Metro Science: Smart dogs, dumb cats, alien asteroids and baby planets
This fall, an asteroid, now named ‘Oumuamua, slingshotted around our sun at a blistering 87.3 kilometres per second. Here's a break down of the weirdest visitor, ever.
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Call it an interstellar hit-and-run. This fall, an asteroid, now named ‘Oumuamua, slingshotted around our sun at a blistering 87.3 kilometres per second and sailed past Earth and Mars on track to reach Jupiter’s orbit by May. Scientists quickly realized it must have come from beyond our solar system — the first such alien object ever detected.
WEIRDEST. VISITOR. EVER.
Dimensions: Like a flattened pencil, 10 times longer than it is wide. Nothing that shape has ever been seen in our solar system before. Scientists aren’t sure how it formed or why it has that shape. Rapid changes in brightness show it’s spinning, logroll-like, every seven hours.
Speed: Way too fast to be powered by the sun’s gravity alone. The last star it passed was in the constellation Lyra, but that was hundreds of thousands of years ago, when Lyra looked very different. Scientists suspect ‘Oumuamua started as debris from the birth of a faraway planet in a solar system very unlike our own.
Composition: No ice, dust or gas, like a comet would have. Our outer solar system is surrounded by comets. Why our first interstellar visitor was asteroid is a mystery. Alien objects like this probably pass us a couple times a year. Only recently has technology been able to spot them.
How fast is fast?
SO FAST. 87.3 km/s is more than 314,000 km/hour.
The fastest a spacecraft ever launched was 16 km/s.
'Oumuamua passed through Earth’s orbit Oct. 14 and reached Mars 18 days later. That trip took NASA’s Curiosity rover 254 days.
SCIENCE STORY: DOGGONE SMART
Sorry cat people, science says dogs are smarter than cats. A paper in Frontiers in Neuroanatomy counts the cerebral cortex neurons in several different mammals. The abundance of these cells is an indicator of thinking, planning and complex behavioural abilities. Dogs have about 530 million; cats just 250 million. (Compare this to our 16 billion.) Also — no surprise anyone who's been outwitted by a trash panda — racoons are smarter than either pet. They have the brainpower of a dog, packed into a cat-sized skull.
SOUND SMART: YOUR SCIENCE VOCABULARY WORD FOR THE WEEK
DEFINITION: A planetesimal is a rocky bit of space stuff (usually a few metres to few hundred kilometres wide) that can coalesce to form a new planet.
USE IT IN A SENTENCE: The pumpkin is so big it's practically a planetesimal at this point.