Disappearing sea ice in Antarctica is putting emperor penguins at risk of extinction, researchers warn.

"The population is declining," says Hal Caswell, senior scientist at Woods Hole Oceanographic Institute and an author of a new study in Nature Climate Change. "Unless something changes to stop that, the population will go into extinction."

By 2100, the entire population could decrease by one-third, with all 45 of the known emperor penguin colonies in Antarctica taking a hit. The biggest drops will happen on the coasts of the western Indian Ocean and eastern Weddell Sea, The Guardian says.

The main food source of penguins is krill, and young krill eat the algae on ice; as the ice is lost, the supply of krill drops. The researchers say that one way to help the penguins would be putting them under the protection of the Endangered Species Act. Also, "given this new research, and what we already know about global temperatures warming and the changing climate," says Andrea Kavanagh, director of global penguin conservation for the Pew Charitable Trusts, the U.S. should immediately "put a marine reserve in place so we can make sure we are not fishing in areas where the penguins need to forage for food."

Japanese officials said they are attempting to authenticate a video released on Saturday which shows the apparent beheading of Kenji Goto, a hostage of Islamic State militants, The Associated Press reports.

The video, titled "A Message to the Government of Japan," shows an apparent ISIS militant with a British accent, along with Goto, who kneels in an orange jumpsuit and does not speak in the minute-long video.

The militant speaks directly to Japanese Prime Minister Shinzo Abe, saying that Abe's "decision to take part in an unwinnable war," is to blame for Goto's beheading.

"Let the nightmare for Japan begin," he adds.

Japanese and Jordanian officials had been attempting to negotiate through indirect channels for the release of Goto and Jordanian pilot Muath al-Kasaesbeh.

After nearly 7,000 miles in the air, Troy Bradley of Albuquerque and Leonid Tiukhtyaev of Russia came back to earth on Saturday, landing their helium-filled balloon four miles offshore of Baja California, The Associated Press reports.

Bradley (left) and Tiukhtyaev | (AP Photo/Tami Bradley-Two Eagles Balloon Team)

The Two Eagles Balloon team took off from Japan early on Sunday morning; a little less than a week later, they had broken at least two long-standing records for ballooning; the pilots easily exceeded the previous distance record of 5,209 miles, and also set a new duration record of six days, 16 hours, and 38 minutes in the air.

The official distance and time of the flight still has to be confirmed by the Federation Aeronautique Internationale, so in the meantime, feast your eyes on the views from above. —Sarah Eberspacher

Crossing the Pacific Ocean | (AP Photo/Two Eagles Balloon Team)

Passing over Mount Fuji | (AP Photo/Two Eagles Balloon Team)

Jurors in the murder trial of former New England Patriots player Aaron Hernandez will be allowed to watch the Super Bowl, so long as they remain vigilant, Bristol County Superior Court Judge Susan Garsh warned them on Friday.

"I am not going to forbid you from watching the Super Bowl if that's something that's really important to you," CNN reports that Garsh told the jurors. "(But), you hear that word, you've got to walk out of the room."

"That word" is of course "Hernandez." As a former star for the Patriots who helped carry the team to a Super Bowl victory three years ago, Aaron Hernandez's name could very well come up during Sunday's broadcast featuring New England and the Seattle Seahawks.

The jurors had heard two days of testimony as of Friday; Hernandez, 25, has pleaded not guilty to the 2013 killing of Odin Lloyd, who was dating the sister of Hernandez's fiancee.

While saying that "we're not there yet," outgoing Defense Secretary Chuck Hagel told CNN on Friday that the United States may eventually have to send ground troops back into Iraq.

"I think (turning back Islamic State militants) may require a forward deployment of some of our troops," Hagel said. "Whether we get there or not, I don't know."

Hagel noted that the ground troops could remain in non-combat roles, such as intelligence gathering on ISIS targets. There are already 4,500 U.S. troops in Iraq, which are operating in training and advising capacities with Iraqi forces.

The National Highway Traffic Safety Administration has recalled more than 2 million vehicles from Toyota, Chrysler, and Honda due to possible air bag problems, Reuters reports. 

About 400 cases of inadvertent air bag deployments have been reported in the recalled vehicle models, although the incidents have not resulted in any known deaths, an official for the NHTSA said. The three automakers will have to fix a defective chip in the air bag systems, which will require the entire air bag module and its circuits to be replaced.

Ah, Super Bowl weekend.

We could talk more about Deflategate, but why do that when Key & Peele released this perfectly delightful sketch spoofing Seattle Seahawks players Richard Sherman and Marshawn Lynch?

"Richard Sherman" spends his time critiquing the Academy Award nominations, questioning why Selma and Foxcatcher were overlooked. And "Marshawn Lynch" trots out a new catchphrase, before throwing us a surprise around the 2:20 mark. Check out the fun in the video, below. —Sarah Eberspacher

Ohio's Department of Rehabilitation and Correction announced on Friday that it will postpone all six executions scheduled for 2015, because it needs more time to develop a new execution drug formula, Reuters reports. 

In January 2014, Ohio executed Dennis McGuire using a combination of midazolam and hydromorphone; witnesses reported that McGuire's execution took 25 minutes, during which he gasped and seized for 15 minutes. The state halted use of the two-drug combination, but it also passed a law in December 2014 providing confidentiality to pharmacies that prepare the lethal drug formulas. Four death row inmates filed a lawsuit, saying their right to due process is violated by the new law.

The state's decision to postpone its scheduled executions comes just days after the Supreme Court agreed to temporarily block the executions of three Oklahoma inmates challenging that state's lethal-injection formula.

This is why planes have co-pilots.

A Delta Air Lines flight bound for Las Vegas made an emergency landing at the airport on Thursday after the pilot was locked out of the cockpit. Officials said the malfunctioning door will be examined by maintenance technicians, and a Delta spokeswoman told The Associated Press that the airline's crews are trained for such emergency situations (the co-pilot landed the plane alone).

Even more impressive: Despite the eventful landing, the plane still pulled into its gate at McCarran International Airport on time.

Japanese and Jordanian officials are struggling to secure the release of two nationals being held by Islamic State militants, but they say negotiations are "deadlocked," Reuters reports. 

"We can't predict (what will happen) at all," Japanese Foreign Minister Fumio Kishida said on Saturday. "While preparing for every situation, I want to make every effort for Mr. Goto's release."

ISIS militants have threatened to kill Japanese journalist Kenji Goto, along with Jordanian pilot Muath al-Kasaesbeh. They said the latter would be spared if Jordan released would-be suicide bomber Sajida al-Rishawi, who is currently being held on death row in Amman.

Chances are good this workday was a little more exciting than yours.

Los Angeles firefighters received a call about a little dog trapped in a swollen river, and the ensuing rescue involved a helicopter and some serious daring from the diver. The operation was successful, and officials say the pup was shaken, but healthy. Now, the search is on for the owners, because the firefighters believe the dog could have been swept more than a mile away from where he likely went into the water.

Watch the daring rescue, courtesy of BBC News, in the video, below. —Sarah Eberspacher