ADVERTISEMENT
  About the SA Blog Network













Life, Unbounded

Life, Unbounded


Discussion and news about planets, exoplanets, and astrobiology
Life, Unbounded Home

Astrobiology Roundup

The views expressed are those of the author and are not necessarily those of Scientific American.


Email   PrintPrint



 

 

 

 

 

 

 

 

 

 

 

Lots of new scientific results in the past couple of weeks feed directly into the central questions of astrobiology – from the search for life, to the environment of interplanetary and interstellar space, and the grand cosmological terrain we find ourselves in.

No Methane For Mars

The latest measurements of atmospheric methane on Mars, made in-situ by the Tunable Laser Spectrometer onboard the Curiosity rover, peg it at less than 1.3 parts per billion. This is in stark contrast to earlier claims, from telescopic studies, of concentrations as high as 45 parts per billion in certain locations, with seasonal variation. Methane could be a key indicator of the metabolic activity of microorganisms, as it is here on Earth. The lack of a detection is not yet definitive proof that earlier measurements were in error, but it certainly calls them into some doubt.

Voyager’s Magnetic Puzzle

Now it’s clear that Voyager 1 has indeed passed into the interstellar medium, one of the next puzzles is why the configuration of magnetic fields around the spacecraft have not shifted very significantly. The expectation had been for a magnetic change in this transition to the region outside the Sun’s electromagnetic dominance. There may be more surprises in store.

Europa Askew

A study of the configuration of the great cracks and creases adorning Jupiter’s icy moon Europa suggests that the patterning seen is evidence that the satellite tilts – its spin axis pointing away from a ‘straight’ up and down orientation by a mere degree or so. This small change could explain the distribution of stresses across Europa’s icy crust (due to Jupiter’s gravitational tides) – and it could be happening over days and months. It could also tell us something about the longevity of Europa’s long speculated interior ocean. A mission to Europa could help resolve this question.

A Vast Galactic Belch

The supermassive black hole at the center of our galaxy has long been thought a quiet and relatively diminutive object (a mere 4.3 million times the mass of the Sun). But, in recent years, evidence has been accumulating that it does occasionally tear up passing matter and generate a great outpouring of energy – radiation and fast moving particles. Now another observation could add to these clues – the ethereal glow of radiation from the Magellanic Stream may be an echo of just such an episode some 2 million years ago, one that could have produced the great ‘Fermi Bubbles’ reported earlier. The impact on our remote backwoods area of the Milky Way might have been small, but we don’t know for sure. Across the history of the galaxy such events could have played an influential role in setting the character of the stellar population, and ultimately the environment our solar system formed from.

Caleb A. Scharf About the Author: Caleb Scharf is the director of Columbia University's multidisciplinary Astrobiology Center. He has worked in the fields of observational cosmology, X-ray astronomy, and more recently exoplanetary science. His books include Gravity's Engines (2012) and The Copernicus Complex (2014) (both from Scientific American / Farrar, Straus and Giroux.) Follow on Twitter @caleb_scharf.

The views expressed are those of the author and are not necessarily those of Scientific American.





Rights & Permissions

Add Comment

Add a Comment
You must sign in or register as a ScientificAmerican.com member to submit a comment.

More from Scientific American

Scientific American Holiday Sale

Give a Gift &
Get a Gift - Free!

Give a 1 year subscription as low as $14.99

Subscribe Now! >

X

Email this Article

X