‘Space’ Archives
‘Island-Hopping’ to the Stars
We tend to think of interstellar journeys as leaps into the void, leaving the security of one solar system to travel non-stop to another. But a number of alternatives exist, a fact that becomes clear when we ponder that our own cloud of comets — the Oort Cloud — is thought to extend a light year out and perhaps a good deal further. [...]
Of Ice and the Planetesimal
Mindful of the recent work on axial tilt I’ve reported in these pages, I was interested to learn that Vesta’s axial tilt is just a bit greater than the Earth’s, about 27 degrees. We’ve been pondering the consequences of such obliquity on planets in the habitable zone, but in Vesta’s case, the issue isn’t habitability but water ice. For [...]
A ‘Super-Oort’ Cloud at Galactic Center?
Not long ago we looked at comet C/2011 N3 (SOHO), discovered last July just two days before it plunged into the Sun, evaporating some 100,000 kilometers above the solar surface. It was startling to learn that the SOHO observatory is tracking numerous ‘Sun-grazers,’ comets whose fatal encounters with our star are occurring roughly once every [...]
Two Takes on Extraterrestrial Life
“With exoplanets we are entering new territory,” says René Heller (Leibniz Institute for Astrophysics, Potsdam), talking about recent studies looking at axial tilt as a parameter for habitability on a planet. Heller is getting at the fact that while we’ve studied the axis of a planet’s spin relative to the plane of its orbit rather [...]
Untangling a Lensed Galaxy
Gravitational lensing always gets my attention not only because of its growing use in astronomy but because of its potential for deep space missions like FOCAL, Claudio Maccone’s concept for a deep space probe that would be sent beyond the Sun’s 550 AU gravitational lensing distance to make observations of astronomical targets. FOCAL is an [...]
Targeting Primitive Asteroids
I see that there is a symposium on the MarcoPolo-R mission coming up in late March, which reminds me that at a time when asteroid missions are increasingly in the news, I have yet to cover this one. It was about a year ago that the European Space Agency selected MarcoPolo-R as one of four candidates for a medium-class mission that would launch [...]
SETI in the News
Let me draw your attention to two interesting stories this morning, one harking back to the night in August of 1977 when the Big Ear radio telescope at Ohio State University recorded the famous ‘Wow!’ signal. For those unfamiliar with it, the ‘Wow!’ signal gets its name from Big Ear volunteer Jerry Ehman’s annotation (several days later) [...]
‘Super-Earth’ in a Triple Star System
GJ 667C is an M-class dwarf, part of a triple star system some 22 light years from Earth. Hearing rumors that a ‘super-Earth’ — and one in the habitable zone to boot — has been detected around a nearby triple star system might cause the pulse to quicken, but this is not Alpha Centauri, about which we continue to await news from the [...]
IBEX: The Heliosphere in Motion
The beauty of having spacecraft that far outlive their expected lives is that they can corroborate and supplement data coming in from much newer missions. That’s the case with our Voyager spacecraft as they continue their progress at system’s edge. The Voyagers will be moving outside the heliopause in not so many years, and when they do, they [...]
Cloud Cover’s Role in Exoplanet Studies
I confess it had never occurred to me to consider cloud cover on exoplanets in quite the same light that a new study does. But two Spanish astronomers from the Astrophysical Institute of the Canary Islands (IAC) are taking a look at how clouds operate over different kinds of surfaces, in the process figuring out what our Earth would have looked [...]
