Kentucky Space

Astronomers find Water world

[Cross-posted from the IdeaFestival] In recent years, astronomers have cataloged over 400 planets orbiting other stars in our galaxy, and, as techniques are continuously refined and new missions carried out, more are being discovered regularly. Targeting a rich area of the Milky Way, scientists, for example, are pouring over the data returned by the newly launched observatory Kepler, which is seeking transiting terrestrial worlds in the habitable zone of their parent star. Follow-up missions that might directly observe these planetary finds are being considered.  

Yesterday, however, news emerged that the ground based telescopes of the MEarth Project in Arizona had located a transiting water world orbiting a star very much like ours. Though the second so-called super-Earth, this one is interesting because subsequent observations in South America have demonstrated that this planet has an atmosphere - though perhaps not for long, given the proximity to its host. Paul Gilster at Centauri Dreams provided this other bit of interesting news.

At a distance of 1.3 million miles, the planet orbits its star every 38 hours, with an estimated temperature a little over 200 degrees Celsius. Because GJ 1214b transits the star, astronomers are able to measure its radius, which turns out to be 2.7 times that of Earth. The density derived from this suggests a composition of about three-fourths water and other ices and one-fourth rock.

The atmospheric pressures and resulting lack of light reaching the planet's surface make life improbable, or at least unlike anything we might know, but it's another step along the path toward what could be truly extraordinary find in our lifetimes.

Wayne

The credit for the artist's impression of GJ 1214b goes to ESO/L. Calçada.

Kentucky Space

Biological past for Mars rock?

Features of Martian meteorite ALH 84001 could be of biological origin, according to NewScientist.

Wayne

Kentucky Space, Space

"Potentially habitable exoplanet found." What's next?

Given the pace of discovery using Earth and spaceborne observatories, it's not too much of a stretch to assume that sooner or later a planet orbiting its parent star in the "habitable" zone, a region where liquid water is likely to exist, will be found. So let's assume that a planet has been found in this "Goldilocks" zone. How would we go about inspecting that planet to determine if there is, in fact, life present? What's next? Paul Gilster explains.

Wayne

Our ever-changing solar system

While the number of planets orbiting other stars stands at 373, it's easy to forget that the estimate of the number of significant bodies in our own solar system is constantly changing. Thought to be covered in water ice, Haumea is the fourth largest dwarf planet in the Kuiper Belt, following Eris, Pluto and Makemake. And in the just last ten years many more trans-Neptunian objects with a diameter of at least 500 km have been added to the catalog, according to Paul Gilster at Centauri Dreams. That total now numbers seventy.

Wayne

Kentucky Space, Space

Video: Triton flyby

The video below is a simulated fly-by of Neptune's moon Triton produced from imagery returned by Voyager 2 just over 20 years ago. Believed to be a Kuiper Belt object, high internal heat is believed to be responsible for the moon's young surface. New Horizons detected Triton last October from a much greater distance.

Wayne

Kentucky Space, Neptune, New Horizons, Robotics, Triton

Cometary debris contained building blocks of life

Evidence collected from the comet Wild2 in 2004 backs the "life is common' school of thought, according to Centauri Dreams.

Wayne

Kentucky Space, Space

Titan-like life: Would we know it if we saw it?

Sure, water ice and liquid water may have been confirmed on the surface of Mars. And microbial life has been resurrected from a million year old dirt nap on Earth. But given the distance from its parent star and the presence of an active hydrology of liquid methane and ethane, Titan might be the best place to find brand new kinds of life. Key question: Given our complete lack of understanding of such life, would we know it if we encountered it?

Wayne

Kentucky Space, Saturn, Titan

What surprises await?

One of my favorite bloggers, the "bad astronmer" Phil Plait, is hosts a Discover panel on the big questions of universe. Here is part two - "what surprises might be lurking out there?" - of that panel. As astrophysicist Saul Perlmutter explains near the end, a theory about everything would truly be unexpected.

Wayne

Space

Astrobiology on Earth

Paul Gilster follows up on a story I first saw at MSNBC describing how microbial life can make the iciest and most inhospitable places home. Project SLIce (Signatures of Life in Ice) studies how organic material might behave on other worlds by studying here it on Earth - and it's yielded some useful information.

An early SLIce result, described at the Goldschmidt2009 geochemistry meeting in Davos last week: The best place to look for microorganisms in ice is in the layers close to the surface. That’s good to know, because a planetary rover is going to be able to sample such environments much more readily than those several meters beneath. Also helpful is the team’s discovery that cleaning the rover’s sample scoop is harder than it looks, leaving dead micro-organisms on it even after it had apparently been sterilized. New procedures have resolved the problem, ensuring we don’t inadvertently ‘discover’ Earth organisms that have found their way along for the ride.

Wayne

"Briny Breath of Enceladus"

Salt in Saturn's E ring and evidence in the form of spectacular geysers on the moon itself suggests that Enceladus could have an underground ocean. The video below also contains some of the best photographic stills of the moon from Cassini's imaging team, CICLOPS. Have a look.

Wayne