For the first time, an experimental treatment made from human embryonic stem cells has shown evidence of helping someone, partly restoring sight to two people suffering from slowly progressing forms of blindness.WASHINGTON – The moon might be shrinking.
Not to worry, though, lovers and crooners, it won’t be disappearing soon.
New research indicates cracks in the moon’s crust that have formed as the interior has cooled and shrunk over the past billion years or so. That means the surface has shrunk, too, though not so you’d notice just from gazing at it.
Scientists have identified 14 landforms called lobate scarps scattered over the surface of the moon, explained Thomas R. Watters of the Center for Earth and Planetary Studies at the Smithsonian’s National Air and Space Museum.
Watters and colleagues describe their find in today’s edition of the journal Science.
The scarps had previously been noted at the moon’s equator, but this is the first evidence in other areas.
The study calls the scarps “evidence of recent thrust faulting on the moon.” But this is planetary science, where “recent” can mean a billion years ago.
The scarps, or cliffs, extend across some small craters, and small craters tend to be obliterated over time, Watters explained.
In addition, there are no large craters imposed on top of the scarps, another indication they are relatively recent, he said.
The size of the scarps indicates a shrinkage of about 328 feet, which wouldn’t be nearly enough to be noticed with the naked eye. The moon is about one-fourth the size of the Earth in diameter.
The scarps range up to a little more than 30 feet high and a few kilometers long, he said. The moon’s not going to disappear and its shrinkage won’t affect the Earth in any way, Watters stressed.
