Tag Archives: Earth

NASA plans to save Earth by knocking asteroid off its orbit

Aiming to show how to protect Earth from a future killer asteroid strike, NASA plans to crash a refrigerator-sized spacecraft at a speed about nine times faster than a bullet into a space rock, forcing it to change its orbit.

The target for the first-ever mission to demonstrate an asteroid deflection technique for planetary defense — the Double Asteroid Redirection Test (DART) — is an asteroid that will have a distant approach to Earth in October 2022, and then again in 2024, NASA said.

“DART would be NASA’s first mission to demonstrate what’s known as the kinetic impactor technique — striking the asteroid to shift its orbit — to defend against a potential future asteroid impact,” said Lindley Johnson, planetary defence officer at NASA Headquarters in Washington.

The asteroid is called Didymos — Greek for “twin” — because it is an asteroid binary system that consists of two bodies — Didymos A, about 780 metres in size, and a smaller asteroid orbiting it called Didymos B, about 160 metres in size.

DART, scheduled for launch in 2020, would impact only the smaller of the two bodies, Didymos B.

The Didymos system has been closely studied since 2003. The primary body is a rocky S-type object, with composition similar to that of many asteroids.

The composition of its small companion, Didymos B, is unknown, but the size is typical of asteroids that could potentially create regional effects should they impact Earth.

“A binary asteroid is the perfect natural laboratory for this test,” said Tom Statler, programme scientist for DART at NASA Headquarters.

“The fact that Didymos B is in orbit around Didymos A makes it easier to see the results of the impact, and ensures that the experiment doesn’t change the orbit of the pair around the sun,” Statler added.

After launch, DART would fly to Didymos, and use an on-board autonomous targeting system to aim itself at Didymos B.

Then the spacecraft would strike the smaller body at a speed about nine times faster than a bullet, approximately six kilometres per second.

Earth-based observatories would be able to see the impact and the resulting change in the orbit of Didymos B around Didymos A, allowing scientists to better determine the capabilities of kinetic impact as an asteroid mitigation strategy.

The kinetic impact technique works by changing the speed of a threatening asteroid by a small fraction of its total velocity, but by doing it well before the predicted impact so that this small nudge will add up over time to a big shift of the asteroid’s path away from Earth.

“DART is a critical step in demonstrating we can protect our planet from a future asteroid impact,” saiid Andy Cheng of The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, the DART investigation co-lead.

Source:

http://www.hindustantimes.com/world-news/nasa-plans-to-save-earth-by-knocking-asteroid-off-its-orbit/story-WBGEaheAa8RHBZ8hx3dyrN.html

Big tobacco leaves huge ecological footprint

Tobacco growing causes “massive harm” to the environment through extensive use of chemicals, energy and water, and pollution from manufacturing and distribution, the World Health Organization (WHO) said on Tuesday.

The United Nations agency called for the tobacco industry to compensate for its products that contribute to greenhouse gases blamed for climate change, but gave no estimate of damage.

The ecological footprint goes far beyond the effects of cigarette smoke, the WHO said in its first report on tobacco’s impact on the environment. “From start to finish, the tobacco life cycle is an overwhelmingly polluting and damaging process.”

“We’ve not estimated the full economic impact of what’s happening to the environment, that will require more studies,” Vinayak Prasad, WHO tobacco control coordinator, told a news briefing.

Tobacco use kills 7 million people a year, according to the WHO, which marks World No Tobacco Day on Wednesday.

It drew up a landmark treaty in 2005, now ratified by 179 countries, that calls for a ban on tobacco advertising and sponsorship, and taxes to discourage use.

Tobacco plants require large quantities of insecticides, herbicides, fungicides and fumigants to control pest or disease outbreaks.

“Many of these chemicals are so harmful to both the environment and farmers’ health that they are banned in some countries,” the report said.

Vast quantities of wood are burned to cure tobacco leaves, contributing to deforestation. Some big growers like China and Zimbabwe are also using coal, which emits carbon dioxide, the main greenhouse gas blamed for global warming, the WHO said.

Millions of kilogrammes of non-biodegradable cigarette butts are discarded every year, it said.

Tobacco waste contains over 7,000 toxic chemicals that poison the environment, including human carcinogens, it added.

Japan Tobacco Inc, Philip Morris International and British American Tobacco report on their use of environmental resources and waste streams, but the self-reported data is “limited and opaque”, the report noted.

Michelle McKeown, Japan Tobacco (JTI) corporate communications vice-president, accused the WHO of “trying to highjack the climate change agenda” from other U.N. agencies and its leadership of being “off-track”. “The report is misleading and disconnected with reality,” she said in an emailed response. “Of all major crops, tobacco is one that requires the least crop protection agents. This is coupled by JTI’s efforts to encourage environmentally-friendly techniques.”

Source:

http://af.reuters.com/article/zimbabweNews/idAFL8N1IW4EC?pageNumber=2&virtualBrandChannel=0

 

Caterpillars could be the answer to the Earth’s massive plastic bag problem

Even the smallest among us can be big heroes. Take the lowly wax worm, for instance.

The larva of the greater wax moth is considered a huge pest in Europe, because it acts as a parasite in bee colonies.

However, its bizarre eating habits may help solve a huge environmental problem.

See, the wax worm is apparently not averse to eating plastic. An amateur beekeeper in Spain discovered this when she plucked some of the pests from her beehives and put them in a plastic bag. The worms eventually ate little holes in the bag, chewing through the plastic at an alarming rate.

This led to a wonderful idea: What if these so-called pests could actually help break down polyethylene, a common and non-biodegradable plastic currently clogging up landfills around the world?

How good are these little grubs?

The beekeeper is actually Federica Bertocchini, a scientist at the Institute of Biomedicine and Biotechnology of Cantabria. She and two researchers from the University of Cambridge’s Department of Biochemistry put together a study to see just how good these little grubs were at passing the plastic, so to speak.

The answer? Very. The team found the wax worms broke down polyethylene plastic bags faster than other recently-tested methods. There are still more tests that need to be done, but if scientists can replicate whatever causes the breakdown, if could be used to alleviate the burden of non-biodegradable waste.

“If a single enzyme is responsible for this chemical process, its reproduction on a large scale using biotechnological methods should be achievable,” said Cambridge’s Paolo Bombelli, first author of the study.

The team also used a rather analog method to make sure it was an actual chemical process helping the caterpillars get rid of the plastic, and not just some voracious, bag-centric appetite:

“To confirm it wasn’t just the chewing mechanism of the caterpillars degrading the plastic, the team mashed up some of the worms and smeared them on polyethylene bags, with similar results,” a summary of the study reads.

The findings were published in the journal Current Biology.

Source:

How a plastic-munching caterpillar could help save the earth