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  Interstellar visitor 'Oumuamua could still be alien technology, new study hints   'Oumuamua — a mysterious, interstellar object that crashed through our solar system two years ago — might in fact be alien technology. That’s because an alternative, non-alien explanation might be fatally flawed, as a new study argues. But most scientists think the idea that we spotted alien technology in our solar system is a long shot. In 2018, our solar system ran into an object lost in interstellar space. The object, dubbed 'Oumuamua, seemed to be long and thin — cigar-shaped — and tumbling end over end. Then, close observations showed it was accelerating, as if something were pushing on it. Scientists still aren't sure why. One explanation? The object was propelled by an alien machine, such as a lightsail — a wide, millimeter-thin machine that accelerates as it's pushed by solar radiation. The main proponent of this argument was Avi Loeb, a Harvard University astrophy

  The 11 biggest unanswered questions about dark matter   Dark Matter Web In the 1930s, a Swiss astronomer named Fritz Zwicky noticed that galaxies in a distant cluster were orbiting one another much faster than they should have been given the amount of visible mass they had. He proposed than an unseen substance, which he called dark matter, might be tugging gravitationally on these galaxies. Since then, researchers have confirmed that this mysterious material can be found throughout the cosmos, and that it is six times more abundant than the normal matter that makes up ordinary things like stars and people. Yet despite seeing dark matter throughout the universe, scientists are mostly still scratching their heads over it. Here are the 11 biggest unanswered questions about dark matter. What is dark matter? First and perhaps most perplexingly, researchers remain unsure about what exactly dark matter is. Originally, some scientists conjectured that the missing mass in the univ

  Why does outer space look black?   Look up at the night sky with your own eyes, or marvel at images of the universe online, and you'll see the same thing: the inky, abysmal blackness of space, punctuated by bright stars, planets or spacecraft. But why is it black? Why isn't space colorful, like the blue daytime sky on Earth ?  Surprisingly, the answer has little to do with a lack of light.  "You would think that since there are billions of stars in our galaxy, billions of galaxies in the universe and other objects, such as planets, that reflect light, that when we look up at the sky at night, it would be extremely bright," Tenley Hutchinson-Smith, a graduate student of astronomy and astrophysics at the University of California, Santa Cruz (UCSC), told Live Science in an email. "But instead, it's actually really dark."  Hutchinson-Smith said this contradiction, known in physics and astronomy circles as Olbers' paradox, can be explained b

  Jupiter Just Got Hit by a Comet or Asteroid ... Again    Amateur astronomer John McKeon was observing the king of planets by telescope from Swords, Ireland, on March 17 when he captured this stunning time-lapse video of something hitting Jupiter . McKeon was recording the transit of Jupiter's moons Io and Ganymede with an 11-inch Schmidt-Cassegrain telescope and his ASI120mm camera when something struck Jupiter, and he struck cosmic pay dirt. "The original purpose of the imaging session was to get this time-lapse, with a happy coincidence of the impact in the second, last capture of the night," McKeon wrote in a YouTube video description . While it's still too early to know exact details on the Jupiter crash, NASA asteroid expert Paul Chodas, who heads the agency's Center for Near-Earth Object Studies at the Jet Propulsion Laboratory in Pasadena, California, said there's greater chance that an asteroid, not comet, is the culprit. "It's m

  Hear the 1st sounds from China's Mars rover Zhurong   China's first rover on Mars , the six-wheeled Zhurong, rolled onto the Red Planet's surface late Friday (May 21) to begin exploring its new home: the vast Martian plain of Utopia Planitia. Zhurong, which landed on Mars a week earlier on May 14, drove on to the Martian surface from its landing platform at 10:40 p.m. EDT on Friday (10:40 a.m. Saturday, May 22 Beijing Time). It is expected to spend the next 90 days mapping the area, searching for signs of water ice, monitoring weather and studying the surface composition. Photos from Zhurong released by the China National Space Administration show views from the rover's navigation cameras. In one image, the rover is still atop its lander and looking down at the twin ramps it took to roll onto the Martian surface. A second photo looks back at Zhurong's three-legged lander, which delivered the rover to the Martian surface last week. The 530-lb. (240 k

  Sun erupts with biggest solar flare in 4 years in early Fourth of July fireworks (video) The sun erupted with a surprise solar flare on Saturday (July 3), the largest since 2017, in an early explosion of cosmic fireworks ahead of the Fourth of July.  The solar flare occurred from a sunspot called AR2838 at 10:29 a.m. EDT (1429 GMT) on Saturday and registered as a powerful  X1-class sun event, according to the U.S. Space Weather Prediction Center (SWPC) tracking the sun's weather. It caused a brief radio blackout on Earth, center officials said in an update .  A video of the solar flare from NASA's Solar Dynamics Observatory shows the flare erupting from the upper right limb of the star as seen by the spacecraft, one of many used to monitor the sun's weather.   X-class solar flares are the strongest kind of eruptions on the sun . When aimed directly at Earth, the most powerful ones can endanger astronauts and satellites in space, as well as interfere with powe