Top 5 Space Discoveries of 2012
By: Patrick Kiger
The biggest space exploration discovery of 2012 is the one that existed only in the collective consciousness of the Internet rumor mill. After a NASA scientist teased National Public Radio in November by saying that the Mars robotic rover Curiosity had collected data that was going to be "one for the history books," some predicted that the space agency might announce the discovery of a life form on Mars. That didn't quite happen — at least not yet. Nevertheless, it was a year that featured other important discoveries. Here are five of what we think may turn out to be the most significant milestones in the exploration of space during 2012.
5. The Milky Way probably has a whole lot of planets
An international team of astronomers, who used an investigative method called gravitational microlensing to spot planets by looking for their gravitational effect upon distant stars. In a January article in Nature, they estimated that there are 160 billion stars with planets orbiting around them in our galaxy. That's about an average of 1.6 planets per star.
Watch Video: Learn more about the Milky Way
4. A rectangular galaxy
If you're used to thinking of galaxies as flattened discs resembling the Milky Way's graceful spiral, this one may be hard to get your head around. Astronomers already knew that some galaxies actually were ellipsoids, shaped more like rugby balls, while others were completely irregular. But in March, a team of astronomers led by Alister Graham of Swinburne University of Technology in Australia announced the discovery of the dwarf galaxy LEDA 074886, which has a distinctively rectangular shape. According to Technology Review, what Graham describes as an "emerald cut galaxy" lies about 70 million light years from Earth, and may have formed when two disc-shaped galaxies merged. From our vantage point, the combination looks like a rectangle, just as a gigantic stack of pancakes would.
Watch Video: Carl Sagan explains how galaxies are born
3. Fifth moon of Pluto discovered
Okay, so Pluto isn't a full-fledged planet anymore, at least according to the official definition of a planet accepted by astronomers. But for a humble dwarf planet, it sure has a lot of satellites orbiting around it. In July, a steam of astronomers using NASA's Hubble Space Telescope announced that they had discovered Pluto's fifth moon, an irregular object six to 15 miles across that follows a 58,000 mile-long circular orbit about the dwarf planet. The big mystery is why Pluto has so many satellites. One popular theory is that they're leftovers from a collision between Pluto and another large Kuiper Belt object billions of years ago.
Watch Video: What do we know about Pluto?
2. Building block of life may exist in stars before planets
In August, Copenhagen University astronomers revealed that they had detected a sugar molecule in a young protostar about 400 light years from Earth. The sugar molecule, glycolaldehyde, is needed to form ribonucleic acid, or RNA — a molecule similar to DNA, which helps carry genetic information from one generation to the next. The discovery suggests that complex organic molecules involved in life exist in star systems before the planets on which life might develop.
Watch Video: Morgan Freeman how DNA formed from RNA
1. Curiosity Rover finds organic compounds on Mars
Okay, drum roll here. In early December, when NASA finally did announce the important finding made by its Curiosity Rover, it revealed that the probe had not found signs of life in Martian soil, as many had hoped to see. (The NASA scientist who'd talked about "one for the history books" meant the quality of the data rather than that the discovery's significance, he later revealed.) But what Curiosity did find in an ancient Martian riverbed — water, sulfur and chlorine-containing compounds such as chlorinate methane gas — was indeed significant. The gas contains carbon, which might have been deposited upon the Martian surface by meteors and comets--or which might be evidence of the existence of life sometime in the Red Planet's past. As for which it turns out to be, we'll have to await additional research by Curiosity. But the tantalizing prospect of discovering evidence of life on Mars will keep us watching closely in 2013.
Watch Video: See how the Curiosity rover safely arrived on Mars
Think something else should have made the countdown? Let me know in the comments!