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:
Comments (0)
This discussion is now closed. We welcome comments on our articles for a limited period after their publication.

  • Most Popular
  • Most Shared

Markets

REUTERS SHOWCASE

Canada Shooting

Canada Shooting

Attack on parliament, killing of soldier stun Canada's capital.  Full Article 

Earnings Season

Earnings Season

Wipro sees rosier end to year as U.S. clients spend.  Full Article 

Business Climate

Business Climate

Fears for tough penalties grow as India cleans up business  Full Article 

New Email Service

New Email Service

Google launches new email service dubbed "Inbox".  Full Article 

DLF Appeals

DLF Appeals

DLF seeks interim relief from capital market ban  Full Article 

Falling Oil Prices

Falling Oil Prices

Indian consumers respond to softer oil, food prices  Full Article 

Book Keeping

Book Keeping

RBI fires warning shots on companies' lack of FX hedging.  Full Article 

Policy Repo Rate

Policy Repo Rate

Most external members suggested rate cut in RBI's Sept review.  Full Article 

Reuters India Mobile

Reuters India Mobile

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