Breakthroughs in 2011

Science magazine picks one scientific event to be the number 1 breakthrough of the year. In 1998 it was the discovery that the expansion of the universe is accelerating, the topic of Alex Filippenko’s talk at January General meeting. For 2011, the breakthrough of the year was the unambiguous success of HIV antiretroviral drugs in the prevention. But astronomical events showed up in the runner-up list.

First, the Japanese spacecraft called Hayabusa returned a few grains from asteroid Itokawa. That it managed to do so was a major accomplishment. Hayabusa lost 2 of 3 gyros, sprang a leak in its attitude-control thrusters, lost solar power, froze the batteries, and a very small rover was shot into deep space instead of landing on Itokawa. But it managed to prove that the most common meteorites, chondrites, were indeed from the most common asteroids, the S class. That was a slight surprise because the colors of the meteorites didn’t match the too-red asteroids. The difference was tracked down to tiny blobs of iron that scatter sunlight causing the asteroid to look redder (kind of like a sunset). This story was covered in the SJAA Ephemeris last October (http://ephemeris.sjaa.net/1110/g.html).

Second, exoplanets were a big item this year. Science focused on the “strange” exoplanets. There was the case of Kepler 11 with 5 giant planets in orbit closer than Mercury. This breaks two theories of planetary formation: if large planets are formed far from the star and then move inward why didn’t some of these create a chaotic situation that kicked out some of these planets? If planets form where they are found, how was there so much stuff so close to the star? Another strange star known as HAT-P-6b is orbiting its star in a retrograde motion. This is more explainable. A planet or companion star could knock a planet into a new orbit and eventually it flips. Another odd exoplanet was the so-called Tatooine planet. This last story was in the November Ephemeris (http://ephemeris.sjaa.net/1111/g.html).

Third, some very low metallic regions of space were found. These areas have not seen a lot of star formation so some recently created stars consist of hydrogen and helium and almost nothing else. This means that supernovae did not seed the entire universe.

So what didn’t even make the runner-up list? Perhaps the recent discovery of Earth-sized planets detected by Kepler occurred too late. The Higgs boson almost detection was listed as an area to watch. Mars Curiosity is another item listed as probably big for 2012.