A large piece of space debris, possibly weighing several tonnes, is currently on an uncontrolled reentry phase (that's space speak for "out of control"), and parts of it are expected to crash down to Earth over the next few weeks.

If that isn't worrying enough, it is impossible to predict exactly where the pieces that don't burn up in the atmosphere might land. Given the object's orbit, the possible landing points are anywhere in a band of latitudes "a little farther north than New York, Madrid and Beijing and as far south as southern Chile and Wellington, New Zealand".

The debris is part of the Long March 5B rocket that recently successfully launched China's first module for its proposed space station. The incident comes roughly a year after another similar Chinese rocket fell to Earth, landing in the Atlantic Ocean but not before it reportedly left a trail of debris in the African nation of Cote D'Ivoire.

Former Florida senator Bill Nelson was sworn in Monday as head of NASA, hailing a "new day" for space exploration as the United States seeks to return to the Moon.

With his hand on a Bible, Nelson took the oath of office from Vice President Kamala Harris as he officially took up the role of NASA administrator.

"It's a new day in space," he said, after bringing a Moon rock to the event.

Nelson, 78, who traveled into space in 1986, takes over the agency with the United States hoping to put astronauts back on the Moon by 2024.

Humans last set foot on the Moon in 1972 during the Apollo program.

Under the Artemis program, NASA wants to establish a sustainable presence, complete with a lunar space station, to test new technologies that would pave the way for a crewed mission to Mars.

The interaction of two doomed stars has created this spectacular ring adorned with bright clumps of gas—a diamond necklace of cosmic proportions. Fittingly known as the "Necklace Nebula," this planetary nebula is located 15,000 light-years away from Earth in the small, dim constellation of Sagitta (the Arrow).

A pair of tightly orbiting sun-like stars produced the Necklace Nebula, which also goes by the less glamorous name of PN G054.203.4. Roughly 10,000 years ago, one of the aging stars expanded and engulfed its smaller companion, creating something astronomers call a "common envelope." The smaller star continued to orbit inside its larger companion, increasing the bloated giant's rotation rate until large parts of it spun outwards into space. This escaping ring of debris formed the Necklace Nebula, with particularly dense clumps of gas forming the bright "diamonds" around the ring.

The pair of stars which created the Necklace Nebula remain so close together—separated by only several million miles—that they appear as a single bright dot in the center of this image.

In an alternate reality playing out at this year's international Planetary Defense Conference, a fictional asteroid crashes over Europe, 'destroying' a region about 100 km wide near the Czech Republic and German border. The scenario was imagined, but the people who took part are very real, and the lessons learnt will shape our ability to respond to dangerous asteroids for years to come.