The data from the Cassini spacecraft is said to strengthen the idea that Enceladus harbours a sub-surface sea.

BBC: Enceladus has 'spreading surface'

Relief is in sight for some: from 2010 air-conditioned trains will begin to appear on the four sub-surface lines.

ECONOMIST: London Underground

It will also examine the general chemistry of the sub-surface layers, to see if it is within the limits tolerable by living things on Earth.

ECONOMIST: Exploring Mars

On Europa this induces an electrical current within the sub-surface ocean.

ECONOMIST: Blue moon

The revised plan also includes a new Euston Tube station ticket hall and a sub-surface pedestrian link between Euston and the nearby Euston Square Underground station.

BBC: HS2 scraps Euston station rebuild plans

Sub-surface soil samples will be analysed by an onboard laboratory.

BBC: Mars robots begin test campaign

The closest thing out there to LED photomodulation is a controversial procedure called nonablative laser treatment, which uses heat to burn away sub-surface skin so that new cells will replace it.

FORBES: Magazine Article

It will look for sub-surface water.

NPR: Revisiting the Viking Missions to Mars

Sri Lanka's chances of overhauling England were not helped by the sub-standard surface in Colombo, where they were reduced to 56-7 after 20 overs.

BBC: SPORT | Cricket | Inzamam criticises Colombo pitch

In another scheme to resurface the main route for vehicles in the square, sub-contractors are having to relay the road surface after problems were identified.

BBC: Caernarfon Castle Square parking ban for many motorists

Chevron began drilling this ultradeep well over a year ago, with the objective of boring down to big sub-salt prospects 29, 000 feet beneath the surface.

FORBES: Chevron Makes Big Discovery In Louisiana - And It's Not Even Done Drilling Yet