Top 25 stories of 2013, from microbes to meteorites

ESA and Planck Collaboration

Last year it was easy to choose a story to lead our annual Top 25 list. The discovery of the Higgs boson was a watershed moment, ending a decades-long quest by thousands of physicists to fully describe the subatomic realm.

This year, nothing so momentous came to pass. But science isn’t just about dramatic announcements and tremendous technical feats. Anyone who reads Science News regularly appreciates that great new insights often arise from countless little bits and pieces of new knowledge. This year, careful readers may have noticed a steady accumulation of revelations about the bacterial communities that call the human body home. It has long been known that those microbes are essential to processes like extracting nutrients from food and fighting off their less benign brethren. But this year a growing body of research demonstrated that bacteria engage their hosts so vigorously that in some situations, scientists are left wondering which party is the tail and which is the dog.

Human evolution has also produced an impressive body of new knowledge, though some of it only deepens existing mysteries. For example, the oldest hominid DNA ever analyzed linked 400,000-year-old bones from Spain not to the Neandertals that later dominated the region, but to mysterious early hominids known from sites thousands of kilometers to the east. It will probably be a few more years before anyone can explain what is becoming an increasingly controversial era of human evolution.

This year also demonstrated that big findings can be big letdowns. After a spectacular landing on Mars in August 2012, the Curiosity rover looked for elevated atmospheric methane concentrations that would have been telltale evidence for the presence of microbial life. Anything over a few parts per billion would have given us a clear choice for 2013’s top story. But Curiosity detected an average methane concentration of only 0.18 ppb, a finding that landed it in 17th place.

Science News Top Stories of 2013

Microbiome results argue for new view of animals as superorganisms. <a href=””>Full Story &raquo;</a> MARTIN OEGGERLI
New techniques produce mimics of a brain, liver, heart, kidney and retina. <a href=””>Full Story &raquo;</a> M.A. LANCASTER
The satellite’s results hint at a slower expansion rate for the universe. <a href=””>Full Story &raquo;</a> ESA AND THE PLANCK COLLABORATION
Relationships among early hominids are disputed in recent studies. <a href=””>Full Story &raquo;</a> COURTESY OF L. BERGER/UNIV. OF THE WITWATERSRAND
MERS and H7N9 have joined the list of potential pandemics. <a href=””>Full Story &raquo;</a> CDC
The gunk between cells gets flushed out during slumber. <a href=””>Full Story &raquo;</a> L. XIE, H. KANG AND M. NEDERGAARD
The justices’ decision opens the way for choices in DNA testing. <a href=””>Full Story &raquo;</a> Uschools/iStockphoto
Babies seem familiar with vowels and words they heard before birth. <a href=””>Full Story &raquo;</a> C. Moon
Reprogramming adult human cells requires a dunk in caffeine. <a href=””>Full Story &raquo;</a> COURTESY OF M. TACHIBANA
Carbon dioxide hits 400 parts per million. <a href=””>Full Story &raquo;</a> Arnold Paul/Wikimedia Commons
Parents are putting off kids’ shots. <a href=””>Full Story &raquo;</a> AMANDA MILLS/CDC
The planetary probe is the first human-made object to break out of the heliosphere. <a href=””>Full Story &raquo;</a> JPL-CALTECH/NASA
The Kepler space telescope finishes a brilliant career. <a href=””>Full Story &raquo;</a> NASA/KEPLER MISSION; STARRY BACKGROUND: IMAGEMAN/SHUTTERSTOCK
Lab trickery pushes atoms below absolute zero. <a href=””>Full Story &raquo;</a> Schneider/Science
The diagnostic manual updates disorder criteria. <a href=””>Full Story &raquo;</a> APA
The president proposes a campaign to pursue secrets of thinking and learning. <a href=””>Full Story &raquo;</a>
A trace of methane is not enough to be a sign of life. <a href=””>Full Story &raquo;</a> JPL-CALTECH/NASA AND MSSS
Competing clues confuse the story of dog domestication. <a href=””>Full Story &raquo;</a> DOBAK/FLICKR
New data raise the prospect of a ‘Big Rip’ destroying the cosmos. <a href=””>Full Story &raquo;</a> © PS1SC
The king’s skeleton reveals fatal wounds. <a href=””>Full Story &raquo;</a> UNIV. OF LEICESTER
A surprising advance sparks a flurry of work on the mathematical conjecture. <a href=””>Full Story &raquo;</a> MICHAEL BRANIGAN
A visitor from the outer solar system flies past the sun. <a href=””>Full Story &raquo;</a> SDO/SOHO/ESA & NASA
Brood II returns better understood. <a href=””>Full Story &raquo;</a> TOM SIEGFRIED
Mouse muscles stay juiced long after doping ends. <a href=””>Full Story &raquo;</a> J.C. BRUUSGAARD/UNIV. OF OSLO
A falling rock delivers a wake-up call. <a href=””>Full Story &raquo;</a> COURTESY OF SCIENCE/AAAS
  1. Your body is mostly microbes
    Microbiome results argue for new view of animals as superorganisms

  2. Bioengineers make headway on human body parts
    New techniques produce mimics of brain, liver, heart, kidney, retina

  3. Planck refines cosmic history
    Satellite hints at slower expansion rate for universe

  4. New discoveries reshape debate over human ancestry
    Relationships among early hominids disputed

  5. A double dose of virus scares
    MERS, H7N9 join list of potential pandemics

  6. Sleep clears the cluttered brain
    Gunk between cells is cleansed during slumber

  7. High court rules against gene patents
    Justices open way for choices in DNA testing

  8. Language learning starts before birth
    Babies seem familiar with vowels, words heard while in womb

  9. Caffeine triggers cloning advance
    Human embryonic stem cells copied successfully

  10. Carbon dioxide levels pass milestone
    Panel affirms humans’ role in warming

  11. Putting kids at risk
    Parents lax on vaccinations
  12. Voyager 1 reaches interstellar space
    Planetary probe is first to pass beyond heliosphere
  13. Death of a planet hunter
    Kepler ends successful mission

  14. Below absolute zero, but hot
    Lab trickery achieves negative temperature

  15. DSM-5’s controversial debut
    Diagnostic manual updates disorder criteria

  16. Obama unveils brain initiative
    Project to seek secrets of thinking, learning

  17. Methane shortage on Mars
    Trace of gas not enough to be sign of life

  18. Canine genealogy
    Competing clues confuse story of dog domestication

  19. Dark energy gets more confusing
    New data raise prospect of ‘Big Rip’ destroying cosmos

  20. Slain king’s bones dug up
    Richard III’s skeleton reveals fatal wounds

  21. Progress made toward twin prime proof
    Surprising advance sparks flurry of work on mathematical conjecture

  22. Visitor from the Oort cloud
    Comet ISON meets demise in solar flyby

  23. Odd cicada history emerges
    Brood II returns better understood

  24. Gift of steroids keeps on giving
    Mouse muscles stay juiced long after doping ends

  25. Meteorite makes an impact
    Space rock fires a warning shot

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