforts than the news out of the American Astronomical Society’s annual meeting in Honolulu. There, the California & Carnegie Planet Search team announced at least 28 new planets, with four multi-planet systems among them and two borderline cases that need further investigation. That’s a bump [...]

Read the full article →

Gliese 581: Right System, Wrong Planet?

May 28, 2007

New work on Gliese 581′s interesting planetary system may prove dismaying for those hoping for a planet in the habitable zone. With two ‘super-Earths’ and a Neptune class world, this is a system that cries out for close analysis. The Geneva team that detected the super-Earths had calculated surface temperatures on Gliese 581 c at [...]

Read the full article →

A Nanotech Comeback for Big Ideas

May 26, 2007

There was a time when images like that of the space station under construction below were standard issue for futurists. It seemed inevitable that after our first tentative orbital flights, we would quickly graduate to building an enormous platform above the Earth, using it as a base for a Moon landing as well as a [...]

Read the full article →

Brown Dwarf Emitting Jets

May 25, 2007

Brown dwarfs, most of them unobserved, doubtless litter the galaxy. The more we can learn about them and their possible companions, the better for our understanding of how planets form and stars evolve. These minute ‘failed stars,’ far less massive than the Sun, cannot sustain hydrogen fusion, but they’re players in the exoplanet hunt. The [...]

Read the full article →

Multiple Planet System Found

May 24, 2007

Two gas giants discovered around the star HD 155358 raise again the question of planetary formation and the mechanisms behind it. Most planets detected through radial-velocity methods, which measure the effects unseen companions have on a star’s motion, have been found to orbit stars that are high in metal content. ‘Metals’ in this context means [...]

Read the full article →

Carnival of Space #4 Now Available

May 24, 2007

The Carnival of Space #4 is now up at Universe Today, and is well worth a look to find out what a wide range of writers are saying about everything from terraforming Mars to the linkages between science and science fiction. Ian Musgrave’s Astroblog offers good background on GJ 436 b, and I particularly like [...]

Read the full article →

Toward a Disappearing Cosmos

May 23, 2007

Centauri Dreams‘ recent post on the eventual merging of the Milky Way with the Andromeda galaxy took us to a future some five billion years from now. But it also speculated on something even more distant in time. What happens if the universe’s expansion does not stop accelerating? Eventually the galaxies beyond our own Local [...]

Read the full article →

Deep Space Propulsion via Magnetic Fields

May 22, 2007

The beauty of magnetic sail concepts — magsails — is that they let us leave heavy tanks of propellants behind and use naturally occurring phenomena like the solar wind to push us where we’re going. Solar sails, of course, do the same thing, though they use the momentum imparted by photons rather than the energetic [...]

Read the full article →

← Previous Entries