Lucy’s new neighbor, downloading New Horizon’s data and more reader feedback

New Horizons phones home

In “Pluto: Explored” (SN: 6/27/15, p. 16), Christopher Crockett chronicled New Horizons’ long journey to the dwarf planet. He followed up with a report on the successful flyby in “Pluto’s icy landscape comes into view” (SN: 8/8/15, p. 6).

“Having read that early images of Pluto encoded in radio waves would take 4.5 hours to reach Earth from the New Horizons space probe, I was surprised to read further on that ‘the data won’t finish downloading until late 2016,’ ” wrote Greg Skala. “Why the long delay for the later data?”

It’s not light’s travel time that’s holding up the data, says Crockett. New Horizons gathered a lot of data during its short flyby of Pluto, some of it quite complex. Now it has to deliver all that information through what amounts to a really cruddy Internet connection. “The amount of data you can stuff through a radio link depends strongly on how much power is left in the signal by the time it hits the receiver. The signal coming from Pluto is really weak. New Horizons has a download bandwidth of a whopping two kilobits per second. The dial-up modem I had in high school could transfer data about 28 times faster than that,” he says. “The spacecraft has something like 50 gigabits of data onboard. That alone would take several months to download.”

Crockett adds that the mission also has to share the Deep Space Network of radio antennas with every other spacecraft in the solar system. New Horizons got priority during the flyby, but for the download period, it has to get back in line with everyone else.

The inventive brain

Creativity may get a boost from a surprising part of the brain. The cerebellum, usually associated with body movements, lit up in brain scans when people played Pictionary, Laura Sanders reported in “Cerebellum may foster creativity” (SN: 6/27/15, p. 11).

Skeptical about the findings, some readers offered other explanations for what might be going on in the brain. “The cerebellum is being activated in drawing because its role in motor control is to make error corrections,” argued Charles Muncal on Facebook. “The more you draw, the more precise your motor control becomes. This is what is occurring when the cerebellum is lighting up.” In an e-mail, John Lord asked, “Isn’t drawing a muscular activity? Doesn’t that always activate the cerebellum, creative or not?”

Drawing relies on movements, and the cerebellum does become active when the body moves, Sanders says. In the study, the researchers attempted to compensate for this by having the participants draw a zigzag, which required motion but not creativity. The researchers found that the cerebellum’s activity increased with creativity, even though people were drawing and moving all the while. But it is possible that the findings could be explained by differences in the drawing motions, particularly those movements needed to draw scenes more elaborate than a zigzag.

One hominid or two?

In “Hominid family gets a new member” (SN: 6/27/15, p. 7), Bruce Bower described jaw fossils from Ethiopia that suggest Lucy shared her neighborhood with another early human relative.

Scientists are still debating whether the find represents a new species or just a variation on Lucy’s. “There is a tendency amongst some paleoanthropologists to give every specimen a new name,” observed Tim Cliffe. “It’s also true that some have equally vigorously adopted the opposite agenda — that is, they always see new specimens as merely indicating variation within previously described species. Both these tendencies should be viewed as provisional. There is variation within species; there are also separate species. I suppose this will sort itself out eventually as more specimens round out the picture. But my impression is that DNA evidence will be hard or impossible to get in this multimillion-year-old time range, so the arguments will probably not end soon.”