2013 Year in Science Stories
Exploratorium Picks:

From the “shmeaty” goodness of a test-tube hamburger to the glimmer of water on Mars, it’s been a year in science to remember—and in some cases (yep, we’re talking to you, comet ISON) to forget. Here are some of our picks for the year in science.

1. Molecular Movie

IBM debuted A Boy and His Atom, the smallest movie ever made, in which the actors are made up of individual molecules of carbon monoxide.

2. Record-High Carbon Dioxide

In May, atmospheric levels of carbon dioxide measured at the Mauna Loa Observatory reached a new high, surpassing 400 parts per million for the first time since data-taking began there in 1955. The last time CO2 levels reached this level was roughly 4.5 million years ago, during the Pliocene Epoch, when the earth was roughly 6° F warmer and sea level ranged between 16 to 131 feet higher.

3. Penises: Not for the Birds

A whopping 97% of living male birds have no penis—instead, they eject sperm through an anatomical catch-all called the cloaca. In June, researchers announced the genetic culprit: a gene called Bmp4 thatshuts off penis development shortly after it begins, causing the nascent member to dissolve away. http://news.sciencemag.org/evolution/2013/06/scienceshot-birds-disappearing-penis

4. In Vitro Meat

In a year already boasting in vitro kidneys, ears, livers, and even a nascent brain, what remained but to craft a cultured burger? Costing $325,000—fries not included—the in vitro cow muscle cells were sautéed in butter to create arguably the world’s most expensive hamburger.

5. Water on Mars

After celebrating its first anniversary on Mars, NASA’s car-sized Curiosity rover sent a gift back to Earth, discovering water in the Martian soil—along with other evidence that the Martian environment was once habitable.

6. Comet ISON Flyby

Inbound from the mysterious Oort cloud near the boundary of our solar system, comet ISON promised to (possibly) light up the December sky with a dazzling day-visible display. Alas, hype and hyperbole provided most of the entertainment, as the actual performance fizzled when the comet broke into bits after performing a hairpin turn around the sun. Astronomers were nonetheless pleased by the dazzling data payload.

7. HIV: Negatives and Positives

Hope for an HIV cure surged after bone marrow transplants resulted in several months of undetectable viral levels in two patients’ blood then flagged when the virus subsequently rebounded. But hope springs afresh: An HIV-infected toddler who received antiretroviral drugs hours after birth still shows no signs of the virus after 2.5 years.