giant comets may threaten earth
Last Updated : GMT 09:40:38
Themuslimchronicle, themuslimchronicle
Themuslimchronicle, themuslimchronicle
Last Updated : GMT 09:40:38
Themuslimchronicle, themuslimchronicle

Giant comets may threaten Earth

Themuslimchronicle, themuslimchronicle

Themuslimchronicle, themuslimchronicleGiant comets may threaten Earth

A comet strike is believed to have ended the reign of the dinosaurs 65m years ago
Paris - AFP

Planet Earth could be at higher risk of a space rock impact than widely thought, according to astronomers who suggested Tuesday keeping a closer eye on distant giant comets.

Most studies of potential Earth-smashers focus on objects in the asteroid belt roughly between Mars, Earth's outside neighbour, and Jupiter on its other flank, said the researchers.

But they noted that the discovery in the last two decades of hundreds of giant comets dubbed centaurs, albeit with much larger orbits, requires expanding the list of potential hazards.

These balls of ice and dust, typically 50-100 kilometres (31-62 miles) wide, have unstable, elliptical orbits that start way beyond Neptune, the most distant planet from the Sun.

Their paths cross those of the giant planets Jupiter, Saturn, Uranus and Neptune, whose gravity fields occasionally deflect a comet towards Earth -- once about every 40,000-100,000 years.

As they draw closer to the Sun, the comets would gradually break up, which is what causes the trademark cometary debris tail -- "making impacts on our planet inevitable".

"The disintegration of such giant comets would produce intermittent but prolonged periods of bombardment lasting up to 100,000 years," the research team wrote in the Royal Astronomical Society journal, Astronomy and Geophysics.

And they argued that "assessment of the extraterrestrial impact risk based solely on near-Earth asteroid counts, underestimates its nature and magnitude."

They noted that a single centaur contains more mass than the entire population of Earth-crossing asteroids discovered to date.

"In the last three decades, we have invested a lot of effort in tracking and analysing the risk of a collision between the Earth and an asteroid," said co-author Bill Napier of the University of Buckingham.

"Our work suggests we need to look beyond our immediate neighbourhood too, and look out beyond the orbit of Jupiter to find centaurs.

"If we are right, then these distant comets could be a serious hazard, and it's time to understand them better."

Scientists believe a comet bombardment may have kickstarted life on Earth by bringing water and organic molecules.

A comet strike is also a leading contender for having ended the reign of the dinosaurs 65 million years ago.

The team said no risk was "known to be imminent", although cometary encounters were largely unpredictable.

"A centaur arrival carries the risk of injecting, into the atmosphere... a mass of dust and smoke comparable to that assumed in nuclear winter studies," wrote the researchers, referring to the hypothesised climate effects from the soot that would be released by firestorms caused in an atomic war.

"Thus, in terms of magnitude, its ranking among natural existential risks appears to be high," they said.

 

themuslimchronicle
themuslimchronicle

Name *

E-mail *

Comment Title*

Comment *

: Characters Left

Mandatory *

Terms of use

Publishing Terms: Not to offend the author, or to persons or sanctities or attacking religions or divine self. And stay away from sectarian and racial incitement and insults.

I agree with the Terms of Use

Security Code*

giant comets may threaten earth giant comets may threaten earth

 



Themuslimchronicle, themuslimchronicle
Themuslimchronicle, themuslimchronicle
Themuslimchronicle, themuslimchronicle

GMT 21:49 2018 Tuesday ,23 January

Trump to tell Erdogan of concern over Syria offensive

GMT 08:26 2018 Tuesday ,23 January

Five things to know about Davos

GMT 16:13 2018 Sunday ,14 January

Netanyahu urges Macron to 'fix' Iran nuclear deal

GMT 10:17 2016 Thursday ,21 January

WHO confirms second new Ebola case in Sierra Leone

GMT 13:33 2011 Wednesday ,06 July

Russia bids to expand Arctic border to seek gas

GMT 09:06 2011 Wednesday ,21 September

Powerful typhoon hits Japan

GMT 11:15 2011 Wednesday ,03 August

2 glaciers in Nepal to disappear

GMT 19:01 2017 Saturday ,19 August

Finland suspect an asylum seeker, targeted women

GMT 02:45 2017 Wednesday ,08 February

Coup defeat a matter of time, says Yemeni VP

GMT 17:38 2017 Friday ,14 July

Saad Lamjarred denied issuance of new song

GMT 16:02 2011 Thursday ,21 April

Chelsea squad not good enough

GMT 11:29 2011 Tuesday ,19 July

Etihad Towers on track for delivery

GMT 02:05 2017 Wednesday ,22 February

UAE takes keen interest in supporting higher education

GMT 07:17 2017 Saturday ,01 July

Key US inflation measure declines in May
Themuslimchronicle, themuslimchronicle
Themuslimchronicle, themuslimchronicle
 
 Themuslimchronicle Facebook,themuslimchronicle facebook  Themuslimchronicle Twitter,themuslimchronicle twitter Themuslimchronicle Rss,themuslimchronicle rss  Themuslimchronicle Youtube,themuslimchronicle youtube  Themuslimchronicle Youtube,themuslimchronicle youtube

Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2023 ©

Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2023 ©

muslimchronicle muslimchronicle muslimchronicle muslimchronicle
themuslimchronicle themuslimchronicle themuslimchronicle
themuslimchronicle
بناية النخيل - رأس النبع _ خلف السفارة الفرنسية _بيروت - لبنان
themuslimchronicle, themuslimchronicle, themuslimchronicle