Japan's space agency said its Hayabusa2 will follow up its touchdown on an asteroid with another risky mission — dropping an 4.4 pound explosive on the asteroid to make a crater and then collect underground samples for possible clues to the origin of the solar system. The mission on April 5 will require the spacecraft to move quickly so it won't get hit by shards from the blast, JAXA project engineer Takanao Saeki said. "It will be very challenging."

Questions rise over origins of waterfalls

To investigate how waterfalls form, researchers built a 26-foot long, 12-inch wide, 3.3-foot deep channel. They filled it with a foamy bedrock, tilted it 20 percent and let sediment-rich water flow down its surface. By using foam rather than rock, the team was able to watch millenniums of erosion play out under very short time scales. The turbulent flow unevenly dug out parts of the riverbed. Eventually, with no externally triggered changes, a deep pocket of erosion formed — one that made the river jet off from the higher section of the riverbed and splash down some distance away. A waterfall appeared, all by itself. Scientists had assumed that waterfalls always arose from geological or climate-driven changes.

Whale deaths rise from container ships

Ten whale deaths were attributed to ship strikes in 2018, the highest number on record in California since NOAA Fisheries began tracking in 1982. It's an enormous increase from the average 3.4 ship strike victims recorded annually in the five previous years. Cargo ships are so big that crews often have no idea they hit a whale. In the past 10 years, at least 60 blue, gray, fin, and humpback whales with signs of ship strikes have been found dead in California, Oregon and Washington, NOAA said. Many go unreported because whales tend to sink upon death or are never spotted because of ocean currents.

Will space tourism be booming by 2030?

Flying people to hang out in outer space could be worth $23 billion by 2030, UBS Group AG predicted. Space hotels, theme park rides and flying wealthy long-haul passengers into orbit are among the opportunities to tap once the industry gets off the ground, analysts said.

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