When you look back at the past year in space, one achievement stands out: the unprecedented touchdown of the Philae lander on a comet hundreds of millions of miles from Earth, at the climax of the European Space Agency's Rosetta mission.
Don't just take our word for it: Last month's landing on Comet 67P/Churyumov-Gerasimenko is already figuring prominently in year-end roundups, including Nature's top 10 people who mattered in science, Science News' top 25 stories of the year, Euronews' top people of 2014, Physics World's 2014 Breakthrough of the Year, Discover magazine's top 100 stories of 2014 and more.
The best thing is that the $1.7 billion (€1.3 billion) mission is far from over: During this week's American Geophysical Union meeting in San Francisco, scientists showed off new pictures and talked about the next phase of the journey for the car-sized Rosetta spacecraft that's tailing the comet. They also voiced hopes for reviving the Philae lander, a probe that's about the size of a washing machine and is currently hibernating on the comet's surface.
Project scientist Matt Taylor says the team plans to send the Rosetta spacecraft to within 4 miles (6 kilometers) of the surface next February. That will be the closest approach made by the craft during its primary mission.
"It is the earliest we could carry it out without impacting the vitally important bound orbits that are currently being flown," Taylor said in a NASA news release. "As the comet becomes more and more active, it will not be possible to get so close to the comet. So this opportunity is very unique."
During the close encounter, Rosetta will be able to obtain high-resolution imagery as well as data about the effect of cometary gas emissions on the dust flying off the surface. It may also be possible to pinpoint the place where Philae landed after its double-bounce on Nov. 12.
The imagery collected so far suggests that Philae landed in a shadowed area of the comet, where it couldn't use its solar panels to recharge its batteries. That's why it had to go into hibernation mode. As the comet nears the sun, a shift in lighting conditions could allow Philae to power up again — assuming that the lander's electronics have survived the chill.
Rosetta team members say Philae could start soaking up sunlight in April or May, and communications could resume by May or June. If Philae is revived, the lander could continue taking pictures and analyzing the comet's surface chemistry as Churyumov-Gerasimenko and the Rosetta spacecraft swing around the sun.
The primary mission is scheduled to last for another year, and if all goes well, it could be extended into 2016. Will Rosetta be next year's top story as well? Stay tuned.
In the meantime, here are four more space sagas to round out our top-five list for 2014:
- The SpaceShipTwo tragedy: Virgin Galactic's rocket plane had a successful powered flight in January, but a tragic outing in October. The craft disintegrated during a test flight, killing one pilot and injuring the other. The investigation of the crash is continuing, and some would-be space passengers are wondering about their ride. In any case, it will be months before SpaceShipTwo Serial No. 2 takes to the air.
- Looking for life on Mars: NASA's Mars Curiosity rover detected elevated methane levels in the Martian atmosphere, as well as organic chemicals in Red Planet rocks. Those are clues worth following up in the search for traces of ancient and present-day life on Mars. But Curiosity isn't the only detective on the case. In September, two probes successfully entered Martian orbit in September to study the planet's atmosphere: NASA's Maven and India's Mars Orbiter Mission. The MOM mission has the capability to trace methane levels in Martian air.
- Closing in on alien Earths: As scientists sift through the data from NASA's Kepler planet-hunting mission, they're seeing the signatures of extrasolar planets that are increasingly similar to Earth. The even better news is that Kepler is back in business.
- One small step for NASA's Orion: An uncrewed version of the spaceship that NASA plans to use when it sends astronauts to an asteroid and eventually to Mars aced its first flight test this month.
What'll be big in 2015? Here's our list of five top space trends to watch over the next year:
- Day of the dwarf planets: In March, NASA's Dawn spacecraft is due to settle into orbit around the dwarf planet Ceres for its first close-up. Then, in July, the New Horizons probe will make a historic flyby past Pluto and its moons.
- Private-sector spaceships: The SpaceShipTwo program isn't the only game in town when it comes to commercial spaceships. XCOR Aerospace may begin testing its Lynx rocket plane next year, and the crew-worthy space taxis proposed by Boeing and SpaceX are likely to take shape as well.
- One year on the space station: U.S. and Russian spacefliers are due to begin a yearlong tour of duty on the International Space Station as a practice run for future deep-space expeditions. During their stint, singer Sarah Brightman is scheduled for a shorter stay in orbit.
- Cosmic conclusions: The final batch of data from the European Space Agency's Planck mission is due for release next month, and more data should be on the way from the Alpha Magnetic Spectrometer as well as the Large Hadron Collider. When you factor in the controversy over BICEP2's gravitational-wave findings, there's plenty for fans of cosmic mysteries to look forward to.
- Eclipse on the equinox: Skywatchers can look forward to a combination of astronomical events on March 20, 2015: It's the spring equinox for the Northern Hemisphere, as well as the day for a total solar eclipse by a "new supermoon," as EarthSky.org's Bruce McClure explains. The eclipse's total phase will be visible only in Greenland and Iceland, but you can be sure there'll be streaming video.
Looking back at 'Years in Space'