Tensions remain extremely high over concerns that Russia might attack Ukraine. Russia has brought more soldiers and military equipment to the border. The US and Europe say they'll react strongly to any attack, but still hope to solve the crisis through talks.
Scientists have come up with a new way of identifying animals in an area - by testing DNA sucked out of the air. The researchers believe their new method could help scientists keep track of animals that are hard to spot, including endangered animals.
Over the last few weeks, Covid-19 case numbers have been hitting record levels around the world. Governments are struggling to figure out safe ways to keep schools open and avoid going back to remote classes, but it's a complicated challenge.
Antarctica is one of the hardest to reach places on Earth. But a recent report reveals that ships going to Antarctica have connections to ports around the world. That greatly raises the chance that plants or animals from outside could invade this protected area.
Scientists exploring the ocean floor in Antartica have found the largest group of fish nests ever discovered. The huge area of nests came as a surprise, and will help scientists develop a more complete idea of the ocean food web in the area.
On Saturday, an underwater volcano erupted in the South Pacific Ocean near Tonga. The damage in Tonga isn't fully known yet. But the massive explosion raised concerns of tsunamis all through the Pacific and as far away as the west coast of the United States.
In today's news roundup, British Prime Minister Boris Johnson is being encouraged to step down for breaking UK Covid-19 rules, Georgia beats Alabama to win their first national football championship in 41 years, and Japan faces a french fry shortage.
Aung San Suu Kyi, who was removed as Myanmar's leader and arrested following a coup last year, has been given a prison term of four years for having walkie-talkies and for breaking Covid-19 rules.
The United States Mint began sending out a special new quarter honoring author Maya Angelou on Monday, making Ms. Angelou the first Black woman to appear on a US coin. The coin is part of a series of quarters honoring important women in US history.
Last Friday, doctors at the University of Maryland Medical Center successfully replaced the heart of a very sick man with a specially-grown pig's heart. It's the first time this surgery has ever been done. After three days, the patient appears to be doing very well.