Robosub prowls Pacific's hadal depths

US scientists are hailing a "new era" of deep-sea exploration after successfully dispatching a robotic vehicle to the bottom of the Mariana Trench - 10,902 metres or 6.8 miles beneath the Pacific's surface. The Nereus (pictured below during tests off Hawaii in 2007) hit the bottom of the Challenger Deep on Sunday, making it …

[Anonymous Coward]

"placed a marker on the seafloor signed by those onboard the surface ship"

Rather than use a robotic submarine they could have just thrown their marker overboard from the surface ship. It would have ended up in the same place, and it would probably have got there faster.

[Anonymous Coward]

Ummmm someone's not been checking their comparisons

'braving pressures greater than 1,000 times that at Earth’s surface, or "crushing forces similar to those on the surface of Venus"'

The pressure at the bottom of the Marianas Trench *IS* about 100 MegaPascals (really big French mathematicians), but the surface pressure on Venus is only (HAH!) 9.3 MegaPascals.

This sort of confusion would be avoided if the World switched to a sensible measure of pressure we could all understand such as the force generated by 1 metric Wales balanced on a double-decker bus.

[Jason]

Nereus etymology

You mention correctly that the craft is named Nereus, after the mythological Greek sea-god who "had the gift of prophecy and could change himself into any shape". However, you omitted to mention that the robosub namesake changes form according to which mode it is working in (underwater 'flying' or 'hovering'), hence the name.

Ob. RoTM postscript: I may as well take this opportunity to hopefully be the first to welcome our new autonomous, shape-shifting mechanical over-, ahem, under-lords.

[M E H]

Great - Now put it to use

Perhaps they could sail full steam ahead for the Air France crash site in the Atlantic and locate the black boxes while they are still giving off a location signal.

[BOBSta]

Measurements

I'm having trouble understading how deep that trench is. Can someone work it out in football pitches please?

[Dodgy Geezer]

A marker for all eternity?

"..It collected samples and "placed a marker on the seafloor signed by those onboard the surface ship"."...

Of course, the trench is a subduction zone. So the marker will be carried down with the descending plate, melted into the core, or possibly ejected again through one of the volcanos in the Ring of Fire.

Apart from that - good idea...

[Marvin the Martian]

"a large coffee can"?

Now how much is that in approved ISO or ElReg units? An oil barrel would be the size of a very large coffee can, or what?

[Paul Schofield]

@BOBSta re Measurements

Football pitches are a measure of area.... but in more realistic terms 10,902 metres is:

77871.4286 Linguine

1182.5578 Double-Decker buses

78.8371 Brontosaurus

[Havin_it]

Is it just me or

does anyone else find this a teensy bit less noteworthy or impressive than the *manned* conquest of the trench nearly fifty years ago?

There's nothing brave about delivering pizza in Govanhill either, if you get a robot to do it for you.

"meh" icon required.

[Anonymous Coward]

Sea Hunt

How many leagues would that be?

20,000?

[Anonymous Coward]

@Paul Schofield

So you're saying an ISO Brontosaur is 138.28m long, ie about 1.4 football pitches?

Maybe you might want to re-check your calc, I'm just saying.

[Colin]

10,911 metres

According to the first paragraph, the trench is only 10,902 metres deep. So did the Trieste burrow its way 9 metres into the sea bed ? Seems like a lot of effort just to go one-up on other contenders who are content merely to reach the sea floor ....