Space collisions could rise due to more CO2 - study

LONDON Sun Nov 11, 2012 11:35pm IST

A 3D animation of China's Tiangong-1 space module is shown in this still image taken from video released September 28, 2011. REUTERS/Jiuquan Satellite Launch Centre/Handout/Files

A 3D animation of China's Tiangong-1 space module is shown in this still image taken from video released September 28, 2011.

Credit: Reuters/Jiuquan Satellite Launch Centre/Handout/Files

Related Topics

LONDON (Reuters) - More satellites and orbiting debris could collide in the upper atmosphere because a buildup of carbon dioxide (CO2) has reduced the "drag effect" which can eventually send some space junk back down to Earth, a study shows.

Over the past eight years CO2 concentrations in the upper atmosphere have risen from burning fossil fuels that have warmed the Earth's surface and caused temperatures to increase, the study in the journal Nature Geoscience said.

This can result in a cooler, less dense atmosphere above a 90-km (55-mile) altitude, the study said, adding that this "will reduce atmospheric drag on satellites and may have adverse consequences for the orbital debris environment that is already unstable".

Less drag, or friction, in the upper atmosphere means space debris such as redundant satellites and defunct rocket bodies will stay at a certain altitude for longer, increasing the risk of collisions.

Global temperatures are now about 0.8 degree C (1.4 F) above pre-industrial times. Two degrees is viewed as a threshold to dangerous change including more powerful storms like Sandy that struck the United States this month, more heatwaves, droughts and rising sea levels.

The scientists, from the Naval Research Laboratory in Washington, Old Dominion University in Virginia, University of Waterloo in Ontario and the University of York in Britain, used satellite data to study changes in CO2 concentrations at a 101-km altitude between 2004 and 2012 and found that CO2 rose significantly over that time.

So far, CO2 trends have been measured only up to a 35-km altitude because balloons and aircraft do not reach high altitudes, and ground measurements and rockets only provide limited coverage.

Debris is always a danger to spacecraft and collisions can prove costly for spacecraft manufacturers.

There are 21,000 bits of debris larger than 10 cm (4 inches) in orbit, but collisions occur infrequently - about once a year on average, according to NASA, the U.S. space agency.

However, a U.S. National Research Council report in 2011 warned NASA that the amount of space debris orbiting the Earth was at critical level and the United States has been trying to develop technologies to remove debris and reduce hazards.

(Editing by Michael Roddy)

FILED UNDER:
Photo

After wave of QE, onus shifts to leaders to boost economy

DAVOS, Switzerland - Central banks have done their best to rescue the world economy by printing money and politicians must now act fast to enact structural reforms and pro-investment policies to boost growth, central bankers said on Saturday.

Barack Obama in India

Reuters Showcase

Coal Mining

Coal Mining

India to open coal to commercial mining firms soon, minister says  Full Article 

RBI Loan Rules

RBI Loan Rules

RBI relaxes overseas loan recast rules   Full Article 

E-commerce Firms

E-commerce Firms

Amazon, e-commerce rivals fuel commercial property boom in India  Full Article 

Growth Forecasts

Growth Forecasts

Indian economic growth forecasts pegged back, despite rate cuts: Reuters Poll.  Full Article 

Uber is Back

Uber is Back

Uber back in Delhi; govt says must await approval.  Full Article 

Markets at Record

Markets at Record

Sensex rises to record after ECB stimulus programme.  Full Article 

Pharma Sector

Pharma Sector

Ipca Labs hit by FDA ban on plant for standard violations.  Full Article | Related Story 

Forex Reserves

Forex Reserves

India FX reserves at record high as RBI fortifies defences  Full Article 

QE for Euro Zone

QE for Euro Zone

ECB launches 1 trillion euro rescue plan to revive euro economy.  Full Article 

Reuters India Mobile

Reuters India Mobile

Get the latest news on the go. Visit Reuters India on your mobile device  Full Coverage