C/2012 S1 as captured by Hubble Space Telescope on 10–11 April 2013
Call it premature disintegration? A cometary astronomer has identified signs in the spectra of Comet ISON that are consistent with a poorly understood process of rapid disintegration. A new webpage has been established here to track this dramatic event should it unfold. We’ll know in the next few weeks: [Read more…]
A hypothetical water world with the red dwarf Gleise 1214 glowering on the horizon.
Nearby is relative, this world is more than 40 light-years away. Thousands of times farther from us than Pluto is from our sun. But exo-astronomers have narrowed down the likelihood that a planet two and-a-half times more massive than earth may have a water rich atmosphere and possibly vast oceans on its surface: [Read more…]
NASA released details on how it might grab an asteroid and bring it in orbit about the moon for more leisurely inspection. Here’s the scenario as it stands: [Read more…]
“From its perch in the Saturn system, NASA’s Cassini spacecraft took pictures of Earth from nearly 900 million miles (nearly 1.5 billion kilometers) today. To celebrate the first time the public has had advance notice that Earth’s portrait was being taken from interplanetary distances, scientists and engineers at NASA’s Jet Propulsion Laboratory and other Earthlings elsewhere gathered to wave at Saturn on July 19. Cassini took pictures of Earth between 2:27 and 2:42 p.m. PDT today.”
Not long ago, a rare form of iron was found in oceanic crust worldwide dating to about 3.5 million years ago. Astronomers at the time noted that would be consistent with a relatively nearby supernova explosion. Now, another groups of scientists have the same substances incorporated into bacteria dating to the same time:
Columbus Dispatch — Dust from supernovae contains a radioactive isotope of iron called Fe-60, which could settle on Earth and be taken up by certain types of bacteria called magnetotactic. These single-cell organisms take up small bits of iron, producing nanometer-size grains of an iron-oxygen compound called magnetite, which they presumably use for navigation.The recent news from the American Physical Society meeting is that Fe-60 was detected in these bacterial fossils using clever technology developed for particle accelerators. Fe-60 does not occur naturally on Earth and is produced almost exclusively in supernova explosions.
These measured amounts of Fe-60 are small, but they are well within the detection limits of modern technology. In fact, two previous measurements by a different group using the same accelerator technology found Fe-60 in other ocean-floor sediments of about the same age — about 2.5 million years ago. The newly reported results are different in that the Fe-60 is now linked to fossils of magnetotactic bacteria.
And what is the most likely candidate for that supernova? The Scorpius–Centaurus Association, which our system drifted by beginning about three millions years ago and which includes, among other massive stars, the mighty Antares. Better known as the ruby red heart of Scorpio.
Hubble finds another blue planet! It needs a name — if we keep with the mythological gods and goddesses and demons and whatnot convention, we’re gonna run out of deities awful quick. There is however a one big complication with moving there, beyond it’s 63 light-year distance: [Read more…]
A hypothetical water world with the red dwarf Gleise 581 glowering on the horizon.
Look at a big spiral galaxy like the Milky Way and its blazing with the blue-white light of hot, young stars. But the vast majority of stars in our galaxy are the smaller, redder types. Of the estimated 400 billion suns in our galaxy, astronomers believe at least half of them are red dwarfs. One problem with red dwarfs is they tend to be active, they can flare and dim dramatically over short periods of time compared to our reliable, stable yellow sun. Because they are so much dimmer, planets in the Goldilocks zone where water might exist as a liquid on the surface would need to huddle much closer to the red stars. Not only would those planets would be pummeled by stellar outburst, they’d become tidally locked, always the same side facing the sun, similar to the way our moon always presents the same face to earth. All things being equal, a planet that takes a few weeks to rotate instead of a day would have a less powerful magnetic field to ward off the solar wind. Both Mars and Venus have mostly lost whatever primeval magnetic field they once had and that probably played a role in vaporizing whatever oceans they may have started out with.
But there’s a newer consideration, one which could help protect the planets of red dwarfs, now being modeled and tested. This increases the number of potentially habitable exo-planets to 60 billion! How? Think of a cold Venus: [Read more…]
If the face of Mars indicates alien interest in human beings long before we evolved, Penguins must rule intergalactic space. Or possibly dolphins, I always suspected the dolphins, acting so cute and playful and all! Or maybe both are just a product of chance and the penchant of our little bulging primate brains to arrange random images into familiar patterns. I’m going for the latter: [Read more…]
There are more than one-hundred sizable objects in our solar system, many of them with ice or liquid water, including planets, moons, asteroids, and KBOs, each reachable and explorable with present day technology
Small probes the size of a human hand or smaller could be a big help to planetary exploration. Moore’s Law and tightening budgets could team up to make that technological leap sooner rather than later. In particular, small probes packed with microelectronics and advanced software capable of learning on the alien spot might bring the deep subcyrosphere of moons like Europa or Saturn’s Dionne under scrutiny: [Read more…]
If you read science fiction or science fact, you know the nearest star to the sun is called Proxima Centauri, a tiny red dwarf that happens to lay on this side of its triple star system containing Alpha Centauri A and B. Since its so close, astronomers have been able to mostly eliminate the chances of a really large unseen companion in close orbit around the little star, like a brown dwarf or a hot Jupiter. But the possibility of smaller planets exists and there’s reason to think there could be a few. Now, astronomers may get a chance to find out: [Read more…]