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Enceladus: Hotter Chemical Plume Found

March 26, 2008

Initial results of Cassini’s March 12 flyby of Enceladus have been published. You can watch a replay of today’s press briefing, read the blog, and read illustrated bulletins about the organic material, chemical signatures, hot spot locations, the stellar occultation (see also the Quicktime animation). Another article shows the plume locations. An astrobiologist (Chris McKay) […]

Physics

Crater Dater Deflator: Impactors Can Be Recycled

March 25, 2008

They came from outer space – that was the old paradigm about impactors that made craters on planetary bodies. Then, we learned how secondary craters can confuse a surface’s history (06/08/2006, 09/25/2007). Now, two papers in Icarus show that moons can do a lateral pass. Alvarellos et al,1 showed that Jupiter’s moon Io […]

Solar System

March Moon Madness

March 25, 2008

Moons of our planetary system are supposed to behave themselves. They were expected to just quietly orbit their host planets like nice, cold, frozen, inactive chunks of rock and ice. It seems like whenever we get a close look at them, they are madly at work destroying theories – just like their planets have been […]

Origin of Life

Simple Molecules: The Building Blocks of Lie

March 19, 2008

At a physical level, everything in the universe is made of atoms and molecules. Life, being a subset of everything in the universe, is composed of a subset of all molecules that exist. It could be said that any atom or molecule present in a living thing is a building block of life, but how […]

Bible and Theology

How to Address an Alien

March 17, 2008

How would you like this job: your assignment is to be the speechwriter for planet earth. You are to figure out what our first message is to the aliens – to give them a good first impression as we introduce the human species to the galactic community. “No kidding? What does it pay?” […]

Astronomy

Astrobiology Justifying Itself

March 16, 2008

Is astrobiology a legitimate science? Seth Shostak, director of the SETI Institute, tried to answer that question in the weekly SETI Thursday column on Space.com. He estimates there are “approximately a thousand scientists who would be proud to print ‘astrobiologist’ on their business cards.” Astrobiology still gets a cool reception in some quarters. Shostak likened […]

Astronomy

How to Avoid Dark Energy

March 15, 2008

Who needs dark energy? Copernicus? George Ellis (U. of Cape Town) said we could get rid of dark energy by throwing the Copernican Principle overboard. Writing in Nature,1 he said that dark energy may simply be an artifact of the geometry of space-time. Copernicus did not invent the Copernican Principle. He was just […]

Physics

Falling Rocks Leave Holes in Science

March 13, 2008

Hard data in astronomy is hard to come by, except when it comes by special delivery – as with meteorites. If there is any class of phenomena that should be well understood, it should be space debris and the craters they form, because the processes involved can be watched in real time. Meteorites adorn many […]

Solar System

Saturn Moons Continue to Surprise Scientists

March 10, 2008

Just days before a long-awaited dive into the plume of Enceladus (see PhysOrg and JPL press release, flyby stats and news release), Cassini found another surprise in the Saturn system: a moon with rings. A Jet Propulsion Lab press release on March 6 reported that the large moon Rhea may have rings – […]

Astronomy

Is Cosmology Getting Wimp-y?

February 28, 2008

Physics and astronomy are usually thought of as the “hard” sciences, where empiricism is king. Read the following excerpts from a story on the BBC News science page with that in mind (suggestion: replace “dark matter” with “mysterious unknown stuff”). The first stars to appear in the Universe may have been powered by dark matter, […]

Astronomy

Distant Galaxy Surprises Astronomers

February 19, 2008

Using the Hubble Space Telescope viewing a distant galaxy cluster as a gravitational lens, astronomers detected a new record-holder: a galaxy bright with stars almost as old as the big bang. The story on Science Daily called this a galaxy, with redshift 7.6, a “strong contender for the galaxy distance record.” According to […]

Origin of Life

Mars Life Hung Out to Dry in Salt

February 18, 2008

Scientists have just about hanged the possibility for life on Mars. At first, the acid measured by the Spirit and Opportunity rovers made the environment look inhospitable. “Now, we also appreciate the high salinity of the water when it left behind the minerals Opportunity found,” said Mark Knoll on a JPL press release. “This tightens […]

Solar System

Titan Is Old-Age Problem, Despite News Media Coverage

February 15, 2008

A paper in Geophysical Research Letters1 about Saturn’s largest moon, Titan, reads like a good-news, bad-news joke. The good news is that Titan appears to have more hydrocarbons than Earth. The bad news is that it is not enough to save the assumption that Titan is 4.5 billion years old. Several science news […]

Solar System

Something is Cooking Under Enceladus

February 9, 2008

Planetary scientists have been puzzling over Enceladus, a small moon of Saturn, since geysers were discovered erupting from its south pole three years ago. Some models suggested that eruptions could occur without liquid water, but others were not sure. Opinion now seems to be shifting back to the necessity of a wet interior, […]

Physics

Are Long-Term Climate Models Trustworthy?

February 5, 2008

Everything from global warming policy to evolutionary history depends on long-term climate models. Textbooks make it seem like earth keeps reliable recordings that allow scientists to simply read off the record of years, decades, centuries, millennia and millions of years objectively. It’s not that simple, wrote Maureen E. Raymo and Peter Huybers in Nature last […]

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