1. How hard it is to clone a human.
Last year, a Korean team became the first to clone a human embryo, coaxing it to the blastocyst stage at which embryonic stem cells can be obtained.
In August last year, a team from the UK was given the first British license to perform therapeutic cloning for human embryos, with a further license granted to Professor Ian Wilmut's team at the Roslin Institute.
Even with this sort of expertise, stem cell expert Dr Steven Minger of King's College London does not expect success this year, "it's going to be very difficult."
Meanwhile, although cloning of primates has succeeded in Pittsburgh, it appears that all attempts at implantation have failed.
2. More about Titan.
A few hours' worth of information could be all scientists get for 20 years of endeavor as Huygens, the dinner table-sized probe of the Cassini spacecraft, parachuted through the atmosphere of Titan Friday.
But what information? Titan is the mystery moon of Saturn. Its opaque, smoggy, orange atmosphere means that its surface has never been seen before. "By next week, we could have a completely different view of another world in our solar system," says TV science presenter Dr Chris Riley. "It may be the last time in history that we'll be able to say that."
Titan is a world dominated by constantly reacting organic compounds with lakes, or even oceans, of liquid ethane, methane and nitrogen.
3. What it's like inside a comet
Deep impact is a six-year NASA mission to discover what lies deep inside a comet. Like Cassini, this is two spacecraft in one -- a flyby craft and a smaller impactor.
In July, in a piece of spectacular cosmic vandalism, the impactor will be launched directly into the path of comet Tempel 1 for a "planned collision," forming a crater 14 storeys deep and a football stadium wide, all of which will be filmed by the onboard camera.
"Comets are time capsules that hold clues about the formation and evolution of the solar system," says NASA. If they find complex molecules, rather than the simple ones anticipated, expect the history of Earth to be rapidly rewritten in 2005.
4. How someone looks after a face transplant.
A surgical team from Louisville, Kentucky, is hotly tipped to perform the world's first face transplant this year, taking a face from a donor corpse and attaching it to a severely disfigured recipient.
The team, which includes bioethicists, submitted a detailed proposal to an ethics panel last May, and the lengthy approvals process concludes soon. In Britain, meanwhile, plans have been put on hold after a Royal College of Surgeons' working party concluded that the risks outweighed the benefits.
5. Whether the world's oceans are becoming more acidic and what it means for wildlife.
The UK's Royal Society's working party on rising acidity of oceans reports in the spring. Environmental biologist professor John Raven, who is chairing it, says: "The same pollution that we believe is heating the world's oceans through global warming is also altering its chemical balance."
Of particular concern is the impact of rising acidity on ocean creatures needing calcium carbonate for their structure, such as corals and molluscs. It might also affect plankton and have a potentially disastrous consequence on marine food webs.
6. Whether carbon trading works.
Carbon trading, a key plank of the Kyoto agreement, began two weeks ago but, like much to do with Kyoto, already seems to be going nowhere.