Feeds

Tempel-1: iceberg or galactic rubber ball?

Deep Impact team ponders comet's composition

  • alert
  • submit to reddit

Build a business case: developing custom apps

April Fool special NASA's Deep Impact probe launched successfully on 12 January, on a mission to more accurately understand the properties of comets.

Its target is Tempel-1 - chosen because although it might be rock and ice like most other comets, scientists have reason to suspect that much of its structure is highly elastic frozen cross-linked hydrocarbons (very much like Kevlar or stiff rubber).

Ice can be a notoriously tough material, being resistant to both heat and shock, but scientists still don't know if the average comet has enough ice to be as tough as an iceberg or if it is as weak as the famous Shumacher-Levy comet which broke up under the influence of Jupiter's gravity. If, however, Tempel-1 is indeed comprised of rubber-like hydrocarbons, as mission planners suspect, then the results of the Deep Impact strike will be very interesting.

The plan is to hit Tempel-1 with a 370kg (~820lb) impactor (49 per cent copper) at 10km per second, releasing 19GJ of energy (around 4.8 tonnes of TNT) with a view to determining the comet's coefficient of elasticity by bouncing the impactor back into space and measuring its trajectory carefully with the following "mothership" and various Earth-based telescopes. Some scientists, though, are betting that the comet will simply shatter.

So much the better, say many experts. With our growing awareness of the risks of the Earth being struck by a rogue comet or meteor, understanding the physical properties of the comet has become a matter of the very survival of humanity. Just how hard must we hit a comet before it breaks up? Which technologies will work? Will we need to gently land on a shatter-proof comet and use rockets to nudge it onto a different course, or will nuclear weapons achieve the desired result?

Multiple interdisciplinary teams (geologists, physicists, computer programmers and statisticians) have been trying to determine the optimal conditions to strike the comet to achieve the best possible science.

To add a little spice to the mission, the teams are also running a competition to see who can most accurately predict - in the event of cometal disintegration - the paths of any pieces during the 1000 solar orbits after impact. Remnants over 50 metres in diameter which are captured by a planet (regarded as "potting" a comet) score 100 points each. If they succeed in getting the comet to spin rapidly and thus "screw back" using the solar wind to crash into Jupiter then that is worth 1000 points. Hitting the mothership with the projectile ("snookered") gains 5000 points.

There is, of course, the remote possibility that a substantial piece of Tempel-1 will eventually impact with Earth - a scenario chillingly described by scientists as "Pot Black". Said one cometologist: "We don't really want to think about that too much. We're just hoping that everything goes on cue..." ®

Related stories

Deep Impact en route to Tempel 1
Countdown to launch for Deep Impact
Boffins issue stealth comet apocalypse alert

Boost IT visibility and business value

More from The Register

next story
Yes, but what are your plans if a DRAGON attacks?
Local UK gov outs most ridiculous FoI requests...
Cops baffled by riddle of CHICKEN who crossed ROAD
'Officers were unable to determine Chicken's intent'
Drunkards warned: If you can't walk in a straight line, don't shop online, you fool!
Put it away boys. Cover them up ladies. Your credit cards, we mean
Murder accused DIDN'T ask Siri 'how to hide my roommate'
US court hears of cached browser image - not actual request
Why your mum was WRONG about whiffy tattooed people
They're a future source of RENEWABLE ENERGY
Chomp that sausage: Brits just LOVE scoffing a Full Monty
Sales of traditional brekkie foods soar as hungry folk get their mitts greasy
Nuts to your poncey hipster coffees, I want a TESLA ELECTRO-CAFE
Examining the frothy disconnect in indie cafe culture
Ex-Apple man Sam Sung - for it is he - sticks namebadge on eBay
Stump up via tat bazaar, do a good thing for ill kids
Check your Clungene, Irish women warned
Have a quick shufti, you may not be pregnant after all
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.