Thick smoke hung over New Delhi this week as millions of Indians lit firecrackers to mark the Diwali festival, but calls for a boycott highlighted growing concerns over air quality in one of the world's most polluted cities.

Pollution in the Indian capital reached "severe" levels on Friday, the day after Diwali, according to a new air quality index launched earlier this month as part of Prime Minister Narendra Modi's "Clean India" mission.

A mysterious Chinese tycoon who plans to dig a $40 billion canal linking the Caribbean and the Pacific is spreading his reach into space with ambitions for a network of satellites, reports said Monday.

Wang Jing, who won a 50-year concession to build and operate the canal from Nicaragua last year, announced that one of his companies launched a test orbiter last month.

Europe said Friday it was postponing the launch next month of its first-ever "space plane" to give scientists time to finetune the mission's flight plan.

Dubbed the IXV, for Intermediate eXperimental Vehicle, the plane had been scheduled for launch on November 18 by a Vega light rocket from Kourou, French Guiana.

Spain on Friday launched a legal challenge to defend plans to explore for oil and gas off the Canary Islands, a popular tourist destination.

Authorities in the Canaries oppose the government-backed plan by oil giant Repsol to prospect under the seabed near the Spanish Atlantic archipelago and have said they will let locals vote on the plan on November 23.

A growing lava stream threatening homes and inching closer to a rural road on Hawaii's Big Island oozed forward in fits and starts this week, frustrating some residents but giving officials a window of time to prepare.

The narrow, leading edge of the lava flow is now just 250 yards from the one-lane country road, which has been closed. Crews are working on an alternate route for remote communities in the Puna district in case the lava crosses a major thoroughfare.

Six people have sealed themselves inside a white vinyl dome in Hawaii to embark on an eight-month test of how their mental health might fare during a mission to Mars.

The NASA-funded project, the longest US Mars simulation yet, involves three men and three women who have no access to fresh food and limited access to Internet that requires 20-minute intervals between click and response, as it might be in deep space.

A woman and child wear masks on a polluted day in Beijing on October 20, 2014

European Union leaders agreed Friday what they hailed as the world's most ambitious climate change targets for 2030, paving the way for a new U.N.-backed global treaty next year.

Every year in spring, Australians are seen wearing bicycle helmets with spikes on top or caps that have images of eyes on their back. The colorful head gear is not a fashion statement.

Instead, it protects wearers from the swooping magpie, a quintessentially Australian experience where the bird flies low, clacking its beak and sometimes drawing blood by pecking the head of a human victim.

China launched an experimental spacecraft Friday to fly around the moon and back to Earth in preparation for the country's first unmanned return trip to the lunar surface.

The eight-day program is a test run for a 2017 mission that aims to have a Chinese spacecraft land on the moon, retrieve samples and return to Earth. That would make burgeoning space power China only the third country after the United States and Russia to have carried out such a mission.

Japan could be nearly destroyed by a massive volcanic eruption over the next century, putting almost all of the country's 127 million-strong population at risk, according to a new study.

"It is not an overstatement to say that a colossal volcanic eruption would leave Japan extinct as a country," Kobe University earth sciences professor Yoshiyuki Tatsumi and associate professor Keiko Suzuki said in a study publicly released on Wednesday.