In the UK, generally a man and a woman may marry if they are both over 16 and not married or in a civil partnership with someone else. Individuals aged 16 or 17 in England, Wales, and Northern Ireland, however, can only marry if they obtain their parents consent. Moreover, close blood relatives cannot marry -- although this does not include first cousins, who can still legally wed one another in the UK. Lastly, people of the same sex cannot marry, but they can register a civil partnership instead.

No. Even though essentially the law treats civil partners and married partners equally, opposite-sex couples cannot register a civil partnership. In order to form a civil partnership in the UK, a couple must: (1) be of the same sex; (2) not be civil partners with or married to other people; (3) be 16 years of age or older (NB. people aged 16 or 17 in England, Wales, and Northern Ireland also require parental consent); and (4) not be close blood relatives.

This depends on where in the UK you live. If you plan to get hitched in England or Wales, your best bet is to visit DirectGov to find out where you can do it. For Scotland, contact the General Register Office for Scotland. And for Northern Ireland, go to the General Register Office for Northern Ireland.

You can hold a ceremony -- of sorts! -- in the wicker basket under the balloon, but to become legally married or civil partners you will need to hold another one in a registry/registrar's office or other "approved" location when you return to earth.

Yes, you can surprise your spouse with a wedding ceremony, as you might with a surprise birthday party, but it will not be legally valid. For a wedding to be valid, both of you must give notice of your intent to marry 1-3 months ahead of time and comply with various formalities. Failure to provide proper notice can result in a marriage being postponed or prevented from proceeding.